Publications

Abstract

A number of recent studies have hypothesized that monitoring in speech production may occur via domain-general mechanisms responsible for the detection of response conflict. Outside of language, two ERP components have consistently been elicited in conflict-inducing tasks (e.g., the flanker task): the stimulus-locked N2 on correct trials, and the response-locked error-related negativity (ERN). The present investigation used these electrophysiological markers to test whether a common response conflict monitor is responsible for monitoring in speech and non-speech tasks. Electroencephalography (EEG) was recorded while participants performed a tongue twister (TT) task and a manual version of the flanker task. In the TT task, people rapidly read sequences of four nonwords arranged in TT and non-TT patterns three times. In the flanker task, people responded with a left/right button press to a center-facing arrow, and conflict was manipulated by the congruency of the flanking arrows. Behavioral results showed typical effects of both tasks, with increased error rates and slower speech onset times for TT relative to non-TT trials and for incongruent relative to congruent flanker trials. In the flanker task, stimulus-locked EEG analyses replicated previous results, with a larger N2 for incongruent relative to congruent trials, and a response-locked ERN. In the TT task, stimulus-locked analyses revealed broad, frontally-distributed differences beginning around 50 ms and lasting until just before speech initiation, with TT trials more negative than non-TT trials; response-locked analyses revealed an ERN. Correlation across these measures showed some correlations within a task, but little evidence of systematic cross-task correlation. Although the present results do not speak against conflict signals from the production system serving as cues to self-monitoring, they are not consistent with signatures of response conflict being mediated by a single, domain-general conflict monitor

Abstract

The aim of the present study was to investigate whether reading failure in the context of an orthography of intermediate consistency is linked to inefficient use of the lexical orthographic reading procedure. The performance of typically developing and dyslexic Portuguese-speaking children was examined in a lexical decision task, where the stimulus lexicality, word frequency and length were manipulated. Both lexicality and length effects were larger in the dyslexic group than in controls, although the interaction between group and frequency disappeared when the data were transformed to control for general performance factors. Children with dyslexia were influenced in lexical decision making by the stimulus length of words and pseudowords, whereas age-matched controls were influenced by the length of pseudowords only. These findings suggest that non-impaired readers rely mainly on lexical orthographic information, but children with dyslexia preferentially use the phonological decoding procedure—albeit poorly—most likely because they struggle to process orthographic inputs as a whole such as controls do. Accordingly, dyslexic children showed significantly poorer performance than controls for all types of stimuli, including words that could be considered over-learned, such as high-frequency words. This suggests that their orthographic lexical entries are less established in the orthographic lexicon

Abstract

Even though language allows us to say exactly what we mean, we often use language to say things indirectly, in a way that depends on the specific communicative context. For example, we can use an apparently straightforward sentence like "It is hard to give a good presentation" to convey deeper meanings, like "Your talk was a mess!" One of the big puzzles in language science is how listeners work out what speakers really mean, which is a skill absolutely central to communication. However, most neuroimaging studies of language comprehension have focused on the arguably much simpler, context-independent process of understanding direct utterances. To examine the neural systems involved in getting at contextually constrained indirect meaning, we used functional magnetic resonance imaging as people listened to indirect replies in spoken dialog. Relative to direct control utterances, indirect replies engaged dorsomedial prefrontal cortex, right temporo-parietal junction and insula, as well as bilateral inferior frontal gyrus and right medial temporal gyrus. This suggests that listeners take the speaker's perspective on both cognitive (theory of mind) and affective (empathy-like) levels. In line with classic pragmatic theories, our results also indicate that currently popular "simulationist" accounts of language comprehension fail to explain how listeners understand the speaker's intended message.

Abstract

Heschl's gyrus (HG) is a core region of the auditory cortex whose morphology is highly variable across individuals. This variability has been linked to sound perception ability in both speech and music domains. Previous studies show that variations in morphological features of HG, such as cortical surface area and thickness, are heritable. To identify genetic variants that affect HG morphology, we conducted a genome-wide association scan (GWAS) meta-analysis in 3054 healthy individuals using HG surface area and thickness as quantitative traits. None of the single nucleotide polymorphisms (SNPs) showed association P values that would survive correction for multiple testing over the genome. The most significant association was found between right HG area and SNP rs72932726 close to gene DCBLD2 (3q12.1; P=2.77x10(-7)). This SNP was also associated with other regions involved in speech processing. The SNP rs333332 within gene KALRN (3q21.2; P=2.27x10(-6)) and rs143000161 near gene COBLL1 (2q24.3; P=2.40x10(-6)) were associated with the area and thickness of left HG, respectively. Both genes are involved in the development of the nervous system. The SNP rs7062395 close to the X-linked deafness gene POU3F4 was associated with right HG thickness (Xq21.1; P=2.38x10(-6)). This is the first molecular genetic analysis of variability in HG morphology

Abstract

Modulations of occipito-parietal α-band (8–14 Hz) power that are opposite in direction (α-enhancement vs. α-suppression) and origin of generation (ipsilateral vs. contralateral to the locus of attention) are a robust correlate of anticipatory visuospatial attention. Yet, the neural generators of these α-band modulations, their interdependence across homotopic areas, and their respective contribution to subsequent perception remain unclear. To shed light on these questions, we employed magnetoencephalography, while human volunteers performed a spatially cued detection task. Replicating previous findings, we found α-power enhancement ipsilateral to the attended hemifield and contralateral α-suppression over occipitoparietal sensors. Source localization (beamforming) analysis showed that α-enhancement and suppression were generated in 2 distinct brain regions, located in the dorsal and ventral visual streams, respectively. Moreover, α-enhancement and suppression showed different dynamics and contribution to perception. In contrast to the initial and transient dorsal α-enhancement, α-suppression in ventro-lateral occipital cortex was sustained and influenced subsequent target detection. This anticipatory biasing of ventrolateral extrastriate α-activity probably reflects increased receptivity in the brain region specialized in processing upcoming target features. Our results add to current models on the role of α-oscillations in attention orienting by showing that α-enhancement and suppression can be dissociated in time, space, and perceptual relevance.

Abstract

Sentence production is the process we use to create language-specific sentences that convey particular meanings. In production, there are complex interactions between meaning, words, and syntax at different points in sentences. Computational models can make these interactions explicit and connectionist learning algorithms have been useful for building such models. Connectionist models use domaingeneral mechanisms to learn internal representations and these mechanisms can also explain evidence of long-term syntactic adaptation in adult speakers. This paper will review work showing that these models can generalize words in novel ways and learn typologically-different languages like English and Japanese. It will also present modeling work which shows that connectionist learning algorithms can account for complex sentence production in children and adult production phenomena like structural priming, heavy NP shift, and conceptual/lexical accessibility.

Abstract

The present study concerns individual differences in gesture production. We used correlational and multiple regression analyses to examine the relationship between individuals’ cognitive abilities and empathy levels and their gesture frequency and saliency. We chose predictor variables according to experimental evidence of the functions of gesture in speech production and communication. We examined 3 types of gestures: representational gestures, conduit gestures, and palm-revealing gestures. Higher frequency of representational gestures was related to poorer visual and spatial working memory, spatial transformation ability, and conceptualization ability; higher frequency of conduit gestures was related to poorer visual working memory, conceptualization ability, and higher levels of empathy; and higher frequency of palm-revealing gestures was related to higher levels of empathy. The saliency of all gestures was positively related to level of empathy. These results demonstrate that cognitive abilities and empathy levels are related to individual differences in gesture frequency and saliency

Abstract

Language and action systems are highly interlinked. A critical piece of evidence is that speech and its accompanying gestures are tightly synchronized. Five experiments were conducted to test 2 hypotheses about the synchronization of speech and gesture. According to the interactive view, there is continuous information exchange between the gesture and speech systems, during both their planning and execution phases. According to the ballistic view, information exchange occurs only during the planning phases of gesture and speech, but the 2 systems become independent once their execution has been initiated. In all experiments, participants were required to point to and/or name a light that had just lit up. Virtual reality and motion tracking technologies were used to disrupt their gesture or speech execution. Participants delayed their speech onset when their gesture was disrupted. They did so even when their gesture was disrupted at its late phase and even when they received only the kinesthetic feedback of their gesture. Also, participants prolonged their gestures when their speech was disrupted. These findings support the interactive view and add new constraints on models of speech and gesture production

Abstract

The present study investigated the neural correlates of infant discrimination of very similar linguistic varieties (Quebecois and Parisian French) using functional Near InfraRed Spectroscopy. In line with previous behavioral and electrophysiological data, there was no evidence that 3-month-olds discriminated the two regional accents, whereas 5-month-olds did, with the locus of discrimination in left anterior perisylvian regions. These neuroimaging results suggest that a developing language network relying crucially on left perisylvian cortices sustains infants' discrimination of similar linguistic varieties within this early period of infancy.

Abstract

There are increasing reports that individual variation in behavioral and neurophysiological measures of infant speech processing predicts later language outcomes, and specifically concurrent or subsequent vocabulary size. If such findings are held up under scrutiny, they could both illuminate theoretical models of language development and contribute to the prediction of communicative disorders. A qualitative, systematic review of this emergent literature illustrated the variety of approaches that have been used and highlighted some conceptual problems regarding the measurements. A quantitative analysis of the same data established that the bivariate relation was significant, with correlations of similar strength to those found for well-established nonlinguistic predictors of language. Further exploration of infant speech perception predictors, particularly from a methodological perspective, is recommended.

Abstract

Typically, the point vowels [i,ɑ,u] are acoustically more peripheral in infant-directed speech (IDS) compared to adult-directed speech (ADS). If caregivers seek to highlight lexically relevant contrasts in IDS, then two sounds that are contrastive should become more distinct, whereas two sounds that are surface realizations of the same underlying sound category should not. To test this prediction, vowels that are phonemically contrastive ([i-ɪ] and [eɪ-ε]), vowels that map onto the same underlying category ([æ- ] and [ε- ]), and the point vowels [i,ɑ,u] were elicited in IDS and ADS by American English mothers of two age groups of infants (four- and eleven-month-olds). As in other work, point vowels were produced in more peripheral positions in IDS compared to ADS. However, there was little evidence of hyperarticulation per se (e.g. [i-ɪ] was hypoarticulated). We suggest that across-the-board lexically based hyperarticulation is not a necessary feature of IDS.

Abstract

This work was supported by grants from the French Agence Nationale de la Recherche (ANR-2010-BLAN-1901) and from French Fondation de France to Anne Christophe, from the National Institute of Child Health and Human Development (HD054448) to Cynthia Fisher, Fondation Fyssen and Ecole de Neurosciences de Paris to Alex Cristia, and a PhD fellowship from the Direction Générale de l'Armement (DGA, France) supported by the PhD program FdV (Frontières du Vivant) to Isabelle Dautriche. We thank Isabelle Brunet for the recruitment, Michel Dutat for the technical support, and Hernan Anllo for his puppet mastery skill. We are grateful to the families that participated in this study. We also thank two anonymous reviewers for their comments on an earlier draft of this manuscript.

Abstract

People often talk about musical pitch using spatial metaphors. In English, for instance, pitches can be “high” or “low” (i.e., height-pitch association), whereas in other languages, pitches are described as “thin” or “thick” (i.e., thickness-pitch association). According to results from psychophysical studies, metaphors in language can shape people’s nonlinguistic space-pitch representations. But does language establish mappings between space and pitch in the first place, or does it only modify preexisting associations? To find out, we tested 4-month-old Dutch infants’ sensitivity to height-pitch and thickness-pitch mappings using a preferential-looking paradigm. The infants looked significantly longer at cross-modally congruent stimuli for both space-pitch mappings, which indicates that infants are sensitive to these associations before language acquisition. The early presence of space-pitch mappings means that these associations do not originate from language. Instead, language builds on preexisting mappings, changing them gradually via competitive associative learning. Space-pitch mappings that are language-specific in adults develop from mappings that may be universal in infants.

Abstract

Relative clauses are a syntactic device to create complex sentences and they make language structurally productive. Despite a considerable number of experimental studies, it is still largely unclear how children learn relative clauses and how these are processed in the language system. Researchers at the MPI for Psycholinguistics used a computational learning model to gain novel insights into these issues. The model explains the differential development of relative clauses in English as well as cross-linguistic differences

Abstract

In this event-related FMRI study we investigated the effect of five days of implicit acquisition on preference classification by means of an artificial grammar learning (AGL) paradigm based on the structural mere-exposure effect and preference classification using a simple right-linear unification grammar. This allowed us to investigate implicit AGL in a proper learning design by including baseline measurements prior to grammar exposure. After 5 days of implicit acquisition, the FMRI results showed activations in a network of brain regions including the inferior frontal (centered on BA 44/45) and the medial prefrontal regions (centered on BA 8/32). Importantly, and central to this study, the inclusion of a naive preference FMRI baseline measurement allowed us to conclude that these FMRI findings were the intrinsic outcomes of the learning process itself and not a reflection of a preexisting functionality recruited during classification, independent of acquisition. Support for the implicit nature of the knowledge utilized during preference classification on day 5 come from the fact that the basal ganglia, associated with implicit procedural learning, were activated during classification, while the medial temporal lobe system, associated with explicit declarative memory, was consistently deactivated. Thus, preference classification in combination with structural mere-exposure can be used to investigate structural sequence processing (syntax) in unsupervised AGL paradigms with proper learning designs.

Abstract

The involvement of neural motor and sensory systems in the processing of language has so far mainly been studied in native (L1) speakers. In an fMRI experiment, we investigated whether non-native (L2) semantic representations are rich enough to allow for activation in motor and somatosensory brain areas. German learners of Dutch and a control group of Dutch native speakers made lexical decisions about visually presented Dutch motor and non-motor verbs. Region-of-interest (ROI) and whole-brain analyses indicated that L2 speakers, like L1 speakers, showed significantly increased activation for simple motor compared to non-motor verbs in motor and somatosensory regions. This effect was not restricted to Dutch-German cognate verbs, but was also present for non-cognate verbs. These results indicate that L2 semantic representations are rich enough for motor-related activations to develop in motor and somatosensory areas.

Abstract

In this functional magnetic resonance imaging (fMRI) long-lag priming study, we investigated the processing of Dutch semantically transparent, derived prefix verbs. In such words, the meaning of the word as a whole can be deduced from the meanings of its parts, e.g., wegleggen “put aside.” Many behavioral and some fMRI studies suggest that native (L1) speakers decompose transparent derived words. The brain region usually implicated in morphological decomposition is the left inferior frontal gyrus (LIFG). In non-native (L2) speakers, the processing of transparent derived words has hardly been investigated, especially in fMRI studies, and results are contradictory: some studies find more reliance on holistic (i.e., non-decompositional) processing by L2 speakers; some find no difference between L1 and L2 speakers. In this study, we wanted to find out whether Dutch transparent derived prefix verbs are decomposed or processed holistically by German L2 speakers of Dutch. Half of the derived verbs (e.g., omvallen “fall down”) were preceded by their stem (e.g., vallen “fall”) with a lag of 4–6 words (“primed”); the other half (e.g., inslapen “fall asleep”) were not (“unprimed”). L1 and L2 speakers of Dutch made lexical decisions on these visually presented verbs. Both region of interest analyses and whole-brain analyses showed that there was a significant repetition suppression effect for primed compared to unprimed derived verbs in the LIFG. This was true both for the analyses over L2 speakers only and for the analyses over the two language groups together. The latter did not reveal any interaction with language group (L1 vs. L2) in the LIFG. Thus, L2 speakers show a clear priming effect in the LIFG, an area that has been associated with morphological decomposition. Our findings are consistent with the idea that L2 speakers engage in decomposition of transparent derived verbs rather than processing them holistically

Abstract

The left and right sides of the human brain are specialized for different kinds of information processing, and much of our cognition is lateralized to an extent towards one side or the other. Handedness is a reflection of nervous system lateralization. Roughly ten percent of people are mixed- or left-handed, and they show an elevated rate of reductions or reversals of some cerebral functional asymmetries compared to right-handers. Brain anatomical correlates of left-handedness have also been suggested. However, the relationships of left-handedness to brain structure and function remain far from clear. We carried out a comprehensive analysis of cortical surface area differences between 106 left-handed subjects and 1960 right-handed subjects, measured using an automated method of regional parcellation (FreeSurfer, Destrieux atlas). This is the largest study sample that has so far been used in relation to this issue. No individual cortical region showed an association with left-handedness that survived statistical correction for multiple testing, although there was a nominally significant association with the surface area of a previously implicated region: the left precentral sulcus. Identifying brain structural correlates of handedness may prove useful for genetic studies of cerebral asymmetries, as well as providing new avenues for the study of relations between handedness, cerebral lateralization and cognition.

Abstract

Functional and anatomical asymmetries are prevalent features of the human brain, linked to gender, handedness, and cognition. However, little is known about the neurodevelopmental processes involved. In zebrafish, asymmetries arise in the diencephalon before extending within the central nervous system. We aimed to identify genes involved in the development of subtle, left-right volumetric asymmetries of human subcortical structures using large datasets. We first tested the feasibility of measuring left-right volume differences in such large-scale samples, as assessed by two automated methods of subcortical segmentation (FSL|FIRST and FreeSurfer), using data from 235 subjects who had undergone MRI twice. We tested the agreement between the first and second scan, and the agreement between the segmentation methods, for measures of bilateral volumes of six subcortical structures and the hippocampus, and their volumetric asymmetries. We also tested whether there were biases introduced by left-right differences in the regional atlases used by the methods, by analyzing left-right flipped images. While many bilateral volumes were measured well (scan-rescan r = 0.6-0.8), most asymmetries, with the exception of the caudate nucleus, showed lower repeatabilites. We meta-analyzed genome-wide association scan results for caudate nucleus asymmetry in a combined sample of 3,028 adult subjects but did not detect associations at genome-wide significance (P < 5 × 10-8). There was no enrichment of genetic association in genes involved in left-right patterning of the viscera. Our results provide important information for researchers who are currently aiming to carry out large-scale genome-wide studies of subcortical and hippocampal volumes, and their asymmetries

Abstract

Current views on the neurobiological underpinnings of language are discussed that deviate in a number of ways from the classical Wernicke–Lichtheim–Geschwind model. More areas than Broca's and Wernicke's region are involved in language. Moreover, a division along the axis of language production and language comprehension does not seem to be warranted. Instead, for central aspects of language processing neural infrastructure is shared between production and comprehension. Three different accounts of the role of Broca's area in language are discussed. Arguments are presented in favor of a dynamic network view, in which the functionality of a region is co-determined by the network of regions in which it is embedded at particular moments in time. Finally, core regions of language processing need to interact with other networks (e.g. the attentional networks and the ToM network) to establish full functionality of language and communication.

Abstract

A hallmark of human language is that we combine lexical building blocks retrieved from memory in endless new ways. This combinatorial aspect of language is referred to as unification. Here we focus on the neurobiological infrastructure for syntactic and semantic unification. Unification is characterized by a high-speed temporal profile including both prediction and integration of retrieved lexical elements. A meta-analysis of numerous neuroimaging studies reveals a clear dorsal/ventral gradient in both left inferior frontal cortex and left posterior temporal cortex, with dorsal foci for syntactic processing and ventral foci for semantic processing. In addition to core areas for unification, further networks need to be recruited to realize language-driven communication to its full extent. One example is the theory of mind network, which allows listeners and readers to infer the intended message (speaker meaning) from the coded meaning of the linguistic utterance. This indicates that sensorimotor simulation cannot handle all of language processing.

Abstract

In human face-to-face communication, language comprehension is a multi-modal, situated activity. However, little is known about how we combine information from different modalities during comprehension, and how perceived communicative intentions, often signaled through visual signals, influence this process. We explored this question by simulating a multi-party communication context in which a speaker alternated her gaze between two recipients. Participants viewed speech-only or speech + gesture object-related messages when being addressed (direct gaze) or unaddressed (gaze averted to other participant). They were then asked to choose which of two object images matched the speaker’s preceding message. Unaddressed recipients responded significantly more slowly than addressees for speech-only utterances. However, perceiving the same speech accompanied by gestures sped unaddressed recipients up to a level identical to that of addressees. That is, when unaddressed recipients’ speech processing suffers, gestures can enhance the comprehension of a speaker’s message. We discuss our findings with respect to two hypotheses attempting to account for how social eye gaze may modulate multi-modal language comprehension.

Abstract

Most words that infants hear occur within fluent speech. To compile a vocabulary, infants therefore need to segment words from speech contexts. This study is the first to investigate whether infants (here: 10-month-olds) can recognize words when both initial exposure and test presentation are in continuous speech. Electrophysiological evidence attests that this indeed occurs: An increased extended negativity (word recognition effect) appears for familiarized target words relative to control words. This response proved constant at the individual level: Only infants who showed this negativity at test had shown such a response, within six repetitions after first occurrence, during familiarization.

Abstract

The relocation of animals can induce stress when animals are placed in novel environmental conditions. The movement of captive animals among facilities is common, especially for non-human primates used in research. The stress response begins with the activation of the hypothalamic-pituitary-adrenal (HPA) axis which results in the release of glucocorticoid hormones (GC), which at chronic levels could lead to deleterious physiological effects. There is a substantial body of data concerning GC levels affecting reproduction, and rank and aggression in primates. However, the effect of transport has received much less attention. Fecal samples from eight (four male and four female) captive-bred cotton-top tamarins (Saguinus oedipus) were collected at four different time points (two pre-transport and two post-transport). The fecal samples were analyzed using an immunoassay to determine GC levels. A repeated measures analysis of variance (ANOVA) demonstrated that GC levels differed among transport times (p = 0.009), but not between sexes (p = 0.963). Five of the eight tamarins exhibited an increase in GC levels after transport. Seven of the eight tamarins exhibited a decrease in GC levels from three to six days post-transport to three weeks post-transport. Most values returned to pre-transport levels after three weeks. The results indicate that these tamarins experienced elevated GC levels following transport, but these increases were of short duration. This outcome would suggest that the negative effects of elevated GC levels were also of short duration.

Abstract

Developmental dyslexia is often characterized by a dual deficit in both word recognition accuracy and general processing speed. While previous research into dyslexic word recognition may have suffered from speed-accuracy trade-off, the present study employed a novel eye-tracking task that is less prone to such confounds. Participants (10 dyslexics and 12 controls) were asked to look at real word stimuli, and to ignore simultaneously presented non-word stimuli, while their eye-movements were recorded. Improvements in word recognition accuracy over time were modeled in terms of a continuous non-linear function. The words' rhyme consistency and the non-words' lexicality (unpronounceable, pronounceable, pseudohomophone) were manipulated within-subjects. Speed-related measures derived from the model fits confirmed generally slower processing in dyslexics, and showed a rhyme consistency effect in both dyslexics and controls. In terms of overall error rate, dyslexics (but not controls) performed less accurately on rhyme-inconsistent words, suggesting a representational deficit for such words in dyslexics. Interestingly, neither group showed a pseudohomophone effect in speed or accuracy, which might call the task-independent pervasiveness of this effect into question. The present results illustrate the importance of distinguishing between speed- vs. accuracy-related effects for our understanding of dyslexic word recognition

Abstract

When speakers describe motion events using different languages, they subsequently classify those events in language-specific ways (Gennari, Sloman, Malt & Fitch, 2002). Here we ask if bilingual speakers flexibly shift their event classification preferences based on the language in which they verbally encode those events. English–Spanish bilinguals and monolingual controls described motion events in either Spanish or English. Subsequently they judged the similarity of the motion events in a triad task. Bilinguals tested in Spanish and Spanish monolinguals were more likely to make similarity judgments based on the path of motion versus bilinguals tested in English and English monolinguals. The effect is modulated in bilinguals by the age of acquisition of the second language. Late bilinguals based their judgments on path more often when Spanish was used to describe the motion events versus English. Early bilinguals had a path preference independent of the language in use. These findings support “thinking-for-speaking” (Slobin, 1996) in late bilinguals.

Abstract

This study investigated processing of emotion words in autism spectrum disorders (ASD) using reaction times and event-related potentials (ERP). Adults with (n = 21) and without (n = 20) ASD performed a lexical decision task on emotion and neutral words while their brain activity was recorded. Both groups showed faster responses to emotion words compared to neutral, suggesting intact early processing of emotion in ASD. In the ERPs, the control group showed a typical late positive component (LPC) at 400-600 ms for emotion words compared to neutral, while the ASD group showed no LPC. The between-group difference in LPC amplitude was significant, suggesting that emotion words were processed differently by individuals with ASD, although their behavioral performance was similar to that of typical individuals

Abstract

Morphology is the aspect of language concerned with the internal structure of words. In the past decades, a large body of masked priming (behavioral and neuroimaging) data has suggested that the visual word recognition system automatically decomposes any morphologically complex word into a stem and its constituent morphemes. Yet the reliance of morphology on other reading processes (e.g., orthography and semantics), as well as its underlying neuronal mechanisms are yet to be determined. In the current magnetoencephalography study, we addressed morphology from the perspective of the unification framework, that is, by applying the Hold/Release paradigm, morphological unification was simulated via the assembly of internal morphemic units into a whole word. Trials representing real words were divided into words with a transparent (true) or a nontransparent (pseudo) morphological relationship. Morphological unification of truly suffixed words was faster and more accurate and additionally enhanced induced oscillations in the narrow gamma band (60–85 Hz, 260–440 ms) in the left posterior occipitotemporal junction. This neural signature could not be explained by a mere automatic lexical processing (i.e., stem perception), but more likely it related to a semantic access step during the morphological unification process. By demonstrating the validity of unification at the morphological level, this study contributes to the vast empirical evidence on unification across other language processes. Furthermore, we point out that morphological unification relies on the retrieval of lexical semantic associations via induced gamma band oscillations in a cerebral hub region for visual word form processing.

Abstract

Purpose While decades of research were devoted to study generation mechanisms of spontaneous spike and wave discharges (SWD), little attention has been paid to network mechanisms associated with the spontaneous termination of SWD. In the current study coupling-dynamics at the onset and termination of SWD were studied in an extended part of the cortico-thalamo-cortical system of freely moving, genetic absence epileptic WAG/Rij rats. Methods Local-field potential recordings of 16 male WAG/Rij rats, equipped with multiple electrodes targeting layer 4 to 6 of the somatosensory-cortex (ctx4, ctx5, ctx6), rostral and caudal reticular thalamic nucleus (rRTN & cRTN), Ventral Postero Medial (VPM), anterior- (ATN) and posterior (Po) thalamic nucleus, were obtained. Six seconds lasting pre-SWD->SWD, SWD->post SWD and control periods were analyzed with time-frequency methods and between-region interactions were quantified with frequencyresolved Granger Causality (GC) analysis. Results Most channel-pairs showed increases in GC lasting from onset to offset of the SWD. While for most thalamo-thalamic pairs a dominant coupling direction was found during the complete SWD, most cortico-thalamic pairs only showed a dominant directional drive (always from cortex to thalamus) during the first 500ms of SWD. Channel-pair ctx4-rRTN showed a longer lasting dominant cortical drive, which stopped 1.5 sec prior to SWD offset. This early decrease in directional coupling was followed by an increase in directional coupling from cRTN to rRTN 1 sec prior to SWD offset. For channel pairs ctx5-Po and ctx6-Po the heightened cortex->thalamus coupling remained until 1.5 sec following SWD offset, while the thalamus->cortex coupling for these pairs stopped at SWD offset. Conclusion The high directional coupling from somatosensory cortex to the thalamus at SWD onset is in good agreement with the idea of a cortical epileptic focus that initiates and entrains other brain structures into seizure activity. The decrease of cortex to rRTN coupling as well as the increased coupling from cRTN to rRTN preceding SWD termination demonstrate that SWD termination is a gradual process that involves both cortico-thalamic as well as intrathalamic processes. The rostral RTN seems to be an important resonator for SWD and relevant for maintenance, while the cRTN might inhibit this oscillation. The somatosensory cortex seems to attempt to reinitiate SWD following its offset via its strong coupling to the posterior thalamus.

Abstract

RTs in conversation, with average gaps of 200 msec and often less, beat standard RTs, despite the complexity of response and the lag in speech production (600 msec or more). This can only be achieved by anticipation of timing and content of turns in conversation, about which little is known. Using EEG and an experimental task with conversational stimuli, we show that estimation of turn durations are based on anticipating the way the turn would be completed. We found a neuronal correlate of turn-end anticipation localized in ACC and inferior parietal lobule, namely a beta-frequency desynchronization as early as 1250 msec, before the end of the turn. We suggest that anticipation of the other's utterance leads to accurately timed transitions in everyday conversations.

Abstract

Recent studies have emphasized that developmental dyslexia is a multiple-deficit disorder, in contrast to the traditional single-deficit view. In this context, cognitive profiling of children with dyslexia may be a relevant contribution to this unresolved discussion. The aim of this study was to profile 36 Portuguese children with dyslexia from the 2nd to 5th grade. Hierarchical cluster analysis was used to group participants according to their phonological awareness, rapid automatized naming, verbal short-term memory, vocabulary, and nonverbal intelligence abilities. The results suggested a two-cluster solution: a group with poorer performance on phoneme deletion and rapid automatized naming compared with the remaining variables (Cluster 1) and a group characterized by underperforming on the variables most related to phonological processing (phoneme deletion and digit span), but not on rapid automatized naming (Cluster 2). Overall, the results seem more consistent with a hybrid perspective, such as that proposed by Pennington and colleagues (2012), for understanding the heterogeneity of dyslexia. The importance of characterizing the profiles of individuals with dyslexia becomes clear within the context of constructing remediation programs that are specifically targeted and are more effective in terms of intervention outcome.

Abstract

We examined language-switching effects in French–English bilinguals using a paradigm where pictures are always named in the same language (either French or English) within a block of trials, and on each trial, the picture is preceded by a printed word from the same language or from the other language. Participants had to either make a language decision on the word or categorize it as an animal name or not. Picture-naming latencies in French (Language 1 [L1]) were slower when pictures were preceded by an English word than by a French word, independently of the task performed on the word. There were no language-switching effects when pictures were named in English (L2). This pattern replicates asymmetrical switch costs found with the cued picture-naming paradigm and shows that the asymmetrical pattern can be obtained (a) in the absence of artificial (nonlinguistic) language cues, (b) when the switch involves a shift from comprehension in 1 language to production in another, and (c) when the naming language is blocked (univalent response). We concluded that language switch costs in bilinguals cannot be reduced to effects driven by task control or response-selection mechanisms.

Abstract

Did one of your parents, siblings, or friends ever tell you that you were talking in your sleep? Nothing to be ashamed of! A recent study found that more than half of all people have had the experience of speaking out loud while being asleep [1]. This might even be underestimated, because often people do not notice that they are sleep-talking, unless somebody wakes them up or tells them the next day. Most neuroscientists, linguists, and psychologists studying language are interested in our language production and language comprehension skills during the day. In the present article, we will explore what is known about the production of overt speech during the night. We suggest that the study of sleep-talking may be just as interesting and informative as the study of wakeful speech.

Abstract

According to a prominent theory of language production, concepts activate multiple associated words in memory, which enter into competition for selection. However, only a few electrophysiological studies have identified brain responses reflecting competition. Here, we report a magnetoencephalography study in which the activation of competing words was manipulated by presenting pictures (e.g., dog) with distractor words. The distractor and picture name were semantically related (cat), unrelated (pin), or identical (dog). Related distractors are stronger competitors to the picture name because they receive additional activation from the picture relative to other distractors. Picture naming times were longer with related than unrelated and identical distractors. Phase-locked and non-phase-locked activity were distinct but temporally related. Phase-locked activity in left temporal cortex, peaking at 400 ms, was larger on unrelated than related and identical trials, suggesting differential activation of alternative words by the picture-word stimuli. Non-phase-locked activity between roughly 350–650 ms (4–10 Hz) in left superior frontal gyrus was larger on related than unrelated and identical trials, suggesting differential resolution of the competition among the alternatives, as reflected in the naming times. These findings characterise distinct patterns of activity associated with lexical activation and competition, supporting the theory that words are selected by competition.

Abstract

We report on an fMRI syntactic priming experiment in which we measure brain activity for participants who communicate with another participant outside the scanner. We investigated whether syntactic processing during overt language production and comprehension is influenced by having a (shared) goal to communicate. Although theory suggests this is true, the nature of this influence remains unclear. Two hypotheses are tested: i. syntactic priming effects (fMRI and RT) are stronger for participants in the communicative context than for participants doing the same experiment in a non-communicative context, and ii. syntactic priming magnitude (RT) is correlated with the syntactic priming magnitude of the speaker’s communicative partner. Results showed that across conditions, participants were faster to produce sentences with repeated syntax, relative to novel syntax. This behavioral result converged with the fMRI data: we found repetition suppression effects in the left insula extending into left inferior frontal gyrus (BA 47/45), left middle temporal gyrus (BA 21), left inferior parietal cortex (BA 40), left precentral gyrus (BA 6), bilateral precuneus (BA 7), bilateral supplementary motor cortex (BA 32/8) and right insula (BA 47). We did not find support for the first hypothesis: having a communicative intention does not increase the magnitude of syntactic priming effects (either in the brain or in behavior) per se. We did find support for the second hypothesis: if speaker A is strongly/weakly primed by speaker B, then speaker B is primed by speaker A to a similar extent. We conclude that syntactic processing is influenced by being in a communicative context, and that the nature of this influence is bi-directional: speakers are influenced by each other.

Abstract

Speakers sometimes repeat syntactic structures across sentences, a phenomenon called syntactic priming. We investigated the influence of verb-bound syntactic preferences on syntactic priming effects in response choices and response latencies for German ditransitive sentences. In the response choices we found inverse preference effects: There were stronger syntactic priming effects for primes in the less preferred structure, given the syntactic preference of the prime verb. In the response latencies we found positive preference effects: There were stronger syntactic priming effects for primes in the more preferred structure, given the syntactic preference of the prime verb. These findings provide further support for the idea that syntactic processing is lexically guided.

Abstract

We investigated the neural basis of inhibitory control during lexical selection. Participants overtly named pictures while response times (RTs) and event-related brain potentials (ERPs) were recorded. The difficulty of lexical selection was manipulated by using object and action pictures with high name agreement (few response candidates) versus low name agreement (many response candidates). To assess the involvement of inhibition, we conducted delta plot analyses of naming RTs and examined the N2 component of the ERP. We found longer mean naming RTs and a larger N2 amplitude in the low relative to the high name agreement condition. For action naming we found a negative correlation between the slopes of the slowest delta segment and the difference in N2 amplitude between the low and high name agreement conditions. The converging behavioral and electrophysiological evidence suggests that selective inhibition is engaged to reduce competition during lexical selection in picture naming.

Abstract

We investigated global integration (wrap-up) processes at the boundaries of musical phrases by comparing the effects of well and non-well formed phrases on event-related potentials time-locked to two boundary points: the onset and the offset of the boundary pause. The Closure Positive Shift, which is elicited at the boundary offset, was not modulated by the quality of phrase structure (well vs. non-well formed). In contrast, the boundary onset potentials showed different patterns for well and non-well formed phrases. Our results contribute to specify the functional meaning of the Closure Positive Shift in music, shed light on the large-scale structural integration of musical input, and raise new hypotheses concerning shared resources between music and language.

Abstract

Neuroscientific and musicological approaches to music cognition indicate that listeners familiarized in the Western tonal tradition expect a musical phrase boundary at predictable time intervals. However, phrase boundary prediction processes in music remain untested. We analyzed event-related potentials (ERPs) and event-related induced power changes at the onset and offset of a boundary pause. We made comparisons with modified melodies, where the pause was omitted and filled by tones. The offset of the pause elicited a closure positive shift (CPS), indexing phrase boundary detection. The onset of the filling tones elicited significant increases in theta and beta powers. In addition, the P2 component was larger when the filling tones started than when they ended. The responses to boundary omission suggest that listeners expected to hear a boundary pause. Therefore, boundary prediction seems to coexist with boundary detection in music segmentation.

Abstract

An ability to decode semantic information from fMRI spatial patterns has been demonstrated in previous studies mostly for 1 specific input modality. In this study, we aimed to decode semantic category independent of the modality in which an object was presented. Using a searchlight method, we were able to predict the stimulus category from the data while participants performed a semantic categorization task with 4 stimulus modalities (spoken and written names, photographs, and natural sounds). Significant classification performance was achieved in all 4 modalities. Modality-independent decoding was implemented by training and testing the searchlight method across modalities. This allowed the localization of those brain regions, which correctly discriminated between the categories, independent of stimulus modality. The analysis revealed large clusters of voxels in the left inferior temporal cortex and in frontal regions. These voxels also allowed category discrimination in a free recall session where subjects recalled the objects in the absence of external stimuli. The results show that semantic information can be decoded from the fMRI signal independently of the input modality and have clear implications for understanding the functional mechanisms of semantic memory.

Abstract

How can we understand each other during communicative interactions? An influential suggestion holds that communicators are primed by each other’s behaviors, with associative mechanisms automatically coordinating the production of communicative signals and the comprehension of their meanings. An alternative suggestion posits that mutual understanding requires shared conceptualizations of a signal’s use, i.e., “conceptual pacts” that are abstracted away from specific experiences. Both accounts predict coherent neural dynamics across communicators, aligned either to the occurrence of a signal or to the dynamics of conceptual pacts. Using coherence spectral-density analysis of cerebral activity simultaneously measured in pairs of communicators, this study shows that establishing mutual understanding of novel signals synchronizes cerebral dynamics across communicators’ right temporal lobes. This interpersonal cerebral coherence occurred only within pairs with a shared communicative history, and at temporal scales independent from signals’ occurrences. These findings favor the notion that meaning emerges from shared conceptualizations of a signal’s use.

Abstract

Despite the ambiguity inherent in human communication, people are remarkably efficient in establishing mutual understanding. Studying how people communicate in novel settings provides a window into the mechanisms supporting the human competence to rapidly generate and understand novel shared symbols, a fundamental property of human communication. Previous work indicates that the right posterior superior temporal sulcus (pSTS) is involved when people understand the intended meaning of novel communicative actions. Here, we set out to test whether normal functioning of this cerebral structure is required for understanding novel communicative actions using inhibitory low-frequency repetitive transcranial magnetic stimulation (rTMS). A factorial experimental design contrasted two tightly matched stimulation sites (right pSTS vs. left MT+, i.e. a contiguous homotopic task-relevant region) and tasks (a communicative task vs. a visual tracking task that used the same sequences of stimuli). Overall task performance was not affected by rTMS, whereas changes in task performance over time were disrupted according to TMS site and task combinations. Namely, rTMS over pSTS led to a diminished ability to improve action understanding on the basis of recent communicative history, while rTMS over MT+ perturbed improvement in visual tracking over trials. These findings qualify the contributions of the right pSTS to human communicative abilities, showing that this region might be necessary for incorporating previous knowledge, accumulated during interactions with a communicative partner, to constrain the inferential process that leads to action understanding.

Abstract

To investigate the neural underpinnings of word decoding, and how it changes as a function of repeated exposure, we trained Dutch participants repeatedly over the course of a month of training to articulate a set of novel disyllabic input strings written in Greek script to avoid the use of familiar orthographic representations. The syllables in the input were phonotactically legal combinations but non-existent in the Dutch language, allowing us to assess their role in novel word decoding. Not only trained disyllabic pseudowords were tested but also pseudowords with recombined patterns of syllables to uncover the emergence of syllabic representations. We showed that with extensive training, articulation became faster and more accurate for the trained pseudowords. On the neural level, the initial stage of decoding was reflected by increased activity in visual attention areas of occipito-temporal and occipito-parietal cortices, and in motor coordination areas of the precentral gyrus and the inferior frontal gyrus. After one month of training, memory representations for holistic information (whole word unit) were established in areas encompassing the angular gyrus, the precuneus and the middle temporal gyrus. Syllabic representations also emerged through repeated training of disyllabic pseudowords, such that reading recombined syllables of the trained pseudowords showed similar brain activation to trained pseudowords and were articulated faster than novel combinations of letter strings used in the trained pseudowords.

Abstract

Although the majority of evidence on perceptual narrowing in speech sounds is based on consonants, most models of infant speech perception generalize these findings to vowels, assuming that vowel perception improves for vowel sounds that are present in the infant's native language within the first year of life, and deteriorates for non-native vowel sounds over the same period of time. The present meta-analysis contributes to assessing to what extent these descriptions are accurate in the first comprehensive quantitative meta-analysis of perceptual narrowing in infant vowel discrimination, including results from behavioral, electrophysiological, and neuroimaging methods applied to infants 0–14 months of age. An analysis of effect sizes for native and non-native vowel discrimination over the first year of life revealed that they changed with age in opposite directions, being significant by about 6 months of age

Abstract

In this fMRI study we investigate the neural correlates of information structure integration during sentence comprehension in Dutch. We looked into how prosodic cues (pitch accents) that signal the information status of constituents to the listener (new information) are combined with other types of information during the unification process. The difficulty of unifying the prosodic cues into overall sentence meaning was manipulated by constructing sentences in which the pitch accent did (focus-accent agreement), and sentences in which the pitch accent did not (focus-accent disagreement) match the expectations for focus constituents of the sentence. In case of a mismatch, the load on unification processes increases. Our results show two anatomically distinct effects of focus-accent disagreement, one located in the posterior left inferior frontal gyrus (LIFG, BA6/44), and one in the more anterior-ventral LIFG (BA 47/45). Our results confirm that information structure is taken into account during unification, and imply an important role for the LIFG in unification processes, in line with previous fMRI studies.

Abstract

The generation of subject–verb agreement is a central component of grammatical encoding. It is sensitive to conceptual and grammatical influences, but the interplay between these factors is still not fully understood. We investigate how semantic integration of the subject noun phrase (‘the secretary of/with the governor’) and the Local Noun Number (‘the secretary with the governor/governors’) affect the ease of selecting the verb form. Two hypotheses are assessed: according to the notional hypothesis, integration encourages the assignment of the singular notional number to the noun phrase and facilitates the choice of the singular verb form. According to the lexical interference hypothesis, integration strengthens the competition between nouns within the subject phrase, making it harder to select the verb form when the nouns mismatch in number. In two experiments, adult speakers of Dutch completed spoken preambles (Experiment 1) or selected appropriate verb forms (Experiment 2). Results showed facilitatory effects of semantic integration (fewer errors and faster responses with increasing integration). These effects did not interact with the effects of the Local Noun Number (slower response times and higher error rates for mismatching than for matching noun numbers). The findings thus support the notional hypothesis and a model of agreement where conceptual and lexical factors independently contribute to the determination of the number of the subject noun phrase and, ultimately, the verb.

Abstract

Compared to the large body of work on lexical access, little research has been done on grammatical encoding in language production. An exception is the generation of subject-verb agreement. Here, two key findings have been reported: (1) Speakers make more agreement errors when the head and local noun of a phrase mismatch in number than when they match (e.g., the key to the cabinet(s)); and (2) this attraction effect is asymmetric, with stronger attraction for singular than for plural head nouns. Although these findings are robust, the cognitive processes leading to agreement errors and their significance for the generation of correct agreement are not fully understood. We propose that future studies of agreement, and grammatical encoding in general, may benefit from using paradigms that tightly control the variability of the lexical content of the material. We report two experiments illustrating this approach. In both of them, the experimental items featured combinations of four nouns, four color adjectives, and two prepositions. In Experiment 1, native speakers of Dutch described pictures in sentences such as the circle next to the stars is blue. In Experiment 2, they carried out a forced-choice task, where they read subject noun phrases (e.g., the circle next to the stars) and selected the correct verb-phrase (is blue or are blue) with a button press. Both experiments showed an attraction effect, with more errors after subject phrases with mismatching, compared to matching head and local nouns. This effect was stronger for singular than plural heads, replicating the attraction asymmetry. In contrast, the response times recorded in Experiment 2 showed similar attraction effects for singular and plural head nouns. These results demonstrate that critical agreement phenomena can be elicited reliably in lexically-reduced contexts. We discuss the theoretical implications of the findings and the potential and limitations of studies using lexically simple materials.

Abstract

Humans differ widely in their navigational abilities. Studies have shown that self-reports on navigational abilities are good predictors of performance on navigation tasks in real and virtual environments. The caudate nucleus and medial temporal lobe regions have been suggested to subserve different navigational strategies. The ability to use different strategies might underlie navigational ability differences. This study examines the anatomical correlates of self-reported navigational ability in both gray and white matter. Local gray matter volume was compared between a group (N = 134) of good and bad navigators using voxel-based morphometry (VBM), as well as regional volumes. To compare between good and bad navigators, we also measured white matter anatomy using diffusion tensor imaging (DTI) and looked at fractional anisotropy (FA) values. We observed a trend toward higher local GM volume in right anterior parahippocampal/rhinal cortex for good versus bad navigators. Good male navigators showed significantly higher local GM volume in right hippocampus than bad male navigators. Conversely, bad navigators showed increased FA values in the internal capsule, the white matter bundle closest to the caudate nucleus and a trend toward higher local GM volume in the caudate nucleus. Furthermore, caudate nucleus regional volume correlated negatively with navigational ability. These convergent findings across imaging modalities are in line with findings showing that the caudate nucleus and the medial temporal lobes are involved in different wayfinding strategies. Our study is the first to show a link between self-reported large-scale navigational abilities and different measures of brain anatomy.

Abstract

Studies on metacognition have shown that participants can report on their performance on a wide range of perceptual, memory and behavioral tasks. We know little, however, about the ability to report on one's attentional focus. The degree and direction of somatosensory attention can, however, be readily discerned through suppression of alpha band frequencies in EEG/MEG produced by the somatosensory cortex. Such top-down attentional modulations of cortical excitability have been shown to result in better discrimination performance and decreased response times. In this study we asked whether the degree of attentional focus is also accessible for subjective report, and whether such evaluations correspond to the amount of somatosensory alpha activity. In response to auditory cues participants maintained somatosensory attention to either their left or right hand for intervals varying randomly between 5 and 32seconds, while their brain activity was recorded with MEG. Trials were terminated by a probe sound, to which they reported their level of attention on the cued hand right before probe-onset. Using a beamformer approach, we quantified the alpha activity in left and right somatosensory regions, one second before the probe. Alpha activity from contra- and ipsilateral somatosensory cortices for high versus low attention trials were compared. As predicted, the contralateral somatosensory alpha depression correlated with higher reported attentional focus. Finally, alpha activity two to three seconds before the probe-onset was correlated with attentional focus. We conclude that somatosensory attention is indeed accessible to metacognitive awareness.

Abstract

Left-handers are often excluded from study cohorts in neuroscience and neurogenetics in order to reduce variance in the data. However, recent investigations have shown that the inclusion or targeted recruitment of left-handers can be informative in studies on a range of topics, such as cerebral lateralization and the genetic underpinning of asymmetrical brain development. Left-handed individuals represent a substantial portion of the human population and therefore left-handedness falls within the normal range of human diversity; thus, it is important to account for this variation in our understanding of brain functioning. We call for neuroscientists and neurogeneticists to recognize the potential of studying this often-discarded group of research subjects.

Abstract

While most people prefer to use their right hand to brush their teeth, throw a ball, or hold a tennis racket, left-handers prefer to use their left hand. This is the case for around 10 per cent of all people. There was a time (not so long ago) when left-handers were stigmatized in Western (and other) communities: it was considered a bad sign if you were left-handed, and left-handed children were often forced to write with their right hand. This is nonsensical: there is nothing wrong with being left-handed, and trying to write with the non-preferred hand is frustrating for almost everybody. As a matter of fact, science can learn from left-handers, and in this paper, we discuss how this may be the case. We review why some people are left-handed and others are not, how left-handers' brains differ from right-handers’, and why scientists study left-handedness in the first place

Abstract

For most people, speech production is relatively effortless and error-free. Yet it has long been recognized that we need some type of control over what we are currently saying and what we plan to say. Precisely how we monitor our internal and external speech has been a topic of research interest for several decades. The predominant approach in psycholinguistics has assumed monitoring of both is accomplished via systems responsible for comprehending others' speech.

This special topic aimed to broaden the field, firstly by examining proposals that speech production might also engage more general systems, such as those involved in action monitoring. A second aim was to examine proposals for a production-specific, internal monitor. Both aims require that we also specify the nature of the representations subject to monitoring.

Abstract

Given the limited processing capabilities of the sensory system, it is essential that attended information is gated to downstream areas, whereas unattended information is blocked. While it has been proposed that alpha band (8–13 Hz) activity serves to route information to downstream regions by inhibiting neuronal processing in task-irrelevant regions, this hypothesis remains untested. Here we investigate how neuronal oscillations detected by electroencephalography in visual areas during working memory encoding serve to gate information reflected in the simultaneously recorded blood-oxygenation-level-dependent (BOLD) signals recorded by functional magnetic resonance imaging in downstream ventral regions. We used a paradigm in which 16 participants were presented with faces and landscapes in the right and left hemifields; one hemifield was attended and the other unattended. We observed that decreased alpha power contralateral to the attended object predicted the BOLD signal representing the attended object in ventral object-selective regions. Furthermore, increased alpha power ipsilateral to the attended object predicted a decrease in the BOLD signal representing the unattended object. We also found that the BOLD signal in the dorsal attention network inversely correlated with visual alpha power. This is the first demonstration, to our knowledge, that oscillations in the alpha band are implicated in the gating of information from the visual cortex to the ventral stream, as reflected in the representationally specific BOLD signal. This link of sensory alpha to downstream activity provides a neurophysiological substrate for the mechanism of selective attention during stimulus processing, which not only boosts the attended information but also suppresses distraction. Although previous studies have shown a relation between the BOLD signal from the dorsal attention network and the alpha band at rest, we demonstrate such a relation during a visuospatial task, indicating that the dorsal attention network exercises top-down control of visual alpha activity.

Abstract

Verbal working memory (VWM), the ability to maintain and manipulate representations of speech sounds over short periods, is held by some influential models to be independent from the systems responsible for language production and comprehension [e.g., Baddeley, A. D. Working memory, thought, and action. New York, NY: Oxford University Press, 2007]. We explore the alternative hypothesis that maintenance in VWM is subserved by temporary activation of the language production system [Acheson, D. J., & MacDonald, M. C. Verbal working memory and language production: Common approaches to the serial ordering of verbal information. Psychological Bulletin, 135, 50–68, 2009b]. Specifically, we hypothesized that for stimuli lacking a semantic representation (e.g., nonwords such as mun), maintenance in VWM can be achieved by cycling information back and forth between the stages of phonological encoding and articulatory planning. First, fMRI was used to identify regions associated with two different stages of language production planning: the posterior superior temporal gyrus (pSTG) for phonological encoding (critical for VWM of nonwords) and the middle temporal gyrus (MTG) for lexical–semantic retrieval (not critical for VWM of nonwords). Next, in the same subjects, these regions were targeted with repetitive transcranial magnetic stimulation (rTMS) during language production and VWM task performance. Results showed that rTMS to the pSTG, but not the MTG, increased error rates on paced reading (a language production task) and on delayed serial recall of nonwords (a test of VWM). Performance on a lexical–semantic retrieval task (picture naming), in contrast, was significantly sensitive to rTMS of the MTG. Because rTMS was guided by language production-related activity, these results provide the first causal evidence that maintenance in VWM directly depends on the long-term representations and processes used in speech production.

Abstract

The influence of semantic processing on the serial ordering of items in short-term memory was explored using a novel dual-task paradigm. Participants engaged in 2 picture-judgment tasks while simultaneously performing delayed serial recall. List material varied in the presence of phonological overlap (Experiments 1 and 2) and in semantic content (concrete words in Experiment 1 and 3; nonwords in Experiments 2 and 3). Picture judgments varied in the extent to which they required accessing visual semantic information (i.e., semantic categorization and line orientation judgments). Results showed that, relative to line-orientation judgments, engaging in semantic categorization judgments increased the proportion of item-ordering errors for concrete lists but did not affect error proportions for nonword lists. Furthermore, although more ordering errors were observed for phonologically similar relative to dissimilar lists, no interactions were observed between the phonological overlap and picture-judgment task manipulations. These results demonstrate that lexical-semantic representations can affect the serial ordering of items in short-term memory. Furthermore, the dual-task paradigm provides a new method for examining when and how semantic representations affect memory performance.

Abstract

Research on written language comprehension has generally assumed that the phonological properties of a word have little effect on sentence comprehension beyond the processes of word recognition. Two experiments investigated this assumption. Participants silently read relative clauses in which two pairs of words either did or did not have a high degree of phonological overlap. Participants were slower reading and less accurate comprehending the overlap sentences compared to the non-overlapping controls, even though sentences were matched for plausibility and differed by only two words across overlap conditions. A comparison across experiments showed that the overlap effects were larger in the more difficult object relative than in subject relative sentences. The reading patterns showed that phonological representations affect not only memory for recently encountered sentences but also the developing sentence interpretation during on-line processing. Implications for theories of sentence processing and memory are discussed. Highlights The work investigates the role of phonological information in sentence comprehension, which is poorly understood. ► Subjects read object and subject relative clauses +/- phonological overlap in two pairs of words. ► Unique features of the study were online reading measures and pinpointed overlap locations. ► Phonological overlap slowed reading speed and impaired sentence comprehension, especially for object relatives. ► The results show a key role for phonological information during online comprehension, not just later sentence memory.

Abstract

The current study investigated which time components of rapid automatized naming (RAN) predict group differences between dyslexic and non-dyslexic readers (matched for age and reading level), and how these components relate to different reading measures. Subjects performed two RAN tasks (letters and objects), and data were analyzed through a response time analysis. Our results demonstrated that impaired RAN performance in dyslexic readers mainly stem from enhanced inter-item pause times and not from difficulties at the level of post-access motor production (expressed as articulation rates). Moreover, inter-item pause times account for a significant proportion of variance in reading ability in addition to the effect of phonological awareness in the dyslexic group. This suggests that non-phonological factors may lie at the root of the association between RAN inter-item pauses and reading ability. In normal readers, RAN performance was associated with reading ability only at early ages (i.e. in the reading-matched controls), and again it was the RAN inter-item pause times that explain the association.

Abstract

In the present study, the authors investigate how some visual factors related to early stages of visual-object naming modulate naming performance in dyslexia. The performance of dyslexic children was compared with 2 control groups—normal readers matched for age and normal readers matched for reading level—while performing a discrete naming task in which color and dimensionality of the visually presented objects were manipulated. The results showed that 2-dimensional naming performance improved for color representations in control readers but not in dyslexics. In contrast to control readers, dyslexics were also insensitive to the stimulus's dimensionality. These findings are unlikely to be explained by a phonological processing problem related to phonological access or retrieval but suggest that dyslexics have a lower capacity for coding and decoding visual surface features of 2-dimensional representations or problems with the integration of visual information stored in long-term memory.

Abstract

This article summarizes some of the important findings from research evaluating the relationship between poor rapid naming and impaired reading performance. Substantial evidence shows that dyslexic readers have problems with rapid naming of visual items. Early research assumed that this was a consequence of phonological processing deficits, but recent findings suggest that non-phonological processes may lie at the root of the association between slow naming speed and poor reading. The hypothesis that rapid naming reflects an independent core deficit in dyslexia is supported by the main findings: (1) some dyslexics are characterized by rapid naming difficulties but intact phonological skills; (2) evidence for an independent association between rapid naming and reading competence in the dyslexic readers, when the effect of phonological skills was controlled; (3) rapid naming and phonological processing measures are not reliably correlated. Recent research also reveals greater predictive power of rapid naming, in particular the inter-item pause time, for high-frequency word reading compared to pseudoword reading in developmental dyslexia. Altogether, the results are more consistent with the view that a phonological component alone cannot account for the rapid naming performance in dyslexia. Rather, rapid naming problems may emerge from the inefficiencies in visual-orthographic processing as well as in phonological processing.

Abstract

At least three cognitive brain components are necessary in order for us to be able to produce and comprehend language: a Memory repository for the lexicon, a Unification buffer where lexical information is combined into novel structures, and a Control apparatus presiding over executive function in language. Here we describe the brain networks that support Memory and Unification in semantics. A dynamic account of their interactions is presented, in which a balance between the two components is sought at each word-processing step. We use the theory to provide an explanation of the N400 effect.

Abstract

In this study, we systematically review the scientific literature on the effect of color on object recognition. Thirty-five independent experiments, comprising 1535 participants, were included in a meta-analysis. We found a moderate effect of color on object recognition (d = 0.28). Specific effects of moderator variables were analyzed and we found that color diagnosticity is the factor with the greatest moderator effect on the influence of color in object recognition; studies using color diagnostic objects showed a significant color effect (d = 0.43), whereas a marginal color effect was found in studies that used non-color diagnostic objects (d = 0.18). The present study did not permit the drawing of specific conclusions about the moderator effect of the object recognition task; while the meta-analytic review showed that color information improves object recognition mainly in studies using naming tasks (d = 0.36), the literature review revealed a large body of evidence showing positive effects of color information on object recognition in studies using a large variety of visual recognition tasks. We also found that color is important for the ability to recognize artifacts and natural objects, to recognize objects presented as types (line-drawings) or as tokens (photographs), and to recognize objects that are presented without surface details, such as texture or shadow. Taken together, the results of the meta-analysis strongly support the contention that color plays a role in object recognition. This suggests that the role of color should be taken into account in models of visual object recognition.

Abstract

In the present study, the authors explore in detail the level of visual object recognition at which perceptual color information improves the recognition of color diagnostic and noncolor diagnostic objects. To address this issue, 3 object recognition tasks, with different cognitive demands, were designed: (a) an object verification task; (b) a category verification task; and (c) a name verification task. They found that perceptual color information improved color diagnostic object recognition mainly in tasks for which access to the semantic knowledge about the object was necessary to perform the task; that is, in category and name verification. In contrast, the authors found that perceptual color information facilitates noncolor diagnostic object recognition when access to the object’s structural description from long-term memory was necessary—that is, object verification. In summary, the present study shows that the role of perceptual color information in object recognition is dependent on color diagnosticity

Abstract

Do people with different kinds of bodies think differently? According to the bodyspecificity hypothesis (Casasanto 2009), they should. In this article, I review evidence that right- and left-handers, who perform actions in systematically different ways, use correspondingly different areas of the brain for imagining actions and representing the meanings of action verbs. Beyond concrete actions, the way people use their hands also influences the way they represent abstract ideas with positive and negative emotional valence like “goodness,” “honesty,” and “intelligence,” and how they communicate about them in spontaneous speech and gesture. Changing how people use their right and left hands can cause them to think differently, suggesting that motoric differences between right- and left-handers are not merely correlated with cognitive differences. Body-specific patterns of motor experience shape the way we think, communicate, and make decisions

Abstract

Right- and left-handers implicitly associate positive ideas like "goodness"and "honesty"more strongly with their dominant side
of space, the side on which they can act more fluently, and negative ideas more strongly with their nondominant side. Here we show that right-handers’ tendency to associate "good" with "right" and "bad" with "left" can be reversed as a result of both
long- and short-term changes in motor fluency. Among patients who were right-handed prior to unilateral stroke, those with disabled left hands associated "good" with "right," but those with disabled right hands associated "good" with "left,"as natural left-handers do. A similar pattern was found in healthy right-handers whose right or left hand was temporarily handicapped in the laboratory. Even a few minutes of acting more fluently with the left hand can change right-handers’ implicit associations between space and emotional valence, causing a reversal of their usual judgments. Motor experience plays a causal role in shaping abstract thought.

Abstract

1 Introduction In spoken sentence processing, listeners do not wait till the end of a sentence to decipher what message is conveyed. Rather, they make predictions on the most plausible interpretation at every possible point in the auditory signal on the basis of all kinds of linguistic information (e.g., Eberhard et al. 1995; Alman and Kamide 1999, 2007). Intonation is one such kind of linguistic information that is efficiently used in spoken sentence processing. The evidence comes primarily from recent work on online reference resolution conducted in the visual-world eyetracking paradigm (e.g., Tanenhaus et al. 1995). In this paradigm, listeners are shown a visual scene containing a number of objects and listen to one or two short sentences about the scene. They are asked to either inspect the visual scene while listening or to carry out the action depicted in the sentence(s) (e.g., 'Touch the blue square'). Listeners' eye movements directed to each object in the scene are monitored and time-locked to pre-defined time points in the auditory stimulus. Their predictions on the upcoming referent and sources for the predictions in the auditory signal are examined by analysing fixations to the relevant objects in the visual scene before the acoustic information on the referent is available

Abstract

People spontaneously produce gestures when they solve problems or explain their solutions to a problem. In this chapter, we will review and discuss evidence on the role of representational gestures in problem solving. The focus will be on our recent experiments (Chu & Kita, 2008), in which we used Shepard-Metzler type of mental rotation tasks to investigate how spontaneous gestures revealed the development of problem solving strategy over the course of the experiment and what role gesture played in the development process. We found that when solving novel problems regarding the physical world, adults go through similar symbolic distancing (Werner & Kaplan, 1963) and internalization (Piaget, 1968) processes as those that occur during young children’s cognitive development and gesture facilitates such processes.

Abstract

Methods
The present study provides a systematic analysis of co-speech gestures which spontaneously accompany the description of actions in a group of PD patients (N = 23, Hoehn and Yahr Stage III or less) and age-matched healthy controls (N = 22). The analysis considers different co-speech gesture types, using established classification schemes from the field of gesture research. The analysis focuses on the rate of these gestures as well as on their qualitative nature. In doing so, the analysis attempts to overcome several methodological shortcomings of research in this area.
Results
Contrary to expectation, gesture rate was not significantly affected in our patient group, with relatively mild PD. This indicates that co-speech gestures could compensate for speech problems. However, while gesture rate seems unaffected, the qualitative precision of gestures representing actions was significantly reduced.
Conclusions
This study demonstrates the feasibility of carrying out fine-grained, detailed analyses of gestures in PD and offers insights into an as yet neglected facet of communication in patients with PD. Based on the present findings, an important next step is the closer investigation of the qualitative changes in gesture (including different communicative situations) and an analysis of the heterogeneity in co-speech gesture production in PD.

Abstract

Many children with Specific Language Impairment (SLI) show impairments in discriminating auditorily presented stimuli. The present study investigates whether these discrimination problems are speech specific or of a general auditory nature. This was studied by using a linguistic and nonlinguistic contrast that were matched for acoustic complexity in an active behavioral task and a passive ERP paradigm, known to elicit the mismatch negativity (MMN). In addition, attention skills and a variety of language skills were measured. Participants were 25 five-year-old Dutch children with SLI having receptive as well as productive language problems and 25 control children with typical speechand language development. At the behavioral level, the SLI group was impaired in discriminating the linguistic contrast as compared to the control group, while both groups were unable to distinguish the non-linguistic contrast. Moreover, the SLI group tended to have impaired attention skills which correlated with performance on most of the language tests. At the neural level, the SLI group, in contrast to the control group, did not show an MMN in response to either the linguistic or nonlinguistic contrast. The MMN data are consistent with an account that relates the symptoms in children with SLI to non-speech processing difficulties.

Abstract

Language is a hallmark of our species and understanding linguistic diversity is an area of major interest. Genetic factors influencing the cultural transmission of language provide a powerful and elegant explanation for aspects of the present day linguistic diversity and a window into the emergence and evolution of language. In particular, it has recently been proposed that linguistic tone—the usage of voice pitch to convey lexical and grammatical meaning—is biased by two genes involved in brain growth and development, ASPM and Microcephalin. This hypothesis predicts that tone is a stable characteristic of language because of its ‘genetic anchoring’. The present paper tests this prediction using a Bayesian phylogenetic framework applied to a large set of linguistic features and language families, using multiple software implementations, data codings, stability estimations, linguistic classifications and outgroup choices. The results of these different methods and datasets show a large agreement, suggesting that this approach produces reliable estimates of the stability of linguistic data. Moreover, linguistic tone is found to be stable across methods and datasets, providing suggestive support for the hypothesis of genetic influences on its distribution.

Abstract

Investigating human cognitive faculties such as language, attention, and memory most often relies on testing small and homogeneous groups of volunteers coming to research facilities where they are asked to participate in behavioral experiments. We show that this limitation and sampling bias can be overcome by using smartphone technology to collect data in cognitive science experiments from thousands of subjects from all over the world. This mass coordinated use of smartphones creates a novel and powerful scientific ‘‘instrument’’ that yields the data necessary to test universal theories of cognition. This increase in power represents a potential revolution in cognitive science

Abstract

Relative clause processing depends on the grammatical role of the head noun in the subordinate clause. This has traditionally been explained in terms of cognitive limitations. We suggest that structure-related processing differences arise from differences in experience with these structures. We present a connectionist model which learns to produce utterances with relative clauses from exposure to message-sentence pairs. The model shows how various factors such as frequent subsequences, structural variations, and meaning conspire to create differences in the processing of these structures. The predictions of this learning-based account have been confirmed in behavioral studies with adults. This work shows that structural regularities that govern relative clause processing can be explained within a usage-based approach to recursion.

Abstract

The present study addresses questions concerning bilinguals’ attainment in the two languages by investigating the extent to which early bilinguals manage to apply the information structure required in each language when producing a complex text. In re-narrating the content of a film, speakers have to break down the perceived series of dynamic situations and structure relevant information into units that are suited for linguistic expression. The analysis builds on typological studies of Germanic and Romance languages which investigate the role of grammaticized concepts in determining core features in information structure. It takes a global perspective in that it focuses on factors that determine information selection and information structure that hold in macrostructural terms for the text as a whole (factors driving information selection, the temporal frame used to locate events on the time line, and the means used in reference management). A first comparison focuses on Dutch and German monolingual native speakers and shows that despite overall typological similarities, there are subtle though systematic differences between the two languages in the aforementioned areas of information structure. The analyses of the bilinguals focus on their narratives in both languages, and compares the patterns found to those found in the monolingual narratives. Findings show that the method used provides insights into the individual bilingual’s attainment in the two languages and identifies either balanced levels of attainment, patterns showing higher degrees of conformity with one of the languages, as well as bilingual-specific patterns of performance.

Abstract

This paper focuses on native speaker judgments of a construction in Dutch that functions as a progressive aspectual marker (aan het X zijn, referred to as aan het-construction) and represents an event as in progression at the time of speech. The method was chosen in order to investigate how native speakers assess the scope and conditions of use of a construction which is in the process of grammaticalization. It allows for the inclusion of a large group of participants of different age groups and an investigation of potential age-related differences. The study systematically covers a range of temporal variables that were shown to be relevant in elicitation and corpus-based studies on the grammaticalization of progressive aspect constructions. The results provide insights into the selectional preferences and constraints of the aan het-construction in contemporary Dutch, as judged by native speakers, and the extent to which they correlate with production tasks.

Abstract

The first objective of this study was to compare the brain network engaged by preference classification and the standard grammaticality classification after implicit artificial syntax acquisition by re-analyzing previously reported event-related fMRI data. The results show that preference and grammaticality classification engage virtually identical brain networks, including Broca’s region, consistent with previous behavioral findings. Moreover, the results showed that the effects related to artificial syntax in Broca’s region were essentially the same when masked with variability related to natural syntax processing in the same participants. The second objective was to explore CNTNAP2-related effects in implicit artificial syntax learning by analyzing behavioral and event-related fMRI data from a subsample. The CNTNAP2 gene has been linked to specific language impairment and is controlled by the FOXP2 transcription factor. CNTNAP2 is expressed in language related brain networks in the developing human brain and the FOXP2–CNTNAP2 pathway provides a mechanistic link between clinically distinct syndromes involving disrupted language. Finally, we discuss the implication of taking natural language to be a neurobiological system in terms of bounded recursion and suggest that the left inferior frontal region is a generic on-line sequence processor that unifies information from various sources in an incremental and recursive manner.

Abstract

During face-to-face communication, one does not only hear speech but also see a speaker's communicative hand movements. It has been shown that such hand gestures play an important role in communication where the two modalities influence each other's interpretation. A gesture typically temporally overlaps with coexpressive speech, but the gesture is often initiated before (but not after) the coexpressive speech. The present ERP study investigated what degree of asynchrony in the speech and gesture onsets are optimal for semantic integration of the concurrent gesture and speech. Videos of a person gesturing were combined with speech segments that were either semantically congruent or incongruent with the gesture. Although gesture and speech always overlapped in time, gesture and speech were presented with three different degrees of asynchrony. In the SOA 0 condition, the gesture onset and the speech onset were simultaneous. In the SOA 160 and 360 conditions, speech was delayed by 160 and 360 msec, respectively. ERPs time locked to speech onset showed a significant difference between semantically congruent versus incongruent gesture–speech combinations on the N400 for the SOA 0 and 160 conditions. No significant difference was found for the SOA 360 condition. These results imply that speech and gesture are integrated most efficiently when the differences in onsets do not exceed a certain time span because of the fact that iconic gestures need speech to be disambiguated in a way relevant to the speech context.

Abstract

Students who are learning to write in a foreign language, often want feedback on the grammatical quality of the sentences they produce. The usual NLP approach to this problem is based on parsing student-generated text. Here, we propose a generation-based ap- proach aiming at preventing errors ("scaffolding"). In our ICALL system, the student constructs sentences by composing syntactic trees out of lexically anchored "treelets" via a graphical drag & drop user interface. A natural-language generator computes all possible grammatically well-formed sentences entailed by the student-composed tree. It provides positive feedback if the student-composed tree belongs to the well-formed set, and negative feedback otherwise. If so requested by the student, it can substantiate the positive or negative feedback based on a comparison between the student-composed tree and its own trees (informative feedback on demand). In case of negative feedback, the system refuses to build the structure attempted by the student. Frequently occurring errors are handled in terms of "malrules." The system we describe is a prototype (implemented in JAVA and C++) which can be parameterized with respect to L1 and L2, the size of the lexicon, and the level of detail of the visually presented grammatical structures.

Abstract

The present paper explores cross-cultural variation in spatial cognition by comparing spatial reconstruction tasks by Dutch and Namibian elementary school children. These two communities differ in the way they predominantly express spatial relations in language. Four experiments investigate cognitive strategy preferences across different levels of task-complexity and instruction. Data show a correlation between dominant linguistic spatial frames of reference and performance patterns in non-linguistic spatial memory tasks. This correlation is shown to be stable across an increase of complexity in the spatial array. When instructed to use their respective non-habitual cognitive strategy, participants were not easily able to switch between strategies and their attempts to do so impaired their performance. These results indicate a difference not only in preference but also in competence and suggest that spatial language and non-linguistic preferences and competences in spatial cognition are systematically aligned across human populations.

Abstract

Mimicry has been observed regarding a range of nonverbal behaviors, but only recently have researchers started to investigate mimicry in co-speech gestures. These gestures are considered to be crucially different from other aspects of nonverbal behavior due to their tight link with speech. This study provides evidence of mimicry in co-speech gestures in face-to-face dialogue, the most common forum of everyday talk. In addition, it offers an analysis of the functions that mimicked co-speech gestures fulfill in the collaborative process of creating a mutually shared understanding of referring expressions. The implications bear on theories of gesture production, research on grounding, and the mechanisms underlying behavioral mimicry.

Abstract

There is evidence that co-speech gestures communicate information to addressees and that they are often communicatively intended. However, we still know comparatively little about the role of gestures in the actual process of communication. The present study offers a systematic investigation of speakers’ gesture use before and after addressee feedback. The findings show that when speakers responded to addressees’ feedback gesture rate remained constant when this feedback encouraged clarification, elaboration or correction. However, speakers gestured proportionally less often after feedback when providing confirmatory responses. That is, speakers may not be drawing on gesture in response to addressee feedback per se, but particularly with responses that enhance addressees’ understanding. Further, the large majority of speakers’ gestures changed in their form. They tended to be more precise, larger, or more visually prominent after feedback. Some changes in gesture viewpoint were also observed. In addition, we found that speakers used deixis in speech and gaze to increase the salience of gestures occurring in response to feedback. Speakers appear to conceive of gesture as a useful modality in redesigning utterances to make them more accessible to addressees. The findings further our understanding of recipient design and co-speech gestures in face-to-face dialogue.
Highlights

► Gesture rate remains constant in response to addressee feedback when the response aims to correct or clarify understanding. ► But gesture rate decreases when speakers provide confirmatory responses to feedback signalling correct understanding. ► Gestures are more communicative in response to addressee feedback, particularly in terms of precision, size and visual prominence. ► Speakers make gestures in response to addressee feedback more salient by using deictic markers in speech and gaze.

Abstract

Studies exploring the role of neural oscillations in cognition have revealed sustained increases in alpha-band (∼8–14 Hz) power during the delay period of delayed-recognition short-term memory tasks. These increases have been proposed to reflect the inhibition, for example, of cortical areas representing task-irrelevant information, or of potentially interfering representations from previous trials. Another possibility, however, is that elevated delay-period alpha-band power (DPABP) reflects the selection and maintenance of information, rather than, or in addition to, the inhibition of task-irrelevant information. In the present study, we explored these possibilities using a delayed-recognition paradigm in which the presence and task relevance of shape information was systematically manipulated across trial blocks and electroencephalographic was used to measure alpha-band power. In the first trial block, participants remembered locations marked by identical black circles. The second block featured the same instructions, but locations were marked by unique shapes. The third block featured the same stimulus presentation as the second, but with pretrial instructions indicating, on a trial-by-trial basis, whether memory for shape or location was required, the other dimension being irrelevant. In the final block, participants remembered the unique pairing of shape and location for each stimulus. Results revealed minimal DPABP in each of the location-memory conditions, whether locations were marked with identical circles or with unique task-irrelevant shapes. In contrast, alpha-band power increases were observed in both the shape-memory condition, in which location was task irrelevant, and in the critical final condition, in which both shape and location were task relevant. These results provide support for the proposal that alpha-band oscillations reflect the retention of shape information and/or shape–location associations in short-term memory.

Abstract

Theorists of language have argued that co-­speech hand gestures are an
intentional part of social communication. The present study provides evidence for these
claims by showing that speakers adjust their gesture use according to their perceived relevance to the audience. Participants were asked to read about items that were and were not useful in a wilderness survival scenario, under the pretense that they would then
explain (on camera) what they learned to one of two different audiences. For one audience (a group of college students in a dormitory orientation activity), the stakes of successful
communication were low;; for the other audience (a group of students preparing for a
rugged camping trip in the mountains), the stakes were high. In their explanations to the camera, participants in the high stakes condition produced three times as many
representational gestures, and spent three times as much time gesturing, than participants in the low stakes condition. This study extends previous research by showing that the anticipated consequences of one’s communication—namely, the degree to which information may be useful to an intended recipient—influences speakers’ use of gesture.

Abstract

A contentious issue in memory research is whether verbal short-term memory (STM) depends on a neural system specifically dedicated to the temporary maintenance of information, or instead relies on the same brain areas subserving the comprehension and production of language. In this study, we examined a large sample of adults with acquired brain lesions to identify the critical neural substrates underlying verbal STM and the relationship between verbal STM and language processing abilities. We found that patients with damage to selective regions of left perisylvian cortex – specifically the inferior frontal and posterior temporal sectors – were impaired on auditory–verbal STM performance (digit span), as well as on tests requiring the production and/or comprehension of language. These results support the conclusion that verbal STM and language processing are mediated by the same areas of left perisylvian cortex.

Abstract

Why does chanting, drumming or dancing together make people feel united? Here we investigate the neural mechanisms underlying interpersonal synchrony and its subsequent effects on prosocial behavior among synchronized individuals. We hypothesized that areas of the brain associated with the processing of reward would be active when individuals experience synchrony during drumming, and that these reward signals would increase prosocial behavior toward this synchronous drum partner. 18 female non-musicians were scanned with functional magnetic resonance imaging while they drummed a rhythm, in alternating blocks, with two different experimenters: one drumming in-synchrony and the other out-of-synchrony relative to the participant. In the last scanning part, which served as the experimental manipulation for the following prosocial behavioral test, one of the experimenters drummed with one half of the participants in-synchrony and with the other out-of-synchrony. After scanning, this experimenter "accidentally" dropped eight pencils, and the number of pencils collected by the participants was used as a measure of prosocial commitment. Results revealed that participants who mastered the novel rhythm easily before scanning showed increased activity in the caudate during synchronous drumming. The same area also responded to monetary reward in a localizer task with the same participants. The activity in the caudate during experiencing synchronous drumming also predicted the number of pencils the participants later collected to help the synchronous experimenter of the manipulation run. In addition, participants collected more pencils to help the experimenter when she had drummed in-synchrony than out-of-synchrony during the manipulation run. By showing an overlap in activated areas during synchronized drumming and monetary reward, our findings suggest that interpersonal synchrony is related to the brain's reward system.

Abstract

Whether the brain’s speech-production system is also involved in speech comprehension is a topic of much debate. Research has focused on whether motor areas are involved in listening, but overlap between speaking and listening might occur not only at primary sensory and motor levels, but also at linguistic levels (where semantic, lexical, and syntactic processes occur). Using functional MRI adaptation during speech comprehension and production, we found that the brain areas involved in semantic, lexical, and syntactic processing are mostly the same for speaking and for listening. Effects of primary processing load (indicative of sensory and motor processes) overlapped in auditory cortex and left inferior frontal cortex, but not in motor cortex, where processing load affected activity only in speaking. These results indicate that the linguistic parts of the language system are used for both speaking and listening, but that the motor system does not seem to provide a crucial contribution to listening.

Abstract

Neste artigo fazemos uma revisão breve de investigações actuais com técnicas comportamentais e de neuroimagem funcional sobre a aprendizagem de uma linguagem artificial em crianças e adultos. Na secção final, discutimos uma possível associação entre dislexia e aprendizagem implícita. Resultados recentes sugerem que a presença de um défice ao nível da aprendizagem implícita pode contribuir para as dificuldades de leitura e escrita observadas em indivíduos disléxicos.

Abstract

Defeasible inferences are inferences that can be revised in the light of new information. Although defeasible inferences are pervasive in everyday communication, little is known about how and when they are processed by the brain. This study examined the electrophysiological signature of defeasible reasoning using a modified version of the suppression task. Participants were presented with conditional inferences (of the type “if p, then q; p, therefore q”) that were preceded by a congruent or a disabling context. The disabling context contained a possible exception or precondition that prevented people from drawing the conclusion. Acceptability of the conclusion was indeed lower in the disabling condition compared to the congruent condition. Further, we found a large sustained negativity at the conclusion of the disabling condition relative to the congruent condition, which started around 250 msec and was persistent throughout the entire epoch. Possible accounts for the observed effect are discussed.

Abstract

A aquisição de competências de leitura e de escrita pode ser vista como um processo formal de transmissão cultural, onde interagem factores neurobiológicos e culturais. O treino sistemático exigido pela aprendizagem da leitura e da escrita poderá produzir mudanças quantitativas e qualitativas tanto a nível cognitivo como ao nível da organização do cérebro. Estudar sujeitos iletrados e letrados representa, assim, uma oportunidade para investigar efeitos de uma aprendizagem específica no desenvolvimento cognitivo e suas bases cerebrais. Neste trabalho, revemos um conjunto de investigações comportamentais e com métodos de imagem cerebral que indicam que a literacia tem um impacto nas nossas funções cognitivas e na organização cerebral. Mais especificamente, discutiremos diferenças entre letrados e iletrados para domínios cognitivos verbais e não-verbais, sugestivas de que a arquitectura cognitiva é formatada, em parte, pela aprendizagem da leitura e da escrita. Os dados de neuroimagem funcionais e estruturais são também indicadores que a aquisição de uma ortografia alfabética interfere nos processos de organização e lateralização das funções cognitivas.

Abstract

Work on animals indicates that BOLD is preferentially sensitive to local field potentials, and that it correlates most strongly with gamma band neuronal synchronization. Here we investigate how the BOLD signal in humans performing a cognitive task is related to neuronal synchronization across different frequency bands. We simultaneously recorded EEG and BOLD while subjects engaged in a visual attention task known to induce sustained changes in neuronal synchronization across a wide range of frequencies. Trial-by-trial BOLD luctuations correlated positively with trial-by-trial fluctuations in high-EEG gamma power (60–80 Hz) and negatively with alpha and beta power. Gamma power on the one hand, and alpha and beta power on the other hand, independently contributed to explaining BOLD variance. These results indicate that the BOLD-gamma coupling observed in animals can be extrapolated to humans performing a task and that neuronal dynamics underlying high- and low-frequency synchronization contribute independently to the BOLD signal.

Abstract

Speakers tend to repeat syntactic structures across sentences, a phenomenon called syntactic priming. Although it has been suggested that repeating syntactic structures should result in speeded responses, previous research has focused on effects in response tendencies. We investigated syntactic priming effects simultaneously in response tendencies and response latencies for active and passive transitive sentences in a picture description task. In Experiment 1, there were priming effects in response tendencies for passives and in response latencies for actives. However, when participants' pre-existing preference for actives was altered in Experiment 2, syntactic priming occurred for both actives and passives in response tendencies as well as in response latencies. This is the first investigation of the effects of structure frequency on both response tendencies and latencies in syntactic priming. We discuss the implications of these data for current theories of syntactic processing.

Abstract

In individuals with ASD, difficulties with language comprehension are most evident when higher-level semantic-pragmatic language processing is required, for instance when context has to be used to interpret the meaning of an utterance. Until now, it is unclear at what level of processing and for what type of context these difficulties in language comprehension occur. Therefore, in the current fMRI study, we investigated the neural correlates of the integration of contextual information during auditory language comprehension in 24 adults with ASD and 24 matched control participants. Different levels of context processing were manipulated by using spoken sentences that were correct or contained either a semantic or world knowledge anomaly. Our findings demonstrated significant differences between the groups in inferior frontal cortex that were only present for sentences with a world knowledge anomaly. Relative to the ASD group, the control group showed significantly increased activation in left inferior frontal gyrus (LIFG) for sentences with a world knowledge anomaly compared to correct sentences. This effect possibly indicates reduced integrative capacities of the ASD group. Furthermore, world knowledge anomalies elicited significantly stronger activation in right inferior frontal gyrus (RIFG) in the control group compared to the ASD group. This additional RIFG activation probably reflects revision of the situation model after new, conflicting information. The lack of recruitment of RIFG is possibly related to difficulties with exception handling in the ASD group.

Abstract

Synesthesia provides an elegant model to investigate neural mechanisms underlying individual differences in subjective experience in humans. In grapheme–color synesthesia, written letters induce color sensations, accompanied by activation of color area V4. Competing hypotheses suggest that enhanced V4 activity during synesthesia is either induced by direct bottom-up cross-activation from grapheme processing areas within the fusiform gyrus, or indirectly via higher-order parietal areas. Synesthetes differ in the way synesthetic color is perceived: “projector” synesthetes experience color externally colocalized with a presented grapheme, whereas “associators” report an internally evoked association. Using dynamic causal modeling for fMRI, we show that V4 cross-activation during synesthesia was induced via a bottom-up pathway (within fusiform gyrus) in projector synesthetes, but via a top-down pathway (via parietal lobe) in associators. These findings show how altered coupling within the same network of active regions leads to differences in subjective experience. Our findings reconcile the two most influential cross-activation accounts of synesthesia.