Publications

Abstract

Research on pattern perception and rule learning, grounded in formal language theory (FLT) and using artificial grammar learning paradigms, has exploded in the last decade. This approach marries empirical research conducted by neuroscientists, psychologists and ethologists with the theory of computation and FLT, developed by mathematicians, linguists and computer scientists over the last century. Of particular current interest are comparative extensions of this work to non-human animals, and neuroscientific investigations using brain imaging techniques. We provide a short introduction to the history of these fields, and to some of the dominant hypotheses, to help contextualize these ongoing research programmes, and finally briefly introduce the papers in the current issue.

Abstract

Event-related potentials (ERPs) provide a window into how the brain is processing language. Here, we propose a theory that argues that ERPs such as the N400 and P600 arise as side effects of an error-based learning mechanism that explains linguistic adaptation and language learning. We instantiated this theory in a connectionist model that can simulate data from three studies on the N400 (amplitude modulation by expectancy, contextual constraint, and sentence position), five studies on the P600 (agreement, tense, word category, subcategorization and garden-path sentences), and a study on the semantic P600 in role reversal anomalies. Since ERPs are learning signals, this account explains adaptation of ERP amplitude to within-experiment frequency manipulations and the way ERP effects are shaped by word predictability in earlier sentences. Moreover, it predicts that ERPs can change over language development. The model provides an account of the sensitivity of ERPs to expectation mismatch, the relative timing of the N400 and P600, the semantic nature of the N400, the syntactic nature of the P600, and the fact that ERPs can change with experience. This approach suggests that comprehension ERPs are related to sentence production and language acquisition mechanisms

Abstract

The language faculty is physically realized in the neurobiological infrastructure of the human brain. Despite significant efforts, an integrated understanding of this system remains a formidable challenge. What is missing from most theoretical accounts is a specification of the neural mechanisms that implement language function. Computational models that have been put forward generally lack an explicit neurobiological foundation. We propose a neurobiologically informed causal modeling approach which offers a framework for how to bridge this gap. A neurobiological causal model is a mechanistic description of language processing that is grounded in, and constrained by, the characteristics of the neurobiological substrate. It intends to model the generators of language behavior at the level of implementational causality. We describe key features and neurobiological component parts from which causal models can be built and provide guidelines on how to implement them in model simulations. Then we outline how this approach can shed new light on the core computational machinery for language, the long-term storage of words in the mental lexicon and combinatorial processing in sentence comprehension. In contrast to cognitive theories of behavior, causal models are formulated in the “machine language” of neurobiology which is universal to human cognition. We argue that neurobiological causal modeling should be pursued in addition to existing approaches. Eventually, this approach will allow us to develop an explicit computational neurobiology of language.

Abstract

Electrophysiological studies consistently find N400 effects of semantic incongruity in nonnative (L2) language comprehension. These N400 effects are often delayed compared with native (L1) comprehension, suggesting that semantic integration in one's second language occurs later than in one's first language. In this study, we investigated whether such a delay could be attributed to (1) intralingual lexical competition and/or (2) interlingual lexical competition. We recorded EEG from Dutch–English bilinguals who listened to English (L2) sentences in which the sentence-final word was (a) semantically fitting and (b) semantically incongruent or semantically incongruent but initially congruent due to sharing initial phonemes with (c) the most probable sentence completion within the L2 or (d) the L1 translation equivalent of the most probable sentence completion. We found an N400 effect in each of the semantically incongruent conditions. This N400 effect was significantly delayed to L2 words but not to L1 translation equivalents that were initially congruent with the sentence context. Taken together, these findings firstly demonstrate that semantic integration in nonnative listening can start based on word initial phonemes (i.e., before a single lexical candidate could have been selected based on the input) and secondly suggest that spuriously elicited L1 lexical candidates are not available for semantic integration in L2 speech comprehension.

Abstract

No abstract is available for this article

Abstract

This article briefly reviews some recent work on artificial language learning in children and adults. The final part of the article is devoted to a theoretical formulation of the language learning problem from a mechanistic neurobiological viewpoint and we show that it is logically possible to combine the notion of innate language constraints with, for example, the notion of domain general learning mechanisms. A growing body of empirical evidence suggests that the mechanisms involved in artificial language learning and in structured sequence processing are shared with those of natural language acquisition and natural language processing. Finally, by theoretically analyzing a formal learning model, we highlight Fodor’s insight that it is logically possible to combine innate, domain-specific constraints with domain-general learning mechanisms.

Abstract

Understanding the progression of neurological diseases is vital for accurate and early diagnosis and treatment planning. We introduce a new characterization of disease progression, which describes the disease as a series of events, each comprising a significant change in patient state. We provide novel algorithms to learn the event ordering from heterogeneous measurements over a whole patient cohort and demonstrate using combined imaging and clinical data from familial-Alzheimer's and Huntington's disease cohorts. Results provide new detail in the progression pattern of these diseases, while confirming known features, and give unique insight into the variability of progression over the cohort. The key advantage of the new model and algorithms over previous progression models is that they do not require a priori division of the patients into clinical stages. The model and its formulation extend naturally to a wide range of other diseases and developmental processes and accommodate cross-sectional and longitudinal input data.

Abstract

Accurate reconstruction of prehistoric social organization is important if we are to put together satisfactory multidisciplinary scenarios about, for example, the dispersal of human groups. Such considerations apply in the case of Indo-European and Austronesian, two large-scale language families that are thought to represent Neolithic expansions. Ancestral kinship patterns have mostly been inferred through reconstruction of kin terminologies in ancestral proto-languages using the linguistic comparative method, and through geographical or distributional arguments based on the comparative patterns of kin terms and ethnographic kinship ‘facts’. While these approaches are detailed and valuable, the processes through which conclusions have been drawn from the data fail to provide explicit criteria for systematic testing of alternative hypotheses. Here, we use language trees derived using phylogenetic tree-building techniques on Indo-European and Austronesian vocabulary data. With these trees, ethnographic data and Bayesian phylogenetic comparative methods, we statistically reconstruct past marital residence and infer rates of cultural change between different residence forms, showing Proto-Indo-European to be virilocal and Proto-Malayo-Polynesian uxorilocal. The instability of uxorilocality and the rare loss of virilocality once gained emerge as common features of both families

Abstract

An MEG experiment was carried out in order to compare the processing of lexical-tonal and intonational contrasts, based on the tonal dialect of Roermond (the Netherlands). A set of words with identical phoneme sequences but distinct pitch contours, which represented different lexical meanings or discourse meanings (statement vs. question), were presented to native speakers as well as to a control group of speakers of Standard Dutch, a non-tone language. The stimuli were arranged in a mismatch paradigm, under three experimental conditions: in the first condition (lexical), the pitch contour differences between standard and deviant stimuli reflected differences between lexical meanings; in the second condition (intonational), the stimuli differed in their discourse meaning; in the third condition (combined), they differed both in their lexical and discourse meaning. In all three conditions, native as well as non-native responses showed a clear MMNm (magnetic mismatch negativity) in a time window from 150 to 250 ms after the divergence point of standard and deviant pitch contours. In the lexical condition, a stronger response was found over the left temporal cortex of native as well as non-native speakers. In the intonational condition, the same activation pattern was observed in the control group, but not in the group of native speakers, who showed a right-hemisphere dominance instead. Finally, in the combined (lexical and intonational) condition, brain reactions appeared to represent the summation of the patterns found in the other two conditions. In sum, the lateralization of pitch processing is condition-dependent in the native group only, which suggests that language experience determines how processes should be distributed over both temporal cortices, according to the functions available in the grammar.

Abstract

Earlier work has explored spoken word production during irrelevant background speech such as intelligible and unintelligible word lists. The present study compared how different types of irrelevant background speech (word lists vs. sentences) influenced spoken word production relative to a quiet control condition, and whether the influence depended on the intelligibility of the background speech. Experiment 1 presented native Dutch speakers with Chinese word lists and sentences. Experiment 2 presented a similar group with Dutch word lists and sentences. In both experiments, the lexical selection demands in speech production were manipulated by varying name agreement (high vs. low) of the to-be-named pictures. Results showed that background speech, regardless of its intelligibility, disrupted spoken word production relative to a quiet condition, but no effects of word lists versus sentences in either language were found. Moreover, the disruption by intelligible background speech compared with the quiet condition was eliminated when planning low name agreement pictures. These findings suggest that any speech, even unintelligible speech, interferes with production, which implies that the disruption of spoken word production is mainly phonological in nature. The disruption by intelligible background speech can be reduced or eliminated via top–down attentional engagement.

Abstract

Traditionally, language processing has been thought of in terms of complete processing of the input. In contrast to this, Ferreira and colleagues put forth the idea of good enough processing. The proposal was that during everyday processing, ambiguities remain unresolved, we rely on heuristics instead of full analyses, and we carry out deep processing only if we need to for the task at hand. This idea has gathered substantial traction since its conception. In the current work, I review the papers that have tested the three key claims of good enough processing: ambiguities remain unresolved and underspecified, we use heuristics to parse sentences, and deep processing is only carried out if required by the task. I find mixed evidence for these claims and conclude with an appeal to further refinement of the claims and predictions of the theory.

Abstract

Genomewide quantitative-trait locus (QTL) linkage analysis was performed using a continuous measure of relative hand skill (PegQ) in a sample of 195 reading-disabled sibling pairs from the United Kingdom. This was the first genomewide screen for any measure related to handedness. The mean PegQ in the sample was equivalent to that of normative data, and PegQ was not correlated with tests of reading ability (correlations between −0.13 and 0.05). Relative hand skill could therefore be considered normal within the sample. A QTL on chromosome 2p11.2-12 yielded strong evidence for linkage to PegQ (empirical P=.00007), and another suggestive QTL on 17p11-q23 was also identified (empirical P=.002). The 2p11.2-12 locus was further analyzed in an independent sample of 143 reading-disabled sibling pairs, and this analysis yielded an empirical P=.13. Relative hand skill therefore is probably a complex multifactorial phenotype with a heterogeneous background, but nevertheless is amenable to QTL-based gene-mapping approaches.

Abstract

A locus on chromosome 2p12-16 has been implicated in dyslexia susceptibility by two independent linkage studies, including our own study of 119 nuclear twin-based families, each with at least one reading-disabled child. Nonetheless, no variant of any gene has been reported to show association with dyslexia, and no consistent clinical evidence exists to identify candidate genes with any strong a priori logic. We used 21 microsatellite markers spanning 2p12-16 to refine our 1-LOD unit linkage support interval to 12cM between D2S337 and D2S286. Then, in quantitative association analysis, two microsatellites yielded P values<0.05 across a range of reading-related measures (D2S2378 and D2S2114). The exon/intron borders of two positional candidate genes within the region were characterized, and the exons were screened for polymorphisms. The genes were Semaphorin4F (SEMA4F), which encodes a protein involved in axonal growth cone guidance, and OTX1, encoding a homeodomain transcription factor involved in forebrain development. Two non-synonymous single nucleotide polymorphisms were found in SEMA4F, each with a heterozygosity of 0.03. One intronic single nucleotide polymorphism between exons 12 and 13 of SEMA4F was tested for quantitative association, but no significant association was found. Only one single nucleotide polymorphism was found in OTX1, which was exonic but silent. Our data therefore suggest that linkage with reading disability at 2p12-16 is not caused by coding variants of SEMA4F or OTX1. Our study outlines the approach necessary for the identification of genetic variants causing dyslexia susceptibility in an epidemiological population of dyslexics.

Abstract

Population-based linkage analysis is a new method for analysing genomewide single nucleotide polymorphism (SNP) genotype data in case-control samples, which does not assume a common disease, common variant model. The genome is scanned for extended segments that show increased identity-by-descent sharing within case-case pairs, relative to case-control or control-control pairs. The method is robust to allelic heterogeneity and is suited to mapping genes which contain multiple, rare susceptibility variants of relatively high penetrance. We analysed genomewide SNP datasets for two schizophrenia case-control cohorts, collected in Aberdeen (461 cases, 459 controls) and Munich (429 cases, 428 controls). Population-based linkage testing must be performed within homogeneous samples and it was therefore necessary to analyse the cohorts separately. Each cohort was first subjected to several procedures to improve genetic homogeneity, including identity-by-state outlier detection and multidimensional scaling analysis. When testing only cases who reported a positive family history of major psychiatric disease, consistent with a model of strongly penetrant susceptibility alleles, we saw a distinct peak on chromosome 19q in both cohorts that appeared in meta-analysis (P=0.000016) to surpass the traditional level for genomewide significance for complex trait linkage. The linkage signal was also present in a third case-control sample for familial bipolar disorder, such that meta-analysing all three datasets together yielded a linkage P=0.0000026. A model of rare but highly penetrant disease alleles may be more applicable to some instances of major psychiatric diseases than the common disease common variant model, and we therefore suggest that other genome scan datasets are analysed with this new, complementary method.

Abstract

Dyslexia, a disorder of reading and spelling, is a heterogeneous neurological syndrome with a complex genetic and environmental aetiology. People with dyslexia differ in their individual profiles across a range of cognitive, physiological, and behavioural measures related to reading disability. Some or all of the subtypes of dyslexia might have partly or wholly distinct genetic causes. An understanding of the role of genetics in dyslexia could help to diagnose and treat susceptible children more effectively and rapidly than is currently possible and in ways that account for their individual disabilities. This knowledge will also give new insights into the neurobiology of reading and language cognition. Genetic linkage analysis has identified regions of the genome that might harbour inherited variants that cause reading disability. In particular, loci on chromosomes 6 and 18 have shown strong and replicable effects on reading abilities. These genomic regions contain tens or hundreds of candidate genes, and studies aimed at the identification of the specific causal genetic variants are underway.

Abstract

Attention deficit/hyperactivity disorder (ADHD) is one of the most common neuropsychiatric disorders with a worldwide prevalence around 4–5% in children and 1–4% in adults. Although ADHD is highly heritable and familial risk may contribute most strongly to the persistent form of the disorder, there are few studies on the genetics of ADHD in adults. In this paper, we present the first results of the International Multicentre Persistent ADHD Genetics CollaboraTion (IMpACT) that has been set up with the goal of performing research into the genetics of persistent ADHD. In this study, we carried out a combined analysis as well as a meta-analysis of the association of the SLC6A3/DAT1 gene with persistent ADHD in 1440 patients and 1769 controls from IMpACT and an earlier report. DAT1, encoding the dopamine transporter, is one of the most frequently studied genes in ADHD, though results have been inconsistent. A variable number tandem repeat polymorphism (VNTR) in the 3′-untranslated region (UTR) of the gene and, more recently, a haplotype of this VNTR with another VNTR in intron 8 have been the target of most studies. Although the 10/10 genotype of the 3′-UTR VNTR and the 10-6 haplotype of the two VNTRs are thought to be risk factors for ADHD in children, we found the 9/9 genotype and the 9-6 haplotype associated with persistent ADHD. In conclusion, a differential association of DAT1 with ADHD in children and in adults might help explain the inconsistencies observed in earlier association studies. However, the data might also imply that DAT1 has a modulatory rather than causative role in ADHD.

Abstract

Previous research on the effect of perturbed auditory feedback in speech production has focused on two types of responses. In the short term, speakers generate compensatory motor commands in response to unexpected perturbations. In the longer term, speakers adapt feedforward motor programmes in response to feedback perturbations, to avoid future errors. The current study investigated the relation between these two types of responses to altered auditory feedback. Specifically, it was hypothesised that consistency in previous feedback perturbations would influence whether speakers adapt their feedforward motor programmes. In an altered auditory feedback paradigm, formant perturbations were applied either across all trials (the consistent condition) or only to some trials, whereas the others remained unperturbed (the inconsistent condition). The results showed that speakers’ responses were affected by feedback consistency, with stronger speech changes in the consistent condition compared with the inconsistent condition. Current models of speech-motor control can explain this consistency effect. However, the data also suggest that compensation and adaptation are distinct processes, which are not in line with all current models.

Abstract

A spelling disorder that received much attention recently is the so-called graphemic buffer impairment. Caramazza et al. (1987) presented the first systematic case study of a patient with this disorder. Miceli & Capasso (2006) provide an extensive overview of the relevant literature. This article adds to the literature by describing a Dutch case, i.e. patient BM. We demonstrate how specific features of Dutch and Dutch orthography interact with the graphemic buffer impairment. In addition, we paid special attention to the influence of grapheme position on the patient’s spelling accuracy. For this we used, in contrast with most of the previous literature, the proportional accountability method described in Machtynger & Shallice (2009). We show that by using this method the underlying error distribution can be more optimally captured than with classical methods. The result of this analysis replicates two distributions that have been previously reported in the literature. Finally, attention will be paid to the role of phonology in the described disorder.

Abstract

Theeffects of spatial filtering in functional magnetic resonance imaging were investigated by reevaluating the data of a previous study of episodic memory encoding at 2 × 2 × 4-mm3 resolution with use of a SPM99 analysis involving a Gaussian kernel of 8-mm full width at half maximum. In addition, a multisubject analysis of activated regions was performed by normalizing the functional images to an approximate Talairach brain atlas. In individual subjects, spatial filtering merged activations in anatomically separated brain regions. Moreover, small foci of activated pixels which originated from veins became blurred and hence indistinguishable from parenchymal responses. The multisubject analysis resulted in activation of the hippocampus proper, a finding which could not be confirmed by the activation maps obtained at high resolution. It is concluded that the validity of multisubject fMRI analyses can be considerably improved by first analyzing individual data sets at optimum resolution to assess the effects of spatial filtering and minimize the risk of signal contamination by macroscopically visible vessels.

Abstract

To identify genetic variants associated with birth weight, we meta-analyzed six genome-wide association (GWA) studies (n = 10,623 Europeans from pregnancy/birth cohorts) and followed up two lead signals in 13 replication studies (n = 27,591). rs900400 near LEKR1 and CCNL1 (P = 2 x 10(-35)) and rs9883204 in ADCY5 (P = 7 x 10(-15)) were robustly associated with birth weight. Correlated SNPs in ADCY5 were recently implicated in regulation of glucose levels and susceptibility to type 2 diabetes, providing evidence that the well-described association between lower birth weight and subsequent type 2 diabetes has a genetic component, distinct from the proposed role of programming by maternal nutrition. Using data from both SNPs, we found that the 9% of Europeans carrying four birth weight-lowering alleles were, on average, 113 g (95% CI 89-137 g) lighter at birth than the 24% with zero or one alleles (P(trend) = 7 x 10(-30)). The impact on birth weight is similar to that of a mother smoking 4-5 cigarettes per day in the third trimester of pregnancy.

Abstract

Kleefstra syndrome (KS) is a neurodevelopmental disorder caused by mutations in the histone methyltransferase EHMT1. To study the impact of decreased EHMT1 function in human cells, we generated excitatory cortical neurons from induced pluripotent stem (iPS) cells derived from KS patients. Neuronal networks of patient-derived cells exhibit network bursting with a reduced rate, longer duration, and increased temporal irregularity compared to control networks. We show that these changes are mediated by upregulation of NMDA receptor (NMDAR) subunit 1 correlating with reduced deposition of the repressive H3K9me2 mark, the catalytic product of EHMT1, at the GRIN1 promoter. In mice EHMT1 deficiency leads to similar neuronal network impairments with increased NMDAR function. Finally, we rescue the KS patient-derived neuronal network phenotypes by pharmacological inhibition of NMDARs. Summarized, we demonstrate a direct link between EHMT1 deficiency and NMDAR hyperfunction in human neurons, providing a potential basis for more targeted therapeutic approaches for KS.

Abstract

Disruptions of the FOXP2 gene cause a speech and language disorder involving difficulties in sequencing orofacial movements. FOXP2 is expressed in cortico-striatal and cortico-cerebellar circuits important for fine motor skills, and affected individuals show abnormalities in these brain regions. We selectively disrupted Foxp2 in the cerebellar Purkinje cells, striatum or cortex of mice and assessed the effects on skilled motor behaviour using an operant lever-pressing task. Foxp2 loss in each region impacted behaviour differently, with striatal and Purkinje cell disruptions affecting the variability and the speed of lever-press sequences, respectively. Mice lacking Foxp2 in Purkinje cells showed a prominent phenotype involving slowed lever pressing as well as deficits in skilled locomotion. In vivo recordings from Purkinje cells uncovered an increased simple spike firing rate and decreased modulation of firing during limb movements. This was caused by increased intrinsic excitability rather than changes in excitatory or inhibitory inputs. Our findings show that Foxp2 can modulate different aspects of motor behaviour in distinct brain regions, and uncover an unknown role for Foxp2 in the modulation of Purkinje cell activity that severely impacts skilled movements.

Abstract

Mutations in the human FOXP2 gene cause impaired speech development and linguistic deficits, which have been best characterised in a large pedigree called the KE family. The encoded protein is highly conserved in many vertebrates and is expressed in homologous brain regions required for sensorimotor integration and motor-skill learning, in particular corticostriatal circuits. Independent studies in multiple species suggest that the striatum is a key site of FOXP2 action. Here, we used in vivo recordings in awake-behaving mice to investigate the effects of the KE-family mutation on the function of striatal circuits during motor-skill learning. We uncovered abnormally high ongoing striatal activity in mice carrying an identical mutation to that of the KE family. Furthermore, there were dramatic alterations in striatal plasticity during the acquisition of a motor skill, with most neurons in mutants showing negative modulation of firing rate, starkly contrasting with the predominantly positive modulation seen in control animals. We also observed striking changes in the temporal coordination of striatal firing during motor-skill learning in mutants. Our results indicate that FOXP2 is critical for the function of striatal circuits in vivo, which are important not only for speech but also for other striatal-dependent skills.

Abstract

High frequency words have been suggested to benefit both speech segmentation and grammatical categorization of the words around them. Despite utilizing similar information, these tasks are usually investigated separately in studies examining learning. We determined whether including high frequency words in continuous speech could support categorization when words are being segmented for the first time. We familiarized learners with continuous artificial speech comprising repetitions of target words, which were preceded by high-frequency marker words. Crucially, marker words distinguished targets into 2 distributionally defined categories. We measured learning with segmentation and categorization tests and compared performance against a control group that heard the artificial speech without these marker words (i.e., just the targets, with no cues for categorization). Participants segmented the target words from speech in both conditions, but critically when the marker words were present, they influenced acquisition of word-referent mappings in a subsequent transfer task, with participants demonstrating better early learning for mappings that were consistent (rather than inconsistent) with the distributional categories. We propose that high-frequency words may assist early grammatical categorization, while speech segmentation is still being learned.

Abstract

Sleep plays an important role in neural reorganisation which underpins memory consolidation. The gradual replacement of
hippocampal binding of new memories with intracortical connections helps to link new memories to existing knowledge. This process appears to be faster for memories which fit more easily into existing schemas. Here we seek to investigate whether this more rapid consolidation of schema-conformant information is facilitated by
sleep, and the neural basis of this process.

Abstract

Several studies report an association between REM Sleep Behavior Disorder (RBD) and neurodegenerative diseases, in particular synucleinopathies. Interestingly, the onset of RBD precedes the development of neurodegeneration by several years. This review and meta-analysis aims to establish the rate of conversion of RBD into neurodegenerative diseases. Longitudinal studies were searched from the PubMed, Web of Science, and SCOPUS databases. Using random-effect modeling, we performed a meta-analysis on the rate of RBD conversions into neurodegeneration. Furthermore, we fitted a Kaplan-Meier analysis and compared the differences between survival curves of different diseases with log-rank tests. The risk for developing neurodegenerative diseases was 33.5% at five years follow-up, 82.4% at 10.5 years and 96.6% at 14 years. The average conversion rate was 31.95% after a mean duration of follow-up of 4.75 ± 2.43 years. The majority of RBD patients converted to Parkinson's Disease (43%), followed by Dementia with Lewy Bodies (25%). The estimated risk for RBD patients to develop a neurodegenerative disease over a long-term follow-up is more than 90%. Future studies should include control group for the evaluation of REM sleep without atonia as marker for neurodegeneration also in non-clinical population and target RBD as precursor of neurodegeneration to develop protective trials.

Abstract

As the popularity of sending messages electronically increases, so does the necessity of conveying messages more efficiently. One way of increasing efficiency is to abbreviate words and expressions by combining letters with numbers such as gr8 for “great,” using acronyms, such as lol for “laughing out loud,” or clippings such as msg for “message.” The present study compares the processing of shortcuts to the processing of closely matched pseudo-shortcuts. ERPs were recorded while participants were performing a lexical decision task. Response times showed that shortcuts were categorized more slowly as nonwords than pseudo-shortcuts. The ERP results showed no differences between shortcuts and pseudo-shortcuts at time windows 50–150 ms and 150–270 ms, but there were significant differences between 270 and 500 ms. These results suggest that at early stages of word recognition, the orthographic and phonological processing is similar for shortcuts and pseudo-shortcuts. However, at the time of lexical access, shortcuts diverge from pseudo-shortcuts, suggesting that shortcuts activate stored lexical representations.

Abstract

The current event-related brain potential study examined the processing of observed speech errors.
Participants were asked to detect errors in the speech of others while listening to the description of a visual
network. Networks consisted of colored drawings of objects connected by straight or curved lines. We
investigated the processing of two types of errors in the network descriptions, i.e., incorrect color and errors
in determiners usage (gender agreement violations). In the 100- to 300-ms and 300- to 550-ms time
windows, we found larger PMN and N400 amplitudes for both color and determiner error trials compared to
correct trials. Furthermore, color but not determiner errors led to larger P600 amplitudes compared to
correct color trials. Color errors also showed enhanced P600 amplitudes compared to determiner errors.
Taken together, processing erroneous network descriptions elicits different brain potentials than listening to
the corresponding correct utterances. Hence, speech is monitored for errors not only during speech
production but also during listening to the naturally occurring speech of others.

Abstract

Many contemporary texts include shortcuts, such as cu or phones4u. The aim of this study was to investigate how the meanings of shortcuts are retrieved. A primed lexical decision paradigm was used with shortcuts and the corresponding words as primes. The target word was associatively related to the meaning of the whole prime (cu/see you – goodbye), to a component of the prime (cu/see you – look), or unrelated to the prime. In Experiment 1, primes were presented for 57 ms. For both word and shortcut primes, responses were faster to targets preceded by whole-related than by unrelated primes. No priming from component-related primes was found. In Experiment 2, the prime duration was 1000 ms. The priming effect seen in Experiment 1 was replicated. Additionally, there was priming from component-related word primes, but not from component-related shortcut primes. These results indicate that the meanings of shortcuts can be retrieved without translating them first into corresponding words.

Abstract

For efficiency reasons, words in electronic messages are sometimes formed by combining letters with numbers, as in gr8 for “great.” The aim of this study was to investigate whether a digit incorporated into a letter—digit shortcut would retain its numerosity. A priming paradigm was used with letter—digit shortcuts (e.g., gr8) and matched pseudoshortcuts (e.g., qr8) as primes. The primes were presented simultaneously with sets of dots (targets) for which even/odd decisions were required, or they appeared 250 msec before target onset. When pseudoshortcuts were presented, decision latencies were shorter when the target and the digit in the prime were matched in parity than when they were mismatched. This main effect of match was not significant for shortcuts. The results suggest that the number concepts of digits combined with letters become activated but are quickly suppressed or deactivated when the digit is part of an existing shortcut.

Abstract

Learning to read a second language (L2) can pose a great challenge for children who have already been struggling to read in their first language (L1). Moreover, it is not clear whether, to what extent, and under what circumstances L1 reading difficulty increases the risk of L2 reading difficulty. This study investigated Chinese (L1) and English (L2) reading skills in a large representative sample of 1,824 Chinese–English bilingual children in Grades 4 and 5 from both urban and rural schools in Beijing. We examined the prevalence of reading difficulty in Chinese only (poor Chinese readers, PC), English only (poor English readers, PE), and both Chinese and English (poor bilingual readers, PB) and calculated the co-occurrence, that is, the chances of becoming a poor reader in English given that the child was already a poor reader in Chinese. We then conducted a multinomial logistic regression analysis and compared the prevalence of PC, PE, and PB between children in Grade 4 versus Grade 5, in urban versus rural areas, and in boys versus girls. Results showed that compared to girls, boys demonstrated significantly higher risk of PC, PE, and PB. Meanwhile, compared to the 5th graders, the 4th graders demonstrated significantly higher risk of PC and PB. In addition, children enrolled in the urban schools were more likely to become better second language readers, thus leading to a concerning rural–urban gap in the prevalence of L2 reading difficulty. Finally, among these Chinese–English bilingual children, regardless of sex and school location, poor reading skill in Chinese significantly increased the risk of also being a poor English reader, with a considerable and stable co-occurrence of approximately 36%. In sum, this study suggests that despite striking differences between alphabetic and logographic writing systems, L1 reading difficulty still significantly increases the risk of L2 reading difficulty. This indicates the shared meta-linguistic skills in reading different writing systems and the importance of understanding the universality and the interdependent relationship of reading between different writing systems. Furthermore, the male disadvantage (in both L1 and L2) and the urban–rural gap (in L2) found in the prevalence of reading difficulty calls for special attention to disadvantaged populations in educational practice.

Abstract

Previous research shows conflicting findings for the effect of font readability on comprehension and memory for language. It has been found that—perhaps counterintuitively–a hard to read font can be beneficial for language comprehension, especially for difficult language. Here we test how font readability influences the subjective experience of poetry reading. In three experiments we tested the influence of poem difficulty and font readability on the subjective experience of poems. We specifically predicted that font readability would have opposite effects on the subjective experience of easy versus difficult poems. Participants read poems which could be more or less difficult in terms of conceptual or structural aspects, and which were presented in a font that was either easy or more difficult to read. Participants read existing poems and subsequently rated their subjective experience (measured through four dependent variables: overall liking, perceived flow of the poem, perceived topic clarity, and perceived structure). In line with previous literature we observed a Poem Difficulty x Font Readability interaction effect for subjective measures of poetry reading. We found that participants rated easy poems as nicer when presented in an easy to read font, as compared to when presented in a hard to read font. Despite the presence of the interaction effect, we did not observe the predicted opposite effect for more difficult poems. We conclude that font readability can influence reading of easy and more difficult poems differentially, with strongest effects for easy poems.

Abstract

The effortfulness hypothesis implies that difficulty in decoding the surface form, as in the case of age-related sensory limitations or background noise, consumes the attentional resources that are then unavailable for semantic integration in language comprehension. Because ageing is associated with sensory declines, degrading of the surface form by a noisy background can pose an extra challenge for older adults. In two experiments, this hypothesis was tested in a self-paced moving window paradigm in which younger and older readers' online allocation of attentional resources to surface decoding and semantic integration was measured as they read sentences embedded in varying levels of visual noise. When visual noise was moderate (Experiment 1), resource allocation among young adults was unaffected but older adults allocated more resources to decode the surface form at the cost of resources that would otherwise be available for semantic processing; when visual noise was relatively intense (Experiment 2), both younger and older participants allocated more attention to the surface form and less attention to semantic processing. The decrease in attentional allocation to semantic integration resulted in reduced recall of core ideas in both experiments, suggesting that a less organized semantic representation was constructed in noise. The greater vulnerability of older adults at relatively low levels of noise is consistent with the effortfulness hypothesis.

Abstract

It is a common finding across languages that young children have problems in understanding patient-initial sentences. We used Tagalog, a verb-initial language with a reliable voice-marking system and highly frequent patient voice constructions, to test the predictions of several accounts that have been proposed to explain this difficulty: the frequency account, the Competition Model, and the incremental processing account. Study 1 presents an analysis of Tagalog child-directed speech, which showed that the dominant argument order is agent-before-patient and that morphosyntactic markers are highly valid cues to thematic role assignment. In Study 2, we used a combined self-paced listening and picture verification task to test how Tagalog-speaking adults and 5- and 7-year-old children process reversible transitive sentences. Results showed that adults performed well in all conditions, while children’s accuracy and listening times for the first noun phrase indicated more difficulty in interpreting patient-initial sentences in the agent voice compared to the patient voice. The patient voice advantage is partly explained by both the frequency account and incremental processing account.

Abstract

Heterozygous mutations of the human FOXP2 gene are implicated in a severe speech and language disorder. Aetiological mutations of murine Foxp2 yield abnormal synaptic plasticity and impaired motor-skill learning in mutant mice, while knockdown of the avian orthologue in songbirds interferes with auditory-guided vocal learning. Here, we investigate influences of two distinct Foxp2 point mutations on vocalizations of 4-day-old mouse pups (Mus musculus). The R552H missense mutation is identical to that causing speech and language deficits in a large well-studied human family, while the S321X nonsense mutation represents a null allele that does not produce Foxp2 protein. We ask whether vocalizations, based solely on innate mechanisms of production, are affected by these alternative Foxp2 mutations. Sound recordings were taken in two different situations: isolation and distress, eliciting a range of call types, including broadband vocalizations of varying noise content, ultrasonic whistles and clicks. Sound production rates and several acoustic parameters showed that, despite absence of functional Foxp2, homozygous mutants could vocalize all types of sounds in a normal temporal pattern, but only at comparably low intensities. We suggest that altered vocal output of these homozygotes may be secondary to developmental delays and somatic weakness. Heterozygous mutants did not differ from wild-types in any of the measures that we studied (R552H ) or in only a few (S321X ), which were in the range of differences routinely observed for different mouse strains. Thus, Foxp2 is not essential for the innate production of emotional vocalizations with largely normal acoustic properties by mouse pups.

Abstract

The way the human brain represents speech in memory is still unknown. An obvious characteristic of speech is its evolvement over time.
During speech processing, neural oscillations are modulated by the temporal properties of the acoustic speech signal, but also acquired
knowledge on the temporal structure of language influences speech perception-related brain activity. This suggests that speech could be
represented in the temporal domain, a form of representation that the brain also uses to encode autobiographic memories. Empirical
evidence for such a memory code is lacking. We investigated the nature of speech memory representations using direct cortical recordings
in the left perisylvian cortex during delayed sentence reproduction in female and male patients undergoing awake tumor surgery.
Our results reveal that the brain endogenously represents speech in the temporal domain. Temporal pattern similarity analyses revealed
that the phase of frontotemporal low-frequency oscillations, primarily in the beta range, represents sentence identity in working memory.
The positive relationship between beta power during working memory and task performance suggests that working memory
representations benefit from increased phase separation.

Abstract

An endophenotype for attention deficit/hyperactivity disorder (AD/HD) is executive functioning. In the autism and developmental literature executive dysfunctions has also been linked to theory of mind (ToM) and pragmatic language use. The central question of this review is whether deficits in ToM and pragmatic language use are common in AD/HD. AD/HD seems to be associated with pragmatic deficits, but not with ToM deficits. In this review we address how this pattern of findings might facilitate the understanding of the commonalities and differences between executive functioning, ToM, and pragmatic abilities. Based on the reviewed studies we conclude that ToM is not likely to be a potential endophenotype for AD/HD, while it is too early to draw such a conclusion for pragmatic language use.

Abstract

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

Abstract

In principle mutational records make it possible to estimate frequencies of disease alleles (q) for autosomal recessive disorders using a novel approach based on the calculation of the Homozygosity Index (HI), i.e., the proportion of homozygous patients, which is complementary to the proportion of compound heterozygous patients P(CH). In other words, the rarer the disorder, the higher will be the HI and the lower will be the P(CH). To test this hypothesis we used mutational records of individuals affected with Familial Mediterranean Fever (FMF) and Phenylketonuria (PKU), born to either consanguineous or apparently unrelated parents from six population samples of the Mediterranean region. Despite the unavailability of precise values of the inbreeding coefficient for the general population, which are needed in the case of apparently unrelated parents, our estimates of q are very similar to those of previous descriptive epidemiological studies. Finally, we inferred from simulation studies that the minimum sample size needed to use this approach is 25 patients either with unrelated or first cousin parents. These results show that the HI can be used to produce a ranking order of allele frequencies of autosomal recessive disorders, especially in populations with high rates of consanguineous marriages.

Abstract

Developmental dyslexia (DD) is one of the most prevalent learning disorders, with high impact on school and psychosocial development and high comorbidity with conditions like attention-deficit hyperactivity disorder (ADHD), depression, and anxiety. DD is characterized by deficits in different cognitive skills, including word reading, spelling, rapid naming, and phonology. To investigate the genetic basis of DD, we conducted a genome-wide association study (GWAS) of these skills within one of the largest studies available, including nine cohorts of reading-impaired and typically developing children of European ancestry (N = 2562–3468). We observed a genome-wide significant effect (p < 1 × 10−8) on rapid automatized naming of letters (RANlet) for variants on 18q12.2, within MIR924HG (micro-RNA 924 host gene; rs17663182 p = 4.73 × 10−9), and a suggestive association on 8q12.3 within NKAIN3 (encoding a cation transporter; rs16928927, p = 2.25 × 10−8). rs17663182 (18q12.2) also showed genome-wide significant multivariate associations with RAN measures (p = 1.15 × 10−8) and with all the cognitive traits tested (p = 3.07 × 10−8), suggesting (relational) pleiotropic effects of this variant. A polygenic risk score (PRS) analysis revealed significant genetic overlaps of some of the DD-related traits with educational attainment (EDUyears) and ADHD. Reading and spelling abilities were positively associated with EDUyears (p ~ [10−5–10−7]) and negatively associated with ADHD PRS (p ~ [10−8−10−17]). This corroborates a long-standing hypothesis on the partly shared genetic etiology of DD and ADHD, at the genome-wide level. Our findings suggest new candidate DD susceptibility genes and provide new insights into the genetics of dyslexia and its comorbities.

Abstract

The neural correlates of sentence production have been mostly studied with constraining task paradigms that introduce artificial task effects. In this study, we aimed to gain a better understanding of syntactic processing in spontaneous production vs. naturalistic comprehension. We extracted word-by-word metrics of phrase-structure building with top-down and bottom-up parsers that make different hypotheses about the timing of structure building. In comprehension, structure building proceeded in an integratory fashion and led to an increase in activity in posterior temporal and inferior frontal areas. In production, structure building was anticipatory and predicted an increase in activity in the inferior frontal gyrus. Newly developed production-specific parsers highlighted the anticipatory and incremental nature of structure building in production, which was confirmed by a converging analysis of the pausing patterns in speech. Overall, the results showed that the unfolding of syntactic processing diverges between speaking and listening.

Abstract

BACKGROUND: It is unclear to what extent non-clinical psychotic experiences during childhood and adolescence share underlying aetiological mechanisms with schizophrenia. One candidate mechanism for schizophrenia involves the epigenetic status of the developing fetus, which depends on the internal folate-status of mother and child. Our study examines the relationships between multiple determinants of perinatal folate-status and development of psychotic experiences in adolescence. METHODS: Study participants were up to 5344 mother-child pairs from the Avon Longitudinal Study of Parents and their Children, UK, with information on maternal and/or child MTHFR C677T genotype, maternal folate intake (supplementation at 18/32- weeks gestation; dietary intake at 32- weeks gestation) and psychosis-like symptoms (PLIKS) for children assessed at age 12. RESULTS: Nominal evidence was observed that maternal folate supplementation at 18 weeks increased the odds of PLIKS in children (odds ratio(OR)=1.34; 95%-CI:[1.00;1.76]) and, consistent with this, that children of MTHFR C667T TT homozygous mothers had decreased odds of PLIKS (OR=0.72; 95%CI:[0.50;1.02]; recessive model) with strongest effects in boys (OR=0.44, 95%-CI:[0.22;0.79]; sex-specific p=0.029). None of the reported effects remained significant when corrected for multiple testing. CONCLUSIONS: Overall, this study found no support that maternal/child MTHFR C677T genotype and maternal folate intake during pregnancy contribute to common aetiological pathways that are shared between schizophrenia and non-clinical psychotic symptoms in adolescents, assuming that decreased folate-status increases schizophrenia risk.

Abstract

PURPOSE: Conduct problems and peer effects are among the strongest risk factors for adolescent substance use and problem use. However, it is unclear to what extent the effects of conduct problems and peer behavior interact, and whether adolescents' capacity to refuse the offer of substances may moderate such links. This study was conducted to examine relationships between conduct problems, close friends' substance use, and refusal assertiveness with adolescents' alcohol use problems, tobacco, and marijuana use. METHODS: We studied a population-based sample of 1,237 individuals from the Cardiff Study of All Wales and North West of England Twins aged 11-18 years. Adolescent and mother-reported information was obtained. Statistical analyses included cross-sectional and prospective logistic regression models and family-based permutations. RESULTS: Conduct problems and close friends' substance use were associated with increased adolescents' substance use, whereas refusal assertiveness was associated with lower use of cigarettes, alcohol, and marijuana. Peer substance use moderated the relationship between conduct problems and alcohol use problems, such that conduct problems were only related to increased risk for alcohol use problems in the presence of substance-using friends. This effect was found in both cross-sectional and prospective analyses and confirmed using the permutation approach. CONCLUSIONS: Reduced opportunities for interaction with alcohol-using peers may lower the risk of alcohol use problems in adolescents with conduct problems.

Abstract

Patterns formed by reaction-diffusion mechanisms are crucial for the development or sustenance of most organisms in nature. Patterns include dynamic waves, but are more often found as static distributions, such as animal skin patterns. Yet, a simplistic biological model system to reproduce and quantitatively investigate static reaction-diffusion patterns has been missing so far. Here, we demonstrate that the Escherichia coli MM system, known for its oscillatory behavior between the cell poles, is under certain conditions capable of transitioning to quasi-stationary protein distributions on membranes closely resembling Turing patterns. We systematically titrated both proteins, MinD and MinE, and found that removing all purification tags and linkers from the N-terminus of MinE was critical for static patterns to occur. At small bulk heights, dynamic patterns dominate, such as in rod-shaped microcompartments. We see implications of this work for studying pattern formation in general, but also for creating artificial gradients as downstream cues in synthetic biology applications.

Abstract

Interactive models of language production predict that it should be possible to observe long-distance interactions; effects that arise at one level of processing influence multiple subsequent stages of representation and processing. We examine the hypothesis that disruptions arising in nonform-based levels of planning—specifically, lexical selection—should modulate articulatory processing. A novel automatic phonetic analysis method was used to examine productions in a paradigm yielding both general disruptions to formulation processes and, more specifically, overt errors during lexical selection. This analysis method allowed us to examine articulatory disruptions at multiple levels of analysis, from whole words to individual segments. Baseline performance by young adults was contrasted with young speakers’ performance under time pressure (which previous work has argued increases interaction between planning and articulation) and performance by older adults (who may have difficulties inhibiting nontarget representations, leading to heightened interactive effects). The results revealed the presence of interactive effects. Our new analysis techniques revealed these effects were strongest in initial portions of responses, suggesting that speech is initiated as soon as the first segment has been planned. Interactive effects did not increase under response pressure, suggesting interaction between planning and articulation is relatively fixed. Unexpectedly, lexical selection disruptions appeared to yield some degree of facilitation in articulatory processing (possibly reflecting semantic facilitation of target retrieval) and older adults showed weaker, not stronger interactive effects (possibly reflecting weakened connections between lexical and form-level representations).

Abstract

* Ole Goltermann and Gökberk Alagöz contributed equally.
Primate brain evolution has involved prominent expansions of the cerebral cortex, with largest effects observed in the human lineage. Such expansions were accompanied by fine-grained anatomical alterations, including increased cortical folding. However, the molecular bases of evolutionary alterations in human sulcal organization are not yet well understood. Here, we integrated data from recently completed large-scale neuroimaging genetic analyses with annotations of the human genome relevant to various periods and events in our evolutionary history. These analyses identified single-nucleotide polymorphism (SNP) heritability enrichments in fetal brain human-gained enhancer (HGE) elements for a number of sulcal structures, including the central sulcus, which is implicated in human hand dexterity. We zeroed in on a genomic region that harbors DNA variants associated with left central sulcus shape, an HGE element, and genetic loci involved in neurogenesis including ZIC4, to illustrate the value of this approach for probing the complex factors contributing to human sulcal evolution.

Abstract

Chicks can convey information about their needs with calls. But it is still unknown if there are any universal need indicators in chick vocalizations. Previous studies have shown that in some species vocal activity and/or temporal-frequency variables of calls are related to the chick state, whereas other studies did not confirm it. Here, we tested experimentally whether vocal activity and temporal-frequency variables of calls change with cooling. We studied 10 human-raised
Siberian crane (Grus leucogeranus) chicks at 3–15 days of age. We found that the cooled chicks produced calls higher in fundamental
frequency and power variables, longer in duration and at a higher calling rate than in the control chicks. However, we did not find
significant changes in level of entropy and occurrence of non-linear phenomena in chick calls recorded during the experimental cooling. We suggest that the level of vocal activity is a universal indicator of need for warmth in precocial and semi-precocial birds (e.g. cranes), but not in altricial ones. We also assume that coding of needs via temporal-frequency variables of calls is typical in species whose adults could not confuse their chicks with other chicks. Siberian cranes stay on separate territories during their breeding season, so parents do not need to check individuality of their offspring in the home area. In this case, all call characteristics are available for other purposes and serve to communicate chicks’ vital needs.

Abstract

Background

Schizophrenia is a highly heritable disorder characterized by increased cortical thinning throughout the lifespan. Studies have reported a shared genetic basis between schizophrenia and cortical thickness. However, no genes whose expression is related to abnormal cortical thinning in schizophrenia have been identified.

Methods

We conducted linear mixed models to estimate the rates of accelerated cortical thinning across 68 regions from the Desikan-Killiany atlas in individuals with schizophrenia compared to healthy controls from a large longitudinal sample (NCases = 169 and NControls = 298, aged 16-70 years). We studied the correlation between gene expression data from the Allen Human Brain Atlas and accelerated thinning estimates across cortical regions. We finally explored the functional and genetic underpinnings of the genes most contributing to accelerated thinning.

Results

We described a global pattern of accelerated cortical thinning in individuals with schizophrenia compared to healthy controls. Genes underexpressed in cortical regions exhibiting this accelerated thinning were downregulated in several psychiatric disorders and were enriched for both common and rare disrupting variation for schizophrenia and neurodevelopmental disorders. In contrast, none of these enrichments were observed for baseline cross-sectional cortical thickness differences.

Conclusions

Our findings suggest that accelerated cortical thinning, rather than cortical thickness alone, serves as an informative phenotype for neurodevelopmental disruptions in schizophrenia. We highlight the genetic and transcriptomic correlates of this accelerated cortical thinning, emphasizing the need for future longitudinal studies to elucidate the role of genetic variation and the temporal-spatial dynamics of gene expression in brain development and aging in schizophrenia.

Abstract

When language abilities in aphasia are assessed in clinical and research settings, the standard practice is to examine each language of a multilingual person separately. But many multilingual individuals, with and without aphasia, mix their languages regularly when they communicate with other speakers who share their languages. We applied a novel approach to scoring language production of a multilingual person with aphasia. Our aim was to discover whether the assessment outcome would differ meaningfully when we count accurate responses in only the target language of the assessment session versus when we apply a translanguaging framework, that is, count all accurate responses, regardless of the language in which they were produced. The participant is a Farsi-German-English speaking woman with chronic moderate aphasia. We examined the participant’s performance on two picture-naming tasks, an answering wh-question task, and an elicited narrative task. The results demonstrated that scores in English, the participant’s third-learned and least-impaired language did not differ between the two scoring methods. Performance in German, the participant’s moderately impaired second language benefited from translanguaging-based scoring across the board. In Farsi, her weakest language post-CVA, the participant’s scores were higher under the translanguaging-based scoring approach in some but not all of the tasks. Our findings suggest that whether a translanguaging-based scoring makes a difference in the results obtained depends on relative language abilities and on pragmatic constraints, with additional influence of the linguistic distances between the languages in question.

Abstract

Adopting the paradigm of a study conducted with chimpanzees, Pan troglodytes (Melis et al. 2006, Journal of Comparative Psychology, 120, 154–162), we investigated orang-utans', Pongo pygmaeus, understanding of others' visual perspectives. More specifically, we examined whether orang-utans would adjust their behaviour in a way that prevents a human competitor from seeing them steal a piece of food. In the task, subjects had to reach through one of two opposing Plexiglas tunnels in order to retrieve a food reward. Both rewards were also physically accessible to a human competitor sitting opposite the subject. Subjects always had the possibility of reaching one piece of food that was outside the human's line of sight. This was because either the human was oriented to one, but not the other, reward or because one tunnel was covered by an opaque barrier and the other remained transparent. In the situation in which the human was oriented towards one reward, the orang-utans successfully avoided the tunnel that the competitor was facing. If one tunnel was covered, they marginally preferred to reach through the opaque versus the transparent tunnel. However, they did so frequently after initially inspecting the transparent tunnel (then switching to the opaque one). Considering only the subjects' initial inspections, they chose randomly between the opaque and transparent tunnel, indicating that their final decision to reach was probably driven by a more egocentric behavioural rule. Overall the results suggest that orang-utans have a limited understanding of others' perspectives, relying mainly on cues from facial and bodily orientation and egocentric rules when making such judgements.

Abstract

This study examined electrophysiological correlates of sentence comprehension of native-accented and foreign-accented
speech in a second language (L2), for sentences produced in a foreign accent different from that associated with the listeners’
L1. Bilingual speaker-listeners process different accents in their L2 conversations, but the effects on real-time L2 sentence
comprehension are unknown. Dutch–English bilinguals listened to native American-English accented sentences and foreign
(and for them unfamiliarly-accented) Chinese-English accented sentences while EEG was recorded. Behavioral sentence
comprehension was highly accurate for both native-accented and foreign-accented sentences. ERPs showed different patterns
for L2 grammar and semantic processing of native- and foreign-accented speech. For grammar, only native-accented speech
elicited an Nref. For semantics, both native- and foreign-accented speech elicited an N400 effect, but with a delayed onset
across both accent conditions. These findings suggest that the way listeners comprehend native- and foreign-accented
sentences in their L2 depends on their familiarity with the accent.

Abstract

Language in high-functioning autism is characterized by pragmatic and semantic deficits, and people with autism have a reduced tendency to integrate information. Because the left and right inferior frontal (LIF and RIF) regions are implicated with integration of speaker information, world knowledge, and semantic knowledge, we hypothesized that abnormal functioning of the LIF and RIF regions might contribute to pragmatic and semantic language deficits in autism. Brain activation of sixteen 12- to 18-year-old, high-functioning autistic participants was measured with functional magnetic resonance imaging during sentence comprehension and compared with that of twenty-six matched controls. The content of the pragmatic sentence was congruent or incongruent with respect to the speaker characteristics (male/female, child/adult, and upper class/lower class). The semantic- and world-knowledge sentences were congruent or incongruent with respect to semantic expectancies and factual expectancies about the world, respectively. In the semanticknowledge and world-knowledge condition, activation of the LIF region did not differ between groups. In sentences that required integration of speaker information, the autism group showed abnormally reduced activation of the LIF region. The results suggest that people with autism may recruit the LIF region in a different manner in tasks that demand integration of social information.

Abstract

Autism spectrum disorder (ASD) is a highly heritable and heterogeneous group of neurodevelopmental phenotypes diagnosed in more than 1% of children. Common genetic variants contribute substantially to ASD susceptibility, but to date no individual variants have been robustly associated with ASD. With a marked sample-size increase from a unique Danish population resource, we report a genome-wide association meta-analysis of 18,381 individuals with ASD and 27,969 controls that identified five genome-wide-significant loci. Leveraging GWAS results from three phenotypes with significantly overlapping genetic architectures (schizophrenia, major depression, and educational attainment), we identified seven additional loci shared with other traits at equally strict significance levels. Dissecting the polygenic architecture, we found both quantitative and qualitative polygenic heterogeneity across ASD subtypes. These results highlight biological insights, particularly relating to neuronal function and corticogenesis, and establish that GWAS performed at scale will be much more productive in the near term in ASD.

Abstract

Partisan gerrymandering poses a threat to democracy. Moreover, the complexity of the districting task may exceed human capacities. One potential solution is using computational models to automate the districting process by optimizing objective and open criteria, such as how spatially compact districts are. We formulated one such model that minimised pairwise distance between voters within a district. Using US Census Bureau data, we confirmed our prediction that the difference in compactness between the computed and actual districts would be greatest for states that are large and, therefore, difficult for humans to properly district given their limited capacities. The computed solutions highlighted differences in how humans and machines solve this task with machine solutions more fully optimised and displaying emergent properties not evident in human solutions. These results suggest a division of labour in which humans debate and formulate districting criteria whereas machines optimise the criteria to draw the district boundaries. We discuss how criteria can be expanded beyond notions of compactness to include other factors, such as respecting municipal boundaries, historic communities, and relevant legislation.

Abstract

PURPOSE: Time spent in "sports/outdoor activity" has shown a negative association with incident myopia during childhood. We investigated the association of incident myopia with time spent outdoors and physical activity separately. METHODS: Participants in the Avon Longitudinal Study of Parents and Children (ALSPAC) were assessed by noncycloplegic autorefraction at ages 7, 10, 11, 12, and 15 years, and classified as myopic (≤-1 diopters) or as emmetropic/hyperopic (≥-0.25 diopters) at each visit (N = 4,837-7,747). Physical activity at age 11 years was measured objectively using an accelerometer, worn for 1 week. Time spent outdoors was assessed via a parental questionnaire administered when children were aged 8-9 years. Variables associated with incident myopia were examined using Cox regression. RESULTS: In analyses using all available data, both time spent outdoors and physical activity were associated with incident myopia, with time outdoors having the larger effect. The results were similar for analyses restricted to children classified as either nonmyopic or emmetropic/hyperopic at age 11 years. Thus, for children nonmyopic at age 11, the hazard ratio (95% confidence interval, CI) for incident myopia was 0.66 (0.47-0.93) for a high versus low amount of time spent outdoors, and 0.87 (0.76-0.99) per unit standard deviation above average increase in moderate/vigorous physical activity. CONCLUSION: Time spent outdoors was predictive of incident myopia independently of physical activity level. The greater association observed for time outdoors suggests that the previously reported link between "sports/outdoor activity" and incident myopia is due mainly to its capture of information relating to time outdoors rather than physical activity.

Abstract

Despite the literature on the role of input in adult second-language (L2) acquisition and on artificial and statistical language learning, surprisingly little is known about how adults break into a new language in the wild. This article reports on a series of behavioral and neuroimaging studies that examine what linguistic information adults can extract from naturalistic but controlled audiovisual input in an unknown and typologically distant L2 after minimal exposure (7–14 min) without instruction or training. We tested the stepwise development of segmental, phonotactic, and lexical knowledge in Dutch adults after minimal exposure to Mandarin Chinese and the role of item frequency, speech-associated gestures, and word length at the earliest stages of learning. In an exploratory neural connectivity study we further examined the neural correlates of word recognition in a new language, identifying brain regions whose connectivity was related to performance both before and after learning. While emphasizing the complexity of the learning task, the results suggest that the adult learning mechanism is more powerful than is normally assumed when faced with small amounts of complex, continuous audiovisual language input.

Abstract

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

This paper will focus on two issues:

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

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

Abstract

Gestures, the symbolic movements speakers perform while they speak, form a closely inter-connected system with speech where gestures serve both addressee-directed (‘communicative’) and speaker-directed (’internal’) functions. This paper aims (1) to show that a combined analysis of gesture and speech offers new ways to address theoretical issues in SLA and bilingualism studies, probing SLA and bilingualism as product and process; and (2) to outline some methodological concerns and desiderata to facilitate the inclusion of gesture in SLA and bilingualism research.

Abstract

Placement verbs describe every-day events like putting a toy in a box. Dutch uses two semi-obligatory caused posture verbs (leggen ‘lay’ and zetten ‘set/stand’) to distinguish between events based on whether the located object is placed horizontally or vertically. Although prevalent in the input, these verbs cause Dutch children difficulties even at age five (Narasimhan & Gullberg, submitted). Children overextend leggen to all placement events and underextend use of zetten. This study examines what gestures can reveal about Dutch three- and five-year-olds’ semantic representations of such verbs. The results show that children gesture differently from adults in this domain. Three-year-olds express only the path of the caused motion, whereas five-year-olds, like adults, also incorporate the located object. Crucially, gesture patterns are tied to verb use: those children who over-use leggen 'lay' for all placement events only gesture about path. Conversely, children who use the two verbs differentially for horizontal and vertical placement also incorporate objects in gestures like adults. We argue that children's gestures reflect their current knowledge of verb semantics, and indicate a developmental transition from a system with a single semantic component – (caused) movement – to an (adult-like) focus on two semantic components – (caused) movement-and-object

Abstract

Discussions about the adult L2 learning capacity often take as their starting point stages where considerable L2 knowledge has already been accumulated. This paper probes the absolute earliest stages of learning and investigates what lexical knowledge adult learners can extract from complex, continuous speech in an unknown language after minimal exposure and without any help. Dutch participants were exposed to naturalistic but controlled audiovisual input in Mandarin Chinese, in which item frequency and gestural highlighting were manipulated. The results from a word recognition task showed that adults are able to draw on frequency to recognize disyllabic words appearing only eight times in continuous speech. The findings from a sound-to-picture matching task revealed that the mapping of meaning to word form requires a combination of cues: disyllabic words accompanied by a gesture were correctly assigned meaning after eight encounters. Overall, the study suggests that the adult learning mechanism is a considerably more powerful than typically assumed in the SLA literature drawing on frequency, gestural cues and syllable structure. Even in the absence of pre-existing knowledge about cognates and sound system to bootstrap and boost learning, it deals efficiently with very little, very complex input.

Abstract

One of the features that distinguishes modern humans from our extinct relatives
and ancestors is a globular shape of the braincase [1-4]. As the endocranium
closely mirrors the outer shape of the brain, these differences might reflect
altered neural architecture [4,5]. However, in the absence of fossil brain tissue the
underlying neuroanatomical changes as well as their genetic bases remain
elusive. To better understand the biological foundations of modern human
endocranial shape, we turn to our closest extinct relatives, the Neandertals.
Interbreeding between modern humans and Neandertals has resulted in
introgressed fragments of Neandertal DNA in the genomes of present-day non-
Africans [6,7]. Based on shape analyses of fossil skull endocasts, we derive a
measure of endocranial globularity from structural magnetic resonance imaging
(MRI) scans of thousands of modern humans, and study the effects of
introgressed fragments of Neandertal DNA on this phenotype. We find that
Neandertal alleles on chromosomes 1 and 18 are associated with reduced
endocranial globularity. These alleles influence expression of two nearby genes,
UBR4 and PHLPP1, which are involved in neurogenesis and myelination,
respectively. Our findings show how integration of fossil skull data with archaic
genomics and neuroimaging can suggest developmental mechanisms that may
contribute to the unique modern human endocranial shape.

Abstract

“The most profound technologies are those that disappear. They weave themselves into the fabric of everyday life until they are indistinguishable from it.” (Weiser 1991, S. 94). – Die Behauptung stammt aus einem vielzitierten Text von Mark Weiser, ehemals Chief Technology Officer am berühmten Xerox Palo Alto Research Center (PARC), wo nicht nur einige bedeutende computertechnische Innovationen ihren Ursprung hatten, sondern auch grundlegende anthropologische Einsichten zum Umgang mit technischen Artefakten gewonnen wurden.1 In einem populärwissenschaftlichen Artikel mit dem Titel „The Computer for the 21st Century” entwarf Weiser 1991 die Vision einer Zukunft, in der wir nicht mehr mit einem einzelnen PC an unserem Arbeitsplatz umgehen – vielmehr seien wir in jedem Raum umgeben von hunderten elektronischer Vorrichtungen, die untrennbar in Alltagsgegenstände eingebettet und daher in unserer materiellen Umwelt gleichsam „verschwunden“ sind. Dabei ging es Weiser nicht allein um das ubiquitäre Phänomen, das in der Medientheorie als „Transparenz der Medien“ bekannt ist2 oder in allgemeineren Theorien der Alltagserfahrung als eine selbstverständliche Verwobenheit des Menschen mit den Dingen, die uns in ihrem Sinn vertraut und praktisch „zuhanden“ sind.3 Darüber hinaus zielte Weisers Vision darauf, unsere bereits existierende Umwelt durch computerlesbare Daten zu erweitern und in die Operationen eines solchen allgegenwärtigen Netzwerks alltägliche Praktiken gleichsam lückenlos zu integrieren: In der Welt, die Weiser entwirft, öffnen sich Türen für denjenigen, der ein bestimmtes elektronisches Abzeichen trägt, begrüßen Räume Personen, die sie betreten, mit Namen, passen sich Computerterminals an die Präferenzen individueller Nutzer an usw. (Weiser 1991, S. 99).

Abstract

“The most profound technologies are those that disappear. They weave themselves into the fabric of everyday life until they are indistinguishable from it.” (Weiser 1991, S. 94). – Die Behauptung stammt aus einem vielzitierten Text von Mark Weiser, ehemals Chief Technology Officer am berühmten Xerox Palo Alto Research Center (PARC), wo nicht nur einige bedeutende computertechnische Innovationen ihren Ursprung hatten, sondern auch grundlegende anthropologische Einsichten zum Umgang mit technischen Artefakten gewonnen wurden.1 In einem populärwissenschaftlichen Artikel mit dem Titel „The Computer for the 21st Century” entwarf Weiser 1991 die Vision einer Zukunft, in der wir nicht mehr mit einem einzelnen PC an unserem Arbeitsplatz umgehen – vielmehr seien wir in jedem Raum umgeben von hunderten elektronischer Vorrichtungen, die untrennbar in Alltagsgegenstände eingebettet und daher in unserer materiellen Umwelt gleichsam „verschwunden“ sind. Dabei ging es Weiser nicht allein um das ubiquitäre Phänomen, das in der Medientheorie als „Transparenz der Medien“ bekannt ist2 oder in allgemeineren Theorien der Alltagserfahrung als eine selbstverständliche Verwobenheit des Menschen mit den Dingen, die uns in ihrem Sinn vertraut und praktisch „zuhanden“ sind.3 Darüber hinaus zielte Weisers Vision darauf, unsere bereits existierende Umwelt durch computerlesbare Daten zu erweitern und in die Operationen eines solchen allgegenwärtigen Netzwerks alltägliche Praktiken gleichsam lückenlos zu integrieren: In der Welt, die Weiser entwirft, öffnen sich Türen für denjenigen, der ein bestimmtes elektronisches Abzeichen trägt, begrüßen Räume Personen, die sie betreten, mit Namen, passen sich Computerterminals an die Präferenzen individueller Nutzer an usw. (Weiser 1991, S. 99).

Abstract

Geen andere soort dan homo sapiens heeft in de loop van zijn evolutionaire geschiedenis een communicatiesysteem ontwikkeld waarin een eindig aantal symbolen samen met een reeks van regels voor het combineren daarvan een oneindig aantal uitdrukkingen mogelijk maakt. Dit natuurlijke taalsysteem stelt leden van onze soort in staat gedachten een uiterlijke vorm te geven en uit te wisselen met de sociale groep en, door de uitvinding van schriftsystemen, met de gehele samenleving. Spraak en taal zijn effectieve middelen voor het behoud van sociale cohesie in samenlevingen waarvan de groepsgrootte en de complexe sociale organisatie van dien aard is dat dit niet langer kan door middel van ‘vlooien’, de wijze waarop onze genetische buren, de primaten van de oude wereld, sociale cohesie bevorderen [1,2].

Abstract

In this contribution, the following four questions are discussed: (i) where is meaning?; (ii) what is meaning?; (iii) what is the meaning of mechanism?; (iv) what are the mechanisms of meaning? I will argue that meanings are in the head. Meanings have multiple facets, but minimally one needs to make a distinction between single word meanings (lexical meaning) and the meanings of multi-word utterances. The latter ones cannot be retrieved from memory, but need to be constructed on the fly. A mechanistic account of the meaning-making mind requires an analysis at both a functional and a neural level, the reason being that these levels are causally interdependent. I will show that an analysis exclusively focusing on patterns of brain activation lacks explanatory power. Finally, I shall present an initial sketch of how the dynamic interaction between temporo-parietal areas and inferior frontal cortex might instantiate the interpretation of linguistic utterances in the context of a multimodal setting and ongoing discourse information.

Abstract

In this Review, I propose a multiple-network view for the neurobiological basis of distinctly human language skills. A much more complex picture of interacting brain areas emerges than in the classical neurobiological model of language. This is because using language is more than single-word processing, and much goes on beyond the information given in the acoustic or orthographic tokens that enter primary sensory cortices. This requires the involvement of multiple networks with functionally nonoverlapping contributions

Abstract

Language is inherently multimodal. In spoken languages, combined spoken and visual signals (e.g., co-speech gestures) are an integral part of linguistic structure and language representation. This requires an extension of the parallel architecture, which needs to include the visual signals concomitant to speech. We present the evidence for the multimodality of language. In addition, we propose that distributional semantics might provide a format for integrating speech and co-speech gestures in a common semantic representation.

Abstract

One attempt at explaining why some language families are large (while others are small) is the hypothesis that the families that are now large became large because their ancestral speakers had a technological advantage, most often agriculture. Variants of this idea are referred to as the Language Farming Dispersal Hypothesis. Previously, detailed language family studies have uncovered various supporting examples and counterexamples to this idea. In the present paper I weigh the evidence from ALL attested language families. For each family, I use the number of member languages as a measure of cardinal size, member language coordinates to measure geospatial size and ethnographic evidence to assess subsistence status. This data shows that, although agricultural families tend to be larger in cardinal size, their size is hardly due to the simple presence of farming. If farming were responsible for language family expansions, we would expect a greater east-west geospatial spread of large families than is actually observed. The data, however, is compatible with weaker versions of the farming dispersal hypothesis as well with models where large families acquire farming because of their size, rather than the other way around.

Abstract

A series of articles by Ross (1995, 2001, 2005) use pronoun sim- ilarities to gauge relatedness between various Papuan microgroups, arguing that the similarities could not be the result of chance or bor- rowing. I argue that a more appropriate manner of calculating chance gives a signicantly dierent result: when cross-comparing a pool of languages the prospects for chance matches of rst and second person pronouns are very good. Using pronoun form data from over 3000 lan- guages and over 300 language families inside and outside New Guinea, I show that there is, nevertheless, a tendency for Papuan pronouns to use certain consonants more often in 1P and 2P SG forms than in the rest of the world. This could reect an underlying family. An alter- native explanation is the established Papuan areal feature of having a small consonant inventory, which results in a higher functional load on the remaining consonants, which is, in turn, reected in the enhanced popularity of certain consonants in pronouns of those languages. A test of surface forms (i.e., non-reconstructed forms) favours the latter explanation.

Abstract

This paper aims to list all known language families that are not yet extinct and all of whose member languages are very poorly documented, i.e., less than a sketch grammar’s worth of data has been collected. It explains what constitutes a valid family, what amount and kinds of documentary data are sufficient, when a language is considered extinct, and more. It is hoped that the survey will be useful in setting priorities for documentation fieldwork, in particular for those documentation efforts whose underlying goal is to understand linguistic diversity.

Abstract

Speech production studies have shown that phonological unit initially used to fill the metrical frame during phonological encoding is language specific, that is, a phoneme for English and Dutch, an atonal syllable for Mandarin Chinese, and a mora for Japanese. However, only a few studies chronometrically investigated speech production in Korean, and they obtained mixed results. Korean is particularly interesting as there might be both phonemic and syllabic influences during phonological encoding. The purpose of this study is to further examine the initial phonological preparation unit in Korean, employing a masked priming task (Experiment 1) and a phonological Stroop task (Experiment 2). The results showed that significant onset (and onset-plus, that is, consonant-vowel [CV]) effects were found in both experiments, but there was no compelling evidence for a prominent role for the syllable. When the prime words were presented in three different forms related to the targets, namely, without any change, with re-syllabified codas, and with nasalised codas, there were no significant differences in facilitation among the three forms. Alternatively, it is also possible that participants may not have had sufficient time to process the primes up to the point that re-syllabification or nasalisation could have been carried out. In addition, the results of a Stroop task demonstrated that the onset phoneme effect was not driven by any orthographic influence. These findings suggest that the onset segment and not the syllable is the initial (or proximate) phonological unit used in the segment-to-frame encoding process during speech planning in Korean.

Abstract

This paper examines the role of morphological structure in the reduced pronunciation of morphologically complex words by discussing and re-analyzing data from the literature. Acoustic reduction refers to the phenomenon that, in spontaneous speech, phonemes may be shorter or absent. We review studies investigating effects of the repetition of a morpheme, of whether a segment plays a crucial role in the identification of its morpheme, and of a word's morphological decomposability. We conclude that these studies report either no effects of morphological structure or effects that are open to alternative interpretations. Our analysis also reveals the need for a uniform definition of morphological decomposability. Furthermore, we examine whether the reduction of segments in morphologically complex words correlates with these segments' contribution to the identification of the whole word, and discuss previous studies and new analyses supporting this hypothesis. We conclude that the data show no convincing evidence that morphological structure conditions reduction, which contrasts with the expectations of several models of speech production and of morphological processing (e.g., weaver++ and dual-route models). The data collected so far support psycholinguistic models which assume that all morphologically complex words are processed as complete units.

Abstract

Many learners of a foreign language (L2) struggle to correctly pronounce newly-learned speech sounds, yet many others achieve this with apparent ease. Here we explored how a training study of learning complex consonant clusters at the very onset of the L2 acquisition can inform us about L2 learning in general and individual differences in particular. To this end, adult Dutch native speakers were trained on Slovak words with complex consonant clusters (e.g., pstruh /pstrux/‘trout’, štvrť /ʃtvrc/ ‘quarter’) using auditory and orthographic input. In the same session following training, participants were tested on a battery of L2 perception and production tasks. The battery of L2 tests was repeated twice more with one week between each session. In the first session, an additional battery of control tests was used to test participants’ native language (L1) skills. Overall, in line with some previous research, participants showed only weak learning effects across the L2 perception tasks. However, there were considerable individual differences across all L2 tasks, which remained stable across sessions. Only two participants showed overall high L2 production performance that fell within 2 standard deviations of the mean ratings obtained for an L1 speaker. The mispronunciation detection task was the only perception task which significantly predicted production performance in the final session. We conclude by discussing several recommendations for future L2 learning studies.

Abstract

Slovak (sometimes also called Slovakian) is an Indo-European language belonging to the West-Slavic branch, and is most closely related to Czech. Slovak is spoken as a native language by 4.6 million speakers in Slovakia (that is by roughly 85% of the population), and by over two million Slovaks living abroad, most of them in the USA, the Czech Republic, Hungary, Canada and Great Britain (Office for Slovaks Living Abroad 2009).

Abstract

We used eyetracking, perceptual discrimination, and production tasks to examine the influences of perceptual similarity and linguistic experience on word recognition in nonnative (L2) speech. Eye movements to printed words were tracked while German and Dutch learners of English heard words containing one of three pronunciation variants (/t/, /s/, or /f/) of the interdental fricative /θ/. Irrespective of whether the speaker was Dutch or German, looking preferences for target words with /θ/ matched the preferences for producing /s/ variants in German speakers and /t/ variants in Dutch speakers (as determined via the production task), while a control group of English participants showed no such preferences. The perceptually most similar and most confusable /f/ variant (as determined via the discrimination task) was never preferred as a match for /θ/. These results suggest that linguistic experience with L2 pronunciations facilitates recognition of variants in an L2, with effects of frequency outweighing effects of perceptual similarity.

Abstract

The possible-word constraint (PWC; Norris, McQueen, Cutler, & Butterfield, 1997) has been proposed as a language-universal segmentation principle: Lexical candidates are disfavoured if the resulting segmentation of continuous speech leads to vowelless residues in the input—for example, single consonants. Three word-spotting experiments investigated segmentation in Slovak, a language with single-consonant words and fixed stress. In Experiment 1, Slovak listeners detected real words such as ruka “hand” embedded in prepositional-consonant contexts (e.g., /gruka/) faster than those in nonprepositional-consonant contexts (e.g., /truka/) and slowest in syllable contexts (e.g., /dugruka/). The second experiment controlled for effects of stress. Responses were still fastest in prepositional-consonant contexts, but were now slowest in nonprepositional-consonant contexts. In Experiment 3, the lexical and syllabic status of the contexts was manipulated. Responses were again slowest in nonprepositional-consonant contexts but equally fast in prepositional-consonant, prepositional-vowel, and nonprepositional-vowel contexts. These results suggest that Slovak listeners use fixed stress and the PWC to segment speech, but that single consonants that can be words have a special status in Slovak segmentation. Knowledge about what constitutes a phonologically acceptable word in a given language therefore determines whether vowelless stretches of speech are or are not treated as acceptable parts of the lexical parse.

Abstract

How do native listeners process grammatical errors that are frequent in non-native speech? We investigated whether the neural correlates of syntactic processing are modulated by speaker identity. ERPs to gender agreement errors in sentences spoken by a native speaker were compared with the same errors spoken by a non-native speaker. In line with previous research, gender violations in native speech resulted in a P600 effect (larger P600 for violations in comparison with correct sentences), but when the same violations were produced by the non-native speaker with a foreign accent, no P600 effect was observed. Control sentences with semantic violations elicited comparable N400 effects for both the native and the non-native speaker, confirming no general integration problem in foreign-accented speech. The results demonstrate that the P600 is modulated by speaker identity, extending our knowledge about the role of speaker's characteristics on neural correlates of speech processing.

Abstract

Drawings of objects were presented in series of 54 each to 14 German speaking subjects with the tasks to indicate by button presses a) whether the grammatical gender of an object name was masculine ("der") or feminine ("die") and b) whether the depicted object was man-made or nature-made. The magnetoencephalogram (MEG) was recorded with a whole-head neuromagnetometer and task-specific patterns of brain activity were determined in the source space (Minimum Norm Estimates, MNE). A left-temporal focus of activity 150-275 ms after stimulus onset in the gender decision compared to the semantic classification task was discussed as indicating the retrieval of syntactic information, while a more expanded left hemispheric activity in the gender relative to the semantic task 300-625 ms after stimulus onset was discussed as indicating phonological encoding. A predominance of activity in the semantic task was observed over right fronto-central region 150-225 ms after stimulus-onset, suggesting that semantic and syntactic processes are prominent in this stage of lexical selection.

Abstract

Feedback has been shown to be effective in shifting attention across perceptual cues to a phonological contrast in speech perception (Francis, Baldwin & Nusbaum, 2000). However, the learning mechanisms behind this process remain obscure. We compare the predictions of supervised error-driven learning (Rescorla & Wagner, 1972) and reinforcement learning (Sutton & Barto, 1998) using computational simulations. Supervised learning predicts downweighting of an informative cue when the learner receives evidence that it is no longer informative. In contrast, reinforcement learning suggests that a reduction in cue weight requires positive evidence for the informativeness of an alternative cue. Experimental evidence supports the latter prediction, implicating reinforcement learning as the mechanism behind the effect of feedback on cue weighting in speech perception. Native English listeners were exposed to either bimodal or unimodal VOT distributions spanning the unaspirated/aspirated boundary (bear/pear). VOT is the primary cue to initial stop voicing in English. However, lexical feedback in training indicated that VOT was no longer predictive of voicing. Reduction in the weight of VOT was observed only when participants could use an alternative cue, F0, to predict voicing. Frequency distributions had no effect on learning. Overall, the results suggest that attention shifting in learning the phonetic cues to phonological categories is accomplished using simple reinforcement learning principles that also guide the choice of actions in other domains.

Abstract

Previous studies have linked the low expression variant of a variable number of tandem repeat polymorphism in the monoamine oxidase A gene (MAOA‐L) to the risk for impulsivity and aggression, brain developmental abnormalities, altered cortico‐limbic circuit function, and an exaggerated neural serotonergic tone. However, the neurobiological effects of this variant on human brain network architecture are incompletely understood. We studied healthy individuals and used multimodal neuroimaging (sample size range: 219–284 across modalities) and network‐based statistics (NBS) to probe the specificity of MAOA‐L‐related connectomic alterations to cortical‐limbic circuits and the emotion processing domain. We assessed the spatial distribution of affected links across several neuroimaging tasks and data modalities to identify potential alterations in network architecture. Our results revealed a distributed network of node links with a significantly increased connectivity in MAOA‐L carriers compared to the carriers of the high expression (H) variant. The hyperconnectivity phenotype primarily consisted of between‐lobe (“anisocoupled”) network links and showed a pronounced involvement of frontal‐temporal connections. Hyperconnectivity was observed across functional magnetic resonance imaging (fMRI) of implicit emotion processing (pFWE = .037), resting‐state fMRI (pFWE = .022), and diffusion tensor imaging (pFWE = .044) data, while no effects were seen in fMRI data of another cognitive domain, that is, spatial working memory (pFWE = .540). These observations are in line with prior research on the MAOA‐L variant and complement these existing data by novel insights into the specificity and spatial distribution of the neurogenetic effects. Our work highlights the value of multimodal network connectomic approaches for imaging genetics.

Abstract

CONTEXT Recent studies have shown an association between cigarettes per day (CPD) and a nonsynonymous single-nucleotide polymorphism in CHRNA5, rs16969968. OBJECTIVE To determine whether the association between rs16969968 and smoking is modified by age at onset of regular smoking. DATA SOURCES Primary data. STUDY SELECTION Available genetic studies containing measures of CPD and the genotype of rs16969968 or its proxy. DATA EXTRACTION Uniform statistical analysis scripts were run locally. Starting with 94 050 ever-smokers from 43 studies, we extracted the heavy smokers (CPD >20) and light smokers (CPD ≤10) with age-at-onset information, reducing the sample size to 33 348. Each study was stratified into early-onset smokers (age at onset ≤16 years) and late-onset smokers (age at onset >16 years), and a logistic regression of heavy vs light smoking with the rs16969968 genotype was computed for each stratum. Meta-analysis was performed within each age-at-onset stratum. DATA SYNTHESIS Individuals with 1 risk allele at rs16969968 who were early-onset smokers were significantly more likely to be heavy smokers in adulthood (odds ratio [OR] = 1.45; 95% CI, 1.36-1.55; n = 13 843) than were carriers of the risk allele who were late-onset smokers (OR = 1.27; 95% CI, 1.21-1.33, n = 19 505) (P = .01). CONCLUSION These results highlight an increased genetic vulnerability to smoking in early-onset smokers.

Abstract

Cultural transmission is a key component of human evolution. Two of humans' closest living relatives, chimpanzees and orangutans, have also been argued to transmit behavioral traditions across generations culturally [ [1], [2] and [3]], but how much the process might resemble the human process is still in large part unknown. One key phenomenon of human cultural transmission is majority-biased transmission: the increased likelihood for learners to end up not with the most frequent behavior but rather with the behavior demonstrated by most individuals. Here we show that chimpanzees and human children as young as 2 years of age, but not orangutans, are more likely to copy an action performed by three individuals, once each, than an action performed by one individual three times. The tendency to acquire the behaviors of the majority has been posited as key to the transmission of relatively safe, reliable, and productive behavioral strategies [ [4], [5], [6] and [7]] but has not previously been demonstrated in primates.