Publications

Abstract

This paper discusses four experiments on Dutch which show that distinctive phonological features differ in their relevance for word recognition. The relevance of a feature for word recognition depends on its phonological stability, that is, the extent to which that feature is generally realized in accordance with its lexical specification in the relevant word position. If one feature value is uninformative, all values of that feature are less relevant for word recognition, with the least informative feature being the least relevant. Features differ in their relevance both in spoken and written word recognition, though the differences are more pronounced in auditory lexical decision than in self-paced reading.

Abstract

This study addresses the question to what extent the production of regular past tense forms in Dutch is a¤ected by analogical processes. We report an experiment in which native speakers of Dutch listened to existing regular verbs over headphones, and had to indicate which of the past tense allomorphs, te or de, was appropriate for these verbs. According to generative analyses, the choice between the two su‰xes is completely regular and governed by the underlying [voice]-specification of the stem-final segment. In this approach, no analogical e¤ects are expected. In connectionist and analogical approaches, by contrast, the phonological similarity structure in the lexicon is expected to a¤ect lexical processing. Our experimental results support the latter approach: all participants created more nonstandard past tense forms, produced more inconsistency errors, and responded more slowly for verbs with stronger analogical support for the nonstandard form.

Abstract

Manganese (Mn2+)-enhanced magnetic resonance imaging (MEMRI) offers the possibility to generate longitudinal maps of brain activity in unrestrained and behaving animals. However, Mn2+ is a metabolic toxin and a competitive inhibitor for Ca2+, and therefore, a yet unsolved question in MEMRI studies is whether the concentrations of metal ion used may alter brain physiology. In the present work we have investigated the behavioral, electrophysiological and histopathological consequences of MnCl2 administration at concentrations and dosage protocols regularly used in MEMRI. Three groups of animals were sc injected with saline, 0.1 and 0.5 mmol/kg MnCl2, respectively. In vivo electrophysiological recordings in the hippocampal formation revealed a mild but detectable decrease in both excitatory postsynaptic potentials (EPSP) and population spike (PS) amplitude under the highest MnCl2 dose. The EPSP to PS ratio was preserved at control levels, indicating that neuronal excitability was not affected. Experiments of pair pulse facilitation demonstrated a dose dependent increase in the potentiation of the second pulse, suggesting presynaptic Ca2+ competition as the mechanism for the decreased neuronal response. Tetanization of the perforant path induced a long-term potentiation of synaptic transmission that was comparable in all groups, regardless of treatment. Accordingly, the choice accuracy tested on a hippocampal-dependent learning task was not affected. However, the response latency in the same task was largely increased in the group receiving 0.5 mmol/kg of MnCl2. Immunohistological examination of the hippocampus at the end of the experiments revealed no sign of neuronal toxicity or glial reaction. Although we show that MEMRI at 0.1 mmol/Kg MnCl2 may be safely applied to the study of cognitive networks, a detailed assessment of toxicity is strongly recommended for each particular study and Mn2+ administration protocol.

Abstract

Magnetic resonance imaging (MRI) is widely used in basic and clinical research to map the structural and functional organization of the brain. An important need of MR research is for contrast agents that improve soft-tissue contrast, enable visualization of neuronal tracks, and enhance the capacity of MRI to provide functional information at different temporal scales. Unchelated manganese can be such an agent, and manganese-enhanced MRI (MEMRI) can potentially be an excellent technique for localization of brain activity (for review see Silva et al., 2004). Yet, the toxicity of manganese presents a major limitation for employing MEMRI in behavioral paradigms. We have tested systematically the voluntary wheel running behavior of rats after systemic application of MnCl2 in a dose range of 16–80 mg/kg, which is commonly used in MEMRI studies. The results show a robust dose-dependent decrease in motor performance, which was accompanied by weight loss and decrease in food intake. The adverse effects lasted for up to 7 post-injection days. The lowest dose of MnCl2 (16 mg/kg) produced minimal adverse effects, but was not sufficient for functional mapping. We have therefore evaluated an alternative method of manganese delivery via osmotic pumps, which provide a continuous and slow release of manganese. In contrast to a single systemic injection, the pump method did not produce any adverse locomotor effects, while achieving a cumulative concentration of manganese (80 mg/kg) sufficient for functional mapping. Thus, MEMRI with such an optimized manganese delivery that avoids toxic effects can be safely applied for longitudinal studies in behaving animals.

Abstract

This study examines the effect of L2 and L3 proficiency on L3 word learning. Native speakers of Spanish with different proficiencies in L2 English and L3 Dutch and a control group of Dutch native speakers participated in a Dutch word learning task involving minimal and non-minimal word pairs. The minimal word pairs were divided into ‘minimal-easy’ and ‘minimal-difficult’ pairs on the basis of whether or not they are known to pose perceptual problems for L1 Spanish learners. Spanish speakers’ proficiency in Dutch and English was independently established by their scores on general language comprehension tests. All participants were trained and subsequently tested on the mapping between pseudo-words and non-objects. The results revealed that, first, both native and non-native speakers produced more errors and longer reaction times for minimal than for non-minimal word pairs, and secondly, Spanish learners had more errors and longer reaction times for minimal-difficult than for minimal-easy pairs. The latter finding suggests that there is a strong continuity between sound perception and L3 word recognition. With respect to proficiency, only the learner’s proficiency in their L2, namely English, predicted their accuracy on L3 minimal pairs. This shows that learning an L2 with a larger vowel inventory than the L1 is also beneficial for word learning in an L3 with a similarly large vowel inventory.

Abstract

Genetic variation affecting absorption, distribution or excretion of essential trace elements may lead to health effects related to sub-clinical deficiency. We have tested for allelic effects of single-nucleotide polymorphisms (SNPs) on blood copper, selenium and zinc in a genome-wide association study using two adult cohorts from Australia and the UK. Participants were recruited in Australia from twins and their families and in the UK from pregnant women. We measured erythrocyte Cu, Se and Zn (Australian samples) or whole blood Se (UK samples) using inductively coupled plasma mass spectrometry. Genotyping was performed with Illumina chips and > 2.5 m SNPs were imputed from HapMap data. Genome-wide significant associations were found for each element. For Cu, there were two loci on chromosome 1 (most significant SNPs rs1175550, P = 5.03 × 10(-10), and rs2769264, P = 2.63 × 10(-20)); for Se, a locus on chromosome 5 was significant in both cohorts (combined P = 9.40 × 10(-28) at rs921943); and for Zn three loci on chromosomes 8, 15 and X showed significant results (rs1532423, P = 6.40 × 10(-12); rs2120019, P = 1.55 × 10(-18); and rs4826508, P = 1.40 × 10(-12), respectively). The Se locus covers three genes involved in metabolism of sulphur-containing amino acids and potentially of the analogous Se compounds; the chromosome 8 locus for Zn contains multiple genes for the Zn-containing enzyme carbonic anhydrase. Where potentially relevant genes were identified, they relate to metabolism of the element (Se) or to the presence at high concentration of a metal-containing protein (Cu).

Abstract

Author SummaryThe standard approach in genome-wide association studies is to analyse the relationship between genetic variants and disease one marker at a time. Significant associations between markers and disease are then used as evidence to implicate biological intermediates and pathways likely to be involved in disease aetiology. However, single genetic variants typically only explain small amounts of disease risk. Our idea is to construct allelic scores that explain greater proportions of the variance in biological intermediates than single markers, and then use these scores to data mine genome-wide association studies. We show how allelic scores derived from known variants as well as allelic scores derived from hundreds of thousands of genetic markers across the genome explain significant portions of the variance in body mass index, levels of C-reactive protein, and LDLc cholesterol, and many of these scores show expected correlations with disease. Power calculations confirm the feasibility of scaling our strategy to the analysis of tens of thousands of molecular phenotypes in large genome-wide meta-analyses. Our method represents a simple way in which tens of thousands of molecular phenotypes could be screened for potential causal relationships with disease.

Abstract

Twin and family studies indicate that the timing of primary tooth eruption is highly heritable, with estimates typically exceeding 80%. To identify variants involved in primary tooth eruption, we performed a population-based genome-wide association study of 'age at first tooth' and 'number of teeth' using 5998 and 6609 individuals, respectively, from the Avon Longitudinal Study of Parents and Children (ALSPAC) and 5403 individuals from the 1966 Northern Finland Birth Cohort (NFBC1966). We tested 2 446 724 SNPs imputed in both studies. Analyses were controlled for the effect of gestational age, sex and age of measurement. Results from the two studies were combined using fixed effects inverse variance meta-analysis. We identified a total of 15 independent loci, with 10 loci reaching genome-wide significance (P < 5 × 10(-8)) for 'age at first tooth' and 11 loci for 'number of teeth'. Together, these associations explain 6.06% of the variation in 'age of first tooth' and 4.76% of the variation in 'number of teeth'. The identified loci included eight previously unidentified loci, some containing genes known to play a role in tooth and other developmental pathways, including an SNP in the protein-coding region of BMP4 (rs17563, P = 9.080 × 10(-17)). Three of these loci, containing the genes HMGA2, AJUBA and ADK, also showed evidence of association with craniofacial distances, particularly those indexing facial width. Our results suggest that the genome-wide association approach is a powerful strategy for detecting variants involved in tooth eruption, and potentially craniofacial growth and more generally organ development.

Abstract

Two-year-old children’s reasoning about the relation between their own and others’ preferences was investigated across two studies. In Experiment 1, children first observed 2 actors display their individual preferences for various toys. Children were then asked to make inferences about new, visually inaccessible toys and books that were described as being the favorite of each actor, unfamiliar to each actor, or disliked by each actor. Children tended to select the favorite toys and books from the actor who shared their own preference but chose randomly when the new items were unfamiliar to or disliked by the two actors. Experiment 2 extended these findings, showing that children do not generalize a shared preference across unrelated categories of items. Taken together, the results suggest that young children readily recognize when another person holds a preference similar to their own and use that knowledge appropriately to achieve desired outcomes.

Abstract

Two studies examined the influence of similarity on 3-year-old children’s initial liking of their peers. Children were presented with pairs of childlike puppets who were either similar or dissimilar to them on a specified dimension and then were asked to choose one of the puppets to play with as a measure of liking. Children selected the puppet whose food preferences or physical appearance matched their own. Unpacking the physical appearance finding revealed that the stable similarity of hair color may influence liking more strongly than the transient similarity of shirt color. A second study showed that children also prefer to play with a peer who shares their toy preferences, yet importantly, show no bias toward a peer who is similar on an arbitrary dimension. The findings provide insight into the earliest development of peer relations in young children.

Abstract

This study investigates the way adult second language (L2) learners of English resolve relative clause attachment ambiguities in sentences such as The dean liked the secretary of the professor who was reading a letter. Two groups of advanced L2 learners of English with Greek or German as their first language participated in a set of off-line and on-line tasks. The results indicate that the L2 learners do not process ambiguous sentences of this type in the same way as adult native speakers of English do. Although the learners’ disambiguation preferences were influenced by lexical–semantic properties of the preposition linking the two potential antecedent noun phrases (of vs. with), there was no evidence that they applied any phrase structure–based ambiguity resolution strategies of the kind that have been claimed to influence sentence processing in monolingual adults. The L2 learners’ performance also differs markedly from the results obtained from 6- to 7-year-old monolingual English children in a parallel auditory study, in that the children’s attachment preferences were not affected by the type of preposition at all. We argue that children, monolingual adults, and adult L2 learners differ in the extent to which they are guided by phrase structure and lexical–semantic information during sentence processing.

Abstract

In this study we describe a distinctive pigment ring that appears in spider eyes after ecdysis and successively decreases in size in the days thereafter. Although pigment stops in spider eyes are well known, size variability is, to our knowledge, reported here for the first time. Representative species from three families (Ctenidae, Sparassidae and Lycosidae) are investigated and, for one of these species (Cupiennius salei, Ctenidae), the progressive increase in pupil diameter is monitored. In this species the pupil occupies only a fourth of the total projected lens surface after ecdysis and reaches its final size after approximately ten days. MicroCT images suggest that the decrease of the pigment ring is linked to the growth of the corneal lens after ecdysis. The pigment rings might improve vision in the immature eye by shielding light rays that would otherwise enter the eye via peripheral regions of the cornea, beside the growing crystalline lens.

Abstract

This article focuses on “perceptual syntax”, the faculty to process patterns in sensory stimuli. Specifically, this study addresses the ability to perceptually connect elements that are: (1) of the same sensory modality; (2) spatially and temporally non-adjacent; or (3) within multiple sensorial domains. The underlying hypothesis is that in each animal species, this core cognitive faculty enables the perception of the environment-world (Umwelt) and consequently the possibility to survive within it. Importantly, it is suggested that in doing so, perceptual syntax determines (and guides) each species’ ontological access to the world. In support of this hypothesis, research on perceptual syntax in nonverbal individuals (preverbal infants and nonhuman animals) and humans is reviewed. This comparative approach results in theoretical remarks on human cognition and ontology, pointing to the conclusion that the ability to map cross-modal connections through verbal language is what makes humans’ form of life species-typical.

Abstract

The aim of this paper is to help refine the definition of humans as “linguistic animals” in light of a comparative approach on nonhuman animals’ cognitive systems. As Uexküll & Kriszat (1934/1992) have theorized, the epistemic access to each species-specific environment (Umwelt) is driven by different biocognitive processes. Within this conceptual framework, I identify the salient cognitive process that distinguishes each species typical perception of the world as the faculty of language meant in the following operational definition: the ability to connect different elements according to structural rules. In order to draw some conclusions about humans’ specific faculty of language, I review different empirical studies on nonhuman animals’ ability to recognize formal patterns of tokens. I suggest that what differentiates human language from other animals’ cognitive systems is the ability to categorize the units of a pattern, going beyond its perceptual aspects. In fact, humans are the only species known to be able to combine semantic units within a network of combinatorial logical relationships (Deacon 1997) that can be linked to the state of affairs in the external world (Wittgenstein 1922). I assume that this ability is the core cognitive process underlying a) the capacity to speak (or to reason) in verbal propositions and b) the general human faculty of language expressed, for instance, in the ability to draw visual conceptual maps or to compute mathematical expressions. In light of these considerations, I conclude providing some research questions that could lead to a more detailed comparative exploration of the faculty of language.

Abstract

State-of-the-art DNA sequencing is providing ever more detailed insights into the genomes of humans, extant apes, and even extinct hominins (1–3), offering unprecedented opportunities to uncover the molecular variants that make us human. A common assumption is that the emergence of behaviorally modern humans after 200,000 years ago required—and followed—a specific biological change triggered by one or more genetic mutations. For example, Klein has argued that the dawn of human culture stemmed from a single genetic change that “fostered the uniquely modern ability to adapt to a remarkable range of natural and social circumstance” (4). But are evolutionary changes in our genome a cause or a consequence of cultural innovation (see the figure)?

Abstract

A significant number of individuals have unexplained difficulties with acquiring normal speech and language, despite adequate intelligence and environmental stimulation. Although developmental disorders of speech and language are heritable, the genetic basis is likely to involve several, possibly many, different risk factors. Investigations of a unique three-generation family showing monogenic inheritance of speech and language deficits led to the isolation of the first such gene on chromosome 7, which encodes a transcription factor known as FOXP2. Disruption of this gene causes a rare severe speech and language disorder but does not appear to be involved in more common forms of language impairment. Recent genome-wide scans have identified at least four chromosomal regions that may harbor genes influencing the latter, on chromosomes 2, 13, 16, and 19. The molecular genetic approach has potential for dissecting neurological pathways underlying speech and language disorders, but such investigations are only just beginning.

Abstract

Between 2 and 5% of children who are otherwise unimpaired have significant difficulties in acquiring expressive and/or receptive language, despite adequate intelligence and opportunity. While twin studies indicate a significant role for genetic factors in developmental disorders of speech and language, the majority of families segregating such disorders show complex patterns of inheritance, and are thus not amenable for conventional linkage analysis. A rare exception is the KE family, a large three-generation pedigree in which approximately half of the members are affected with a severe speech and language disorder which appears to be transmitted as an autosomal dominant monogenic trait. This family has been widely publicised as suffering primarily from a defect in the use of grammatical suffixation rules, thus supposedly supporting the existence of genes specific to grammar. The phenotype, however, is broader in nature, with virtually every aspect of grammar and of language affected. In addition, affected members have a severe orofacial dyspraxia, and their speech is largely incomprehensible to the naive listener. We initiated a genome-wide search for linkage in the KE family and have identified a region on chromosome 7 which co-segregates with the speech and language disorder (maximum lod score = 6.62 at theta = 0.0), confirming autosomal dominant inheritance with full penetrance. Further analysis of microsatellites from within the region enabled us to fine map the locus responsible (designated SPCH1) to a 5.6-cM interval in 7q31, thus providing an important step towards its identification. Isolation of SPCH1 may offer the first insight into the molecular genetics of the developmental process that culminates in speech and language.

Abstract

The testimony of others and direct experience play a major role in the development of children's knowledge. Children actively use questions to seek others' testimony and explore the environment. It is unclear though whether children distinguish when it is better to ask from when it is better to try to find an answer by oneself. In 2 experiments, we examined the ability of 4- and 6-year-olds to select between looking and asking to determine visible and invisible properties of entities (e.g., hair color vs. knowledge of French). All children chose to look more often for visible than invisible properties. However, only 6-year-olds chose above chance to look for visible properties and to ask for invisible properties. Four-year-olds showed a preference for looking in one experiment and asking in the other. The results suggest substantial development in the efficacy of children's learning in early childhood.

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

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

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

Several quantitative trait loci (QTLs) that influence developmental dyslexia (reading disability [RD]) have been mapped to chromosome regions by linkage analysis. The most consistently replicated area of linkage is on chromosome 6p23-21.3. We used association analysis in 223 siblings from the United Kingdom to identify an underlying QTL on 6p22.2. Our association study implicates a 77-kb region spanning the gene TTRAP and the first four exons of the neighboring uncharacterized gene KIAA0319. The region of association is also directly upstream of a third gene, THEM2. We found evidence of these associations in a second sample of siblings from the United Kingdom, as well as in an independent sample of twin-based sibships from Colorado. One main RD risk haplotype that has a frequency of ∼12% was found in both the U.K. and U.S. samples. The haplotype is not distinguished by any protein-coding polymorphisms, and, therefore, the functional variation may relate to gene expression. The QTL influences a broad range of reading-related cognitive abilities but has no significant impact on general cognitive performance in these samples. In addition, the QTL effect may be largely limited to the severe range of reading disability.

Abstract

OBJECTIVE: Recent research has provided evidence for a genetically mediated association between language or reading-related cognitive deficits and impaired motor coordination. Other studies have identified relationships between lateralization of hand skill and cognitive abilities. With a large sample, the authors aimed to investigate genetic relationships between measures of reading-related cognition, hand motor skill, and hand skill lateralization.

METHOD: The authors applied univariate and bivariate correlation and familiality analyses to a range of measures. They also performed genomewide linkage analysis of hand motor skill in a subgroup of 195 sibling pairs.

RESULTS: Hand motor skill was significantly familial (maximum heritability=41%), as were reading-related measures. Hand motor skill was weakly but significantly correlated with reading-related measures, such as nonword reading and irregular word reading. However, these correlations were not significantly familial in nature, and the authors did not observe linkage of hand motor skill to any chromosomal regions implicated in susceptibility to dyslexia. Lateralization of hand skill was not correlated with reading or cognitive ability.

CONCLUSIONS: The authors confirmed a relationship between lower motor ability and poor reading performance. However, the genetic effects on motor skill and reading ability appeared to be largely or wholly distinct, suggesting that the correlation between these traits may have arisen from environmental influences. Finally, the authors found no evidence that reading disability and/or low general cognitive ability were associated with ambidexterity.

Abstract

Schizophrenia and non-right-handedness are moderately associated, and both traits are often accompanied by abnormalities of asymmetrical brain morphology or function. We have found linkage previously of chromosome 2p12-q11 to a quantitative measure of handedness, and we have also found linkage of schizophrenia/schizoaffective disorder to this same chromosomal region in a separate study. Now, we have found that in one of our samples (191 reading-disabled sibling pairs), the relative hand skill of siblings was correlated more strongly with paternal than maternal relative hand skill. This led us to re-analyse 2p12-q11 under parent-of-origin linkage models. We found linkage of relative hand skill in the RD siblings to 2p12-q11 with P=0.0000037 for paternal identity-by-descent sharing, whereas the maternally inherited locus was not linked to the trait (P>0.2). Similarly, in affected-sib-pair analysis of our schizophrenia dataset (241 sibling pairs), we found linkage to schizophrenia for paternal sharing with LOD=4.72, P=0.0000016, within 3 cM of the peak linkage to relative hand skill. Maternal linkage across the region was weak or non-significant. These similar paternal-specific linkages suggest that the causative genetic effects on 2p12-q11 are related. The linkages may be due to a single maternally imprinted influence on lateralized brain development that contains common functional polymorphisms.

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

A computational model of inference during story comprehension is presented, in which story situations are represented distributively as points in a high-dimensional “situation-state space.” This state space organizes itself on the basis of a constructed microworld description. From the same description, causal/temporal world knowledge is extracted. The distributed representation of story situations is more flexible than Golden and Rumelhart’s [Discourse Proc 16 (1993) 203] localist representation. A story taking place in the microworld corresponds to a trajectory through situation-state space. During the inference process, world knowledge is applied to the story trajectory. This results in an adjusted trajectory, reflecting the inference of propositions that are likely to be the case. Although inferences do not result from a search for coherence, they do cause story coherence to increase. The results of simulations correspond to empirical data concerning inference, reading time, and depth of processing. An extension of the model for simulating story retention shows how coherence is preserved during retention without controlling the retention process. Simulation results correspond to empirical data concerning story recall and intrusion.

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

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

In list learning paradigms with free recall, written recall has been found to be less susceptible to intrusions of related concepts than spoken recall when the list items had been visually presented. This effect has been ascribed to the use of stored orthographic representations from the study phase during written recall (Kellogg, 2001). In other memory retrieval paradigms, by contrast, either better recall for modality-congruent items or an input-independent writing superiority effect have been found (Grabowski, 2005). In a series of four experiments using a paired associate learning paradigm we tested (a) whether output modality effects on verbal recall can be replicated in a paradigm that does not involve the rejection of semantically related intrusion words, (b) whether a possible superior performance for written recall was due to a slower response onset for writing as compared to speaking in immediate recall, and (c) whether the performance in paired associate word recall was correlated with performance in an additional episodic memory recall task. We observed better written recall in the first half of the recall phase, irrespective of the modality in which the material was presented upon encoding. An explanation for this effect based on longer response latencies for writing and hence more time for memory retrieval could be ruled out by showing that the effect persisted in delayed response versions of the task. Although there was some evidence that stored additional episodic information may contribute to the successful retrieval of associate words, this evidence was only found in the immediate response experiments and hence is most likely independent from the observed output modality effect. In sum, our results from a paired associate learning paradigm suggest that superior performance for written vs. spoken recall cannot be (solely) explained in terms of additional access to stored orthographic representations from the encoding phase. Our findings rather suggest a general writing-superiority effect at the time of memory retrieval.

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

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

The present study investigated whether Short Message Service shortcuts are more difficult to process in sentence context than the spelled-out word equivalent and, if so, how any additional processing difficulty arises. Twenty-four student participants read 37 Short Message Service shortcuts and word equivalents embedded in semantically plausible and implausible contexts (e.g., He left/drank u/you a note) while their eye movements were recorded. There were effects of plausibility and spelling on early measures of processing difficulty (first fixation durations, gaze durations, skipping, and first-pass regression rates for the targets), but there were no interactions of plausibility and spelling. Late measures of processing difficulty (second run gaze duration and total fixation duration) were only affected by plausibility but not by spelling. These results suggest that shortcuts are harder to recognize, but that, once recognized, they are integrated into the sentence context as easily as ordinary words.

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 Perceptual Loop Theory of speech monitoring assumes that speakers routinely inspect their inner speech. In contrast, Huettig and Hartsuiker (2010) observed that listening to one’s own speech during language production drives eye-movements to phonologically related printed words with a similar time-course as listening to someone else’s speech does in speech perception experiments. This suggests that speakers listen to their own overt speech, but not to their inner speech. However, a direct comparison between production and perception with the same stimuli and participants is lacking so far. The current printed word eye-tracking experiment therefore used a within-subjects design, combining production and perception. Displays showed four words, of which one, the target, either had to be named or was presented auditorily. Accompanying words were phonologically related, semantically related, or unrelated to the target. There were small increases in looks to phonological competitors with a similar time-course in both production and perception. Phonological effects in perception however lasted longer and had a much larger magnitude. We conjecture that this difference is related to a difference in predictability of one’s own and someone else’s speech, which in turn has consequences for lexical competition in other-perception and possibly suppression of activation in self-perception.

Abstract

Our species displays remarkable linguistic diversity. While the uneven distribution of this diversity demands explanation, the drivers of these patterns have not been conclusively determined. We address this issue in two steps. First, we review previous empirical studies that have suggested environmental, geographical, and socio-cultural drivers of linguistic diversification. However, contradictory results and methodological variation make it difficult to draw general conclusions. Second, we outline a program for future research. We suggest that future analyses should account for interactions among causal factors, lack of spatial and phylogenetic independence of data, and transitory patterns. Recent analytical advances in biogeography and evolutionary biology, such as simulation modeling of diversity patterns, hold promise for testing four key mechanisms of language diversification proposed here: neutral change, population movement, contact, and selection. Future modeling approaches should also evaluate how the outcomes of these processes are influenced by demography, environmental heterogeneity, and time.

Abstract

Does spatial language influence how people think about space? To address this question, we observed children who did not know a conventional language, and tested their performance on nonlinguistic spatial tasks. We studied deaf children living in Istanbul whose hearing losses prevented them from acquiring speech and whose hearing parents had not exposed them to sign. Lacking a conventional language, the children used gestures, called homesigns, to communicate. In Study 1, we asked whether homesigners used gesture to convey spatial relations, and found that they did not. In Study 2, we tested a new group of homesigners on a Spatial Mapping Task, and found that they performed significantly worse than hearing Turkish children who were matched to the deaf children on another cognitive task. The absence of spatial language thus went hand-in-hand with poor performance on the nonlinguistic spatial task, pointing to the importance of spatial language in thinking about space.

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

Wilson disease (WD) is an autosomal recessive disorder resulting in pathological progressive copper accumulation in liver and other tissues. The worldwide prevalence (P) is about 30/million, while in Sardinia it is in the order of 1/10 000. However, all of these estimates are likely to suffer from an underdiagnosis bias. Indeed, a recent molecular neonatal screening in Sardinia reported a WD prevalence of 1:2707. In this study, we used a new approach that makes it possible to estimate the allelic frequency (q) of an autosomal recessive disorder if one knows the proportion between homozygous and compound heterozygous patients (the homozygosity index or HI) and the inbreeding coefficient (F) in a sample of affected individuals. We applied the method to a set of 178 Sardinian individuals (3 of whom born to consanguineous parents), each with a clinical and molecular diagnosis of WD. Taking into account the geographical provenance of the parents of every patient within Sardinia (to make F computation more precise), we obtained a q=0.0191 (F=7.8 × 10-4, HI=0.476) and a corresponding prevalence P=1:2732. This result confirms that the prevalence of WD is largely underestimated in Sardinia. On the other hand, the general reliability and applicability of the HI approach to other autosomal recessive disorders is confirmed, especially if one is interested in the genetic epidemiology of populations with high frequency of consanguineous marriages.

Abstract

First paragraph: The study of the transmission of sign languages can give novel insights into the transmission of spoken languages1 and, more generally, into gene–culture coevolution. Over the years, several papers related to the persistence of sign language have been
reported.2–6 All of these studies have emphasized the role of assortative (non-random) mating by deafness state (ie, a tendency for deaf individuals to partner together) for increasing the frequency of recessive deafness, and hence for the persistence of sign language in a population.

Abstract

Irrelevant speech impairs the immediate serial recall of visually presented material. Previously, we have shown that the irrelevant speech effect (ISE) was associated with a relative decrease of regional blood flow in cortical regions subserving the verbal working memory, in particular the superior temporal cortex. In this extension of the previous study, the working memory load was increased and an increased activity as a response to irrelevant speech was noted in the dorsolateral prefrontal cortex. We suggest that the two studies together provide some basic insights as to the nature of the irrelevant speech effect. Firstly, no area in the brain can be ascribed as the single locus of the irrelevant speech effect. Instead, the functional neuroanatomical substrate to the effect can be characterized in terms of changes in networks of functionally interrelated areas. Secondly, the areas that are sensitive to the irrelevant speech effect are also generically activated by the verbal working memory task itself. Finally, the impact of irrelevant speech and related brain activity depends on working memory load as indicated by the differences between the present and the previous study. From a brain perspective, the irrelevant speech effect may represent a complex phenomenon that is a composite of several underlying mechanisms, which depending on the working memory load, include top-down inhibition as well as recruitment of compensatory support and control processes. We suggest that, in the low-load condition, a selection process by an inhibitory top-down modulation is sufficient, whereas in the high-load condition, at or above working memory span, auxiliary adaptive cognitive resources are recruited as compensation

Abstract

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

Abstract

According to the cue-based parsing approach (Lewis, Vasishth, & Van Dyke, 2006), sentence comprehension difficulty derives from interference from material that partially matches syntactic and semantic retrieval cues. In a 2 (low vs. high semantic interference) × 2 (low vs. high syntactic interference) fMRI study, greater activation was observed in left BA44/45 for high versus low syntactic interference conditions following sentences and in left BA45/47 for high versus low semantic interference conditions following comprehension questions. A conjunction analysis showed BA45 associated with both types of interference, while BA47 was associated with only semantic interference. Greater activation was also observed in the left STG in the high interference conditions. Importantly, the results for the LIFG could not be attributed to greater working memory capacity demands for high interference conditions. The results favor a fractionation of the LIFG wherein BA45 is associated with post-retrieval selection and BA47 with controlled retrieval of semantic information.

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

Native listeners make use of higher-level, context-driven semantic and linguistic information during the perception of speech-in-noise. In a recent behavioral study, using a new paradigm that isolated the semantic level of speech by using words, we showed that this native-language benefit is at least partly driven by semantic context (Golestani et al., 2009). Here, we used the same paradigm in a functional magnetic resonance imaging (fMRI) experiment to study the neural bases of speech intelligibility, as well as to study the neural bases of this semantic context effect in the native language. A forced-choice recognition task on the first of two auditorily presented semantically related or unrelated words was employed, where the first, 'target' word was embedded in different noise levels. Results showed that activation in components of the brain language network, including Broca's area and the left posterior superior temporal sulcus, as well as brain regions known to be functionally related to attention and task difficulty, was modulated by stimulus intelligibility. In line with several previous studies examining the role of linguistic context in the intelligibility of degraded speech at the sentence level, we found that activation in the angular gyrus of the left inferior parietal cortex was modulated by the presence of semantic context, and further, that this modulation depended on the intelligibility of the speech stimuli. Our findings help to further elucidate neural mechanisms underlying the interaction of context-driven and signal-driven factors during the perception of degraded speech, and this specifically at the semantic level. (c) 2013 Elsevier Inc. All rights reserved.

Abstract

Semantic verbal fluency tasks are commonly used in neuropsychological assessment. Investigations of the influence of level of literacy have not yielded consistent results in the literature. This prompted us to investigate the ecological relevance of task specifics, in particular, the choice of semantic criteria used. Two groups of literate and illiterate subjects were compared on two verbal fluency tasks using different semantic criteria. The performance on a food criterion (supermarket fluency task), considered more ecologically relevant for the two literacy groups, and an animal criterion (animal fluency task) were compared. The data were analysed using both quantitative and qualitative measures. The quantitative analysis indicated that the two literacy groups performed equally well on the supermarket fluency task. In contrast, results differed significantly during the animal fluency task. The qualitative analyses indicated differences between groups related to the strategies used, especially with respect to the animal fluency task. The overall results suggest that there is not a substantial difference between literate and illiterate subjects related to the fundamental workings of semantic memory. However, there is indication that the content of semantic memory reflects differences in shared cultural background - in other words, formal education –, as indicated by the significant interaction between level of literacy and semantic criterion.

Abstract

Researchers are beginning to uncover the neurogenetic pathways that underlie our unparalleled capacity for spoken language. Initial clues come from identification of genetic risk factors implicated in developmental language disorders. The underlying genetic architecture is complex, involving a range of molecular mechanisms. For example, rare protein-coding mutations of the FOXP2 transcription factor cause severe problems with sequencing of speech sounds, while common genetic risk variants of small effect size in genes like CNTNAP2, ATP2C2 and CMIP are associated with typical forms of language impairment. In this article, we describe how investigations of these and other candidate genes, in humans, animals and cellular models, are unravelling the connections between genes and cognition. This depends on interdisciplinary research at multiple levels, from determining molecular interactions and functional roles in neural cell-biology all the way through to effects on brain structure and activity.

Abstract

Absolute pitch and synesthesia are two uncommon cognitive traits that reflect increased neuronal connectivity and have been anecdotally reported to occur together in a same individual. Here we systematically evaluate the occurrence of syesthesia in a population of 768 subjects with documented absolute pitch. Out of these 768 subjects, 151(20.1%) reported synesthesia, most commonly with color. These self-reports of synesthesia were validated in a subset of 21 study subjects using an established methodology. We further carried out combined linkage analysis of 53 multiplex families with absolute pitch and 36 multiplex families with synesthesia. We observed a peak NPL LOD=4.68 on chromosome 6q, as well as evidence of linkage on chromosome 2 using a dominant model. These data establish the close phenotypic and genetic relationship between absolute pitch and synesthesia. The chromosome 6 linkage region contains 73 genes; several leading candidate genes involved in neurodevelopment were investigated by exon resequencing. However, further studies will be required to definitively establish the identity of the causative gene(s) in the region.

Abstract

The discussion on root infinitives has mainly centered around their supposed modal usage. This article aims at modelling the form-function relation of the root infinitive phenomenon by taking into account the full range of interpretational facets encountered cross-linguistically and interindividually. Following the idea of a subsequent ‘‘cell partitioning’’ in the emergence of form-function correlations, I claim that it is the major fission between [+-finite] which is central to express temporal reference different from the default here&now in tense-oriented languages. In aspectual-oriented languages, a similar opposition is mastered with the marking of early aspectual forms. It is observed that in tense-oriented languages like Dutch and German, the progression of functions associated with the infinitival form proceeds from nonmodal to modal, whereas the reverse progression holds for the Russian infinitive. Based on this crucial observation, a model of acquisition is proposed which allows for a flexible and systematic relationship between morphological forms and their respective interpretational biases dependent on their developmental context. As for early child language, I argue that children entertain only two temporal parameters: one parameter is fixed to the here&now point in time, and a second parameter relates to the time talked about, the topic time; this latter time overlaps the situation time as long as no empirical evidence exists to support the emergence of a proper distinction between tense and aspect.

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

Magnetoencephalographic (MEG) recordings are a rich source of information about the neural dynamics underlying cognitive processes in the brain, with excellent temporal and good spatial resolution. In recent years there have been considerable advances in MEG hardware developments as well as methodological developments. Sophisticated analysis techniques are now routinely applied and continuously improved, leading to fascinating insights into the intricate dynamics of neural processes. However, the rapidly increasing level of complexity of the different steps in a MEG study make it difficult for novices, and sometimes even for experts, to stay aware of possible limitations and caveats. Furthermore, the complexity of MEG data acquisition and data analysis requires special attention when describing MEG studies in publications, in order to facilitate interpretation and reproduction of the results. This manuscript aims at making recommendations for a number of important data acquisition and data analysis steps and suggests details that should be specified in manuscripts reporting MEG studies. These recommendations will hopefully serve as guidelines that help to strengthen the position of the MEG research community within the field of neuroscience, and may foster discussion within the community in order to further enhance the quality and impact of MEG research.

Abstract

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

Abstract

The central topic of this study is to investigate three- and four-place predicate in Yaqui, which are characterized by having multiple object arguments. As with other Southern Uto-Aztecan languages, it has been said that Yaqui follows the Primary/Secondary Object pattern (Dryer 1986). Actually, Yaqui presents three patterns: verbs like nenka ‘sell’ follow the direct–indirect object pattern, verbs like miika ‘give’ follow the primary object pattern, and verbs like chijakta ‘sprinkle’ follow the locative alternation pattern; the primary object pattern is the exclusive one found with derived verbs. This paper shows that the contrast between direct object and primary object languages is not absolute but rather one of degree, and hence two “object” selection principles are needed to explain this mixed system. The two principles are not limited to Yaqui but are found in other languages as well, including English.

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

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

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

Abstract

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

Abstract

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

Abstract

Although the sentences that we hear or read have meaning, this does not necessarily mean that they are also true. Relatively little is known about the critical brain structures for, and the relative time course of, establishing the meaning and truth of linguistic expressions. We present electroencephalogram data that show the rapid parallel integration of both semantic and world
knowledge during the interpretation of a sentence. Data from functional magnetic resonance imaging revealed that the left inferior prefrontal cortex is involved in the integration of both meaning and world knowledge. Finally, oscillatory brain responses indicate that the brain keeps a record of what makes a sentence hard to interpret.

Abstract

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

Abstract

A neurobiological model of language is discussed that overcomes the shortcomings of the classical Wernicke-Lichtheim-Geschwind model. It is based on a subdivision of language processing into three components: Memory, Unification, and Control. The functional components as well as the neurobiological underpinnings of the model are discussed. In addition, the need for extension of the model beyond the classical core regions for language is shown. Attentional networks as well as networks for inferential processing are crucial to realize language comprehension beyond single word processing and beyond decoding propositional content. It is shown that this requires the dynamic interaction between multiple brain regions.

Abstract

First paragraph:
MacDonald (2013) proposes that distributional properties of language and processing biases in language comprehension can to a large extent be attributed to consequences of the language production process. In essence, the account is derived from the principle of least effort that was formulated by Zipf, among others (Zipf, 1949; Levelt, 2013). However, in Zipf's view the outcome of the least effort principle was a compromise between least effort for the speaker and least effort for the listener, whereas MacDonald puts most of the burden on the production process.

Abstract

The present study investigated the developmental interrelationships between play, gesture use and spoken language development in children aged 18–31 months. The children completed two tasks: (i) a structured measure of pretend (or ‘symbolic’) play and (ii) a measure of vocabulary knowledge in which children have been shown to gesture. Additionally, their productive spoken language knowledge was measured via parental report. The results indicated that symbolic play is positively associated with children’s gesture use, which in turn is positively associated with spoken language knowledge over and above the influence of age. The tripartite relationship between gesture, play and language development is discussed with reference to current developmental theory.

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

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

This paper studies the robustness of exemplar effects in word comprehension by means of four long-term priming experiments with lexical decision tasks in Dutch. A prime and target represented the same word type and were presented with the same or different degree of reduction. In Experiment 1, participants heard only a small number of trials, a large proportion of repeated words, and stimuli produced by only one speaker. They recognized targets more quickly if these represented the same degree of reduction as their primes, which forms additional evidence for the exemplar effects reported in the literature. Similar effects were found for two speakers who differ in their pronunciations. In Experiment 2, with a smaller proportion of repeated words and more trials between prime and target, participants recognized targets preceded by primes with the same or a different degree of reduction equally quickly. Also, in Experiments 3 and 4, in which listeners were not exposed to one but two types of pronunciation variation (reduction degree and speaker voice), no exemplar effects arose. We conclude that the role of exemplars in speech comprehension during natural conversations, which typically involve several speakers and few repeated content words, may be smaller than previously assumed.

Abstract

This paper investigates the nature of reduction phenomena in informal speech. It addresses the question whether reduction processes that affect many word types, but only if they occur in connected informal speech, may be categorical in nature. The focus is on reduction of schwa in the prefixes and on word-final /t/ in Dutch past participles. More than 2000 tokens of past participles from the Ernestus Corpus of Spontaneous Dutch and the Spoken Dutch Corpus (both from the interview and read speech component) were transcribed automatically. The results demonstrate that the presence and duration of /t/ are affected by approximately the same phonetic variables, indicating that the absence of /t/ is the extreme result of shortening, and thus results from a gradient reduction process. Also for schwa, the data show that mainly phonetic variables influence its reduction, but its presence is affected by different and more variables than its duration, which suggests that the absence of schwa may result from gradient as well as categorical processes. These conclusions are supported by the distributions of the segments’ durations. These findings provide evidence that reduction phenomena which affect many words in informal conversations may also result from categorical reduction processes.

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

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

We here review existing evidence for majority influences in children under the age of ten years and comparable studies with animals ranging from fish to apes. Throughout the review, we structure the discussion surrounding majority influences by differentiating the behaviour of individuals in the presence of a majority and the underlying mechanisms and motivations. Most of the relevant research to date in both developmental psychology and comparative psychology has focused on the behavioural outcomes, where a multitude of mechanisms could be at play. We further propose that interpreting cross-species differences in behavioural patterns is difficult without considering the psychology of the individual. Some attempts at this have been made both in developmental psychology and comparative psychology. We propose that physiological measures should be used to subsidize behavioural studies in an attempt to understand the composition of mechanisms and motivations underlying majority influence. We synthesize the relevant evidence on human brain function in order to provide a framework for future investigation in this area. In addition to streamlining future research efforts, we aim to create a conceptual platform for productive exchanges across the related disciplines of developmental and comparative psychology.

Abstract

Contemporary comparative cognition has a large repertoire of animal models and methods, with concurrent theoretical advances that are providing initial answers to crucial questions about human cognition. What cognitive traits are uniquely human? What are the species-typical inherited predispositions of the human mind? What is the human mind capable of without certain types of specific experiences with the surrounding environment? Here, we review recent findings from the domains of space, time and number cognition. These findings are produced using different comparative methodologies relying on different animal species, namely birds and non-human great apes. The study of these species not only reveals the range of cognitive abilities across vertebrates, but also increases our understanding of human cognition in crucial ways.

Abstract

OBJECTIVE: Plasma adiponectin is strongly associated with various components of metabolic syndrome, type 2 diabetes and cardiovascular outcomes. Concentrations are highly heritable and differ between men and women. We therefore aimed to investigate the genetics of plasma adiponectin in men and women. METHODS: We combined genome-wide association scans of three population-based studies including 4659 persons. For the replication stage in 13795 subjects, we selected the 20 top signals of the combined analysis, as well as the 10 top signals with p-values less than 1.0 x 10(-4) for each the men- and the women-specific analyses. We further selected 73 SNPs that were consistently associated with metabolic syndrome parameters in previous genome-wide association studies to check for their association with plasma adiponectin. RESULTS: The ADIPOQ locus showed genome-wide significant p-values in the combined (p=4.3 x 10(-24)) as well as in both women- and men-specific analyses (p=8.7 x 10(-17) and p=2.5 x 10(-11), respectively). None of the other 39 top signal SNPs showed evidence for association in the replication analysis. None of 73 SNPs from metabolic syndrome loci exhibited association with plasma adiponectin (p>0.01). CONCLUSIONS: We demonstrated the ADIPOQ gene as the only major gene for plasma adiponectin, which explains 6.7% of the phenotypic variance. We further found that neither this gene nor any of the metabolic syndrome loci explained the sex differences observed for plasma adiponectin. Larger studies are needed to identify more moderate genetic determinants of plasma adiponectin.

Abstract

Here we examined the role of bilingualism on cognitive inhibition using the Stroop Colour Word task. Our hypothesis was that the frequency of use of a second language (L2) in the daily life of successive bilingual individuals impacts the efficiency of their inhibitory control mechanism. Thirty-three highly proficient successive French–German bilinguals, living either in a French or in a German linguistic environment, performed a Stroop task on both French and German words. Moreover, 31 French monolingual individuals were also tested with French words. We showed that the bilingual advantage was (i) reinforced by the use of a third language, and (ii) modulated by the duration of immersion in a second language environment. This suggests that top–down inhibitory control is most involved at the beginning of immersion. Taken together, the present findings lend support to the psycholinguistic models of bilingual language processing that postulate that top–down active inhibition is involved in language control.

Abstract

This paper provides an overview of the question–response system of Danish, based on a collection of 350 questions (and responses) collected from video recordings of naturally occurring face-to-face interactions between native speakers of Danish. The paper identifies the lexico-grammatical options for formulating questions, the range of social actions that can be implemented through questions and the relationship between questions and responses. It further describes features where Danish questions differ from a range of other languages in terms of, for instance, distribution and the relationship between question format and social action. For instance, Danish has a high frequency of interrogatively formatted questions and questions that are negatively formulated, when compared to languages that have the same grammatical options. In terms of action, Danish shows a higher number of questions that are used for making suggestions, offers and requests and does not use repetition as a way of answering a question as often as other languages.

Abstract

Objective: This study investigates the relationship of ‘online commentary’(contemporaneous physician comments about physical examination [PE] findings) with (i) parent questioning of the treatment recommendation and (ii) inappropriate antibiotic prescribing. Methods: A nested cross-sectional study of 522 encounters motivated by upper respiratory symptoms in 27 California pediatric practices (38 pediatricians). Physicians completed a post-visit survey regarding physical examination findings, diagnosis, treatment, and whether they perceived the parent as expecting an antibiotic. Taped encounters were coded for ‘problem’ online commentary (PE findings discussed as significant or clearly abnormal) and ‘no problem’ online commentary (PE findings discussed reassuringly as normal or insignificant). Results: Online commentary during the PE occurred in 73% of visits with viral diagnoses (n = 261). Compared to similar cases with ‘no problem’ online commentary, ‘problem’ comments were associated with a 13% greater probability of parents uestioning a non-antibiotic treatment plan (95% CI 0-26%, p = .05,) and a 27% (95% CI: 2-52%, p < .05) greater probability of an inappropriate antibiotic prescription. Conclusion: With viral illnesses, problematic online comments are associated with more pediatrician-parent conflict over non-antibiotic treatment recommendations. This may increase inappropriate antibiotic prescribing. Practice implications: In viral cases, physicians should consider avoiding the use of problematic online commentary.

Abstract

Research on imitation in infancy has primarily focused on what and when infants imitate. More recently, however, the question why infants imitate has received renewed attention, partly motivated by the finding that infants sometimes selectively imitate the actions of others and sometimes faithfully imitate, or overimitate, the actions of others. The present study evaluates the hypothesis that this varying imitative behavior is related to infants' social traits. To do so, we assessed faithful and selective imitation longitudinally at 12 and 15 months, and extraversion at 15 months. At both ages, selective imitation was dependent on the causal structure of the act. From 12 to 15 months, selective imitation decreased while faithful imitation increased. Furthermore, infants high in extraversion were more faithful imitators than infants low in extraversion. These results demonstrate that the onset of faithful imitation is earlier than previously thought, but later than the onset of selective imitation. The observed relation between extraversion and faithful imitation supports the hypothesis that faithful imitation is driven by the social motivations of the infant. We call this relation the King Louie Effect: like the orangutan King Louie in The Jungle Book, infants imitate faithfully due to a growing interest in the interpersonal nature of interactions.

Abstract

Allergic disease is very common and carries substantial public-health burdens. We conducted a meta-analysis of genome-wide associations with self-reported cat, dust-mite and pollen allergies in 53,862 individuals. We used generalized estimating equations to model shared and allergy-specific genetic effects. We identified 16 shared susceptibility loci with association P<5×10(-8), including 8 loci previously associated with asthma, as well as 4p14 near TLR1, TLR6 and TLR10 (rs2101521, P=5.3×10(-21)); 6p21.33 near HLA-C and MICA (rs9266772, P=3.2×10(-12)); 5p13.1 near PTGER4 (rs7720838, P=8.2×10(-11)); 2q33.1 in PLCL1 (rs10497813, P=6.1×10(-10)), 3q28 in LPP (rs9860547, P=1.2×10(-9)); 20q13.2 in NFATC2 (rs6021270, P=6.9×10(-9)), 4q27 in ADAD1 (rs17388568, P=3.9×10(-8)); and 14q21.1 near FOXA1 and TTC6 (rs1998359, P=4.8×10(-8)). We identified one locus with substantial evidence of differences in effects across allergies at 6p21.32 in the class II human leukocyte antigen (HLA) region (rs17533090, P=1.7×10(-12)), which was strongly associated with cat allergy. Our study sheds new light on the shared etiology of immune and autoimmune disease.