Publications

Abstract

Readers tend to skip words, particularly when they are short, frequent, or predictable. Angele and Rayner (2013) recently reported that readers are often unable to detect syntactic anomalies in parafoveal vision. In the present study, we manipulated target word predictability to assess whether contextual constraint modulates the-skipping behavior. The results provide further evidence that readers frequently skip the article the when infelicitous in context. Readers skipped predictable words more often than unpredictable words, even when the, which was syntactically illegal and unpredictable from the prior context, was presented as a parafoveal preview. The results of the experiment were simulated using E-Z Reader 10 by assuming that cloze probability can be dissociated from parafoveal visual input. It appears that when a short word is predictable in context, a decision to skip it can be made even if the information available parafoveally conflicts both visually and syntactically with those predictions.

Abstract

In the present study, the authors examined with event-related brain potentials whether phonological encoding in picture naming is mediated by basic semantic feature retrieval or proceeds independently. In a manual 2-choice go/no-go task the choice response depended on a semantic classification (animal vs. object) and the execution decision was contingent on a classification of name phonology (vowel vs. consonant). The introduction of a semantic task mixing procedure allowed for selectively manipulating the speed of semantic feature retrieval. Serial and parallel models were tested on the basis of their differential predictions for the effect of this manipulation on the lateralized readiness potential and N200 component. The findings indicate that phonological code retrieval is not strictly contingent on prior basic semantic feature processing.

Abstract

In this article a new approach to the distinction between serial/contingent and parallel/independent processing in the human cognitive system is applied to semantic knowledge retrieval and phonological encoding of the word form in picture naming. In two-choice go/nogo tasks pictures of objects were manually classified on the basis of semantic and phonological information. An additional manipulation of the duration of the faster and presumably mediating process (semantic retrieval) allowed to derive differential predictions from the two alternative models. These predictions were tested with two event-related brain potentials (ERPs), the lateralized readiness potential (LRP) and the N200. The findings indicate that phonological encoding can proceed in parallel to the retrieval of semantic features. A suggestion is made how to accommodate these findings with models of speech production.

Abstract

On seeing familiar persons, biographical (semantic) information is typically retrieved faster and more accurately than name information. Serial stage models explain this pattern by suggesting that access to the name follows the retrieval of semantic information. In contrast, interactive activation and competition (IAC) models hold that both processes start together but name retrieval is slower because of structural peculiarities. With a 2-choice go/no-go procedure based on a semantic and a name-related classification, the authors tested differential predictions of the 2 alternative models for reaction times (RTs) and lateralized readiness potentials (LRP). Both LRP (Experiment 1) and RT (Experiment 2) results are in line with IAC models of face identification and naming.

Abstract

Conformist transmission, defined as a disproportionate likelihood to copy the majority, is considered a potent mechanism underlying the emergence and stabilization of cultural diversity. However, ambiguity within and across disciplines remains as to how to identify conformist transmission empirically. In most studies, a population level outcome has been taken as the benchmark to evidence conformist transmission: a sigmoidal relation between individuals’ probability to copy the majority and the proportional majority size. Using an individual-based model, we show that, under ecologically plausible conditions, this sigmoidal relation can also be detected without equipping individuals with a conformist bias. Situations in which individuals copy randomly from a fixed subset of demonstrators in the population, or in which they have a preference for one of the possible variants, yield similar sigmoidal patterns as a conformist bias would. Our findings warrant a revisiting of studies that base their conformist transmission conclusions solely on the sigmoidal curve. More generally, our results indicate that population level outcomes interpreted as conformist transmission could potentially be explained by other individual-level strategies, and that more empirical support is needed to prove the existence of an individual-level conformist bias in human and other animals.

Abstract

Many accounts of working memory posit specialized storage mechanisms for the maintenance of serial order. We explore an alternative, that maintenance is achieved through temporary activation in the language production architecture. Four experiments examined the extent to which the phonological similarity effect can be explained as a sublexical speech error. Phonologically similar nonword stimuli were ordered to create tongue twister or control materials used in four tasks: reading aloud, immediate spoken recall, immediate typed recall, and serial recognition. Dependent measures from working memory (recall accuracy) and language production (speech errors) fields were used. Even though lists were identical except for item order, robust effects of tongue twisters were observed. Speech error analyses showed that errors were better described as phoneme rather than item ordering errors. The distribution of speech errors was comparable across all experiments and exhibited syllable-position effects, suggesting an important role for production processes. Implications for working memory and language production are discussed.

Abstract

Verbal working memory (WM) tasks typically involve the language production architecture for recall; however, language production processes have had a minimal role in theorizing about WM. A framework for understanding verbal WM results is presented here. In this framework, domain-specific mechanisms for serial ordering in verbal WM are provided by the language production architecture, in which positional, lexical, and phonological similarity constraints are highly similar to those identified in the WM literature. These behavioral similarities are paralleled in computational modeling of serial ordering in both fields. The role of long-term learning in serial ordering performance is emphasized, in contrast to some models of verbal WM. Classic WM findings are discussed in terms of the language production architecture. The integration of principles from both fields illuminates the maintenance and ordering mechanisms for verbal information.

Abstract

Intracranial volume reflects the maximally attained brain size during development, and remains stable with loss of tissue in late
life. It is highly heritable, but the underlying genes remain largely undetermined. In a genome-wide association study of 32,438
adults, we discovered five previously unknown loci for intracranial volume and confirmed two known signals. Four of the loci were
also associated with adult human stature, but these remained associated with intracranial volume after adjusting for height.
We found a high genetic correlation with child head circumference (genetic = 0.748), which indicates a similar genetic
background and allowed us to identify four additional loci through meta-analysis (Ncombined = 37,345). Variants for intracranial
volume were also related to childhood and adult cognitive function, and Parkinson’s disease, and were enriched near genes
involved in growth pathways, including PI3K-AKT signaling. These findings identify the biological underpinnings of intracranial
volume and provide genetic support for theories on brain reserve and brain overgrowth.

Abstract

An evaluation of vowel normalization procedures for the purpose of studying language variation is presented. The procedures were compared on how effectively they (a) preserve phonemic information, (b) preserve information about the talker's regional background (or sociolinguistic information), and (c) minimize anatomical/physiological variation in acoustic representations of vowels. Recordings were made for 80 female talkers and 80 male talkers of Dutch. These talkers were stratified according to their gender and regional background. The normalization procedures were applied to measurements of the fundamental frequency and the first three formant frequencies for a large set of vowel tokens. The normalization procedures were evaluated through statistical pattern analysis. The results show that normalization procedures that use information across multiple vowels ("vowel-extrinsic" information) to normalize a single vowel token performed better than those that include only information contained in the vowel token itself ("vowel-intrinsic" information). Furthermore, the results show that normalization procedures that operate on individual formants performed better than those that use information across multiple formants (e.g., "formant-extrinsic" F2-F1).

Abstract

Speakers vary their speech rate considerably during a conversation, and listeners are able to quickly adapt to these variations in speech rate. Adaptation to fast speech rates is usually measured using artificially time-compressed speech. This study examined adaptation to two types of fast speech: artificially time-compressed speech and natural fast speech. Listeners performed a speeded sentence verification task on three series of sentences: normal-speed sentences, time-compressed sentences, and natural fast sentences. Listeners were divided into two groups to evaluate the possibility of transfer of learning between the time-compressed and natural fast conditions. The first group verified the natural fast before the time-compressed sentences, while the second verified the time-compressed before the natural fast sentences. The results showed transfer of learning when the time-compressed sentences preceded the natural fast sentences, but not when natural fast sentences preceded the time-compressed sentences. The results are discussed in the framework of theories on perceptual learning. Second, listeners show adaptation to the natural fast sentences, but performance for this type of fast speech does not improve to the level of time-compressed sentences.

Abstract

Oppositional defiant disorder (ODD) is a frequent psychiatric disorder seen in children and adolescents with attention-deficit-hyperactivity disorder (ADHD). ODD is also a common antecedent to both affective disorders and aggressive behaviors. Although the heritability of ODD has been estimated to be around 0.60, there has been little research into the molecular genetics of ODD. The present study examined the association of irritable and defiant/vindictive dimensions and categorical subtypes of ODD (based on latent class analyses) with previously described specific polymorphisms (DRD4 exon3 VNTR, 5-HTTLPR, and seven OXTR SNPs) as well as with dopamine, serotonin, and oxytocin genes and pathways in a clinical sample of children and adolescents with ADHD. In addition, we performed a multivariate genome-wide association study (GWAS) of the aforementioned ODD dimensions and subtypes. Apart from adjusting the analyses for age and sex, we controlled for "parental ability to cope with disruptive behavior." None of the hypothesis-driven analyses revealed a significant association with ODD dimensions and subtypes. Inadequate parenting behavior was significantly associated with all ODD dimensions and subtypes, most strongly with defiant/vindictive behaviors. In addition, the GWAS did not result in genome-wide significant findings but bioinformatics and literature analyses revealed that the proteins encoded by 28 of the 53 top-ranked genes functionally interact in a molecular landscape centered around Beta-catenin signaling and involved in the regulation of neurite outgrowth. Our findings provide new insights into the molecular basis of ODD and inform future genetic studies of oppositional behavior. (c) 2015 The Authors. American Journal of Medical Genetics Part B: Neuropsychiatric Genetics Published by Wiley Periodicals, Inc.

Abstract

Gestational diabetes, obesity, and excessive weight gain are known independent risk factors for the birth of a large for gestational age (LGA) infant. However, only 1 of the 10 infants born LGA is born by mothers with diabetes or obesity. Thus, the aim of the present study was to compare placental gene expression between healthy, nondiabetic mothers (n = 22) giving birth to LGA infants and body mass index-matched mothers (n = 24) giving birth to appropriate for gestational age infants. In the whole gene expression analysis, only 29 genes were found to be differently expressed in LGA placentas. Top upregulated genes included insulin-like growth factor binding protein 1, aminolevulinate δ synthase 2, and prolactin, whereas top downregulated genes comprised leptin, gametocyte-specific factor 1, and collagen type XVII α 1. Two enriched gene networks were identified, namely, (1) lipid metabolism, small molecule biochemistry, and organismal development and (2) cellular development, cellular growth, proliferation, and tumor morphology.

Abstract

Listeners efficiently exploit sentence prosody to direct attention to words bearing sentence accent. This effect has been explained as a search for focus, furthering rapid apprehension of semantic structure. A first experiment supported this explanation: English listeners detected phoneme targets in sentences more rapidly when the target-bearing words were in accented position or in focussed position, but the two effects interacted, consistent with the claim that the effects serve a common cause. In a second experiment a similar asymmetry was observed with Dutch listeners and Dutch sentences. In a third and a fourth experiment, proficient Dutch users of English heard English sentences; here, however, the two effects did not interact. The results suggest that less efficient mapping of prosody to semantics may be one way in which nonnative listening fails to equal native listening.

Abstract

We report the performance of two patients with lexico-semantic deficits following left MCA CVA. Both patients produce similar numbers of semantic paraphasias in naming tasks, but presented one crucial difference: grapheme-to-phoneme and phoneme-to-grapheme conversion procedures were available only to one of them. We investigated the impact of this availability on the process of lexical selection during word production. The patient for whom conversion procedures were not operational produced semantic errors in transcoding tasks such as reading and writing to dictation; furthermore, when asked to name a given picture in multiple output modalities—e.g., to say the name of a picture and immediately after to write it down—he produced lexically inconsistent responses. By contrast, the patient for whom conversion procedures were available did not produce semantic errors in transcoding tasks and did not produce lexically inconsistent responses in multiple picture-naming tasks. These observations are interpreted in the context of the summation hypothesis (Hillis & Caramazza, 1991), according to which the activation of lexical entries for production would be made on the basis of semantic information and, when available, on the basis of form-specific information. The implementation of this hypothesis in models of lexical access is discussed in detail.

Abstract

Ferrer-i-Cancho (this volume) presents a mathematical model of both the synchronic and diachronic nature of word order based on the assumption that memory costs are a never decreasing function of distance and a few very general linguistic assumptions. However, even these minimal and seemingly obvious assumptions are not as safe as they appear in light of recent typological and psycholinguistic evidence. The interaction of word order and memory has further depths to be explored.

Abstract

It has been suggested that, during real time language comprehension, the human language processing system attempts to identify the argument primarily responsible for the state of affairs (the “actor”) as quickly and unambiguously as possible. However, previous work on a prominence (e.g. animacy, definiteness, case marking) based heuristic for actor identification has suffered from underspecification of the relationship between different cue hierarchies. Qualitative work has yielded a partial ordering of many features (e.g. MacWhinney et al. 1984), but a precise quantification has remained elusive due to difficulties in exploring the full feature space in a particular language. Feature pairs tend to correlate strongly in individual languages for semantic-pragmatic reasons (e.g., animate arguments tend to be actors and actors tend to be morphosyntactically privileged), and it is thus difficult to create acceptable stimuli for a fully factorial design even for binary features. Moreover, the exponential function grows extremely rapidly and a fully crossed factorial design covering the entire feature space would be prohibitively long for a purely within-subjects design. Here, we demonstrate the feasibility of parameter estimation in a short experiment. We are able to estimate parameters at a single subject level for the parameters animacy, case and number. This opens the door for research into individual differences and population variation. Moreover, the framework we introduce here can be used in the field to measure more “exotic” languages and populations, even with small sample sizes. Finally, pooled single-subject results are used to reduce the number of free parameters in previous work based on the extended Argument Dependency Model (Bornkessel-Schlesewsky and Schlesewsky 2006, 2009, 2013, in press; Alday et al. 2014).

Abstract

Language evolution can be viewed from two viewpoints: the development of a communicative system and the biological adaptations necessary for producing and perceiving said system. The communicative-system vantage point has enjoyed a wealth of mathematical models based on simple distributional properties of language, often formulated as empirical laws. However, be- yond vague psychological notions of “least effort”, no principled explanation has been proposed for the existence and success of such laws. Meanwhile, psychological and neurobiological mod- els have focused largely on the computational constraints presented by incremental, real-time processing. In the following, we show that information-theoretic entropy underpins successful models of both types and provides a more principled motivation for Zipf’s Law

Abstract

Experiments in Artificial Language Learn-
ing have revealed much about the cogni-
tive mechanisms underlying sequence and
language learning in human adults, in in-
fants and in non-human animals. This pa-
per focuses on their ability to generalize
to novel grammatical instances (i.e., in-
stances consistent with a familiarization
pattern). Notably, the propensity to gen-
eralize appears to be negatively correlated
with the amount of exposure to the artifi-
cial language, a fact that has been claimed
to be contrary to the predictions of statis-
tical models (Pe
̃
na et al. (2002); Endress
and Bonatti (2007)). In this paper, we pro-
pose to model generalization as a three-
step process, and we demonstrate that the
use of statistical models for the first two
steps, contrary to widespread intuitions in
the ALL-field, can explain the observed
decrease of the propensity to generalize
with exposure time.

Abstract

One of the challenges that infants have to solve when learn- ing their native language is to identify the words in a con- tinuous speech stream. Some of the experiments in Artificial Grammar Learning (Saffran, Newport, and Aslin (1996); Saf- fran, Aslin, and Newport (1996); Aslin, Saffran, and Newport (1998) and many more) investigate this ability. In these ex- periments, subjects are exposed to an artificial speech stream that contains certain regularities. Adult participants are typ- ically tested with 2-alternative Forced Choice Tests (2AFC) in which they have to choose between a word and another sequence (typically a partword, a sequence resulting from misplacing boundaries).

Abstract

In an influential paper, Marcus et al. [1999] claimed that connectionist models
cannot account for human success at learning tasks that involved generalization
of abstract knowledge such as grammatical rules. This claim triggered a heated
debate, centered mostly around variants of the Simple Recurrent Network model
[Elman, 1990]. In our work, we revisit this unresolved debate and analyze the
underlying issues from a different perspective. We argue that, in order to simulate
human-like learning of grammatical rules, a neural network model should not be
used as a
tabula rasa
, but rather, the initial wiring of the neural connections and
the experience acquired prior to the actual task should be incorporated into the
model. We present two methods that aim to provide such initial state: a manipu-
lation of the initial connections of the network in a cognitively plausible manner
(concretely, by implementing a “delay-line” memory), and a pre-training algorithm
that incrementally challenges the network with novel stimuli. We implement such
techniques in an Echo State Network [Jaeger, 2001], and we show that only when
combining both techniques the ESN is able to learn truly general identity rules.

Abstract

Children's gestures can reveal important information about their problem-solving strategies. This study investigated whether the information children express only in gesture is accessible to adults not trained in gesture coding. Twenty teachers and 20 undergraduates viewed videotaped vignettes of 12 children explaining their solutions to equations. Six children expressed the same strategy in speech and gesture, and 6 expressed different strategies. After each vignette, adults described the child's reasoning. For children who expressed different strategies in speech and gesture, both teachers and undergraduates frequently described strategies that children had not expressed in speech. These additional strategies could often be traced
to the children's gestures. Sensitivity to gesture was comparable for teachers and
undergraduates. Thus, even without training, adults glean information, not only from children's words but also from their hands.

Abstract

In a triangle completion task designed to assess path integration skill, younger and older adults performed
similarly after being led, while blindfolded, along the route segments on foot, which provided both kinesthetic and vestibular information about the outbound path. In contrast, older adults’ performance was impaired, relative to that of younger adults, after they were conveyed, while blindfolded,
along the route segments in a wheelchair, which limited them principally to vestibular information.
Correlational evidence suggested that cognitive resources were significant factors in accounting for age-related decline in path integration performance.

Abstract

Our target paper argued for the ubiquity of frequency effects in acquisition, and that any comprehensive theory must take into account the multiplicity of ways that frequently occurring and co-occurring linguistic units affect the acquisition process. The commentaries on the paper provide a largely unanimous endorsement of this position, but raise additional issues likely to frame further discussion and theoretical development. Specifically, while most commentators did not deny the importance of frequency effects, all saw this as the tip of the theoretical iceberg. In this short response we discuss common themes raised in the commentaries, focusing on the broader issue of what frequency effects mean for language acquisition.

Abstract

Previous studies have shown that children retreat from argument-structure overgeneralization errors (e.g., *Don’t giggle me) by inferring that frequently encountered verbs are unlikely to be grammatical in unattested constructions, and by making use of syntax-semantics correspondences (e.g., verbs denoting internally caused actions such as giggling cannot normally be used causatively). The present study tested a new account based on a unitary learning mechanism that combines both of these processes. Seventy-two participants (ages 5–6, 9–10, and adults) rated overgeneralization errors with higher (*The funny man’s joke giggled Bart) and lower (*The funny man giggled Bart) degrees of direct external causation. The errors with more-direct causation were rated as less unacceptable than those with less-direct causation. This finding is consistent with the new account, under which children acquire—in an incremental and probabilistic fashion—the meaning of particular constructions (e.g., transitive causative = direct external causation) and particular verbs, rejecting generalizations where the incompatibility between the two is too great.

Abstract

To explain the phenomenon that certain English verbs resist passivization (e.g., *£5 was cost by the book), Pinker (1989) proposed a semantic constraint on the passive in the adult grammar: The greater the extent to which a verb denotes an action where a patient is affected or acted upon, the greater the extent to which it is compatible with the passive. However, a number of comprehension and production priming studies have cast doubt upon this claim, finding no difference between highly affecting agent-patient/theme-experiencer passives (e.g., Wendy was kicked/frightened by Bob) and non-actional experiencer theme passives (e.g., Wendy was heard by Bob). The present study provides evidence that a semantic constraint is psychologically real, and is readily observed when more fine-grained independent and dependent measures are used (i.e., participant ratings of verb semantics, graded grammaticality judgments, and reaction time in a forced-choice picture-matching comprehension task). We conclude that a semantic constraint on the passive must be incorporated into accounts of the adult grammar.

Abstract

Positive and negative what, why and yes/no questions with the 3sg auxiliaries can and does were elicited from 50 children aged 3;3–4;3. In support of the constructivist “schema-combination” account, only children who produced a particular positive question type correctly (e.g., What does she want?) produced a characteristic “auxiliary-doubling” error (e.g., *What does she doesn't want?) for the corresponding negative question type. This suggests that these errors are formed by superimposing a positive question frame (e.g., What does THING PROCESS?) and an inappropriate negative frame (e.g., She doesn't PROCESS) learned from declarative utterances. In addition, a significant correlation between input frequency and correct production was observed for 11 of the 12 lexical frames (e.g., What does THING PROCESS?), although some negative question types showed higher rates of error than one might expect based on input frequency alone. Implications for constructivist and generativist theories of question-acquisition are discussed.

Abstract

Participants aged 5;2-6;8, 9;2-10;6 and 18;1-22;2 (72 at each age) rated verb argument structure overgeneralization errors (e.g., *Daddy giggled the baby) using a five-point scale. The study was designed to investigate the feasibility of two proposed construction-general solutions to the question of how children retreat from, or avoid, such errors. No support was found for the prediction of the preemption hypothesis that the greater the frequency of the verb in the single most nearly synonymous construction (for this example, the periphrastic causative; e.g., Daddy made the baby giggle), the lower the acceptability of the error. Support was found, however, for the prediction of the entrenchment hypothesis that the greater the overall frequency of the verb, regardless of construction, the lower the acceptability of the error, at least for the two older groups. Thus while entrenchment appears to be a robust solution to the problem of the retreat from error, and one that generalizes across different error types, we did not find evidence that this is the case for preemption. The implication is that the solution to the retreat from error lies not with specialized mechanisms, but rather in a probabilistic process of construction competition.

Abstract

This review article presents evidence for the claim that frequency effects are pervasive in children's first language acquisition, and hence constitute a phenomenon that any successful account must explain. The article is organized around four key domains of research: children's acquisition of single words, inflectional morphology, simple syntactic constructions, and more advanced constructions. In presenting this evidence, we develop five theses. (i) There exist different types of frequency effect, from effects at the level of concrete lexical strings to effects at the level of abstract cues to thematic-role assignment, as well as effects of both token and type, and absolute and relative, frequency. High-frequency forms are (ii) early acquired and (iii) prevent errors in contexts where they are the target, but also (iv) cause errors in contexts in which a competing lower-frequency form is the target. (v) Frequency effects interact with other factors (e.g. serial position, utterance length), and the patterning of these interactions is generally informative with regard to the nature of the learning mechanism. We conclude by arguing that any successful account of language acquisition, from whatever theoretical standpoint, must be frequency sensitive to the extent that it can explain the effects documented in this review, and outline some types of account that do and do not meet this criterion.

Abstract

Different languages present a variety of ways of talking about emotional experience. Very commonly, feelings are described through the use of ‘body image constructions’ in which they are associated with processes in, or states of, specific body parts. The emotions and the body parts that are thought to be their locus and the kind of activity associated with these body parts vary cross-culturally. This study focuses on the meaning of three ‘body image constructions’ used to describe feelings similar to, but also different from, English ‘jealousy’, ‘envy’, and ‘covetousness’ in the West African language Ewe. It is demonstrated that a ‘moving body’, a pychologised eye, and red eyes are scripted for these feelings. It is argued that the expressions are not figurative and that their semantics provide good clues to understanding the cultural construction of emotions both emotions and the body.

Abstract

Ways of interacting and not interacting in human societies have social, cognitive and cultural dimensions. These various aspects may be reflected in particular in relation to “taboos”. They reflect the ways of thinking and the values of a society. They are recognized as part of the communicative competence of the speakers and are learned in socialization. Some salient taboos are likely to be named in the language of the relevant society, others may not have a name. Interactional taboos can be specific to a cultural linguistic group or they may be shared across different communities that belong to a ‘speech area’ (Hymes 1972). In this article we describe a number of unnamed norms of communicative conduct which are widespread in West Africa such as the taboos on the use of the left hand in social interaction and on the use of personal names in adult address, and the widespread preference for the use of intermediaries for serious communication. We also examine a named avoidance (yaage) behavior specific to the Fulbe, a nomadic cattle-herding group spread from West Africa across the Sahel as far as Sudan. We show how tacit knowledge about these taboos and other interactive norms can be captured using the cultural scripts methodology.

Abstract

We introduce a biomechanical model of oropharyngeal structures that adds the soft-palate, pharynx, and larynx to our previous models of jaw, skull, hyoid, tongue, and face in a unified model. The model includes a comprehensive description of the upper airway musculature, using point-to-point muscles that may either be embedded within the deformable structures or operate exter- nally. The airway is described by an air-tight mesh that fits and deforms with the surrounding articulators, which enables dynamic coupling to our articulatory speech synthesizer. We demonstrate that the biomechanics, in conjunction with the skinning, supports a range from physically realistic to simplified vocal tract geometries to investigate different approaches to aeroacoustic modeling of vocal tract. Furthermore, our model supports inverse modeling to support investigation of plausible muscle activation patterns to generate speech.

Abstract

This ERP study investigated the cognitive nature of the P1–N1 components during orthographic processing. We used an implicit reading task with various types of stimuli involving different amounts of sublexical or lexical orthographic processing (words, pseudohomophones, pseudowords, nonwords, and symbols), and tested average and dyslexic readers. An orthographic regularity effect (pseudowords– nonwords contrast) was observed in the average but not in the dyslexic group. This suggests an early sensitivity to the dependencies among letters in word-forms that reflect orthographic structure, while the dyslexic brain apparently fails to be appropriately sensitive to these complex features. Moreover, in the adults the N1-response may already reflect lexical access: (i) the N1 was sensitive to the familiar vs. less familiar orthographic sequence contrast; (ii) and early effects of the phonological form (words-pseudohomophones contrast) were also found. Finally, the later N320 component was attenuated in the dyslexics, suggesting suboptimal processing in later stages of phonological analysis.

Abstract

Evidence that rapid naming skill is associated with reading ability has become increasingly prevalent in recent years. However, there is considerable variation in the literature concerning the magnitude of this relationship. The objective of the present study was to provide a comprehensive analysis of the evidence on the relationship between rapid automatized naming (RAN) and reading performance. To this end, we conducted a meta-analysis of the correlational relationship between these 2 constructs to (a) determine the overall strength of the RAN–reading association and (b) identify variables that systematically moderate this relationship. A random-effects model analysis of data from 137 studies (857 effect sizes; 28,826 participants) indicated a moderate-to-strong relationship between RAN and reading performance (r = .43, I2 = 68.40). Further analyses revealed that RAN contributes to the 4 measures of reading (word reading, text reading, non-word reading, and reading comprehension), but higher coefficients emerged in favor of real word reading and text reading. RAN stimulus type and type of reading score were the factors with the greatest moderator effect on the magnitude of the RAN–reading relationship. The consistency of orthography and the subjects’ grade level were also found to impact this relationship, although the effect was contingent on reading outcome. It was less evident whether the subjects’ reading proficiency played a role in the relationship. Implications for future studies are discussed.

Abstract

Naming speed deficits are well documented in developmental dyslexia, expressed by slower naming times and more errors in response to familiar items. Here we used event-related potentials (ERPs) to examine at what processing level the deficits in dyslexia emerge during a discrete-naming task. Dyslexic and skilled adult control readers performed a primed object-naming task, in which the relationship between the prime and the target was manipulated along perceptual, semantic and phonological dimensions. A 3×2 design that crossed Relationship Type (Visual, Phonemic Onset, and Semantic) with Relatedness (Related and Unrelated) was used. An attenuated N/P190 – indexing early visual processing – and N300 – which index late visual processing – was observed to pictures preceded by perceptually related (vs. unrelated) primes in the control but not in the dyslexic group. These findings suggest suboptimal processing in early stages of object processing in dyslexia, when integration and mapping of perceptual information to a more form-specific percept in memory take place. On the other hand, both groups showed an N400 effect associated with semantically related pictures (vs. unrelated), taken to reflect intact integration of semantic similarities in both dyslexic and control readers. We also found an electrophysiological effect of phonological priming in the N400 range – that is, an attenuated N400 to objects preceded by phonemic related primes vs. unrelated – while it showed a more widespread distributed and more pronounced over the right hemisphere in the dyslexics. Topographic differences between groups might have originated from a word form encoding process with different characteristics in dyslexics compared to control readers.

Abstract

We investigated music and language processing in a group of early bilinguals who spoke a tone language and a non-tone language (Cantonese and Dutch). We assessed online speech-music processing interactions, that is, interactions that occur when speech and music are processed simultaneously in songs, with a speeded classification task. In this task, participants judged sung pseudowords either musically (based on the direction of the musical interval) or phonologically (based on the identity of the sung vowel). We also assessed longer-term effects of linguistic experience on musical ability, that is, the influence of extensive prior experience with language when processing music. These effects were assessed with a task in which participants had to learn to identify musical intervals and with four pitch-perception tasks. Our hypothesis was that due to their experience in two different languages using lexical versus intonational tone, the early Cantonese-Dutch bilinguals would outperform the Dutch control participants. In online processing, the Cantonese-Dutch bilinguals processed speech and music more holistically than controls. This effect seems to be driven by experience with a tone language, in which integration of segmental and pitch information is fundamental. Regarding longer-term effects of linguistic experience, we found no evidence for a bilingual advantage in either the music-interval learning task or the pitch-perception tasks. Together, these results suggest that being a Cantonese-Dutch bilingual does not have any measurable longer-term effects on pitch and music processing, but does have consequences for how speech and music are processed jointly.

Abstract

Do individuals differ in how efficiently they process non-native sounds? To what extent do these differences relate to individual variability in sound-learning aptitude? We addressed these questions by assessing the sound-learning abilities of Dutch native speakers as they were trained on non-native tone contrasts. We used fMRI repetition suppression to the non-native tones to measure participants' neuronal processing efficiency before and after training. Although all participants improved in tone identification with training, there was large individual variability in learning performance. A repetition suppression effect to tone was found in the bilateral inferior frontal gyri (IFGs) before training. No whole-brain effect was found after training; a region-of-interest analysis, however, showed that, after training, repetition suppression to tone in the left IFG correlated positively with learning. That is, individuals who were better in learning the non-native tones showed larger repetition suppression in this area. Crucially, this was true even before training. These findings add to existing evidence that the left IFG plays an important role in sound learning and indicate that individual differences in learning aptitude stem from differences in the neuronal efficiency with which non-native sounds are processed.

Abstract

Background: Altered levels of urocortin 1 (Ucn1) in the centrally projecting Edinger-Westphal nucleus (EWcp) of depressed suicide attempters or completers mediate the brain’s response to stress, while the mechanism regulating Ucn1 expression is unknown. We tested the hypothesis that microRNAs (miRNAs), which are vital fine-tuners of gene expression during the brain’s response to stress, have the capacity to modulate Ucn1 expression. Methods: Computational analysis revealed that the Ucn1 3’ untranslated region contained a conserved binding site for miR-326. We examined miR-326 and Ucn1 levels in the EWcp of depressed suicide completers. In addition, we evaluated miR-326 and Ucn1 levels in the serum and the EWcp of a chronic variable mild stress (CVMS) rat model of behavioural despair and after recovery from CVMS, respectively. Gain and loss of miR-326 function experiments examined the regulation of Ucn1 by this miRNA in cultured midbrain neurons. Results: We found reduced miR-326 levels concomitant with elevated Ucn1 levels in the EWcp of depressed suicide completers as well as in the EWcp of CVMS rats. In CVMS rats fully recovered from stress, both serum and EWcp miR-326 levels rebounded to nonstressed levels. While downregulation of miR-326 levels in primary midbrain neurons enhanced Ucn1 expression levels, miR-326 overexpression selectively reduced the levels of this neuropeptide. Limitations: This study lacked experiments showing that in vivo alteration of miR-326 levels alleviate depression-like behaviours. We show only correlative data for miR-325 and cocaine- and amphetamine-regulated transcript levels in the EWcp. Conclusion: We identified miR-326 dysregulation in depressed suicide completers and characterized this miRNA as an upstream regulator of the Ucn1 neuropeptide expression in midbrain neurons. © 2016 Joule Inc. or its licensors.

Abstract

People make sense of objects and events around them by classifying them into identifiable categories. The extent to which language affects this process has been the focus of a long-standing debate: Do different languages cause their speakers to behave differently? Here, we show that fluent German-English bilinguals categorize motion events according to the grammatical constraints of the language in which they operate. First, as predicted from cross-linguistic differences in motion encoding, bilingual participants functioning in a German testing context prefer to match events on the basis of motion completion to a greater extent than do bilingual participants in an English context. Second, when bilingual participants experience verbal interference in English, their categorization behavior is congruent with that predicted for German; when bilingual participants experience verbal interference in German, their categorization becomes congruent with that predicted for English. These findings show that language effects on cognition are context-bound and transient, revealing unprecedented levels of malleability in human cognition.

Abstract

Speakers achieve coherence in discourse by alternating between differential lexical forms e.g. noun phrase, pronoun, and null form in accordance with the accessibility of the entities they refer to, i.e. whether they introduce an entity into discourse for the first time or continue referring to an entity they already mentioned before. Moreover, tracking of entities in discourse is a multimodal phenomenon. Studies show that speakers are sensitive to the informational structure of discourse and use fuller forms (e.g. full noun phrases) in speech and gesture more when re-introducing an entity while they use attenuated forms (e.g. pronouns) in speech and gesture less when maintaining a referent. However, those studies focus mainly on non-pro-drop languages (e.g. English, German and French). The present study investigates whether the same pattern holds for pro-drop languages. It draws data from adult native speakers of Turkish using elicited narratives. We find that Turkish speakers mostly use fuller forms to code subject referents in re-introduction context and the null form in maintenance context and they point to gesture space for referents more in re-introduction context compared maintained context. Hence we provide supportive evidence for the reverse correlation between the accessibility of a discourse referent and its coding in speech and gesture. We also find that, as a novel contribution, third person pronoun is used in re-introduction context only when the referent was previously mentioned as the object argument of the immediately preceding clause.

Abstract

Speakers use differential referring expressions in pragmatically appropriate ways to produce coherent narratives. Languages, however, differ in a) whether REs as arguments can be dropped and b) whether personal pronouns encode gender. We examine two languages that differ from each other in these two aspects and ask whether the co-reference context and the gender encoding options affect the use of REs differentially. We elicited narratives from Dutch and Turkish speakers about two types of three-person events, one including people of the same and the other of mixed-gender. Speakers re-introduced referents into the discourse with fuller forms (NPs) and maintained them with reduced forms (overt or null pronoun). Turkish speakers used pronouns mainly to mark emphasis and only Dutch speakers used pronouns differentially across the two types of videos. We argue that linguistic possibilities available in languages tune speakers into taking different principles into account to produce pragmatically coherent narratives

Abstract

Are regular morphologically complex words stored in the mental lexicon? Answers to this question have ranged from full listing to parsing for every regular complex word. We investigated the roles of storage and parsing in the visual domain for the productive Dutch plural suffix -en.Two experiments are reported that show that storage occurs for high-frequency noun plurals. A mathematical formalization of a parallel dual-route race model is presented that accounts for the patterns in the observed reaction time data with essentially one free parameter, the speed of the parsing route. Parsing for noun plurals appears to be a time-costly process, which we attribute to the ambiguity of -en,a suffix that is predominantly used as a verbal ending. A third experiment contrasted nouns and verbs. This experiment revealed no effect of surface frequency for verbs, but again a solid effect for nouns. Together, our results suggest that many noun plurals are stored in order to avoid the time-costly resolution of the subcategorization conflict that arises when the -ensuffix is attached to nouns.

Abstract

In this paper, I present an analysis of the so-called tense forms of Biblical Hebrew. While there is fairly broad consensus on the interpretation of the yiqtol tense form, the interpretation of the qdtal tense form has led to considerable controversy. I will argue that the qātal form has no intrinsic semantic value and that it serves a pragmatic function only, namely, signaling to the hearer that the event or state expressed by the verb cannot be tightly integrated into the discourse representation of the hearer, given the speaker's estimate of their common ground.

Abstract

This paper addresses the relation between meaning, lexical productivity, and frequency of use. Using density estimation as a visualization tool, we show that differences in semantic structure can be reflected in probability density functions estimated for word frequency distributions. We call attention to an example of a bimodal density, and suggest that bimodality arises when distributions of well-entrenched lexical tems, which appear to be lognormal, are mixed with distributions of productively reated nonce formations

Abstract

Integration of separate memories forms the basis of inferential reasoning - an essential cognitive process that enables complex behavior. Considerable evidence suggests that both hippocampus and medial prefrontal cortex (mPFC) play a crucial role in memory integration. Although previous studies indicate that theta oscillations facilitate memory processes, the electrophysiological mechanisms underlying memory integration remain elusive. To bridge this gap, we recorded magnetoencephalography data while participants performed an inference task and employed novel source reconstruction techniques to estimate oscillatory signals from the hippocampus. We found that hippocampal theta power during encoding predicts subsequent memory integration. Moreover, we observed increased theta coherence between hippocampus and mPFC. Our results suggest that integrated memory representations arise through hippocampal theta oscillations, possibly reflecting dynamic switching between encoding and retrieval states, and facilitating communication with mPFC. These findings have important implications for our understanding of memory-based decision making and knowledge acquisition

Abstract

We sketch four applications of Marr's levels-of-analysis methodology to the relations between logic and experimental data in the cognitive neuroscience of language and reasoning. The first part of the paper illustrates the explanatory power of computational level theories based on logic. We show that a Bayesian treatment of the suppression task in reasoning with conditionals is ruled out by EEG data, supporting instead an analysis based on defeasible logic. Further, we describe how results from an EEG study on temporal prepositions can be reanalyzed using formal semantics, addressing a potential confound. The second part of the article demonstrates the predictive power of logical theories drawing on EEG data on processing progressive constructions and on behavioral data on conditional reasoning in people with autism. Logical theories can constrain processing hypotheses all the way down to neurophysiology, and conversely neuroscience data can guide the selection of alternative computational level models of cognition.

Abstract

We examined 33 participants of a one-week Scottish Gaelic course and compared them to 34 controls: 16 active controls who participated in courses of comparable duration and intensity but not involving foreign language learning and 18 passive controls who followed their usual routines. Participants completed auditory tests of attentional inhibition and switching. There was no difference between the groups in any measures at the beginning of the course. At the end of the course, a significant improvement in attention switching was observed in the language group (p < .001) but not the control group (p = .127), independent of the age of participants (18–78 years). Half of the language participants (n = 17) were retested nine months after their course. All those who practiced Gaelic 5 hours or more per week improved from their baseline performance. In contrast, those who practiced 4 hours or fewer showed an inconsistent pattern: some improved while others stayed the same or deteriorated. Our results suggest that even a short period of intensive language learning can modulate attentional functions and that all age groups can benefit from this effect. Moreover, these short-term effects can be maintained through continuous practice.

Abstract

The complementary learning systems account of word learning states that novel words, like other types of memories, undergo an offline consolidation process during which they are gradually integrated into the neocortical memory network. A fundamental change in the neural representation of a novel word should therefore occur in the hours after learning. The present EEG study tested this hypothesis by investigating whether novel words learned before a 24-hr consolidation period elicited more word-like oscillatory responses than novel words learned immediately before testing. In line with previous studies indicating that theta synchronization reflects lexical access, unfamiliar novel words elicited lower power in the theta band (4–8 Hz) than existing words. Recently learned words still showed a marginally lower theta increase than existing words, but theta responses to novel words that had been acquired 24 hr earlier were indistinguishable from responses to existing words. Consistent with evidence that beta desynchronization (16–21 Hz) is related to lexical-semantic processing, we found that both unfamiliar and recently learned novel words elicited less beta desynchronization than existing words. In contrast, no difference was found between novel words learned 24 hr earlier and existing words. These data therefore suggest that an offline consolidation period enables novel words to acquire lexically integrated, word-like neural representations.

Abstract

Mouthings and mouth gestures are omnipresent in Sign Language of the Netherlands (NGT). Mouthings in NGT are mouth actions that have their origin in spoken Dutch, and are usually time aligned with the signs they co-occur with. Frequently, however, they spread over one or more adjacent signs, so that one mouthing co-occurs with multiple manual signs. We conducted a corpus study to explore how frequently this occurs in NGT and whether there is any sociolinguistic variation in the use of spreading. Further, we looked at the circumstances under which spreading occurs. Answers to these questions may give us insight into the prosodic structure of sign languages. We investigated a sample of the Corpus NGT containing 5929 mouthings by 46 participants. We found that spreading over an adjacent sign is independent of social factors. Further, mouthings that spread are longer than non-spreading mouthings, whether measured in syllables or in milliseconds. By using a relatively large amount of natural data, we succeeded in gaining more insight into the way mouth actions are utilised in sign languages

Abstract

This article describes the interactional patterns and linguistic structures associated with otherinitiated repair, as observed in a corpus of video-recorded conversations in Russian. In the discussion of various repair cases special attention is given to the modifications that the trouble source turn undergoes in response to an open versus a restricted repair initiation. Speakers often modify their problematic turn in multiple ways at ones when responding to an open repair initiation. They can alter the word order of the problematic turn, change prosodic contour of the utterance, omit redundant elements and add more specific ones. By contrast, restricted repair initiations usually receive specific repair solutions that target only one problem at a time

Abstract

Reasons play an important role in social interaction. We study reasons-giving in the context of request sequences in Russian. By contrasting request sequences with and without reasons, we are able to shed light on the interactional work people do when they provide reasons or ask for them. In a systematic collection of request sequences in everyday conversation (N = 158), we find reasons in a variety of sequential positions, showing the various points at which participants may orient to the need for a reason. Reasons may be left implicit (as in many minimal requests that are readily complied with), or they can be made explicit. Participants may make reasons explicit either as part of the initial formulation of a request or in an interactionally contingent way. Across sequential positions, we show that reasons for requests recurrently deal with three possible issues: (1) providing information when a request is underspecified, (2) managing relationships between the requester and requestee and (3) explicating ancillary actions implemented by a request. By spelling out information normally left to presuppositions and implicatures, reasons make requests more understandable and help participants to navigate the social landscape of asking assistance from others.

Abstract

Maximum likelihood factor analysis of discrete data within the structural equation modeling framework rests on the assumption that the observed discrete responses are manifestations of underlying continuous scores that are normally distributed. As maximizing the likelihood of multivariate response patterns is computationally very intensive, the sum of the log–likelihoods of the bivariate response patterns is maximized instead. Little is yet known about how to assess model fit when the analysis is based on such a pairwise maximum likelihood (PML) of two–way contingency tables. We propose new fit criteria for the PML method and conduct a simulation study to evaluate their performance in model selection. With large sample sizes (500 or more), PML performs as well the robust weighted least squares analysis of polychoric correlations.

Abstract

Exploratory factor analysis (EFA) is commonly used to determine the dimensionality of continuous data. In a simulation study we investigate its usefulness with discrete data. We vary response scales (continuous, dichotomous, polytomous), factor loadings (medium, high), sample size (small, large), and factor structure (simple, complex). For each condition, we generate 1,000 data sets and apply EFA with 5 estimation methods (maximum likelihood [ML] of covariances, ML of polychoric correlations, robust ML, weighted least squares [WLS], and robust WLS) and 3 fit criteria (chi-square test, root mean square error of approximation, and root mean square residual). The various EFA procedures recover more factors when sample size is large, factor loadings are high, factor structure is simple, and response scales have more options. Robust WLS of polychoric correlations is the preferred method, as it is theoretically justified and shows fewer convergence problems than the other estimation methods.

Abstract

Recent social-cognitive research suggests that the anticipation of co-actors' actions influences people's mental representations. However, the precise nature of such representations is still unclear. In this study we investigated verbal joint representations in a delayed Stroop paradigm, where each participant responded to one color after a short delay. Participants either performed the task as a single actor (single-action, Experiment 1), or they performed it together (joint-action, Experiment 2). We investigated effects of co-actors' actions on the ERP components associated with perceptual conflict (Go N2) and response selection (P3b). Compared to single-action, joint-action reduced the N2 amplitude congruency effect when participants had to respond (Go trials), indicating that representing a co-actor's utterance helped to dissociate action codes and attenuated perceptual conflict for the responding participant. Yet, on NoGo trials the centro-parietal P3 (P3b) component amplitude increased for joint-action, suggesting that participants mapped the stimuli onto the co-actor's upcoming response as if it were their own response. We conclude that people represent others' utterances similarly to the way they represent their own utterances, and that shared perception-action codes for self and others can sometimes reduce, rather than enhance, perceptual conflict.

Abstract

In conversation, interlocutors rarely leave long gaps between turns, suggesting that next speak- ers begin to plan their turns while listening to the previous speaker. The present experiment used analyses of speech onset latencies and eye-movements in a task-oriented dialogue paradigm to investigate when speakers start planning their response. Adult German participants heard a confederate describe sets of objects in utterances that either ended in a noun (e.g. Ich habe eine Tür und ein Fahrrad (‘I have a door and a bicycle’)) or a verb form (Ich habe eine Tür und ein Fahrrad besorgt (‘I have gotten a door and a bicycle’)), while the presence or absence of the final verb either was or was not predictable from the preceding sentence structure. In response, participants had to name any unnamed objects they could see in their own display in utterances such as Ich habe ein Ei (‘I have an egg’). The main question was when participants started to plan their response. The results are consistent with the view that speakers begin to plan their turn as soon as sufficient information is available to do so, irrespective of further incoming words.

Abstract

In using language, people not only exchange information, but also navigate their social world – for example, they can express themselves indirectly to avoid losing face. In this functional magnetic resonance imaging study, we investigated the neural correlates of interpreting face-saving indirect replies, in a situation where participants only overheard the replies as part of a conversation between two other people, as well as in a situation where the participants were directly addressed themselves. We created a fictional job interview context where indirect replies serve as a natural communicative strategy to attenuate one’s shortcomings, and asked fMRI participants to either pose scripted questions and receive answers from three putative job candidates (addressee condition) or to listen to someone else interview the same candidates (overhearer condition). In both cases, the need to evaluate the candidate ensured that participants had an active interest in comprehending the replies. Relative to direct replies, face-saving indirect replies increased activation in medial prefrontal cortex, bilateral temporo-parietal junction (TPJ), bilateral inferior frontal gyrus and bilateral middle temporal gyrus, in active overhearers and active addressees alike, with similar effect size, and comparable to findings obtained in an earlier passive listening study (Bašnáková et al., 2013). In contrast, indirectness effects in bilateral anterior insula and pregenual ACC, two regions implicated in emotional salience and empathy, were reliably stronger in addressees than in active overhearers. Our findings indicate that understanding face-saving indirect language requires additional cognitive perspective-taking and other discourse-relevant cognitive processing, to a comparable extent in active overhearers and addressees. Furthermore, they indicate that face-saving indirect language draws upon affective systems more in addressees than in overhearers, presumably because the addressee is the one being managed by a face-saving reply. In all, face-saving indirectness provides a window on the cognitive as well as affect-related neural systems involved in human communication.

Abstract

Changes in oscillatory brain dynamics can be studied by means of induced band power (IBP) analyses, which quantify event-related changes in amplitude of frequency-specific EEG rhythms. Such analyses capture EEG phenomena that are not part of traditional event-related potential measures. The present study investigated whether IBP changes in the δ, θ, and α frequency ranges are sensitive to syntactic violations in sentences. Subjects read sentences that either were correct or contained a syntactic violation. The violations were either grammatical gender agreement violations, where a prenominal adjective was not appropriately inflected for the head noun's gender, or number agreement violations, in which a plural quantifier was combined with a singular head noun. IBP changes of the concurrently measured EEG were computed in five frequency bands of 2-Hz width, individually adjusted on the basis of subjects' α peak, ranging approximately from 2 to 12 Hz. Words constituting a syntactic violation elicited larger increases in θ power than the same words in a correct sentence context, in an interval of 300–500 ms after word onset. Of all the frequency bands studied, this was true for the θ frequency band only. The scalp topography of this effect was different for different violations: following number violations a left-hemispheric dominance was found, whereas gender violations elicited a right-hemisphere dominance of the θ power increase. Possible interpretations of this effect are considered in closing.

Abstract

An important, but often ignored distinction in the analysis of EEG signals is that between evoked activity and induced activity. Whereas evoked activity reflects the summation of transient post-synaptic potentials triggered by an event, induced activity, which is mainly oscillatory in nature, is thought to reflect changes in parameters controlling dynamic interactions within and between brain structures. We hypothesize that induced activity may yield information about the dynamics of cell assembly formation, activation and subsequent uncoupling, which may play a prominent role in different types of memory operations. We then describe a number of analysis tools that can be used to study the reactivity of induced rhythmic activity, both in terms of amplitude changes and of phase variability.

We briefly discuss how alpha, gamma and theta rhythms are thought to be generated, paying special attention to the hypothesis that the theta rhythm reflects dynamic interactions between the hippocampal system and the neocortex. This hypothesis would imply that studying the reactivity of scalp-recorded theta may provide a window on the contribution of the hippocampus to memory functions.

We review studies investigating the reactivity of scalp-recorded theta in paradigms engaging episodic memory, spatial memory and working memory. In addition, we review studies that relate theta reactivity to processes at the interface of memory and language. Despite many unknowns, the experimental evidence largely supports the hypothesis that theta activity plays a functional role in cell assembly formation, a process which may constitute the neural basis of memory formation and retrieval. The available data provide only highly indirect support for the hypothesis that scalp-recorded theta yields information about hippocampal functioning. It is concluded that studying induced rhythmic activity holds promise as an additional important way to study brain function.

Abstract

Objective: To explore the reactivity of the theta and alpha rhythms during visuo-spatial working memory. Methods: One hundred and seventy-four subjects performed a delayed response task. They had to remember the spatial location of a target stimulus on a computer screen for a 1 or a 4 s retention interval. The target either remained visible throughout the entire interval (sensory trials) or disappeared after 150 ms (memory trials). Changes in induced band power (IBP) in the electroencephalogram (EEG) were analyzed in 4 narrow, individually adjusted frequency bands between 4 and 12 Hz. Results: After presentation of the target stimulus, a phasic power increase was found, irrespective of condition and delay interval, in the lower (roughly, 4–8 Hz) frequency bands, with a posterior maximum. During the retention interval, sustained occipital–parietal alpha power increase and frontal theta power decrease were found. Most importantly, the memory trials showed larger IBP decreases in the theta band over frontal electrodes than the sensory trials. Conclusions: The phasic power increase following target onset is interpreted to reflect encoding of the target location. The sustained theta decrease, which is larger for memory trials, is tentatively interpreted to reflect visuo-spatial working memory processes.

Abstract

By analyzing event-related changes in induced band power in narrow frequency bands of the human electroencephalograph, the present paper explores a possible functional role of the alpha and theta rhythms during the processing of words and of sentences. The results show a phasic power increase in the theta frequency range, together with a phasic power decrease in the alpha frequency range, following the presentation of words in a sentence. These effects may be related to word processing, either lexical or in relation to sentence context. Most importantly, there is a slow and highly frequency-specific increase in theta power as a sentence unfolds, possibly related to the formation of an episodic memory trace, or to incremental verbal working memory load.

Abstract

Previous research has suggested that the stimulus-preceding negativity (SPN) is largely independent of stimulus modality. In contrast, the scalp topography of the event related desynchronization (ERD) related to the anticipation of stimuli providing knowledge of results (KR) is modality dependent. These findings, combined with functional SPN research, lead to the hypothesis that anticipatory ERD reflects anticipatory attention, whereas the SPN mainly depends on the affective-motivational properties of the anticipated stimulus. To further investigate the prestimulus ERD, and compare this measure with the SPN, 12 participants performed a time-estimation task, and were informed about the quality of their time estimation by an auditory or a visual stimulus providing KR. The KR stimuli could be either intact or degraded. Auditory degraded KR stimuli were less effective than other KR stimuli in guiding subsequent behavior, and were preceded by a larger SPN. There were no effects of degradation on the SPN in the visual modality. Preceding auditory KR stimuli no ERD was present, whereas preceding visual stimuli an occipital ERD was found. However, contrary to expectation, the latter was larger preceding intact than preceding degraded stimuli. It is concluded that the data largely agree with an interpretation of the pre-KR SPN as a reflection of the anticipation of the affective-motivational value of KR stimuli, and of the prestimulus ERD as a perceptual anticipatory attention process.

Abstract

During sentence level language comprehension, semantic and syntactic unification are functionally distinct operations. Nevertheless, both recruit roughly the same brain areas (spatially overlapping networks in the left frontotemporal cortex) and happen at the same time (in the first few hundred milliseconds after word onset). We tested the hypothesis that semantic and syntactic unification are segregated by means of neuronal synchronization of the functionally relevant networks in different frequency ranges: gamma (40 Hz and up) for semantic unification and lower beta (10–20 Hz) for syntactic unification. EEG power changes were quantified as participants read either correct sentences, syntactically correct though meaningless sentences (syntactic prose), or sentences that did not contain any syntactic structure (random word lists). Other sentences contained either a semantic anomaly or a syntactic violation at a critical word in the sentence. Larger EEG gamma-band power was observed for semantically coherent than for semantically anomalous sentences. Similarly, beta-band power was larger for syntactically correct sentences than for incorrect ones. These results confirm the existence of a functional dissociation in EEG oscillatory dynamics during sentence level language comprehension that is compatible with the notion of a frequency-based segregation of syntactic and semantic unification.

Abstract

Oscillatory neuronal activity may provide a mechanism for dynamic network coordination. Rhythmic neuronal interactions can be quantified using multiple metrics, each with their own advantages and disadvantages. This tutorial will review and summarize current analysis methods used in the field of invasive and non-invasive electrophysiology to study the dynamic connections between neuronal populations. First, we review metrics for functional connectivity, including coherence, phase synchronization, phase-slope index, and Granger causality, with the specific aim to provide an intuition for how these metrics work, as well as their quantitative definition. Next, we highlight a number of interpretational caveats and common pitfalls that can arise when performing functional connectivity analysis, including the common reference problem, the signal to noise ratio problem, the volume conduction problem, the common input problem, and the sample size bias problem. These pitfalls will be illustrated by presenting a set of MATLAB-scripts, which can be executed by the reader to simulate each of these potential problems. We discuss how these issues can be addressed using current methods.

Abstract

Visual cortical areas subserve cognitive functions by interacting in both feedforward and feedback directions. While feedforward influences convey sensory signals, feedback influences modulate feedforward signaling according to the current behavioral context. We investigated whether these interareal influences are subserved differentially by rhythmic synchronization. We correlated frequency-specific directed influences among 28 pairs of visual areas with anatomical metrics of the feedforward or feedback character of the respective interareal projections. This revealed that in the primate visual system, feedforward influences are carried by theta-band ( approximately 4 Hz) and gamma-band ( approximately 60-80 Hz) synchronization, and feedback influences by beta-band ( approximately 14-18 Hz) synchronization. The functional directed influences constrain a functional hierarchy similar to the anatomical hierarchy, but exhibiting task-dependent dynamic changes in particular with regard to the hierarchical positions of frontal areas. Our results demonstrate that feedforward and feedback signaling use distinct frequency channels, suggesting that they subserve differential communication requirements.