Publications

Abstract

This study investigated how sentence formulation is influenced by a preceding discourse context. In two eye-tracking experiments, participants described pictures of two-character transitive events in Dutch (Experiment 1) and Chinese (Experiment 2). Focus was manipulated by presenting questions before each picture. In the Neutral condition, participants first heard ‘What is happening here?’ In the Object or Subject Focus conditions, the questions asked about the Object or Subject character (What is the policeman stopping? Who is stopping the truck?). The target response was the same in all conditions (The policeman is stopping the truck). In both experiments, sentence formulation in the Neutral condition showed the expected pattern of speakers fixating the subject character (policeman) before the object character (truck). In contrast, in the focus conditions speakers rapidly directed their gaze preferentially only to the character they needed to encode to answer the question (the new, or focused, character). The timing of gaze shifts to the new character varied by language group (Dutch vs. Chinese): shifts to the new character occurred earlier when information in the question can be repeated in the response with the same syntactic structure (in Chinese but not in Dutch). The results show that discourse affects the timecourse of linguistic formulation in simple sentences and that these effects can be modulated by language-specific linguistic structures such as parallels in the syntax of questions and declarative sentences.

Abstract

The constraints that govern acceptable phoneme combinations in speech perception and production have considerable plasticity. We addressed whether sleep influences the acquisition of new constraints and their integration into the speech-production system. Participants repeated sequences of syllables in which two phonemes were artificially restricted to syllable onset or syllable coda, depending on the vowel in that sequence. After 48 sequences, participants either had a 90-min nap or remained awake. Participants then repeated 96 sequences so implicit constraint learning could be examined, and then were tested for constraint generalization in a forced-choice task. The sleep group, but not the wake group, produced speech errors at test that were consistent with restrictions on the placement of phonemes in training. Furthermore, only the sleep group generalized their learning to new materials. Polysomnography data showed that implicit constraint learning was associated with slow-wave sleep. These results show that sleep facilitates the integration of new linguistic knowledge with existing production constraints. These data have relevance for systems-consolidation models of sleep.

Abstract

A key function of attention is to select an appropriate subset of available information by facilitation of attended processes and/or inhibition of irrelevant processing. Functional imaging studies, using positron emission tomography, have during different experimental tasks revealed decreased neuronal activity in areas that process input from unattended sensory modalities. It has been hypothesized that these decreases reflect a selective inhibitory modulation of nonrelevant cortical processing. In this study we addressed this question using a continuous arithmetical task with and without concomitant disturbing auditory input (task-irrelevant speech). During the arithmetical task, irrelevant speech did not affect task-performance but yielded decreased activity in the auditory and midcingulate cortices and increased activity in the left posterior parietal cortex. This pattern of modulation is consistent with a top down inhibitory modulation of a nonattended input to the auditory cortex and a coexisting, attention-based facilitation of taskrelevant processing in higher order cortices. These findings suggest that task-related decreases in cortical activity may be of functional importance in the understanding of both attentional mechanisms and taskrelated information processing.

Abstract

Reading and language abilities are heritable traits that are likely to share some genetic influences with each other. To identify pleiotropic genetic variants affecting these traits, we first performed a Genome-wide Association Scan (GWAS) meta-analysis using three richly characterised datasets comprising individuals with histories of reading or language problems, and their siblings. GWAS was performed in a total of 1862 participants using the first principal component computed from several quantitative measures of reading- and language-related abilities, both before and after adjustment for performance IQ. We identified novel suggestive associations at the SNPs rs59197085 and rs5995177 (uncorrected p≈10−7 for each SNP), located respectively at the CCDC136/FLNC and RBFOX2 genes. Each of these SNPs then showed evidence for effects across multiple reading and language traits in univariate association testing against the individual traits. FLNC encodes a structural protein involved in cytoskeleton remodelling, while RBFOX2 is an important regulator of alternative splicing in neurons. The CCDC136/FLNC locus showed association with a comparable reading/language measure in an independent sample of 6434 participants from the general population, although involving distinct alleles of the associated SNP. Our datasets will form an important part of on-going international efforts to identify genes contributing to reading and language skills.

Abstract

Irrelevant speech effect (ISE) is defined as a decrement in visually presented digit-list short-term memory performance due to exposure to irrelevant auditory material. Perhaps the most successful theoretical explanation of the effect is the changing state hypothesis. This hypothesis explains the effect in terms of confusion between amodal serial order cues, and represents a view based on the interference caused by the processing of similar order information of the visual and auditory materials. An alternative view suggests that the interference occurs as a consequence of the similarity between the visual and auditory contents of the stimuli. An important argument for the former view is the observation that ISE is almost exclusively observed in tasks that require memory for serial order. However, most short-term memory tasks require that both item and order information be retained in memory. An ideal task to investigate the sensitivity of maintenance of serial order to irrelevant speech would be one that calls upon order information but not item information. One task that is particularly suited to address this issue is serial recognition. In a typical serial recognition task, a list of items is presented and then probed by the same list in which the order of two adjacent items has been transposed. Due to the re-presentation of the encoding string, serial recognition requires primarily the serial order to be maintained while the content of the presented items is deemphasized. In demonstrating a highly significant ISE of changing versus steady-state auditory items in a serial recognition task, the present finding lends support for and extends previous empirical findings suggesting that irrelevant speech has the potential to interfere with the coding of the order of the items to be memorized.

Abstract

Positron emission tomography (PET) was performed in normal volunteers during a serial recall task under the influence of irrelevant speech comprising both single item repetition and multi-item sequences. An interaction approach was used to identify brain areas specifically related to the irrelevant speech effect. We interpreted activations as compensatory recruitment of complementary working memory processing, and decreased activity in terms of suppression of task relevant areas invoked by the irrelevant speech. The interaction between the distractors and working memory revealed a significant effect in the left, and to a lesser extent in the right, superior temporal region, indicating that initial phonological processing was relatively suppressed. Additional areas of decreased activity were observed in an a priori defined cortical network related to verbalworking memory, incorporating the bilateral superior temporal and inferior/middle frontal corticesn extending into Broca’s area on the left. We also observed a weak activation in the left inferior parietal cortex, a region suggested to reflect the phonological store, the subcomponent where the interference is assumed to take place. The results suggest that the irrelevant speech effect is correlated with and thus tentatively may be explained in terms of a suppression of components of the verbal working memory network as outlined. The results can be interpreted in terms of inhibitory top–down attentional mechanisms attenuating the influence of the irrelevant speech, although additional studies are clearly necessary to more fully characterize the nature of this phenomenon and its theoretical implications for existing short-term memory models

Abstract

Using parametric and nonparametric techniques, our study investigated the presence of single locus and pairwise effects between 20 markers of the Genetic Analysis Workshop 15 (GAW15) North American Rheumatoid Arthritis Consortium (NARAC) candidate gene data set (Problem 2), analyzing 463 independent patients and 855 controls. Specifically, our work examined the correspondence between logistic regression (LR) analysis of single-locus and pairwise interaction effects, and random forest (RF) single and joint importance measures. For this comparison, we selected small but stable RFs (500 trees), which showed strong correlations (r~0.98) between their importance measures and those by RFs grown on 5000 trees. Both RF importance measures captured most of the LR single-locus and pairwise interaction effects, while joint importance measures also corresponded to full LR models containing main and interaction effects. We furthermore showed that RF measures were particularly sensitive to data imputation. The most consistent pairwise effect on rheumatoid arthritis was found between two markers within MAP3K7IP2/SUMO4 on 6q25.1, although LR and RFs assigned different significance levels. Within a hypothetical two-stage design, pairwise LR analysis of all markers with significant RF single importance would have reduced the number of possible combinations in our small data set by 61%, whereas joint importance measures would have been less efficient for marker pair reduction. This suggests that RF single importance measures, which are able to detect a wide range of interaction effects and are computationally very efficient, might be exploited as pre-screening tool for larger association studies. Follow-up analysis, such as by LR, is required since RFs do not indicate highrisk genotype combinations.

Abstract

Previous studies have described the existence of a phonotactic bias called the Labial–Coronal (LC) bias, corresponding to a tendency to produce more words beginning with a labial consonant followed by a coronal consonant (i.e. “bat”) than the opposite CL pattern (i.e. “tap”). This bias has initially been interpreted in terms of articulatory constraints of the human speech production system. However, more recently, it has been suggested that this presumably language-general LC bias in production might be accompanied by LC and CL biases in perception, acquired in infancy on the basis of the properties of the linguistic input. The present study investigates the origins of these perceptual biases, testing infants learning Japanese, a language that has been claimed to possess more CL than LC sequences, and comparing them with infants learning French, a language showing a clear LC bias in its lexicon. First, a corpus analysis of Japanese IDS and ADS revealed the existence of an overall LC bias, except for plosive sequences in ADS, which show a CL bias across counts. Second, speech preference experiments showed a perceptual preference for CL over LC plosive sequences (all recorded by a Japanese speaker) in 13- but not in 7- and 10-month-old Japanese-learning infants (Experiment 1), while revealing the emergence of an LC preference between 7 and 10 months in French-learning infants, using the exact same stimuli. These crosslinguistic behavioral differences, obtained with the same stimuli, thus reflect differences in processing in two populations of infants, which can be linked to differences in the properties of the lexicons of their respective native languages. These findings establish that the emergence of a CL/LC bias is related to exposure to a linguistic input.

Abstract

Humans appear to rely on spatial mappings to represent and describe concepts. The conceptual cuing effect describes the tendency for participants to orient attention to a spatial location following the presentation of an unrelated cue word (e.g., orienting attention upward after reading the word sky). To date, such effects have predominately been explained within the embodied cognition framework, according to which people’s attention is oriented on the basis of prior experience (e.g., sky → up via perceptual simulation). However, this does not provide a compelling explanation for how abstract words have the same ability to orient attention. Why, for example, does dream also orient attention upward? We report on an experiment that investigated the role of language use (specifically, collocation between concept words and spatial words for up and down dimensions) and found that it predicted the cuing effect. The results suggest that language usage patterns may be instrumental in explaining conceptual cuing.

Abstract

Our recent studies suggest that congenitally blind adults have severely impaired thresholds in an auditory spatial bisection task, pointing to the importance of vision in constructing complex auditory spatial maps (Gon etal., 2014). To explore strategies that may improve the auditory spatial sense in visually impaired people, we investigated the impact of tactile feedback on spatial auditory localization in 48 blindfolded sighted subjects. We measured auditory spatial bisection thresholds before and after training, either with tactile feedback, verbal feedback, or no feedback. Audio thresholds were first measured with a spatial bisection task: subjects judged whether the second sound of a three sound sequence was spatially closer to the first or the third sound. The tactile feedback group underwent two audio-tactile feedback sessions of 100 trials, where each auditory trial was followed by the same spatial sequence played on the subject's forearm; auditory spatial bisection thresholds were evaluated after each session. In the verbal feedback condition, the positions of the sounds were verbally reported to the subject after each feedback trial.The no feedback group did the same sequence of trials, with no feedback. Performance improved significantly only after audio-tactile feedback. The results suggest that direct tactile feedback interacts with the auditory spatial localization system, possibly by a process of cross-sensory recalibration. Control tests with the subject rotated suggested that this effect occurs only when the tactile and acoustic sequences are spatially congruent. Our results suggest that the tactile system can be used to recalibrate the auditory sense of space. These results encourage the possibility of designing rehabilitation programs to help blind persons establish a robust auditory sense of space, through training with the tactile modality.

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

When the dead come home… Remarks on ancestor worship among the Lowland Mayas. In Amerindian ethnographical literature, ancestor worship is often mentioned but evidence of its existence is lacking. This article will try to demonstrate that some Lowland Maya do worship ancestors ; it will use precise criteria taken from ethnological studies of societies where ancestor worship is common, compared to maya beliefs and practices. The All Souls’ Day, or hanal pixan, seems to be the most significant manifestation of this cult. Our approach will be comparative, through time – using colonial and ethnographical data of the twentieth century, and space – contemplating uses and beliefs of two maya groups, the Yucatec and the Lacandon Maya.

Abstract

A large body of evidence has shown that visual context information can rapidly modulate language comprehension for concrete sentences and when it is mediated by a referential or a lexical-semantic link. What has not yet been examined is whether visual context can also modulate comprehension of abstract sentences incrementally when it is neither referenced by, nor lexically associated with, the sentence. Three eye-tracking reading experiments examined the effects of spatial distance between words (Experiment 1) and objects (Experiment 2 and 3) on participants’ reading times for sentences that convey similarity or difference between two abstract nouns (e.g., ‘Peace and war are certainly different...’). Before reading the sentence, participants inspected a visual context with two playing cards that moved either far apart or close together. In Experiment 1, the cards turned and showed the first two nouns of the sentence (e.g., ‘peace’, ‘war’). In Experiments 2 and 3, they turned but remained blank. Participants’ reading times at the adjective (Experiment 1: first-pass reading time; Experiment 2: total times) and at the second noun phrase (Experiment 3: first-pass times) were faster for sentences that expressed similarity when the preceding words/objects were close together (vs. far apart) and for sentences that expressed dissimilarity when the preceding words/objects were far apart (vs. close together). Thus, spatial distance between words or entirely unrelated objects can rapidly and incrementally modulate the semantic interpretation of abstract sentences.

Abstract

Gestures are visuospatial events, meaning carriers, and social interactional phenomena. As such they constitute a particularly favourable area for investigating visual attention in a complex everyday situation under conditions of competitive processing. This chapter discusses visual attention to spontaneous gestures in human face-to-face interaction as explored with eye-tracking. Some basic fixation patterns are described, live and video-based settings are compared, and preliminary results on the relationship between fixations and information processing are outlined.

Abstract

This paper discusses how the gestural modality can contribute to our understanding of anaphoric linkage in learner varieties, focusing on gestural anaphoric linkage marking the introduction, maintenance, and shift of reference in story retellings by learners of French and Swedish. The comparison of gestural anaphoric linkage in native and non-native varieties reveals what appears to be a particular learner variety of gestural cohesion, which closely reflects the characteristics of anaphoric linkage in learners' speech. Specifically, particular forms co-occur with anaphoric gestures depending on the information organisation in discourse. The typical nominal over-marking of maintained referents or topic elements in speech is mirrored by gestural (over-)marking of the same items. The paper discusses two ways in which this finding may further the understanding of anaphoric over-explicitness of learner varieties. An addressee-based communicative perspective on anaphoric linkage highlights how over-marking in gesture and speech may be related to issues of hyper-clarity and ambiguity. An alternative speaker-based perspective is also explored in which anaphoric over-marking is seen as related to L2 speech planning.

Abstract

All accounts of communicative behaviour in general, and communicative strategies in particular, mention gesture1 in relation to language acquisition (cf. Faerch & Kasper 1983 for an overview). However, few attempts have been made to investigate how spoken language and spontaneous gesture combine to determine discourse referents. Referential gesture and referential discourse will be of particular interest, since communicative strategies in second language discourse often involve labelling problems.

This paper will focus on two issues:

1) Within a cognitive account of communicative strategies, gesture will be seen to be part of conceptual or analysis-based strategies, in that relational features in the referents are exploited;

2) It will be argued that communication strategies can be seen in terms of cue manipulation in the same sense as sentence processing has been analysed in terms of competing cues. Strategic behaviour, and indeed the process of referring in general, are seen in terms of cues, combining or competing to determine discourse referents. Gesture can then be regarded as being such a cue at the discourse level, and as a cue-based communicative strategy, in that gesture functions by exploiting physically based cues which can be recognised as being part of the referent. The question of iconicity and motivation vs. the arbitrary qualities of gesture as a strategic cue will be addressed in connection with this.

Abstract

In two studies subjects were required to read Dutch sentences that in some cases contained a syntactic violation, in other cases a semantic violation. All syntactic violations were word category violations. The design excluded differential contributions of expectancy to influence the syntactic violation effects. The syntactic violations elicited an Anterior Negativity between 300 and 500 ms. This negativity was bilateral and had a frontal distribution. Over posterior sites the same violations elicited a P600/SPS starting at about 600 ms. The semantic violations elicited an N400 effect. The topographic distribution of the AN was more frontal than the distribution of the classical N400 effect, indicating that the underlying generators of the AN and the N400 are, at least to a certain extent, non-overlapping. Experiment 2 partly replicated the design of Experiment 1, but with differences in rate of presentation and in the distribution of items over subjects, and without semantic violations. The word category violations resulted in the same effects as were observed in Experiment 1, showing that they were independent of some of the specific parameters of Experiment 1. The discussion presents a tentative account of the functional differences in the triggering conditions of the AN and the P600/SPS.

Abstract

To understand spoken language requires that the brain provides rapid access to different kinds of knowledge, including the sounds and meanings of words, and syntax. Syntax specifies constraints on combining words in a grammatically well formed manner. Agrammatic patients are deficient in their ability to use these constraints, due to a lesion in the perisylvian area of the languagedominant hemisphere. We report a study on real-time auditory sentence processing in agrammatic comprehenders, examining
their ability to accommodate damage to the language system. We recorded event-related brain potentials (ERPs) in agrammatic comprehenders, nonagrammatic aphasics, and age-matched controls. When listening to sentences with grammatical violations, the agrammatic aphasics did not show the same syntax-related ERP effect as the two other subject groups. Instead, the waveforms of the agrammatic aphasics were dominated by a meaning-related ERP effect, presumably reflecting their attempts to achieve understanding by the use of semantic constraints. These data demonstrate that although agrammatic aphasics are impaired in their ability to exploit syntactic information in real time, they can reduce the consequences of a syntactic deficit by exploiting a semantic route. They thus provide evidence for the compensation of a syntactic deficit by a stronger reliance on another route in mapping
sound onto meaning. This is a form of plasticity that we refer to as multiple-route plasticity.

Abstract

A central and influential idea among researchers of language is that our language faculty is organized according to Fregean compositionality, which states that the meaning of an utterance is a function of the meaning of its parts and of the syntactic rules by which these parts are combined. Since the domain of syntactic rules is the sentence, the implication of this idea is that language interpretation takes place in a two-step fashion. First, the meaning of a sentence is computed. In a second step, the sentence meaning is integrated with information from prior discourse, world knowledge, information about the speaker and semantic information from extra-linguistic domains such as co-speech gestures or the visual world. Here, we present results from recordings of event-related brain potentials that are inconsistent with this classical two-step model of language interpretation. Our data support a one-step model in which knowledge about the context and the world, concomitant information from other modalities, and the speaker are brought to bear immediately, by the same fast-acting brain system that combines the meanings of individual words into a message-level representation. Underlying the one-step model is the immediacy assumption, according to which all available information will immediately be used to co-determine the interpretation of the speaker's message. Functional magnetic resonance imaging data that we collected indicate that Broca's area plays an important role in semantic unification. Language comprehension involves the rapid incorporation of information in a 'single unification space', coming from a broader range of cognitive domains than presupposed in the standard two-step model of interpretation.

Abstract

Syntax is one of the components in the architecture of language processing that allows the listener/reader to bind single-word information into a unified interpretation of multiword utterances. This paper discusses ERP effects that have been observed in relation to syntactic processing. The fact that these effects differ from the semantic N400 indicates that the brain honors the distinction between semantic and syntactic binding operations. Two models of syntactic processing attempt to account for syntax-related ERP effects. One type of model is serial, with a first phase that is purely syntactic in nature (syntax-first model). The other type of model is parallel and assumes that information immediately guides the interpretation process once it becomes available. This is referred to as the immediacy model. ERP evidence is presented in support of the latter model. Next, an explicit computational model is proposed to explain the ERP data. This Unification Model assumes that syntactic frames are stored in memory and retrieved on the basis of the spoken or written word form input. The syntactic frames associated with the individual lexical items are unified by a dynamic binding process into a structural representation that spans the whole utterance. On the basis of a meta-analysis of imaging studies on syntax, it is argued that the left posterior inferior frontal cortex is involved in binding syntactic frames together, whereas the left superior temporal cortex is involved in retrieval of the syntactic frames stored in memory. Lesion data that support the involvement of this left frontotemporal network in syntactic processing are discussed.

Abstract

This study investigated the effects of combined semantic and syntactic violations in relation to the effects of single semantic and single syntactic violations on language-related event-related brain potential (ERP) effects (N400 and P600/ SPS). Syntactic violations consisted of a mismatch in grammatical gender or number features of the definite article and the noun in sentence-internal or sentence-final noun phrases (NPs). Semantic violations consisted of semantically implausible adjective–noun combinations in the same NPs. Combined syntactic and semantic violations were a summation of these two respective violation types. ERPs were recorded while subjects read the sentences with the different types of violations and the correct control sentences. ERP effects were computed relative to ERPs elicited by the sentence-internal or sentence-final nouns. The size of the N400 effect to the semantic violation was increased by an additional syntactic violation (the syntactic boost). In contrast, the size of the P600/ SPS to the syntactic violation was not affected by an additional semantic violation. This suggests that in the absence of syntactic ambiguity, the assignment of syntactic structure is independent of semantic context. However, semantic integration is influenced by syntactic processing. In the sentence-final position, additional global processing consequences were obtained as a result of earlier violations in the sentence. The resulting increase in the N400 amplitude to sentence-final words was independent of the nature of the violation. A speeded anomaly detection task revealed that it takes substantially longer to detect semantic than syntactic anomalies. These results are discussed in relation to the latency and processing characteristics of the N400 and P600/SPS effects. Overall, the results reveal an asymmetry in the interplay between syntax and semantics during on-line sentence comprehension.

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 an ERP experiment we investigated how the recruitment and integration of world knowledge information relate to the integration of information within a current discourse context. Participants were presented with short discourse contexts which were followed by a sentence that contained a critical word that was correct or incorrect based on general world knowledge and the supporting discourse context, or was more or less acceptable based on the combination of general world knowledge and the specific local discourse context. Relative to the critical word in the correct world knowledge sentences following a neutral discourse, all other critical words elicited an N400 effect that began at about 300 ms after word onset. However, the magnitude of the N400 effect varied in a way that suggests an interaction between world knowledge and discourse context. The results indicate that both world knowledge and discourse context have an effect on sentence interpretation, but neither overrides the other.

Abstract

Written language comprehension at the word and the sentence level was analysed by the combination of spatial and temporal analysis of functional magnetic resonance imaging (fMRI). Spatial analysis was performed via general linear modelling (GLM). Concerning the temporal analysis, local differences in neurovascular coupling may confound a direct comparison of blood oxygenation level-dependent (BOLD) response estimates between regions. To avoid this problem, we parametrically varied linguistic task demands and compared only task-induced within-region BOLD response differences across areas. We reasoned that, in a hierarchical processing system, increasing task demands at lower processing levels induce delayed onset of higher-level processes in corresponding areas. The flow of activation is thus reflected in the size of task-induced delay increases. We estimated BOLD response delay and duration for each voxel and each participant by fitting a model function to the event-related average BOLD response. The GLM showed increasing activations with increasing linguistic demands dominantly in the left inferior frontal gyrus (IFG) and the left superior temporal gyrus (STG). The combination of spatial and temporal analysis allowed a functional differentiation of IFG subregions involved in written language comprehension. Ventral IFG region (BA 47) and STG subserve earlier processing stages than two dorsal IFG regions (BA 44 and 45). This is in accordance with the assumed early lexical semantic and late syntactic processing of these regions and illustrates the complementary information provided by spatial and temporal fMRI data analysis of the same data set.

Abstract

In the recent past the work on large-scale linguistic distributions across the globe has intensified considerably. Work on macro-areal relationships in Africa (Güldemann, 2010) suggests that the shape of convergence areas may be determined by climatic factors and geophysical features such as mountains, water bodies, coastlines, etc. Worldwide data is now available for geophysical features as well as linguistic features, including numeral systems and basic constituent order. We explore the possibility that the shape of areal aggregations of individual features in these two linguistic domains correlates with Köppen-Geiger climate zones. Furthermore, we test the hypothesis that the shape of such areal feature aggregations is determined by the contour of adjacent geophysical features like mountain ranges or coastlines. In these first basic tests, we do not find clear evidence that either Köppen-Geiger climate zones or the contours of geophysical features are major predictors for the linguistic data at hand

Abstract

While the notion of the ‘area’ or ‘Sprachbund’ has a long history in linguistics, with geographically-defined regions frequently cited as a useful means to explain typological distributions, the problem of delimiting areas has not been well addressed. Lists of general-purpose, largely independent ‘macro-areas’ (typically continent size) have been proposed as a step to rule out contact as an explanation for various large-scale linguistic phenomena. This squib points out some problems in some of the currently widely-used predetermined areas, those found in the World Atlas of Language Structures (Haspelmath et al., 2005). Instead, we propose a principled division of the world’s landmasses into six macro-areas that arguably have better geographical independence properties

Abstract

Whitesands is an Oceanic language of the southern Vanuatu subgroup. Like the related languages of southern Vanuatu, Whitesands has developed a clause-linkage system which monitors referent continuity on new clauses – typically contrasting with the previous clause. In this chapter I address how the construction interacts with topic continuity in discourse. I outline the morphosyntactic form of this anaphoric co-reference device. From a functionalist perspective, I show how the system is used in natural discourse and discuss its restrictions with respect to relative and complement clauses. I conclude with a discussion on its interactions with theoretical notions of information structure – in particular the nature of presupposed versus asserted clauses, information back- and foregrounding and how these affect the use of the switch-reference system

Abstract

Rheumatoid arthritis is the most common systematic autoimmune disease and its etiology is believed to have both strong genetic and environmental components. We demonstrate the utility of including genetic and clinical phenotypes as covariates within a linkage analysis framework to search for rheumatoid arthritis susceptibility loci. The raw genotypes of 1302 affected relative pairs were combined from four large family-based samples (North American Rheumatoid Arthritis Consortium, United Kingdom, European Consortium on Rheumatoid Arthritis Families, and Canada). The familiality of the clinical phenotypes was assessed. The affected relative pairs were subjected to autosomal multipoint affected relative-pair linkage analysis. Covariates were included in the linkage analysis to take account of heterogeneity within the sample. Evidence of familiality was observed with age at onset (p <} 0.001) and rheumatoid factor (RF) IgM (p {< 0.001), but not definite erosions (p = 0.21). Genome-wide significant evidence for linkage was observed on chromosome 6. Genome-wide suggestive evidence for linkage was observed on chromosomes 13 and 20 when conditioning on age at onset, chromosome 15 conditional on gender, and chromosome 19 conditional on RF IgM after allowing for multiple testing of covariates.

Abstract

All primates learn things from conspecifics socially, but it is not clear whether they conform to the behavior of these conspecifics—if conformity is defined as overriding individually acquired behavioral tendencies in order to copy peers’ behavior. In the current study, chimpanzees, orangutans, and 2-year-old human children individually acquired a problem-solving strategy. They then watched several conspecific peers demonstrate an alternative strategy. The children switched to this new, socially demonstrated strategy in roughly half of all instances, whereas the other two great-ape species almost never adjusted their behavior to the majority’s. In a follow-up study, children switched much more when the peer demonstrators were still present than when they were absent, which suggests that their conformity arose at least in part from social motivations. These results demonstrate an important difference between the social learning of humans and great apes, a difference that might help to account for differences in human and nonhuman cultures

Abstract

What kinds of resources to languages have for describing location and position? For some languages, verbs have an important role to play in describing different kinds of situations (e.g., whether a bottle is standing or lying on the table). This task is designed to examine the use of positional verbs in locative constructions, with respect to the presence or absence of a human “positioner”. Participants are asked to describe video clips showing locative states that occur spontaneously, or because of active interference from a person. The task follows on from two earlier tools for the elicitation of static locative descriptions (BowPed and the Ameka picture book task). A number of additional variables (e.g. canonical v. non-canonical orientation of the figure) are also targeted in the stimuli set.

Abstract

Bilingual listeners comprehend speech-in-noise better in their native than non-native language. This native-language benefit is thought to arise from greater use of top-down linguistic information to assist degraded speech comprehension. Using functional magnetic resonance imaging, we recently showed that left angular gyrus activation is modulated when semantic context is used to assist native language speech-in-noise comprehension (Golestani, Hervais-Adelman, Obleser, & Scott, 2013). Here, we extend the previous work, by reanalyzing the previous data alongside the results obtained in the non-native language of the same late bilingual participants. We found a behavioral benefit of semantic context in processing speech-in-noise in the native language only, and the imaging results also revealed a native language context effect in the left angular gyrus. We also find a complementary role of lower-level auditory regions during stimulus-driven processing. Our findings help to elucidate the neural basis of the established native language behavioral benefit of speech-in-noise processing. (C) 2014 Elsevier Inc. All rights reserved.

Abstract

Superiority in visual search for individuals diagnosed with autism spectrum disorder (ASD) is a well-reported finding. We administered two visual search tasks to individuals with ASD and matched controls. One showed no difference between the groups, and one did show the expected superior performance for individuals with ASD. These results offer an explanation, formulated in terms of load theory. We suggest that there is a limit to the superiority in visual search for individuals with ASD, related to the perceptual load of the stimuli. When perceptual load becomes so high that no additional task-(ir)relevant information can be processed, performance will be based on single stimulus identification, in which no differences between individuals with ASD and controls have been demonstrated

Abstract

Theories of embodied language comprehension have proposed that language is understood through perceptual simulation of the sensorimotor characteristics of its meaning. Strong support for this claim requires demonstration of encoding-based activation of sensorimotor representations that is distinct from task-related or goal-driven processes. Participants in 3 eye-tracking experiments were presented with triplets of either numbers or object and animal names. In Experiment 1, participants indicated whether the size of the referent of the middle object or animal name was in between the size of the 2 outer items. In Experiment 2, the object and animal names were encoded for an immediate recognition memory task. In Experiment 3, participants completed the same comparison task of Experiment 1 for both words and numbers. During the comparison tasks, word and number decision times showed a symbolic distance effect, such that response time was inversely related to the size difference between the items. A symbolic distance effect was also observed for animal and object encoding times in cases where encoding time likely reflected some goal-driven processes as well. When semantic size was irrelevant to the task (Experiment 2), it had no effect on word encoding times. Number encoding times showed a numerical distance priming effect: Encoding time increased with numerical difference between items. Together these results suggest that while activation of numerical magnitude representations is encoding-based as well as goal-driven, activation of size information associated with words is goal-driven and does not occur automatically during encoding. This conclusion challenges strong theories of embodied cognition which claim that language comprehension consists of activation of analog sensorimotor representations irrespective of higher level processes related to context or task-specific goals

Abstract

Two eye-tracking experiments were conducted in which the manual response mode typically used in lexical decision tasks (LDTs) was replaced with an eye-movement response through a sequence of 3 words. This ocular LDT combines the explicit control of task goals found in LDTs with the highly practiced ocular response used in reading text. In Experiment 1, forward saccades indicated an affirmative lexical decision (LD) on each word in the triplet. In Experiment 2, LD responses were delayed until all 3 letter strings had been read. The goal of the study was to evaluate the contribution of task goals and response mode to semantic priming. Semantic priming is very robust in tasks that involve recognition of words in isolation, such as LDT, but limited during text reading, as measured using eye movements. Gaze durations in both experiments showed robust semantic priming even though ocular response times were much shorter than manual LDs for the same words in the English Lexicon Project. Ex-Gaussian distribution fits revealed that the priming effect was concentrated in estimates of tau (τ), meaning that priming was most pronounced in the slow tail of the distribution. This pattern shows differential use of the prime information, which may be more heavily recruited in cases in which the LD is difficult, as indicated by longer response times. Compared with the manual LD responses, ocular LDs provide a more sensitive measure of this task-related influence on word recognition as measured by the LDT.

Abstract

Participants in interaction routinely orient to gaze, bodily comportment, and nonlexical vocalizations as salient for developing an analysis of the unfolding course of action. In this article, I address the respiratory phenomenon of sighing, the aim being to describe sighing as a situated practice that contributes to the achievement of particular actions in interaction. I report on the various actions sighs implement or construct and how their positioning and delivery informs participants’ understandings of their significance for interaction. Data are in American English

Abstract

Background: Individuals with autism spectrum disorder (ASD) and their parents demonstrate impaired performance in rapid automatized naming (RAN), a task that recruits a variety of linguistic and executive processes. Though the basic processes that contribute to RAN differences remain unclear, eye-voice relationships, as measured through eye tracking, can provide insight into cognitive and perceptual processes contributing to RAN performance. For example, in RAN, eye-voice span (EVS), the distance ahead the eyes are when articulation of a target item's label begins, is an indirect measure of automaticity of the processes underlying RAN. The primary objective of this study was to investigate automaticity in naming processes, as indexed by EVS during RAN. The secondary objective was to characterize RAN difficulties in individuals with ASD and their siblings. Methods: Participants (aged 15 – 33 years) included 21 individuals with ASD, 23 siblings of individuals with ASD, and 24 control subjects, group-matched on chronological age. Naming time, frequency of errors, and EVS were measured during a RAN task and compared across groups. Results: A stepwise pattern of RAN performance was observed, with individuals with ASD demonstrating the slowest naming across all RAN conditions, controls demonstrating the fastest naming, and siblings demonstrating intermediate performance. Individuals with ASD exhibited smaller EVSs than controls on all RAN conditions, and siblings exhibited smaller EVSs during number naming (the most highly automatized type of naming). EVSs were correlated with naming times in controls only, and only in the more automatized conditions. Conclusions: These results suggest that reduced automaticity in the component processes of RAN may underpin differences in individuals with ASD and their siblings. These findings also provide further support that RAN abilities are impacted by genetic liability to ASD. This study has important implications for understanding the underlying skills contributing to language-related deficits in ASD.

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

The FOXP2 transcription factor is one of the most well-known genes to have been implicated in developmental speech and language disorders. Rare mutations disrupting the function of this gene have been described in different families and cases. In a large three-generation family carrying a missense mutation, neuroimaging studies revealed significant effects on brain structure and function, most notably in the inferior frontal gyrus, caudate nucleus and cerebellum. After the identification of rare disruptive FOXP2 variants impacting on brain structure, several reports proposed that common variants at this locus may also have detectable effects on the brain, extending beyond disorder into normal phenotypic variation. These neuroimaging genetics studies used groups of between 14 and 96 participants. The current study assessed effects of common FOXP2 variants on neuroanatomy using voxel-based morphometry and volumetric techniques in a sample of >1300 people from the general population. In a first targeted stage we analyzed single nucleotide polymorphisms (SNPs) claimed to have effects in prior smaller studies (rs2253478, rs12533005, rs2396753, rs6980093, rs7784315, rs17137124, rs10230558, rs7782412, rs1456031), beginning with regions proposed in the relevant papers, then assessing impact across the entire brain. In the second gene-wide stage, we tested all common FOXP2 variation, focusing on volumetry of those regions most strongly implicated from analyses of rare disruptive mutations. Despite using a sample that is more than ten times that used for prior studies of common FOXP2 variation, we found no evidence for effects of SNPs on variability in neuroanatomy in the general population. Thus, the impact of this gene on brain structure may be largely limited to extreme cases of rare disruptive alleles. Alternatively, effects of common variants at this gene exist but are too subtle to be detected with standard volumetric techniques

Abstract

Objective: To evaluate cognitive outcome in adult survivors of bacterial meningitis. Methods: Data from three prospective multicentre studies were pooled and reanalysed, involving 155 adults surviving bacterial meningitis (79 after pneumococcal and 76 after meningococcal meningitis) and 72 healthy controls. Results: Cognitive impairment was found in 32% of patients and this proportion was similar for survivors of pneumococcal and meningococcal meningitis. Survivors of pneumococcal meningitis performed worse on memory tasks (p<0.001) and tended to be cognitively slower than survivors of meningococcal meningitis (p = 0.08). We found a diffuse pattern of cognitive impairment in which cognitive speed played the most important role. Cognitive performance was not related to time since meningitis; however, there was a positive association between time since meningitis and self-reported physical impairment (p<0.01). The frequency of cognitive impairment and the numbers of abnormal test results for patients with and without adjunctive dexamethasone were similar. Conclusions: Adult survivors of bacterial meningitis are at risk of cognitive impairment, which consists mainly of cognitive slowness. The loss of cognitive speed is stable over time after bacterial meningitis; however, there is a significant improvement in subjective physical impairment in the years after bacterial meningitis. The use of dexamethasone was not associated with cognitive impairment.

Abstract

Experiments 1 and 2 examined the time-course of retrieval of phonological, visual-shape and semantic knowledge as Dutch participants listened to sentences and looked at displays of four pictures. Given a sentence with beker, `beaker', for example, the display contained phonological (a beaver, bever), shape (a bobbin, klos), and semantic (a fork, vork) competitors. When the display appeared at sentence onset, fixations to phonological competitors preceded fixations to shape and semantic competitors. When display onset was 200 ms before (e.g.) beker, fixations were directed to shape and then semantic competitors, but not phonological competitors. In Experiments 3 and 4, displays contained the printed names of the previously-pictured entities; only phonological competitors were fixated preferentially. These findings suggest that retrieval of phonological, shape and semantic knowledge in the spoken-word and picture-recognition systems is cascaded, and that visual attention shifts are co-determined by the time-course of retrieval of all three knowledge types and by the nature of the information in the visual environment.

Abstract

Visual attention can be directed immediately, as a spoken word unfolds, towards conceptually related but nonassociated objects, even if they mismatch on other dimensions that would normally determine which objects in the scene were appropriate referents for the unfolding word (Huettig & Altmann, 2005). Here we demonstrate that the mapping between language and concurrent visual objects can also be mediated by visual-shape relations. On hearing "snake", participants directed overt attention immediately, within a visual display depicting four objects, to a picture of an electric cable, although participants had viewed the visual display with four objects for approximately 5 s before hearing the target word - sufficient time to recognize the objects for what they were. The time spent fixating the cable correlated significantly with ratings of the visual similarity between snakes in general and this particular cable. Importantly, with sentences contextually biased towards the concept snake, participants looked at the snake well before the onset of "snake", but they did not look at the visually similar cable until hearing "snake". Finally, we demonstrate that such activation can, under certain circumstances (e.g., during the processing of dominant meanings of homonyms), constrain the direction of visual attention even when it is clearly contextually inappropriate. We conclude that language-mediated attention can be guided by a visual match between spoken words and visual objects, but that such a match is based on lexical input and may not be modulated by contextual appropriateness.

Abstract

At present, more than one-fifth of humanity is unable to read and write. We critically examine experimental evidence and theories of how (il)literacy affects the human mind. In our discussion we show that literacy has significant cognitive consequences that go beyond the processing of written words and sentences. Thus, cultural inventions such as reading shape general cognitive processing in non-trivial ways. We suggest that this has important implications for educational policy and guidance as well as research into cognitive processing and brain functioning.

Abstract

This chapter investigates the fit of genetic, phenotypic, and linguistic data to two well-known models of population history. The first of these models, termed the population fissions model, emphasizes population splitting, isolation, and independent evolution. It predicts that genetic and linguistic data will be perfectly tree-like. The second model, termed isolation by distance, emphasizes genetic exchange among geographically proximate populations. It predicts a monotonic decline in genetic similarity with increasing geographic distance. While these models are overly simplistic, deviations from them were expected to provide important insights into the population history of northern Island Melanesia. The chapter finds scant support for either model because the prehistory of the region has been so complex. Nonetheless, the genetic and linguistic data are consistent with an early radiation of proto-Papuan speakers into the region followed by a much later migration of Austronesian speaking peoples. While these groups subsequently experienced substantial genetic and cultural exchange, this exchange has been insufficient to erase this history of separate migrations.

Abstract

This paper reports on ongoing research on the role of various kinds of potential substrate languages in the development of the semantic structures of Ndyuka (Eastern Suriname Creole). A set of 100 senses of noun, verb, and other lexemes in Ndyuka were compared with senses of corresponding lexemes in three kinds of languages of the former Slave Coast and Gold Coast areas, and immediately adjoining hinterland: (a) Gbe languages; (b) other Kwa languages, specifically Akan and Ga; (c) non-Kwa Niger-Congo languages. The results of this process provide some evidence for the importance of the Gbe languages in the formation of the Suriname creoles, but also for the importance of other languages, and for the areal nature of some of the collocations studied, rendering specific identification of a single substrate source impossible and inappropriate. These results not only provide information about the role of Gbe and other languages in the formation of Ndyuka, but also give evidence for effects of substrate languages spoken by late arrivals some time after the "founders" of a given creole-speaking society. The conclusions are extrapolated beyond Suriname to creole genesis generally.

Abstract

Spoken language is one of the most compact and structured ways to convey information. The linguistic ability to structure individual words into larger sentence units permits speakers to express a nearly unlimited range of meanings. This ability is rooted in speakers’ knowledge of syntax and in the corresponding process of syntactic encoding. Syntactic encoding is highly automatized, operates largely outside of conscious awareness, and overlaps closely in time with several other processes of language production. With the use of positron emission tomography we investigated the cortical activations during spoken language production that are related to the syntactic encoding process. In the paradigm of restrictive scene description, utterances varying in complexity of syntactic encoding were elicited. Results provided evidence that the left Rolandic operculum, caudally adjacent to Broca’s area, is involved in both sentence-level and local (phrase-level) syntactic encoding during speaking.

Abstract

Neurocognitive studies of language production have provided sufficient evidence on both the spatial and the temporal patterns of brain activation to allow tentative and in some cases not so tentative conclusions about function-structure relationships. This chapter reports meta-analysis results that identify reliable activation areas for a range of word, sentence, and narrative production tasks both in the native language and a second language. Based on a theoretically motivated analysis of language production tasks it is possible to specify relationships between brain areas and functional processing components of language production that could not have been derived from the data provided by any single task.

Abstract

In language comprehension a syntactic representation is built up even when the input is semantically uninterpretable. We report data on brain activation during syntactic processing, from an experiment on the detection of grammatical errors in meaningless sentences. The experimental paradigm was such that the syntactic processing was distinguished from other cognitive and linguistic functions. The data reveal that in syntactic error detection an area of the left dorsolateral prefrontal cortex, adjacent to Broca’s area, is specifically involved in the syntactic processing aspects, whereas other prefrontal areas subserve general error detection processes.

Abstract

Hickok's enterprise to unify psycholinguistic and motor control models is highly stimulating. Nonetheless, there are problems of the model with respect to the time course of neural activation in word production, the flexibility for continuous speech, and the need for non-motor feedback.

Abstract

This study investigates how listeners cope with gradient forms of deletion of word-final /t/ when recognising words in a phonological context that makes /t/-deletion viable. A corpus study confirmed a high incidence of /t/-deletion in an /st#b/ context in Dutch. A discrimination study showed that differences between released /t/, unreleased /t/ and fully deleted /t/ in this specific /st#b/ context were salient. Two on-line experiments were carried out to investigate whether lexical activation might be affected by this form variation. Even though unreleased and released variants were processed equally fast by listeners, a detailed analysis of the unreleased condition provided evidence for gradient activation. Activating a target ending in /t/ is slowest for the most reduced variant because phonological context has to be taken into account. Importantly, activation for a target with /t/ in the absence of cues for /t/ is reduced if there is a surface-matching lexical competitor.

Abstract

In this study we investigate whether speakers, in line with the predictions of the Hyper- and Hypospeech theory, speed up most during the least informative parts and less during the more informative parts, when they are asked to speak faster. We expected listeners to benefit from these changes in timing, and our main goal was to find out whether making the temporal organisation of artificially time-compressed speech more like that of natural fast speech would improve intelligibility over linear time compression. Our production study showed that speakers reduce unstressed syllables more than stressed syllables, thereby making the prosodic pattern more pronounced. We extrapolated fast speech timing to even faster rates because we expected that the more salient prosodic pattern could be exploited in difficult listening situations. However, at very fast speech rates, applying fast speech timing worsens intelligibility. We argue that the non-uniform way of speeding up may not be due to an underlying communicative principle, but may result from speakers’ inability to speed up otherwise. As both prosodic and segmental information contribute to word recognition, we conclude that extrapolating fast speech timing to extremely fast rates distorts this balance between prosodic and segmental information.

Abstract

Many older listeners report difficulties in understanding speech in noisy situations. Working memory and other cognitive skills may modulate, however, older listeners’ ability to use context information to alleviate the effects of noise on spoken-word recognition. In the present study, we investigated whether working memory predicts older adults’ ability to immediately use context information in the recognition of words embedded in sentences, presented in different listening conditions. In a phoneme-monitoring task, older adults were asked to detect as fast and as accurately as possible target phonemes in sentences spoken by a target speaker. Target speech was presented without noise, with fluctuating speech-shaped noise, or with competing speech from a single distractor speaker. The gradient measure of contextual probability (derived from a separate offline rating study) mainly affected the speed of recognition, with only a marginal effect on detection accuracy. Contextual facilitation was modulated by older listeners’ working memory and age across listening conditions. Working memory and age, as well as hearing loss, were also the most consistent predictors of overall listening performance. Older listeners’ immediate benefit from context in spoken-word recognition thus relates to their ability to keep and update a semantic representation of the sentence content in working memory.

Abstract

Successful navigation is facilitated by the presence of landmarks. Previous functional magnetic resonance imaging (fMRI) evidence indicated that the human parahippocampal gyrus automatically distinguishes between landmarks placed at navigationally relevant (decision points) and irrelevant locations (nondecision points). This storage of navigational relevance can provide a neural mechanism underlying successful navigation. However, an efficient wayfinding mechanism requires that important spatial information is learned quickly and maintained over time. The present study investigates whether the representation of navigational relevance is modulated by time and practice. Participants learned 2 film sequences through virtual mazes containing objects at decision and at nondecision points. One maze was shown one time, and the other maze was shown 3 times. Twenty-four hours after study, event-related fMRI data were acquired during recognition of the objects. The results showed that activity in the parahippocampal gyrus was increased for objects previously placed at decision points as compared with objects placed at nondecision points. The decision point effect was not modulated by the number of exposures to the mazes and independent of explicit memory functions. These findings suggest a persistent representation of navigationally relevant information, which is stable after only one exposure to an environment. These rapidly induced and long-lasting changes in object representation provide a basis for successful wayfinding.

Abstract

The human brain distinguishes between landmarks placed at navigationally relevant and irrelevant locations. However, to provide a successful wayfinding mechanism not only landmarks but also the routes between them need to be stored. We examined the neural representation of a memory for route direction and a memory for relevant landmarks. Healthy human adults viewed objects along a route through a virtual maze. Event-related functional magnetic resonance imaging (fMRI) data were acquired during a subsequent subliminal priming recognition task. Prime-objects either preceded or succeeded a target-object on a preciously learned route. Our results provide evidence that the parahippocampal gyri distinguish between relevant and irrelevant landmarks whereas the inferior parietal gyrus, the anterior cingulate gyrus as well as the right caudate nucleus are involved in the coding of route direction. These data show that separated memory systems store different spatial information. A memory for navigationally relevant object information and a memory for route direction exist.

Abstract

A. Caramazza, A. Costa, M. Miozzo, and Y. Bi(2001) reported a series of experiments demonstrating that the ease of producing a word depends only on the frequency of that specific word but not on the frequency of a homophone twin. A. Caramazza, A. Costa, et al. concluded that homophones have separate word form representations and that the absence of frequency-inheritance effects for homophones undermines an important argument in support of 2-stage models of lexical access, which assume that syntactic (lemma) representations mediate between conceptual and phonological representations. The authors of this article evaluate the empirical basis of this conclusion, report 2 experiments demonstrating a frequency-inheritance effect, and discuss other recent evidence. It is concluded that homophones share a common word form and that the distinction between lemmas and word forms should be upheld.

Abstract

Visual cues to the individual segments of speech and to sentence prosody guide speech recognition. The present study tested whether visual suprasegmental cues to the stress patterns of words can also constrain recognition. Dutch listeners use acoustic suprasegmental cues to lexical stress (changes in duration, amplitude, and pitch) in spoken-word recognition. We asked here whether they can also use visual suprasegmental cues. In two categorization experiments, Dutch participants saw a speaker say fragments of word pairs that were segmentally identical but differed in their stress realization (e.g., 'ca-vi from cavia "guinea pig" vs. 'ka-vi from kaviaar "caviar"). Participants were able to distinguish between these pairs from seeing a speaker alone. Only the presence of primary stress in the fragment, not its absence, was informative. Participants were able to distinguish visually primary from secondary stress on first syllables, but only when the fragment-bearing target word carried phrase-level emphasis. Furthermore, participants distinguished fragments with primary stress on their second syllable from those with secondary stress on their first syllable (e.g., pro-'jec from projector "projector" vs. 'pro-jec from projectiel "projectile"), independently of phrase-level emphasis. Seeing a speaker thus contributes to spoken-word recognition by providing suprasegmental information about the presence of primary lexical stress.