Publications

Abstract

Autosomal recessive Stargardt disease (STGD1) is associated with variants in the ABCA4 gene. The phenotypes range from early-onset STGD1, that clinically resembles severe cone-rod dystrophy, to intermediate STGD1 and late-onset STGD1. These different phenotypes can be correlated with different combinations of ABCA4 variants which can be classified according to their degree of severity. A significant fraction of STGD1 cases, particularly late-onset STGD1 cases, were shown to carry only a single ABCA4 variant. A frequent coding variant (p.Asn1868Ile) was recently identified which – in combination with a severe ABCA4 variant – is generally associated with late-onset STGD1. In addition, an increasing number of rare deep-intronic variants have been found and some of these are also associated with late-onset STGD1. The effect of these and other variants on ABCA4 RNA was tested using in vitro assays in human kidney cells using specially designed midigenes. With stem cells and photoreceptor progenitor cells derived from patient skin or blood cells, retina-specific splice defects can be assessed. With expert clinical examination to distinguish STGD1 cases from other maculopathies, as well as in-depth genomics and transcriptomics data, it is now possible to identify both mutant ABCA4 alleles in > 95% of cases.

Abstract

Noncanonical splice-site mutations are an important cause of inherited diseases. Based on in vitro and stem-cell-based studies, some splice-site variants show a stronger splice defect than expected based on their predicted effects, suggesting that other sequence motifs influence the outcome. We investigated whether splice defects due to human-inherited-disease-associated variants in noncanonical splice-site sequences in ABCA4, DMD, and TMC1 could be rescued by strengthening the splice site on the other side of the exon. Noncanonical 5′- and 3′-splice-site variants were selected. Rescue variants were introduced based on an increase in predicted splice-site strength, and the effects of these variants were analyzed using in vitro splice assays in HEK293T cells. Exon skipping due to five variants in noncanonical splice sites of exons in ABCA4, DMD, and TMC1 could be partially or completely rescued by increasing the predicted strengths of the other splice site of the same exon. We named this mechanism “splicing interdependency”, and it is likely based on exon recognition by splicing machinery. Awareness of this interdependency is of importance in the classification of noncanonical splice-site variants associated with disease and may open new opportunities for treatments

Abstract

Humans vary in almost every dimension imaginable, and language is no
exception. In this article, we review the past research that has focused on
individual differences (IDs) in first language acquisition. We first consider
how different theoretical traditions in language acquisition treat IDs, and
we argue that a focus on IDs is important given its potential to reveal the
developmental dynamics and architectural constraints of the linguistic system.
We then review IDs research that has examined variation in children’s
linguistic input, early speech perception, and vocabulary and grammatical
development. In each case, we observe systematic and meaningful variation,
such that variation in one domain (e.g., early auditory and speech
processing) has meaningful developmental consequences for development
in higher-order domains (e.g., vocabulary). The research suggests a high
degree of integration across the linguistic system, in which development
across multiple linguistic domains is tightly coupled.

Abstract

Statistical learning (SL) has been a prominent focus of research in developmental and adult populations, guided by the assumption that it is a fundamental component of learning underlying higher-order cognition. In developmental populations, however, there have been recent concerns regarding the degree to which many current tasks reliably measure SL, particularly in younger children. In the current article, we present the results of two studies that measured auditory statistical learning (ASL) of linguistic stimuli in children aged 5–8 years. Children listened to 6 min of continuous syllables comprising four trisyllabic pseudowords. Following the familiarization phase, children completed (a) a two-alternative forced-choice task and (b) a serial recall task in which they repeated either target sequences embedded during familiarization or foils, manipulated for sequence length. Results showed that, although both measures consistently revealed learning at the group level, the recall task better captured learning across the full range of abilities and was more reliable at the individual level. We conclude that, as has also been demonstrated in adults, the method holds promise for future studies of individual differences in ASL of linguistic stimuli.

Abstract

This article reviews research that has investigated the role of verbal working memory (VWM) in sentence comprehension in both typical and atypical developmental populations. Two theoretical approaches that specify different roles for VWM in sentence comprehension are considered: (i) capacity-limit approaches, which treat VWM as a theoretical primitive that causally constrains language processing and acquisition, and (ii) the experience-based approach, which argues that VWM is an emergent property of long-term linguistic knowledge. The empirical literature relevant to these different approaches is then reviewed. Although there has been considerable recent research on the topic, it is concluded that the current role of working memory in sentence comprehension in development is unclear, calling for a greater number of controlled systematic developmental studies on the topic.

Abstract

This study attempts to reveal the mechanisms behind the online formation of Wh-Filler-Gap Dependencies (WhFGD). Specifically, we aim to uncover the way in which maintenance and retrieval work in WhFGD processing, by paying special attention to the information that is retrieved when the gap is recognized. We use the agreement attraction phenomenon (Wagers, M. W., Lau, E. F., & Phillips, C. (2009). Agreement attraction in comprehension: Representations and processes. Journal of Memory and Language, 61(2), 206-237) as a probe. The first and second experiments examined the type of information that is maintained and how maintenance is motivated, investigating the retrieved information at the gap for reactivated fillers and definite NPs. The third experiment examined the role of the retrieval, comparing reactivated and active fillers. We contend that the information being accessed reflects the extent to which the filler is maintained, where the reader is able to access fine-grained information including category information as well as a representation of both the head and the modifier at the verb.

Abstract

This research investigated the developing inter-relationships between language, graphic symbolism and symbolic play both concurrently and longitudinally from the fourth to the fifth year of childhood. Sixty children (n = 60) aged between 3 and 4 years completed multiple assessments of language and assessments of graphic symbolism, symbolic play and non-verbal intelligence. A year later, 31 children (n = 31) were re-tested using the same assessments. The findings revealed that skills within each symbolic domain were inter-related during the fourth year, appearing to develop in a domain-general type fashion based upon a common underlying symbolic mechanism. However, between the fourth and the fifth years, only language had predictive validity, suggesting a shift towards the verbal mediation of symbolic play and graphic symbolism as language becomes progressively internalized (Vygotsky, 1962, 1978).

Abstract

Vocal development of cranes (Gruidae) has attracted scientifc interest due to its special stage, voice breaking. During voice breaking, chicks of diferent crane species produce calls with two fundamental frequencies that correspond to those in adult low-frequency and juvenile high-frequency vocalizations. However, triggers that afect voice breaking in cranes are mainly unknown. Here we studied the voice breaking in the Siberian Crane (Leucogeranus leucogeranus) and test its relation to the body mass and testosterone level. We analyzed 5846 calls, 39 body mass measurements and 60 blood samples from 11
Siberian Crane chicks in 8 ages from 2.5 to 18 months of life together with 90 body mass measurements and 61 blood samples from 24 Siberian Crane adults. The individual duration of voice breaking and dates of its onset, culmination and completion depended neither on the body mass nor on the testosterone level at various ages. But we found correlation between the testosterone level and mean deltas of percentages of the high and low frequency components in Siberian Crane calls between the closest recording sessions. We also observed some coincidence in time between the mean dates of voice breaking onset and the termination of body mass gain (at 7.5 months of age), and between the mean dates of voice breaking completion and the start of a new breeding season. Similar relations have been shown previously for some other crane species. We also showed for the frst time that the mean dates of voice breaking culmination correlated with the signifcant increase of the testosterone level (at 10.5 months of age). So, we suggest that voice breaking in cranes may be triggered by the end of chicks’ body
growth, is stimulated by the increase of testosterone level and ends soon after adult cranes stop taking care of their chicks.

Abstract

Vocal-based monitoring is increasingly being used as a non-invasive method for identifying individuals within avian populations and is promising for the Siberian Crane, Leucogeranus leucogeranus. This is a poorly studied, long-lived, secretive and critically endangered bird species that breeds in the Arctic tundra of western and eastern regions of Siberia. We assessed between- and within-year stability of individual-specific vocal features in duets of Siberian Crane and tested the effect of pair-mate change on their stability. Previous findings showed that duets are specific to different pairs of birds; however, it is still unknown how long pair-specific traits of duets remain and if they change in the course of a year or when birds re-mate. We recorded duets of 15 reproductively active pairs in the Oka Crane Breeding Centre in 2003–2006 and 2013–2017. We found that pair-specific vocal signatures remained stable both within the year and across ~ 10 years. After a change of mate, most of the variables we measured in the call did not change in any of the birds. Our data suggest that the stability of the
individually specific vocal features may enable Siberian Cranes to be reliably identified by their duets over the birds’ lifetime. We believe that our work can increase confidence in the use of acoustic recognition techniques for endangered crane monitoring programs. Our results also suggest that Siberian Cranes may use their duets to form long-term social bonds between neighbours.

Abstract

In everyday conversation, turns often follow each other immediately or overlap in time. It has been proposed that speakers achieve this tight temporal coordination between their turns by engaging in linguistic dual-tasking, i.e., by beginning to plan their utterance during the preceding turn. This raises the question of how speakers manage to co-ordinate speech planning and listening with each other. Experimental work addressing this issue has mostly concerned the capacity demands and interference arising when speakers retrieve some content words while listening to others. However, many contributions to conversations are not content words, but backchannels, such as “hm”. Backchannels do not provide much conceptual content and are therefore easy to plan and respond to. To estimate how much they might facilitate speech planning in conversation, we determined their frequency in a Dutch and a German corpus of conversational speech. We found that 19% of the contributions in the Dutch corpus, and 16% of contributions in the German corpus were backchannels. In addition, many turns began with fillers or particles, most often translation equivalents of “yes” or “no,” which are likewise easy to plan.We proposed that to generate comprehensive models of using language in conversation psycholinguists should study not only the generation and processing of content words, as is commonly done, but also consider backchannels, fillers, and particles.

Abstract

Warning others about unexpected negative action outcomes is a paradigm case of communicative helping and prospective action understanding. The current study addressed the ontogeny of warning in infants’ gestural communication. We found that 12- and 18-month-olds (n = 84) spontaneously warned an adult by pointing out to her an aversive object hidden in her way (Problem condition). In control conditions the object was either positive (No Problem condition) or the adult had witnessed its’ placing (Problem known condition), which resulted in significantly less pointing. Results show that infants intervene spontaneously and with foresight through communication, in order to help others avoid a problem before it has occurred. These acts of warning entail an understanding of others’ negatively defined goals (to avoid an outcome) and their incorrect representations of reality. Findings support theories of altruism and social-pragmatic competencies in infancy.

Abstract

We aimed at investigating whether formal schooling and literacy favor progress in verbal serial-order short-term memory (STM). In Experiment 1, we presented children varying on age, school level, and socioeconomic background with a serial-order reconstruction task and observed differences related to both age and school level. Two subsequent experiments aimed at separating schooling- and literacy-related effects from age-related ones. In Experiment 2 we compared, on the one hand, performance of children of similar age but different school levels and, on the other hand, performance of children of same school level but different ages. We observed a schooling effect but no age effect on serial-order reconstruction: the youngest first-graders outperformed age-matched kindergartners but performed similarly as older first-graders of the same literacy level. Furthermore, children’s literacy abilities were strongly correlated to their serial-order reconstruction performance, even after controlling for the effects of non-verbal reasoning and vocabulary. In Experiment 3 we examined low socio-economic background adults presenting varying (correlated) levels of schooling and literacy: some had attended school in childhood for only a few years and were either illiterate or very poor readers, whereas others had attended school for at least 12 years. In addition to serial-order memory, item STM was assessed by a delayed single nonword repetition task. The groups differed on both STM tasks, which both correlated with their literacy abilities. Thus, literacy and schooling do not impact only order memory, but more generally verbal STM. Moreover, comparison between the adults’ and children’s data strongly suggests that it is schooling and/or literacy rather than age per se that matters for serial-order memory.

Abstract

People tend to associate the abstract concepts of “good” and “bad” with their fluent and disfluent sides of space, as determined by their natural handedness or by experimental manipulation (Casasanto, 2011). Here we investigated influences of spatial perspective taking on the spatialization of “good” and “bad.” In the first experiment, participants indicated where a schematically drawn cartoon character would locate “good” and “bad” stimuli. Right-handers tended to assign “good” to the right and “bad” to the left side of egocentric space when the character shared their spatial perspective, but when the character was rotated 180° this spatial mapping was reversed: good was assigned to the character’s right side, not the participant’s. The tendency to spatialize valence from the character’s perspective was stronger in the second experiment, when participants were shown a full-featured photograph of the character. In a third experiment, most participants not only spatialized “good” and “bad” from the character’s perspective, they also based their judgments on a salient attribute of the character’s body (an injured hand) rather than their own body. Taking another’s spatial perspective encourages people to compute space-valence mappings using an allocentric frame of reference, based on the fluency with which the other person could perform motor actions with their right or left hand. When people reason from their own spatial perspective, their judgments depend, in part, on the specifics of their bodies; when people reason from someone else’s perspective, their judgments may depend on the specifics of the other person’s body, instead. - See more at: http://journal.frontiersin.org/Journal/10.3389/fpsyg.2013.00266

Abstract

A pivotal question in modern neuroscience is which genes regulate brain circuits that underlie cognitive functions. However, the field is still in its infancy. Here we report an integrated investigation of the high-level language network (i.e., sentence processing network) in the human cerebral cortex, combining regional gene expression profiles, task fMRI, large-scale neuroimaging meta-analysis, and resting-state functional network approaches. We revealed reliable gene expression-functional network correlations using three different network definition strategies, and identified a consensus set of genes related to connectivity within the sentence-processing network. The genes involved showed enrichment for neural development and actin-related functions, as well as association signals with autism, which can involve disrupted language functioning. Our findings help elucidate the molecular basis of the brain’s infrastructure for language. The integrative approach described here will be useful to study other complex cognitive traits.

Abstract

Objective

Lateralized dysfunction has been suggested in Obsessive-Compulsive Disorder (OCD). However, it is currently unclear whether OCD is characterized by abnormal patterns of structural brain asymmetry. Here we carried out by far the largest study of brain structural asymmetry in OCD.
Method

We studied a collection of 16 pediatric datasets (501 OCD patients and 439 healthy controls), as well as 30 adult datasets (1777 patients and 1654 controls) from the OCD Working Group within the ENIGMA (Enhancing Neuro-Imaging Genetics through Meta-Analysis) consortium. Asymmetries of the volumes of subcortical structures, and of regional cortical thickness and surface area measures, were assessed based on T1-weighted MRI scans, using harmonized image analysis and quality control protocols. We investigated possible alterations of brain asymmetry in OCD patients. We also explored potential associations of asymmetry with specific aspects of the disorder and medication status.
Results

In the pediatric datasets, the largest case-control differences were observed for volume asymmetry of the thalamus (more leftward; Cohen’s d = 0.19) and the pallidum (less leftward; d = -0.21). Additional analyses suggested putative links between these asymmetry patterns and medication status, OCD severity, and/or anxiety and depression comorbidities. No significant case-control differences were found in the adult datasets.
Conclusions

The results suggest subtle changes of the average asymmetry of subcortical structures in pediatric OCD, which are not detectable in adults with the disorder. These findings may reflect altered neurodevelopmental processes in OCD.

Abstract

Many companies recruit employees from different parts of the globe, and faking behavior by
potential employees is a ubiquitous phenomenon. It seems that applicants from some
countries are more prone to faking compared to others, but the reasons for these differences
are largely unexplored. This study relates country-level economic variables to faking
behavior in hiring processes. In a cross-national study across 20 countries, participants (N =
3839) reported their faking behavior in their last job interview. This study used the random
response technique (RRT) to ensure participants anonymity and to foster honest answers
regarding faking behavior. Results indicate that general economic indicators (gross domestic
product per capita [GDP] and unemployment rate) show negligible correlations with faking
across the countries, whereas economic inequality is positively related to the extent of
applicant faking to a substantial extent. These findings imply that people are sensitive to
inequality within countries and that inequality relates to faking, because inequality might
actuate other psychological processes (e.g., envy) which in turn increase the probability for
unethical behavior in many forms.

Abstract

The ability to extract word forms from continuous speech is a prerequisite for constructing a vocabulary and emerges in the first year of life. Electrophysiological (ERP) studies of speech segmentation by 9- to 12-month-old listeners in several languages have found a left-localized negativity linked to word onset as a marker of word detection. We report an ERP study showing significant evidence of speech segmentation in Dutch-learning 7-month-olds. In contrast to the left-localized negative effect reported with older infants, the observed overall mean effect had a positive polarity. Inspection of individual results revealed two participant sub-groups: a majority showing a positive-going response, and a minority showing the left negativity observed in older age groups. We retested participants at age three, on vocabulary comprehension and word and sentence production. On every test, children who at 7 months had shown the negativity associated with segmentation of words from speech outperformed those who had produced positive-going brain responses to the same input. The earlier that infants show the left-localized brain responses typically indicating detection of words in speech, the better their early childhood language skills.

Abstract

Recent neuroimaging evidence suggests that the frequency of entrained oscillations in auditory cortices influences the perceived duration of speech segments, impacting word perception (Kösem et al. 2018). We further tested the causal influence of neural entrainment frequency during speech processing, by manipulating entrainment with continuous transcranial alternating
current stimulation (tACS) at distinct oscillatory frequencies (3 Hz and 5.5 Hz) above the auditory cortices. Dutch participants listened to speech and were asked to report their percept of a target Dutch word, which contained a vowel with an ambiguous duration. Target words
were presented either in isolation (first experiment) or at the end of spoken sentences (second experiment). We predicted that the tACS frequency would influence neural entrainment and
therewith how speech is perceptually sampled, leading to a perceptual over- or underestimation of the vowel’s duration. Whereas results from Experiment 1 did not confirm this prediction, results from experiment 2 suggested a small effect of tACS frequency on target word
perception: Faster tACS lead to more long-vowel word percepts, in line with the previous neuroimaging findings. Importantly, the difference in word perception induced by the different tACS frequencies was significantly larger in experiment 1 vs. experiment 2, suggesting that the
impact of tACS is dependent on the sensory context. tACS may have a stronger effect on spoken word perception when the words are presented in continuous speech as compared to when they are isolated, potentially because prior (stimulus-induced) entrainment of brain oscillations
might be a prerequisite for tACS to be effective.

Abstract

In spoken language, pitch accent can mark certain information as focus, whereby more attentional resources are allocated to the focused information. Using functional magnetic resonance imaging, this study examined whether pitch accent, used for marking focus, recruited general attention networks during sentence comprehension. In a language task, we independently manipulated the prosody and semantic/pragmatic congruence of sentences. We found that semantic/pragmatic processing affected bilateral inferior and middle frontal gyrus. The prosody manipulation showed bilateral involvement of the superior/inferior parietal cortex, superior and middle temporal cortex, as well as inferior, middle, and posterior parts of the frontal cortex. We compared these regions with attention networks localized in an auditory spatial attention task. Both tasks activated bilateral superior/inferior parietal cortex, superior temporal cortex, and left precentral cortex. Furthermore, an interaction between prosody and congruence was observed in bilateral inferior parietal regions: for incongruent sentences, but not for congruent ones, there was a larger activation if the incongruent word carried a pitch accent, than if it did not. The common activations between the language task and the spatial attention task demonstrate that pitch accent activates a domain general attention network, which is sensitive to semantic/pragmatic aspects of language. Therefore, attention and language comprehension are highly interactive.

Abstract

A growing number of studies support the partial compositionality of idiomatic phrases, while idioms are thought to vary in their syntactic flexibility. Some idioms, like kick the bucket, have been classified as inflexible and incapable of being passivized without losing their figurative interpretation (i.e., the bucket was kicked ≠ died). Crucially, this has never been substantiated by empirical findings. In the current study, we used eye-tracking to examine whether the passive forms of (flexible and inflexible) idioms retain or lose their figurative meaning. Active and passivized idioms (he kicked the bucket/the bucket was kicked) and incongruous active and passive control phrases (he kicked the apple/the apple was kicked) were inserted in sentences biasing the figurative meaning of the respective idiom (die). Active idioms served as a baseline. We hypothesized that if passivized idioms retain their figurative meaning (the bucket was kicked = died), they should be processed more efficiently than the control phrases, since their figurative meaning would be congruous in the context. If, on the other hand, passivized idioms lose their figurative interpretation (the bucket was kicked = the pail was kicked), then their meaning should be just as incongruous as that of both control phrases, in which case we would expect no difference in their processing. Eye movement patterns demonstrated a processing advantage for passivized idioms (flexible and inflexible) over control phrases, thus indicating that their figurative meaning was not compromised. These findings challenge classifications of idiom flexibility and highlight the creative nature of language.

Abstract

Recent experimental findings suggest stable individual differences in the perception of auditory stimuli lacking energy at the fundamental frequency (F0), here called missing fundamental (MF) tones. Specifically, some individuals readily identify the pitch of such tones with the missing F0 ("F0 listeners"), and some base their judgment on the frequency of the partials that make up the tones ("spectral listeners"). However, the diversity of goals and methods in recent research makes it difficult to draw clear conclusions about individual differences. The first purpose of this article is to discuss the influence of methodological choices on listeners' responses. The second goal is to report findings on individual differences in our own studies of the MF phenomenon. In several experiments, participants judged the direction of pitch change in stimuli composed of two MF tones, constructed so as to reveal whether the pitch percept was based on the MF or the partials. The reported difference between F0 listeners and spectral listeners was replicated, but other stable patterns of responses were also observed. Test-retest reliability is high. We conclude that there are genuine, stable individual differences underlying the diverse findings, but also that there are more than two general types of listeners, and that stimulus variables strongly affect some listeners' responses. This suggests that it is generally misleading to classify individuals as "F0 listeners" or "spectral listeners." It may be more accurate to speak of two modes of perception ("F0 listening" and "spectral listening"), both of which are available to many listeners. The individual differences lie in what conditions the choice between the two modes.

Abstract

Individuals affected with developmental disorders of speech and language have substantial difficulty acquiring expressive and/or receptive language in the absence of any profound sensory or neurological impairment and despite adequate intelligence and opportunity. Although studies of twins consistently indicate that a significant genetic component is involved, most families segregating speech and language deficits show complex patterns of inheritance, and a gene that predisposes individuals to such disorders has not been identified. We have studied a unique three-generation pedigree, KE, in which a severe speech and language disorder is transmitted as an autosomal-dominant monogenic trait. Our previous work mapped the locus responsible, SPCH1, to a 5.6-cM interval of region 7q31 on chromosome 7 (ref. 5). We also identified an unrelated individual, CS, in whom speech and language impairment is associated with a chromosomal translocation involving the SPCH1 interval. Here we show that the gene FOXP2, which encodes a putative transcription factor containing a polyglutamine tract and a forkhead DNA-binding domain, is directly disrupted by the translocation breakpoint in CS. In addition, we identify a point mutation in affected members of the KE family that alters an invariant amino-acid residue in the forkhead domain. Our findings suggest that FOXP2 is involved in the developmental process that culminates in speech and language

Abstract

Cognitive linguists suggest that understanding metaphors requires activation of conceptual mappings between the involved concepts. We tested whether mappings are indeed in use during metaphor comprehension, and what mapping means as a cognitive process with Event-Related Potentials. Participants read literal, conventional metaphorical, novel metaphorical, and anomalous target sentences preceded by primes with related or unrelated mappings. Experiment 1 used sentence-primes to activate related mappings, and Experiment 2 used simile-primes to induce comparison thinking. In the unprimed conditions of both experiments, metaphors elicited N400s more negative than the literals. In Experiment 1, related sentence-primes reduced the metaphor-literal N400 difference in conventional, but not in novel metaphors. In Experiment 2, related simile-primes reduced the metaphor-literal N400 difference in novel, but not clearly in conventional metaphors. We suggest that mapping as a process occurs in metaphors, and the ways in which it can be facilitated by comparison differ between conventional and novel metaphors.

Abstract

Hierarchical centre-embedded structures pose a large difficulty for language learners due to their complexity. A recent artificial grammar learning study (Lai & Poletiek, 2011) demonstrated a starting-small (SS) effect, i.e., staged-input and sufficient exposure to 0-level-of-embedding exemplars were the critical conditions in learning AnBn structures. The current study aims to test: (1) a more sophisticated type of SS (a gradually rather than discretely growing input), and (2) the frequency distribution of the input. The results indicate that SS optimally works under other conditional cues, such as a skewed frequency distribution with simple stimuli being more numerous than complex ones.

Abstract

In this paper we examine whether experience with spatial metaphors for time has an influence on people’s representation of time. In particular we ask whether spatiotemporal metaphors can have both chronic and immediate effects on temporal thinking. In Study 1, we examine the prevalence of ego-moving representations for time in Mandarin speakers, English speakers, and Mandarin-English (ME) bilinguals. As predicted by observations in linguistic analyses, we find that Mandarin speakers are less likely to take an ego-moving perspective than are English speakers. Further, we find that ME bilinguals tested in English are less likely to take an ego-moving perspective than are English monolinguals (an effect of L1 on meaning-making in L2), and also that ME bilinguals tested in Mandarin are more likely to take an ego-moving perspective than are Mandarin monolinguals (an effect of L2 on meaning-making in L1). These findings demonstrate that habits of metaphor use in one language can influence temporal reasoning in another language, suggesting the metaphors can have a chronic effect on patterns in thought. In Study 2 we test Mandarin speakers using either horizontal or vertical metaphors in the immediate context of the task. We find that Mandarin speakers are more likely to construct front-back representations of time when understanding front-back metaphors, and more likely to construct up-down representations of time when understanding up-down metaphors. These findings demonstrate that spatiotemporal metaphors can also have an immediate influence on temporal reasoning. Taken together, these findings demonstrate that the metaphors we use to talk about time have both immediate and long-term consequences for how we conceptualize and reason about this fundamental domain of experience.

Abstract

The Human Connectome Project (HCP) seeks to map the structural and functional connections between network elements in the human brain. Magnetoencephalography (MEG) provides a temporally rich source of information on brain network dynamics and represents one source of functional connectivity data to be provided by the HCP. High quality MEG data will be collected from 50 twin pairs both in the resting state and during performance of motor, working memory and language tasks. These data will be available to the general community. Additionally, using the cortical parcellation scheme common to all imaging modalities, the HCP will provide processing pipelines for calculating connection matrices as a function of time and frequency. Together with structural and functional data generated using magnetic resonance imaging methods, these data represent a unique opportunity to investigate brain network connectivity in a large cohort of normal adult human subjects. The analysis pipeline software and the dynamic connectivity matrices that it generates will all be made freely available to the research community.

Abstract

Vocal production learning (VPL), or the ability to modify vocalizations through the imitation of sounds, is a rare trait in the animal kingdom. While humans are exceptional vocal learners, few other mammalian species share this trait. Owing to their singular ecology and lifestyle, bats are highly specialized for the precise emission and reception of acoustic signals. This specialization makes them ideal candidates for the study of vocal learning, and several bat species have previously shown evidence supportive of vocal learning. Here we use a sophisticated automated set-up and a contingency training paradigm to explore the vocal learning capacity of pale spear-nosed bats. We show that these bats are capable of directional change of the fundamental frequency of their calls according to an auditory target. With this study, we further highlight the importance of bats for the study of vocal learning and provide evidence for the VPL capacity of the pale spear-nosed bat.

Abstract

This paper presents a new approach to functional magnetic resonance imaging (FMRI) data analysis. The main difference lies in the view of what comprises an observation. Here we treat the data from one scanning session (comprising t volumes, say) as one observation. This is contrary to the conventional way of looking at the data where each session is treated as t different observations. Thus instead of viewing the v voxels comprising the 3D volume of the brain as the variables, we suggest the usage of the vt hypervoxels comprising the 4D volume of the brain-over-session as the variables. A linear model is fitted to the 4D volumes originating from different sessions. Parameter estimation and hypothesis testing in this model can be performed with standard techniques. The hypothesis testing generates 4D statistical images (SIs) to which any relevant test statistic can be applied. In this paper we describe two test statistics, one voxel based and one cluster based, that can be used to test a range of hypotheses. There are several benefits in treating the data from each session as one observation, two of which are: (i) the temporal characteristics of the signal can be investigated without an explicit model for the blood oxygenation level dependent (BOLD) contrast response function, and (ii) the observations (sessions) can be assumed to be independent and hence inference on the 4D SI can be made by nonparametric or Monte Carlo methods. The suggested 4D approach is applied to FMRI data and is shown to accurately detect the expected signal

Abstract

Objective Wnt signalling is critical for normal intestinal development and homeostasis. Wnt dysregulation occurs in almost all human and murine intestinal tumours and an optimal but not excessive level of Wnt activation is considered favourable for tumourigenesis. The authors assessed effects of pan-intestinal Wnt activation on tissue homeostasis, taking into account underlying physiological Wnt activity and stem-cell number in each region of the bowel. Design The authors generated mice that expressed temporally controlled, stabilised β-catenin along the crypt–villus axis throughout the intestines. Physiological Wnt target gene activity was assessed in different regions of normal mouse and human tissue. Human intestinal tumour mutation spectra were analysed. Results In the mouse, β-catenin stabilisation resulted in a graduated neoplastic response, ranging from dysplastic transformation of the entire epithelium in the proximal small bowel to slightly enlarged crypts of non-dysplastic morphology in the colorectum. In contrast, stem and proliferating cell numbers were increased in all intestinal regions. In the normal mouse and human intestines, stem-cell and Wnt gradients were non-identical, but higher in the small bowel than large bowel in both species. There was also variation in the expression of some Wnt modulators. Human tumour analysis confirmed that different APC mutation spectra are selected in different regions of the bowel. Conclusions There are variable gradients in stem-cell number, physiological Wnt activity and response to pathologically increased Wnt signalling along the crypt-villus axis and throughout the length of the intestinal tract. The authors propose that this variation influences regional mutation spectra, tumour susceptibility and lesion distribution in mice and humans.

Abstract

In 3 ERP experiments, we investigated how experienced L2 speakers process natural and correct syntactic input that deviates from their own, sometimes incorrect, syntactic representations. Our previous study (Lemhöfer, Schriefers, & Indefrey, 2014) had shown that L2 speakers do engage in native-like syntactic processing of gender agreement but base this processing on their own idiosyncratic (and sometimes incorrect) grammars. However, as in other standard ERP studies, but different from realistic L2 input, the materials in that study contained a large proportion of incorrect sentences. In the present study, German speakers of Dutch read exclusively objectively correct Dutch sentences that did or did not contain subjective determiner “errors” (e.g., de boot “the boat,” which conflicts with the intuition of many German speakers that the correct phrase should be het boot). During reading for comprehension (Experiment 1), no syntax-related ERP responses for subjectively incorrect compared to correct phrases were observed. The same was true even when participants explicitly attended to and learned from the determiners in the sentences (Experiment 2). Only when participants judged the correctness of determiners in each sentence (Experiment 3) did a clear P600 appear. These results suggest that the full and native-like use of subjective grammars, as reflected in the P600 to subjective violations, occurs only when speakers have reason to mistrust the grammaticality of the input, either because of the nature of the task (grammaticality judgments) or because of the salient presence of incorrect sentences.

Abstract

In this article, we propose a novel image segmentation method called the whole mesh deformation (WMD) model, which aims at addressing the problems of modern medical imaging. Such problems have raised from the combination of several factors: (1) significant growth of medical image volumes sizes due to increasing capabilities of medical acquisition devices; (2) the will to increase the complexity of image processing algorithms in order to explore new functionality; (3) change in processor development and turn towards multi processing units instead of growing bus speeds and the number of operations per second of a single processing unit. Our solution is based on the concept of deformable models and is characterized by a very effective and precise segmentation capability. The proposed WMD model uses a volumetric mesh instead of a contour or a surface to represent the segmented shapes of interest, which allows exploiting more information in the image and obtaining results in shorter times, independently of image contents. The model also offers a good ability for topology changes and allows effective parallelization of workflow, which makes it a very good choice for large datasets. We present a precise model description, followed by experiments on artificial images and real medical data.

Abstract

Successful communication is important for both society and people’s personal life. Here we show that people can improve their communication skills by interacting with multiple others, and that this improvement seems to come about by a greater tendency to take the addressee’s perspective when there are multiple partners. In Experiment 1, during a training phase, participants described figures to a new partner in each round or to the same partner in all rounds. Then all participants interacted with a new partner and their recordings from that round were presented to naïve listeners. Participants who had interacted with multiple partners during training were better understood. This occurred despite the fact that the partners had not provided the participants with any input other than feedback on comprehension during the interaction. In Experiment 2, participants were asked to provide descriptions to a different future participant in each round or to the same future participant in all rounds. Next they performed a surprise memory test designed to tap memory for global details, in line with the addressee’s perspective. Those who had provided descriptions for multiple future participants performed better. These results indicate that people can improve their communication skills by interacting with multiple people, and that this advantage might be due to a greater tendency to take the addressee’s perspective in such cases. Our findings thus show how the social environment can influence our communication skills by shaping our own behavior during interaction in a manner that promotes the development of our communication skills.

Abstract

Learning a second language influences speakers’ first language, but there is great variability in the degree of influence that speakers exhibit. We show that some of this variability is due to individual differences in inhibitory skill. Particularly, we propose that poorer inhibitory skill leads to greater activation of competing items from the language not in use, and that this greater co-activation ultimately leads to greater influence of the co-activated items on one another. Specifically, we show that bilinguals with lower inhibitory skill exhibit greater influence of the second language on the first. Late English–French bilinguals residing in France produced and perceived Voice Onset Time of voiceless stops in English in a more French-like manner, the lower their inhibitory skill was. We discuss the implications of these results for the role of inhibitory skill in shaping representation in bilingual as well as monolingual language processing.

Abstract

The first, theoretical part of this paper sketches a framework for phonological encoding in which the speaker successively generates phonological syllables in connected speech. The final stage of this process, phonetic encoding, consists of accessing articulatory gestural scores for each of these syllables in a "mental syllabary". The second, experimental part studies various predictions derived from this theory. The main finding is a syllable frequency effect: words ending in a high-frequent syllable are named faster than words ending in a low-frequent syllable. As predicted, this syllable frequency effect is independent of and additive to the effect of word frequency on naming latency. The effect, moreover, is not due to the complexity of the word-final syllable. In the General Discussion, the syllabary model is further elaborated with respect to phonological underspecification and activation spreading. Alternative accounts of the empirical findings in terms of core syllables and demisyllables are considered.

Abstract

In modern approaches to phonology a lack of clarity exists on the issue of whether phonetic facts are psychological or physical realities. The results from an experiment suggest that phonetic facts can be considered as psychological realities, but with the restriction that they can (but not necessarily always do) take acoustical shape. More specifically, the syntactic material consisted of ambiguous French sentences of the following sort: On a tourné ce film intéressant pour les étudiants. They were spoken (a) in disambiguating contexts, without the (four) readers noticing the ambiguities, and (b) without context, but with the instruction to make a conscious effort to disambiguate. By tape splicing, the contexts were removed from the context-embedded sentences. Twenty-eight native speakers of French listened to the sentences and judged whether one or the other meaning had been intended by the speaker. Subjects performed significantly above chance: 60% correct identifications for context-embedded sentences, 75% for context-free sentences. Pitch-amplitude analyses were made to determine the acoustical differences involved.

Abstract

In 1976, the German Max Planck Society established a new research enterprise in psycholinguistics, which became the Max Planck Institute for Psycholinguistics in Nijmegen, the Netherlands. I was fortunate enough to be invited to direct this institute. It enabled me, with my background in visual and auditory psychophysics and the theory of formal grammars and automata, to develop a long-term chronometric endeavor to dissect the process of speaking. It led, among other work, to my book Speaking (1989) and to my research team's article in Brain and Behavioral Sciences “A Theory of Lexical Access in Speech Production” (1999). When I later became president of the Royal Netherlands Academy of Arts and Sciences, I helped initiate the Women for Science research project of the Inter Academy Council, a project chaired by my physicist sister at the National Institute of Standards and Technology. As an emeritus I published a comprehensive History of Psycholinguistics (2013). As will become clear, many people inspired and joined me in these undertakings.

Abstract

A core operation in speech production is the preparation of words from a semantic base. The theory of lexical access reviewed in this article covers a sequence of processing stages beginning with the speaker’s focusing on a target concept and ending with the initiation of articulation. The initial stages of preparation are concerned with lexical selection, which is zooming in on the appropriate lexical item in the mental lexicon. The following stages concern form encoding, i.e., retrieving a word’s morphemic phonological codes, syllabifying the word, and accessing the corresponding articulatory gestures. The theory is based on chronometric measurements of spoken word production, obtained, for instance, in picture-naming tasks. The theory is largely computationally implemented. It provides a handle on the analysis of multiword utterance production as well as a guide to the analysis and design of neuroimaging studies of spoken utterance production.

Abstract

This paper confronts Kant’s (1768) view of human conceptions of space as fundamentally divided along the three planes of the human body with an empirical case study in the Mayan community of Tenejapa in southern Mexico, whose inhabitants do not use left/right distinctions to project regions in space. Tenejapans have names for the left hand and the right hand, and also a term for hand/arm in general, but they do not generalize the distinction to spatial regions -- there is no linguistic expression glossing as 'to the left' or 'on the left-hand side', for example. Tenejapans also show a remarkable indifference to incongruous counterparts. Nor is there any system of value associations with the left and the right. The Tenejapan evidence that speaks to these Kantian themes points in two directions: (a) Kant was wrong to think that the structure of spatial regions founded on the human frame, and in particular the distinctions based on left and right, are in some sense essential human intuitions; (b) Kant may have been right to think that the left/right opposition, the perception of enantiomorphs, clockwiseness, East-West dichotomies, etc., are intimately connected to an overall system of spatial conception.

Abstract

There has been a recent spate of work on recursion as a central design feature of language. This short report points out that there is little evidence that unlimited recursion, understood as center-embedding, is typical of natural language syntax. Nevertheless, embedded pragmatic construals seem available in every language. Further, much deeper center-embedding can be found in dialogue or conversation structure than can be found in syntax. Existing accounts for the 'performance' limitations on center-embedding are thus thrown into doubt. Dialogue materials suggest that center-embedding is perhaps a core part of the human interaction system, and is for some reason much more highly restricted in syntax than in other aspects of cognition.

Abstract

This paper describes the linguistic description of time, the accompanying gestural system, and the “mental time lines” found in the speakers of Yélî Dnye, an isolate language spoken offshore from Papua New Guinea. Like many indigenous languages, Yélî Dnye has no fixed anchoring of time and thus no calendrical time. Instead, time in Yélî Dnye linguistic
description is primarily anchored to the time of speaking, with six diurnal tenses and special nominals for n days from coding time; this is supplemented with special constructions for overlapping events. Consequently there is relatively little cross-over or metaphor from space to time. The gesture system, on the other hand, uses pointing to sun position to indicate time of day and may make use of systematic time lines. Experimental evidence fails to show a single robust axis used for mapping time to space. This suggests that there may not be a strong, universal tendency for systematic space-time mappings.

Abstract

The notion of efficient trade-offs is frequently used in functional linguis-tics in order to explain language use and structure. In this paper I argue that this notion is more confusing than enlightening. Not every negative correlation between parameters represents a real trade-off. Moreover, trade-offs are usually reported between pairs of variables, without taking into account the role of other factors. These and other theoretical issues are illustrated in a case study of linguistic cues used in expressing “who did what to whom”: case marking, rigid word order and medial verb posi-tion. The data are taken from the Universal Dependencies corpora in 30 languages and annotated corpora of online news from the Leipzig Corpora collection. We find that not all cues are correlated negatively, which ques-tions the assumption of language as a zero-sum game. Moreover, the cor-relations between pairs of variables change when we incorporate the third variable. Finally, the relationships between the variables are not always bi-directional. The study also presents a causal model, which can serve as a more appropriate alternative to trade-offs.

Abstract

The paper demonstrates how verb and noun classes can be used as a common interface in contrastive Construction Grammar. It presents an innovative approach to the contrastive analysis of constructional spaces (sets of constructions covering a certain semantic domain). We compare English and Dutch analytic causatives by using the statistical technique of multiple correspondence analysis applied to data from large monolingual corpora. The method allows us to explore the common conceptual space of the constructions, in particular the salient semantic dimensions and causation types, which emerge on the basis of co-occurring semantic classes of the nominal and verbal slot fillers in constructional exemplars. The formal patterns of the constructions at different levels of specificity are projected onto this space. Our analyses show that an average Dutch analytic causative refers to more indirect and abstract causation with fewer animate than its English counterpart. We have also found that the languages “cut” the common conceptual space in unique ways, although the semantic areas of many English and Dutch constructions overlap substantially. Nevertheless, the form-meaning mapping in the two languages displays commonalities. Both English and Dutch constructions with prepositionally marked or implicit causees are strongly associated with animate causees. We have also observed a correlation between the directness of causation and the crosslinguistic hierarchy of affectedness marking proposed by Kemmer and Verhagen (1994).

Abstract

The integration of three main dimensions of linguistic usage and variation – formal, social and conceptual – can be seen as a major ambition of the Cognitive Sociolinguistics enterprise. The paper illustrates this theoretical approach with a corpus-based study of near-synonymous causative constructions with doen and laten in the Belgian and Netherlandic varieties of Dutch. A series of quantitative analyses show a complex interplay of the dimensions at different levels of constructional schematicity. At the more schematic level, the results indicate that the effects of transitivity and coreferentiality on the probability of the two constructions are slightly different in the two varieties. However, incorporating the effected predicate slot fillers in a mixed-effect model reveals that these differences can be explained to a large extent by the country-specific lexical patterns. These findings suggest that the interplay of the lectal and conceptual factors in constructional variation should be studied at varying degrees of constructional schematicity.

Abstract

Background

Posterior cingulate cortex (PCC) is a key aspect of the default mode network (DMN). Aberrant PCC functional connectivity (FC) is implicated in schizophrenia, but the potential for PCC related changes as biological classifier of schizophrenia has not yet been evaluated.
Methods

We conducted a data-driven approach using resting-state functional MRI data to explore differences in PCC-based region- and voxel-wise FC patterns, to distinguish between patients with first-episode schizophrenia (FES) and demographically matched healthy controls (HC). Discriminative PCC FCs were selected via false discovery rate estimation. A gradient boosting classifier was trained and validated based on 100 FES vs. 93 HC. Subsequently, classification models were tested in an independent dataset of 87 FES patients and 80 HC using resting-state data acquired on a different MRI scanner.
Results

Patients with FES had reduced connectivity between PCC and frontal areas, left parahippocampal regions, left anterior cingulate cortex, and right inferior parietal lobule, but hyperconnectivity with left lateral temporal regions. Predictive voxel-wise clusters were similar to region-wise selected brain areas functionally connected with PCC in relation to discriminating FES from HC subject categories. Region-wise analysis of FCs yielded a relatively high predictive level for schizophrenia, with an average accuracy of 72.28% in the independent samples, while selected voxel-wise connectivity yielded an accuracy of 68.72%.
Conclusion

FES exhibited a pattern of both increased and decreased PCC-based connectivity, but was related to predominant hypoconnectivity between PCC and brain areas associated with DMN, that may be a useful differential feature revealing underpinnings of neuropathophysiology for schizophrenia.

Abstract

We study to what extent linguistic differences in grammatical aspect systems and verb lexicalisation patterns of Dutch and mandarin Chinese affect how speakers conceptualise the path of motion in motion events, using description and memory tasks. We hypothesised that speakers of the two languages would show different preferences towards the selection of endpoint-, trajectory- or location-information in Endpoint-oriented (not reached) events, whilst showing a similar bias towards encoding endpoints in Endpoint-reached events. Our findings show that (1) groups did not differ in endpoint encoding and memory for both event types; (2) Dutch speakers conceptualised Endpoint-oriented motion focusing on the trajectory, whereas Chinese speakers focused on the location of the moving entity. In addition, we report detailed linguistic patterns of how grammatical aspect, verb semantics and adjuncts containing path-information are combined in the two languages. Results are discussed in relation to typologies of motion expression and event cognition theory.

Abstract

Over the past decade the neuromarketing of educational products has become increasingly common. Researchers have however expressed concern about the misapplication of neuroscience to education marketing, fearing that consumers may be deceived into investing in apparently “brain-based” products under the misapprehension that they will be more effective. This study provides the first demonstration that these fears are justified. We presented 180 participants with one of four advertisements for an identical educational program, named either “Right Brain” or “Right Start” Training; the advertisements either did, or did not, include an MRI brain image in one corner. Results demonstrated that “Right Brain” training was deemed more interesting, educationally valuable, and scientifically strong than an identical product named “Right Start” training. Advertisements including an unrelated brain image enhanced ratings of scientific rationale. These results confirm that by implying a strong scientific basis, “brain-based” product names are remarkably effective in implicitly manipulating consumer opinion.

Abstract

The fact that many sub-populations do not take part in research, especially participants fromlower socioeconomic (SES) backgrounds, is a serious problem in education research. Toincrease the participation of such groups we must discover what social, economic andpractical factors prevent participation, and how to overcome these barriers. In the currentpaper, we review the literature on this topic, before describing a case study that demonstratesfour potential solutions to four barriers to participation in a shared reading intervention forfamilies from lower SES backgrounds. We discuss the implications of our findings forfamily-based interventions more generally, and the difficulty of balancing strategies toencourage participation with adhering to the methodological integrity of a research study

Abstract

Background: Shared reading interventions can impact positively on preschool children’s
language development and on their caregiver’s attitudes/behaviours towards
reading. However, a number of barriers may discourage families from engaging with
these interventions, particularly families from lower socio-economic status (SES)
backgrounds. We investigated how families from such backgrounds responded to an
intervention designed explicitly to overcome these barriers.
Methods: In a preregistered cluster randomised controlled trial, 85 lower SES families
and their 3-year-old to 4-year-old children from 10 different preschools were randomly
allocated to take part in The Reader’s Shared Reading programme
(intervention) or an existing ‘Story Time’ group at a library (control) once a week
for 8 weeks. Three outcome measures were assessed at baseline and post intervention:
(1) attendance, (2) enjoyment of the reading groups and (3) caregivers’ knowledge of,
attitudes and behaviours towards reading. A fourth children’s vocabulary – was
assessed at baseline and 4 weeks post intervention.
Results: Families were significantly more likely to attend the intervention group and
rated it more favourably, compared with the control group. However, there were no
significant effects on caregivers’ knowledge, attitudes and behaviours or on children’s
language.
Conclusion: The intervention was only successful in engaging families from disadvantaged
backgrounds in shared reading. Implications for the use, duration and intensity
of shared reading interventions are discussed.

Abstract

The ability to flexibly predict others' behaviors has been ascribed to a theory of mind (ToM) system. Most research has focused on formal conceptual definitions of such a system, and the question of whom to credit with a ToM. In this article, I suggest shifting perspective from formal definitions to a usage-based approach. This approach views action within human interaction as central to the emergence and continuous development of the ability to flexibly predict others' behaviors. Addressing the current debate about whether infants have a ToM, I illustrate how infants use flexible action expectations to interact with others appropriately. I also discuss the continuous development of ToM and its natural structure from a usage-based perspective.

Abstract

Background Cortical inhibition plays a critical role in controlling and modulating cortical excitation and a more detailed understanding of the neuronal circuits contributing to each will provide more insight into their roles in complex cortical computations. Traditional neuronal tracers lack a means for easily distinguishing between circuits of inhibitory and excitatory neurons. To overcome this limitation, we developed a technique for retrogradely labeling inputs to local clusters of inhibitory or excitatory neurons, but not both, using neurotropic adeno-associated and lentiviral vectors, cell-type specific promoters and a modified rabies virus. Results Applied to primary visual cortex (V1) in mouse, the cell-type specific tracing technique labeled thousands of presynaptically connected neurons, and revealed that the dominant source of input to inhibitory and excitatory neurons is local in origin. Neurons in other visual areas are also labeled; the percentage of these inter-cortical inputs to excitatory neurons is somewhat higher (~20%) than to inhibitory neurons (<10%), suggesting that inter-cortical connections have less direct control over inhibition. The inputs to inhibitory neurons were also traced in cat V1, and when aligned with the orientation preference map, revealed for the first time that long-range inputs to inhibitory neurons are well tuned to orientation. Conclusions These novel findings for inhibitory and excitatory circuits in the visual cortex demonstrate the efficacy of our new technique and its ability to work across species, including larger-brained mammals such as the cat. This paves the way for better understanding the roles of specific cell-types in higher-order perceptual and cognitive processes.

Abstract

While much of the literature on bilingualism and cognition focuses on group comparisons (monolinguals vs bilinguals or language learners vs controls), here we examine the potential differential effects of intensive language learning on subjects with distinct language experiences and demographic profiles. Using an individual differences approach, we assessed attentional performance from 105 university-educated Gaelic learners aged 21–85. Participants were tested before and after beginner, elementary, and intermediate courses using tasks measuring i.) sustained attention, ii.) inhibition, and iii.) attention switching. We examined the relationship between attentional performance and Gaelic level, previous language experience, gender, and age. Gaelic level predicted attention switching performance: those in higher levels initially outperformed lower levels, however lower levels improved the most. Age also predicted performance: as age increased attention switching decreased. Nevertheless, age did not interact with session for any attentional measure, thus the impact of language learning on cognition was detectable across the lifespan.

Abstract

Language use is shaped by a pressure to communicate efficiently, yet the tendency towards redundancy is said to increase in older age. The longstanding assumption is that saying more than is necessary is inefficient and may be driven by age-related decline in inhibition (i.e. the ability to filter out irrelevant information). However, recent work proposes an alternative account of efficiency: In certain contexts, redundancy facilitates communication (e.g., when the colour or size of an object is perceptually salient and its mention aids the listener’s search). A critical question follows: Are older adults indiscriminately redundant, or do they modulate their use of redundant information to facilitate communication? We tested efficiency and cognitive capacities in 200 adults aged 19–82. Irrespective of age, adults with better attention switching skills were redundant in efficient ways, demonstrating that the pressure to communicate efficiently continues to shape language use later in life.

Abstract

Purpose The brain is a highly interconnected neuronal assembly in which network analyses can greatly enlarge our knowledge on seizure generation. The cortico-thalamo-cortical network is the brain-network of interest in absence epilepsy. Here, network synchronization is assessed in a genetic absence model during 5 second long pre-ictal- > ictal transition periods. Method 16 male WAG/Rij rats were equipped with multiple electrodes targeting layer 4 to 6 of the somatosensory-cortex, rostral and caudal RTN, VPM, anterior-(ATN) and posterior (Po) thalamic nucleus. Local Field Potentials measured during pre-ictal- > ictal transition and during control periods were subjected to time-frequency and pairwise phase consistency analysis. Results Pre-ictally, all channels showed Spike-Wave Discharge (SWD) precursor activity (increases in spectral power), which were earliest and most pronounced in the somatosensory cortex. The caudal RTN decoupled from VPM, Po and cortical layer 4. Strong increases in synchrony were found between cortex and thalamus during SWD. Although increases between cortex and VPM were seen in SWD frequencies and its harmonics, boarder spectral increases (6-48 Hz) were seen between cortex and Po. All thalamic nuclei showed increased phase synchronization with Po but not with VPM. Conclusion Absence seizures are not sudden and unpredictable phenomena: the somatosensory cortex shows highest and earliest precursor activity. The pre-ictal decoupling of the caudal RTN might be a prerequisite of SWD generation. Po nucleus might be the primary thalamic counterpart to the somatosensory-cortex in the generation of the cortico-thalamic-cortical oscillations referred to as SWD.

Abstract

Face-to-face communication is multimodal at its core: it consists of a combination of vocal and visual signalling. However, current evidence suggests that, in the absence of an established communication system, visual signalling, especially in the form of visible gesture, is a more powerful form of communication than vocalisation, and therefore likely to have played a primary role in the emergence of human language. This argument is based on experimental evidence of how vocal and visual modalities (i.e., gesture) are employed to communicate about familiar concepts when participants cannot use their existing languages. To investigate this further, we introduce an experiment where pairs of participants performed a referential communication task in which they described unfamiliar stimuli in order to reduce reliance on conventional signals. Visual and auditory stimuli were described in three conditions: using visible gestures only, using non-linguistic vocalisations only and given the option to use both (multimodal communication). The results suggest that even in the absence of conventional signals, gesture is a more powerful mode of communication compared to vocalisation, but that there are also advantages to multimodality compared to using gesture alone. Participants with an option to produce multimodal signals had comparable accuracy to those using only gesture, but gained an efficiency advantage. The analysis of the interactions between participants showed that interactants developed novel communication systems for unfamiliar stimuli by deploying different modalities flexibly to suit their needs and by taking advantage of multimodality when required.

Abstract

Although onsets do not arbitrate stress placement in English categorically, results from Kelly (2004) and Ryan (2014) suggest that English stress assignment is nevertheless sensitive to onset complexity. Phonetic work on languages in which onsets participate in categorical weight criteria shows that onsets contribute to stress assignment through their phonetic impact on the nucleus, primarily through their effect on nucleus energy (Gordon, 2005). Onsets in English probabilistically participate in weight-based processes, and here it is predicted that they impact the phonetic realization of the syllable similar to the way that onsets do in languages with categorical onset weight criteria. To test this prediction, speakers in this study produced monosyllabic English words varying in onset complexity, and measures of duration, intensity, and f0 were collected. Results of the current study are consistent with the predictions of Gordon’s perceptual account of categorical weight, showing that integrated intensity of the rime is incapable of driving onset weight behavior in English. Furthermore, results indicate that onsets impact the shape of the intensity envelope in a manner consistent with explanations for gradient onset weight that appeal to onset influence on the perceptual center (Ryan, 2014). Together, these results show that cues to gradient weight act independently of primary cues to categorical weight to probabilistically impact weight sensitive stress assignment in English.

Abstract

It is well established that readers form mental images when reading a narrative. However, the consequences of mental imagery (i.e. the influence of mental imagery on the way people experience stories) are still unclear. Here we manipulated the amount of mental imagery that participants engaged in while reading short literary stories in two experiments. Participants received pre-reading instructions aimed at encouraging or discouraging mental imagery. After reading, participants answered questions about their reading experiences. We also measured individual trait differences that are relevant for literary reading experiences. The results from the first experiment suggests an important role of mental imagery in determining reading experiences. However, the results from the second experiment show that mental imagery is only a weak predictor of reading experiences compared to individual (trait) differences in how imaginative participants were. Moreover, the influence of mental imagery instructions did not extend to reading experiences unrelated to mental imagery. The implications of these results for the relationship between mental imagery and reading experiences are discussed.

Abstract

To English speakers, the distinctions between blue and green, cup and glass, or cut and break seem self-evident. The intuition is that these words label categories that have an existence independent of language, and language merely captures the pre-existing categories. But cross-linguistic work shows that the named distinctions are not nearly as self-evident as they may feel. There is diversity in how languages divide up domains including color, number, plants and animals, drinking vessels and household containers, body parts, spatial relations, locomotion, acts of cutting and breaking, acts of carrying and holding, and more. Still, studies documenting variability across languages also uncover striking commonalities. Such commonalities indicate that there are sources of constraint on the variation. Both the commonalities and divergences carry important lessons for Cognitive Science. They speak to the causal relations among language, thought, and culture; the possibility of cross-culturally shared aspects of perception and cognition; the methods needed for studying general-purpose, nonlinguistic concepts; and how languages are learned

Abstract

Listeners often experience cocktail-party situations, encountering multiple ongoing conversa-
tions while tracking just one. Capturing the words spoken under such conditions requires selec-
tive attention and processing, which involves using phonetic details to discern phonological
structure. How do bilinguals accomplish this in L1-L2 competition? We addressed that question
using a dichotic listening task with fluent Malayalam-English bilinguals, in which they were pre-
sented with synchronized nonce words, one in each language in separate ears, with competing
onsets of a labial stop (Malayalam) and a labial fricative (English), both voiced or both voiceless.
They were required to attend to the Malayalam or the English item, in separate blocks, and report
the initial consonant they heard. We found that perceptual intrusions from the unattended to the
attended language were influenced by voicing, with more intrusions on voiced than voiceless tri-
als. This result supports our proposal for the feature specification of consonants in Malayalam-
English bilinguals, which makes use of privative features, underspecification and the “standard
approach” to laryngeal features, as against “laryngeal realism”. Given this representational
account, we observe that intrusions result from phonetic properties in the unattended signal
being assimilated to the closest matching phonological category in the attended language, and
are more likely for segments with a greater number of phonological feature specifications.

Abstract

Objectives Oppositional behavior in childhood is a probabilistic risk factor for the subsequent development of more serious conduct problems characteristic of conduct disorder (CD). The capacity to understand the subjective states of others (socioemotional competence) helps regulate antisocial behavior in typical development. We hypothesized that socioemotional competence moderates the developmental relationship between oppositionality and CD symptoms, such that oppositional defiant disorder (ODD) symptoms pose the greatest risk for subsequent CD symptoms in children with poor socioemotional competence. Method Parent-report data were collected for 6,218 children at 7 and 10 years of age. Bootstrap multiple regression predicting CD symptoms at age 10 was used to test for an interaction between socioemotional competence and ODD symptoms, while also accounting for direct effects and controlling for sex, maternal education, attention-deficit/hyperactivity disorder symptoms, and CD symptoms at 7 years. We further tested whether the interaction applied to both males and females, and to both aggressive and rule-breaking CD symptoms. Results A significant interaction was found between ODD and socioemotional competence: the association between oppositionality at 7 years and CD traits at 10 years was strongest for children with poor socioemotional capacities. As predicted, this moderation effect was significant in a model predicting aggression, but it was not significant for rule-breaking CD symptoms. Conclusion Socioemotional competence moderates the developmental relationship between mid-childhood oppositionality and more serious conduct problems in later childhood. A capacity to understand the subjective states of others may buffer the risk posed by oppositionality for later CD symptoms, including aggression.

Abstract

To talk about space, spoken languages rely on arbitrary and categorical forms (e.g., left, right). In sign languages, however, the visual–spatial modality allows for iconic encodings (motivated form-meaning mappings) of space in which form and location of the hands bear resemblance to the objects and spatial relations depicted. We assessed whether the iconic encodings in sign languages guide visual attention to spatial relations differently than spatial encodings in spoken languages during message preparation at the sentence level. Using a visual world production eye-tracking paradigm, we compared 20 deaf native signers of Sign-Language-of-the-Netherlands and 20 Dutch speakers’ visual attention to describe left versus right configurations of objects (e.g., “pen is to the left/right of cup”). Participants viewed 4-picture displays in which each picture contained the same 2 objects but in different spatial relations (lateral [left/right], sagittal [front/behind], topological [in/on]) to each other. They described the target picture (left/right) highlighted by an arrow. During message preparation, signers, but not speakers, experienced increasing eye-gaze competition from other spatial configurations. This effect was absent during picture viewing prior to message preparation of relational encoding. Moreover, signers’ visual attention to lateral and/or sagittal relations was predicted by the type of iconicity (i.e., object and space resemblance vs. space resemblance only) in their spatial descriptions. Findings are discussed in relation to how “thinking for speaking” differs from “thinking for signing” and how iconicity can mediate the link between language and human experience and guides signers’ but not speakers’ attention to visual aspects of the world.

Abstract

Although we agree with Pickering & Garrod (P&G) that prediction-by-simulation and prediction-by-association are important mechanisms of anticipatory language processing, this commentary suggests that they: (1) overlook other potential mechanisms that might underlie prediction in language processing, (2) overestimate the importance of prediction-by-association in early childhood, and (3) underestimate the complexity and significance of several factors that might mediate prediction during language processing.

Abstract

What is the relative salience of different aspects of word meaning in the developing lexicon? The current study examines the time-course of retrieval of semantic and color knowledge associated with words during toddler word recognition: at what point do toddlers orient towards an image of a yellow cup upon hearing color-matching words such as “banana” (typically yellow) relative to unrelated words (e.g., “house”)? Do children orient faster to semantic matching images relative to color matching images, e.g., orient faster to an image of a cookie relative to a yellow cup upon hearing the word “banana”? The results strongly suggest a prioritization of semantic information over color information in children’s word-referent mappings. This indicates that, even for natural objects (e.g., food, animals that are more likely to have a prototypical color), semantic knowledge is a more salient aspect of toddler's word meaning than color knowledge. For 24-month-old Dutch toddlers, bananas are thus more edible than they are yellow.

Abstract

Psychological scientists have become increasingly concerned with issues related to methodology and replicability, and infancy researchers in particular face specific challenges related to replicability: For example, high-powered studies are difficult to conduct, testing conditions vary across labs, and different labs have access to different infant populations. Addressing these concerns, we report on a large-scale, multisite study aimed at (a) assessing the overall replicability of a single theoretically important phenomenon and (b) examining methodological, cultural, and developmental moderators. We focus on infants’ preference for infant-directed speech (IDS) over adult-directed speech (ADS). Stimuli of mothers speaking to their infants and to an adult in North American English were created using seminaturalistic laboratory-based audio recordings. Infants’ relative preference for IDS and ADS was assessed across 67 laboratories in North America, Europe, Australia, and Asia using the three common methods for measuring infants’ discrimination (head-turn preference, central fixation, and eye tracking). The overall meta-analytic effect size (Cohen’s d) was 0.35, 95% confidence interval = [0.29, 0.42], which was reliably above zero but smaller than the meta-analytic mean computed from previous literature (0.67). The IDS preference was significantly stronger in older children, in those children for whom the stimuli matched their native language and dialect, and in data from labs using the head-turn preference procedure. Together, these findings replicate the IDS preference but suggest that its magnitude is modulated by development, native-language experience, and testing procedure.

Abstract

This study tested whether individual sensitivity to an auditory perceptual cue called amplitude rise time (ART) facilitates novel word learning. Forty adult native speakers of Polish performed a perceptual task testing their sensitivity to ART, learned associations between nonwords and pictures of common objects, and were subsequently tested on their knowledge with a picture recognition (PR) task. In the PR task participants heard each nonword, followed either by a congruent or incongruent picture, and had to assess if the picture matched the nonword. Word learning efficiency was measured by accuracy and reaction time on the PR task and modulation of the N300 ERP. As predicted, participants with greater sensitivity to ART showed better performance in PR suggesting that auditory sensitivity indeed facilitates learning of novel words. Contrary to expectations, the N300 was not modulated by sensitivity to ART suggesting that the behavioral and ERP measures reflect different underlying processes.

Abstract

Hierarchical structure and compositionality imbue human language with unparalleled expressive power and set it apart from other perception–action systems. However, neither formal nor neurobiological models account for how these defining computational properties might arise in a physiological system. I attempt to reconcile hierarchy and compositionality with principles from cell assembly computation in neuroscience; the result is an emerging theory of how the brain could convert distributed perceptual representations into hierarchical structures across multiple timescales while representing interpretable incremental stages of (de) compositional meaning. The model's architecture—a multidimensional coordinate system based on neurophysiological models of sensory processing—proposes that a manifold of neural trajectories encodes sensory, motor, and abstract linguistic states. Gain modulation, including inhibition, tunes the path in the manifold in accordance with behavior and is how latent structure is inferred. As a consequence, predictive information about upcoming sensory input during production and comprehension is available without a separate operation. The proposed processing mechanism is synthesized from current models of neural entrainment to speech, concepts from systems neuroscience and category theory, and a symbolic-connectionist computational model that uses time and rhythm to structure information. I build on evidence from cognitive neuroscience and computational modeling that suggests a formal and mechanistic alignment between structure building and neural oscillations and moves toward unifying basic insights from linguistics and psycholinguistics with the currency of neural computation.

Abstract

To comprehend speech sounds, listeners tune in to speech rate information in the proximal (immediately adjacent), distal (non-adjacent), and global context (further removed preceding and following sentences). Effects of global contextual speech rate cues on speech perception have been shown to follow constraints not found for proximal and distal speech rate. Therefore, listeners may process such global cues at distinct time points during word recognition. We conducted a printed-word eye-tracking experiment to compare the time courses of distal and global rate effects. Results indicated that the distal rate effect emerged immediately after target sound presentation, in line with a general-auditory account. The global rate effect, however, arose more than 200 ms later than the distal rate effect, indicating that distal and global context effects involve distinct processing mechanisms. Results are interpreted in a two-stage model of acoustic context effects. This model posits that distal context effects involve very early perceptual processes, while global context effects arise at a later stage, involving cognitive adjustments conditioned by higher-level information.

Abstract

The use of generic verbs of speech in functions not related to their primary meaning, such as to introduce complements or adjuncts, is cross-linguistically widespread; it is also characteristic of some languages of Siberia. However, the distribution of non-canonical functions of generic verbs of speech among the languages of Siberia is very uneven, with striking differences even between dialects of one language. In this paper we attempt to elucidate whether shared inheritance, parallel independent developments, or areal convergence are the factors determining this distribution, using fine-scaled investigations of narrative data from a large number of Siberian languages and dialects. This enables us to uncover a wide range of non-canonical functions that the generic verb of speech has acquired in some of the languages investigated, as well as to highlight the very complex historical processes at play.

Abstract

Focus is regularly treated as a cross-linguistically stable category that is merely manifested by different structural means in different languages, such that a common focus feature may be realised through, for example, a morpheme in one language and syntactic movement in another. We demonstrate this conception of focus to be unsustainable on both theoretical and empirical grounds, invoking fundamental argumentation regarding the notions of focus and linguistic category, alongside data from a wide range of languages. Attempts to salvage a cross-linguistic notion of focus through parameterisation, the introduction of additional information-structural primitives such as contrast, or reduction to a single common factor are shown to be equally problematic. We identify the causes of repeated misconceptions about the nature of focus in a number of interrelated theoretical and methodological tendencies in linguistic analysis. We propose to see focus as a heuristic tool and to employ it as a means of identifying structural patterns that languages use to generate a certain number of related pragmatic effects, potentially through quite diverse mechanisms.

Abstract

Is human behavior, and more specifically linguistic behavior, intentional? Some scholars have proposed that action is driven in a top-down manner by one single intention—i.e.,one single conscious goal. Others have argued that actions are mostly non-intentional,insofar as often the single goal driving an action is not consciously represented. We intend to claim that both alternatives are unsatisfactory; more specifically, we claim that actions are intentional, but intentionality is distributed across complex goal-directed representations of action, rather than concentrated in single intentions driving action in a top-down manner. These complex representations encompass a multiplicity of goals, together with other components which are not goals themselves, and are the result of a largely automatic dynamic of activation; such an automatic processing, however, does not preclude the involvement of conscious attention, shifting from one component to the other of the overall goal-directed representation.

Abstract

We present an empirical challenge to Jardine's (2016) assertion that only tonal spreading patterns can be unbounded circumambient, meaning that the determination of a phonological value may depend on information that is an unbounded distance away on both sides. We focus on a demonstration that the ATR harmony pattern found in Tutrugbu is unbounded circumambient, and we also cite several other segmental spreading processes with the same general character. We discuss implications for the complexity of phonology and for the relationship between the explanation of typology and the evaluation of phonological theories.

Abstract

Historically, the study of human identity perception has focused on faces, but the voice is also central to our expressions and experiences of identity [Belin, P., Fecteau, S., & Bedard, C. Thinking the voice: Neural correlates of voice perception. Trends in Cognitive Sciences, 8, 129–135, 2004]. Our voices are highly flexible and dynamic; talkers speak differently, depending on their health, emotional state, and the social setting, as well as extrinsic factors such as background noise. However, to date, there have been no studies of the neural correlates of identity modulation in speech production. In the current fMRI experiment, we measured the neural activity supporting controlled voice change in adult participants performing spoken impressions. We reveal that deliberate modulation of vocal identity recruits the left anterior insula and inferior frontal gyrus, supporting the planning of novel articulations. Bilateral sites in posterior superior temporal/inferior parietal cortex and a region in right middle/anterior STS showed greater responses during the emulation of specific vocal identities than for impressions of generic accents. Using functional connectivity analyses, we describe roles for these three sites in their interactions with the brain regions supporting speech planning and production. Our findings mark a significant step toward understanding the neural control of vocal identity, with wider implications for the cognitive control of voluntary motor acts.

Abstract

Although word boundaries are rarely clearly marked, listeners can rapidly recognize the individual words of spoken sentences. Some theories explain this in terms of competition between multiply activated lexical hypotheses; others invoke sensitivity to prosodic structure. We describe a connectionist model, SHORTLIST, in which recognition by activation and competition is successful with a realistically sized lexicon. Three experiments are then reported in which listeners detected real words embedded in nonsense strings, some of which were themselves the onsets of longer words. Effects both of competition between words and of prosodic structure were observed, suggesting that activation and competition alone are not sufficient to explain word recognition in continuous speech. However, the results can be accounted for by a version of SHORTLIST that is sensitive to prosodic structure.

Abstract

Learning new words entails, inter alia, encoding of novel sound patterns and transferring those patterns from short-term to long-term memory. We report a series of 5 experiments that investigated whether the memory systems engaged in word learning are specialized for speech and whether utilization of these systems results in a benefit for word learning. Sine-wave synthesis (SWS) was applied to spoken nonwords, and listeners were or were not informed (through instruction and familiarization) that the SWS stimuli were derived from actual utterances. This allowed us to manipulate whether listeners would process sound sequences as speech or as nonspeech. In a sound–picture association learning task, listeners who processed the SWS stimuli as speech consistently learned faster and remembered more associations than listeners who processed the same stimuli as nonspeech. The advantage of listening in “speech mode” was stable over the course of 7 days. These results provide causal evidence that access to a specialized, phonological short-term memory system is important for word learning. More generally, this study supports the notion that subsystems of auditory short-term memory are specialized for processing different types of acoustic information.

Abstract

We introduce the papers in this special issue by summarising the current major issues in spoken word recognition. We argue that a full understanding of the process of lexical access during speech comprehension will depend on resolving several key representational issues: what is the form of the representations used for lexical access; how is phonological information coded in the mental lexicon; and how is the morphological and semantic information about each word stored? We then discuss a number of distinct access processes: competition between lexical hypotheses; the computation of goodness-of-fit between the signal and stored lexical knowledge; segmentation of continuous speech; whether the lexicon influences prelexical processing through feedback; and the relationship of form-based processing to the processes responsible for deriving an interpretation of a complete utterance. We conclude that further progress may well be made by swapping ideas among the different sub-domains of the discipline.

Abstract

In two word-spotting experiments, Japanese listeners detected Japanese words faster in vowel contexts (e.g., agura, to sit cross-legged, in oagura) than in consonant contexts (e.g., tagura). In the same experiments, however, listeners spotted words in vowel contexts (e.g., saru, monkey, in sarua) no faster than in moraic nasal contexts (e.g., saruN). In a third word-spotting experiment, words like uni, sea urchin, followed contexts consisting of a consonant-consonant-vowel mora (e.g., gya) plus either a moraic nasal (gyaNuni), a vowel (gyaouni) or a consonant (gyabuni). Listeners spotted words as easily in the first as in the second context (where in each case the target words were aligned with mora boundaries), but found it almost impossible to spot words in the third (where there was a single consonant, such as the [b] in gyabuni, between the beginning of the word and the nearest preceding mora boundary). Three control experiments confirmed that these effects reflected the relative ease of segmentation of the words from their contexts.We argue that the listeners showed sensitivity to the viability of sound sequences as possible Japanese words in the way that they parsed the speech into words. Since single consonants are not possible Japanese words, the listeners avoided lexical parses including single consonants and thus had difficulty recognizing words in the consonant contexts. Even though moraic nasals are also impossible words, they were not difficult segmentation contexts because, as with the vowel contexts, the mora boundaries between the contexts and the target words signaled likely word boundaries. Moraic rhythm appears to provide Japanese listeners with important segmentation cues.

Abstract

Research on speech processing is often focused on a phenomenon termed “entrainment”, whereby the cortex shadows rhythmic acoustic information with oscillatory activity. Entrainment has been observed to a range of rhythms present in speech; in addition, synchronicity with abstract information (e.g. syntactic structures) has been observed. Entrainment accounts face two challenges: First, speech is not exactly rhythmic; second, synchronicity with representations that lack a clear acoustic counterpart has been described. We propose that apparent entrainment does not always result from acoustic information. Rather, internal rhythms may have functionalities in the generation of abstract representations and predictions. While acoustics may often provide punctate opportunities for entrainment, internal rhythms may also live a life of their own to infer and predict information, leading to intrinsic synchronicity – not to be counted as entrainment. This possibility may open up new research avenues in the psycho– and neurolinguistic study of language processing and language development.

Abstract

Could meaning be read from acoustics, or from the refraction rate of pyramidal cells innervated by the cochlea, everyone would be an omniglot. Speech does not contain sufficient acoustic cues to identify linguistic units such as morphemes, words, and phrases without prior knowledge. Our target article (Meyer, L., Sun, Y., & Martin, A. E. (2019). Synchronous, but not entrained: Exogenous and endogenous cortical rhythms of speech and language processing. Language, Cognition and Neuroscience, 1–11. https://doi.org/10.1080/23273798.2019.1693050) thus questioned the concept of “entrainment” of neural oscillations to such units. We suggested that synchronicity with these points to the existence of endogenous functional “oscillators”—or population rhythmic activity in Giraud’s (2020) terms—that underlie the inference, generation, and prediction of linguistic units. Here, we address a series of inspirational commentaries by our colleagues. As apparent from these, some issues raised by our target article have already been raised in the literature. Psycho– and neurolinguists might still benefit from our reply, as “oscillations are an old concept in vision and motor functions, but a new one in linguistics” (Giraud, A.-L. 2020. Oscillations for all A commentary on Meyer, Sun & Martin (2020). Language, Cognition and Neuroscience, 1–8).

Abstract

Many authors have recently highlighted the importance of prediction for language comprehension. Pickering & Garrod (P&G) are the first to propose a central role for prediction in language production. This is an intriguing idea, but it is not clear what it means for speakers to predict their own utterances, and how prediction during production can be empirically distinguished from production proper.

Abstract

Recently, a new theory of timing in sentence production has been proposed by Ferreira (1993). This theory assumes that at the phonological level, each syllable of an utterance is assigned one or more abstract timing units depending on its position in the prosodic structure. The number of timing units associated with a syllable determines the time interval between its onset and the onset of the next syllable. An interesting prediction from the theory, which was confirmed in Ferreira's experiments with speakers of American English, is that the time intervals between syllable onsets should only depend on the syllables' positions in the prosodic structure, but not on their segmental content. However, in the present experiments, which were carried out in Dutch, the intervals between syllable onsets were consistently longer for phonetically long syllables than for short syllables. The implications of this result for models of timing in sentence production are discussed.

Abstract

Homeostatic regulation of serotonin (5-HT) concentration is critical for “normal” topographical organization and development of thalamocortical (TC) afferent circuits. Down-regulation of the serotonin transporter (SERT) and the consequent impaired reuptake of 5-HT at the synapse, results in a reduced terminal branching of developing TC afferents within the primary somatosensory cortex (S1). Despite the presence of multiple genetic models, the effect of high extracellular 5-HT levels on the structure and function of developing intracortical neural networks is far from being understood. Here, using juvenile SERT knockout (SERT−/−) rats we investigated, in vitro, the effect of increased 5-HT levels on the structural organization of (i) the TC projections of the ventroposteromedial thalamic nucleus toward S1, (ii) the general barrel-field pattern, and (iii) the electrophysiological and morphological properties of the excitatory cell population in layer IV of S1 [spiny stellate (SpSt) and pyramidal cells]. Our results confirmed previous findings that high levels of 5-HT during development lead to a reduction of the topographical precision of TCA projections toward the barrel cortex. Also, the barrel pattern was altered but not abolished in SERT−/− rats. In layer IV, both excitatory SpSt and pyramidal cells showed a significantly reduced intracolumnar organization of their axonal projections. In addition, the layer IV SpSt cells gave rise to a prominent projection toward the infragranular layer Vb. Our findings point to a structural and functional reorganization of TCAs, as well as early stage intracortical microcircuitry, following the disruption of 5-HT reuptake during critical developmental periods. The increased projection pattern of the layer IV neurons suggests that the intracortical network changes are not limited to the main entry layer IV but may also affect the subsequent stages of the canonical circuits of the barrel cortex.