Publications

Abstract

Book review of James R. Hurford THE ORIGINS OF GRAMMAR 791pp. Oxford University Press. ISBN 978 0 19 920787 9

Abstract

Noise-vocoded speech is a spectrally highly degraded signal, but it preserves the temporal envelope of speech. Listeners vary considerably in their ability to adapt to this degraded speech signal. Here, we hypothesized that individual differences in adaptation to vocoded speech should be predictable by non-speech auditory, cognitive, and neuroanatomical factors. We tested eighteen normal-hearing participants in a short-term vocoded speech-learning paradigm (listening to 100 4-band-vocoded sentences). Non-speech auditory skills were assessed using amplitude modulation (AM) rate discrimination, where modulation rates were centered on the speech-relevant rate of 4 Hz. Working memory capacities were evaluated (digit span and nonword repetition), and structural MRI scans were examined for anatomical predictors of vocoded speech learning using voxel-based morphometry. Listeners who learned faster to understand degraded speech also showed smaller thresholds in the AM discrimination task. This ability to adjust to degraded speech is furthermore reflected anatomically in increased volume in an area of the left thalamus (pulvinar) that is strongly connected to the auditory and prefrontal cortices. Thus, individual non-speech auditory skills and left thalamus grey matter volume can predict how quickly a listener adapts to degraded speech.

Abstract

We investigated whether regional differences in the native language (L1) influence the perception of second language (L2) sounds. Many cross-language and L2 perception studies have assumed that the degree of acoustic similarity between L1 and L2 sounds predicts cross-linguistic and L2 performance. The present study tests this assumption by examining the perception of the English contrast between /e{open}/ and /æ/ in native speakers of Dutch spoken in North Holland (the Netherlands) and in East- and West-Flanders (Belgium). A Linear Discriminant Analysis on acoustic data from both dialects showed that their differences in vowel production, as reported in and Adank, van Hout, and Van de Velde (2007), should influence the perception of the L2 vowels if listeners focus on the vowels' acoustic/auditory properties. Indeed, the results of categorization tasks with Dutch or English vowels as response options showed that the two listener groups differed as predicted by the discriminant analysis. Moreover, the results of the English categorization task revealed that both groups of Dutch listeners displayed the asymmetric pattern found in previous word recognition studies, i.e. English /æ/ was more frequently confused with English /e{open}/ than the reverse. This suggests a strong link between previous L2 word learning results and the present L2 perceptual assimilation patterns.

Abstract

Nuclear orphan receptor TLX (NR2E1) functions primarily as a transcriptional repressor and its pivotal role in brain development, glioblastoma, mental retardation and retinopathologies make it an attractive drug target. TLX is expressed in the neural stem cells (NSCs) of the subventricular zone and the hippocampus subgranular zone, regions with persistent neurogenesis in the adult brain, and functions as an essential regulator of NSCs maintenance and self-renewal. Little is known about the TLX social network of interactors and only few TLX coregulators are described. To identify and characterize novel TLX-binders and possible coregulators, we performed yeast-two-hybrid (Y2H) screens of a human adult brain cDNA library using different TLX constructs as baits. Our screens identified multiple clones of Atrophin-1 (ATN1), a previously described TLX interactor. In addition, we identified an interaction with the oncoprotein and zinc finger transcription factor BCL11A (CTIP1/Evi9), a key player in the hematopoietic system and in major blood-related malignancies. This interaction was validated by expression and coimmunoprecipitation in human cells. BCL11A potentiated the transrepressive function of TLX in an in vitro reporter gene assay. Our work suggests that BCL11A is a novel TLX coregulator that might be involved in TLX-dependent gene regulation in the brain.

Abstract

In the current eye-tracking study, we explored whether 12-month-old infants can predict others' social preferences. We showed infants scenes in which two characters alternately helped or hindered an agent in his goal of climbing a hill. In a control condition, the two characters moved up and down the hill in identical ways to the helper and hinderer but did not make contact with the agent; thus, they did not cause him to reach or not reach her or his goal. Following six alternating familiarization trials of helping and hindering interactions (help-hinder condition) or up and down interactions (up-down condition), infants were shown one test trial in which they could visually anticipate the agent approaching one of the two characters. As predicted, infants in the help-hinder condition made significantly more visual anticipations toward the helping than hindering character, suggesting that they predicted the agent to approach the helping character. In contrast, infants revealed no difference in visual anticipations between the up and down characters. The up-down condition served to control for low-level perceptual explanations of the results for the help-hinder condition. Thus, together the results reveal that 12-month-old infants make predictions about others' behaviour and social preferences from a third-party perspective.

Abstract

Across two experiments, we examined the relationship between 18-month-old infants’ mimicry and social behavior – particularly invitations to play with an adult play partner. In Experiment 1, we manipulated whether an adult mimicked the infant's play or not during an initial play phase. We found that infants who had been mimicked were subsequently more likely to invite the adult to join their play with a new toy. In addition, they reenacted marginally more steps from a social learning demonstration she gave. In Experiment 2, infants had the chance to spontaneously mimic the adult during the play phase. Complementing Experiment 1, those infants who spent more time mimicking the adult were more likely to invite her to play with a new toy. This effect was specific to play and not apparent in other communicative acts, such as directing the adult's attention to an event or requesting toys. Together, the results suggest that infants use mimicry as a tool to establish social connections with others and that mimicry has specific influences on social behaviors related to initiating subsequent joint interactions.

Abstract

Infants imitate others’ individual actions, but do they also replicate others’ joint activities? To examine whether observing joint action influences infants’ initiation of joint action, forty-eight 18-month-old infants observed object demonstrations by 2 models acting together (joint action), 2 models acting individually (individual action), or 1 model acting alone (solitary action). Infants’ behavior was examined after they were given each object. Infants in the joint action condition attempted to initiate joint action more often than infants in the other conditions, yet they were equally likely to communicate for other reasons and to imitate the demonstrated object-directed actions. The findings suggest that infants learn to replicate others’ joint activity through observation, an important skill for cultural transmission of shared practices.

Abstract

We examine representations of time among the Mianmin of Papua New Guinea. We begin by describing the patterns of spatial and temporal reference in Mian. Mian uses a system of spatial terms that derive from the orientation and direction of the Hak and Sek rivers and the surrounding landscape. We then report results from a temporal arrangement task administered to a group of Mian speakers. The results reveal evidence for a variety of temporal representations. Some participants arranged time with respect to their bodies (left to right or toward the body). Others arranged time as laid out on the landscape, roughly along the east/west axis (either east to west or west to east). This absolute pattern is consistent both with the axis of the motion of the sun and the orientation of the two rivers, which provides the basis for spatial reference in the Mian language. The results also suggest an increase in left-to-right temporal representations with increasing years of formal education (and the reverse pattern for absolute spatial representations for time). These results extend previous work on spatial representations for time to a new geographical region, physical environment, and linguistic and cultural system.

Abstract

Aging, often considered a result of random cellular damage, can be accurately estimated using DNA methylation profiles, the foundation of pan-tissue epigenetic clocks. Here, we demonstrate the development of universal pan-mammalian clocks, using 11,754 methylation arrays from our Mammalian Methylation Consortium, which encompass 59 tissue types across 185 mammalian species. These predictive models estimate mammalian tissue age with high accuracy (r > 0.96). Age deviations correlate with human mortality risk, mouse somatotropic axis mutations and caloric restriction. We identified specific cytosines with methylation levels that change with age across numerous species. These sites, highly enriched in polycomb repressive complex 2-binding locations, are near genes implicated in mammalian development, cancer, obesity and longevity. Our findings offer new evidence suggesting that aging is evolutionarily conserved and intertwined with developmental processes across all mammals.

Abstract

Our understanding of dual-process models of cognition may benefit from a consideration of language processing, as language comprehension involves fast and slow processes analogous to those used for reasoning. More specifically, De Neys's criticisms of the exclusivity assumption and the fast-to-slow switch mechanism are consistent with findings from the literature on the construction and revision of linguistic interpretations.

Abstract

The constituents of attractiveness differ across the sexes. Many relevant traits are dimorphic, suggesting that they are the product of intersexual selection. However, direction of causality is generally difficult to determine, as aesthetic criteria can as readily result from, as cause, dimorphism. Women have proportionately smaller feet than men. Prior work on the role of foot size in attractiveness suggests an asymmetry across the sexes, as small feet enhance female appearance, yet average, rather than large, feet are preferred on men. Previous investigations employed crude stimuli and limited samples. Here, we report on multiple cross-cultural studies designed to overcome these limitations. With the exception of one rural society, we find that small foot size is preferred when judging women, yet no equivalent preference applies to men. Similarly, consonant with the thesis that a preference for youth underlies intersexual selection acting on women, we document an inverse relationship between foot size and perceived age. Examination of preferences regarding, and inferences from, feet viewed in isolation suggests different roles for proportionality and absolute size in judgments of female and male bodies. Although the majority of these results bolster the conclusion that pedal dimorphism is the product of intersexual selection, the picture is complicated by the reversal of the usual preference for small female feet found in one rural society. While possibly explicable in terms of greater emphasis on female economic productivity relative to beauty, the latter finding underscores the importance of employing diverse samples when exploring postulated evolved aesthetic preferences.

Abstract

The evolutionary origins of music are much debated. One theory holds that the ability to produce complex musical sounds might reflect qualities that are relevant in mate choice contexts and hence, that music is functionally analogous to the sexually-selected acoustic displays of some animals. If so, women may be expected to show heightened preferences for more complex music when they are most fertile. Here, we used computer-generated musical pieces and ovulation predictor kits to test this hypothesis. Our results indicate that women prefer more complex music in general; however, we found no evidence that their preference for more complex music increased around ovulation. Consequently, our findings are not consistent with the hypothesis that a heightened preference/bias in women for more complex music around ovulation could have played a role in the evolution of music. We go on to suggest future studies that could further investigate whether sexual selection played a role in the evolution of this universal aspect of human culture.

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

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

Abstract

Studies of rhythm processing and of reward have progressed separately, with little connection between the two. However, consistent links between rhythm and reward are beginning to surface, with research suggesting that synchronization to rhythm is rewarding, and that this rewarding element may in turn also boost this synchronization. The current mini review shows that the combined study of rhythm and reward can be beneficial to better understand their independent and combined roles across two central aspects of cognition: 1) learning and memory, and 2) social connection and interpersonal synchronization; which have so far been studied largely independently. From this basis, it is discussed how connections between rhythm and reward can be applied to learning and memory and social connection across different populations, taking into account individual differences, clinical populations, human development, and animal research. Future research will need to consider the rewarding nature of rhythm, and that rhythm can in turn boost reward, potentially enhancing other cognitive and social processes.

Abstract

No abstract is available for this article

Abstract

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

Abstract

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

Abstract

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

Abstract

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

Abstract

This paper investigates the lexical semantics and relative distributions of verbs describing putting and taking events in Kuuk Thaayorre, a Pama-Nyungan language of Cape York (Australia). Thaayorre put/take verbs can be subcategorised according to whether they may combine with an NP encoding a goal, an NP encoding a source, or both. Goal NPs are far more frequent in natural discourse: initial analysis shows 85% of goal-oriented verb tokens to be accompanied by a goal NP, while only 31% of source-oriented verb tokens were accompanied by a source. This finding adds weight to Ikegami’s (1987) assertion of the conceptual primacy of goals over sources, reflected in a cross-linguistic dissymmetry whereby goal-marking is less marked and more widely used than source-marking.

Abstract

Lifelong graph learning deals with the problem of continually adapting graph neural network (GNN) models to changes in evolving graphs. We address two critical challenges of lifelong graph learning in this work: dealing with new classes and tackling imbalanced class distributions. The combination of these two challenges is particularly relevant since newly emerging classes typically resemble only a tiny fraction of the data, adding to the already skewed class distribution. We make several contributions: First, we show that the amount of unlabeled data does not influence the results, which is an essential prerequisite for lifelong learning on a sequence of tasks. Second, we experiment with different label rates and show that our methods can perform well with only a tiny fraction of annotated nodes. Third, we propose the gDOC method to detect new classes under the constraint of having an imbalanced class distribution. The critical ingredient is a weighted binary cross-entropy loss function to account for the class imbalance. Moreover, we demonstrate combinations of gDOC with various base GNN models such as GraphSAGE, Simplified Graph Convolution, and Graph Attention Networks. Lastly, our k-neighborhood time difference measure provably normalizes the temporal changes across different graph datasets. With extensive experimentation, we find that the proposed gDOC method is consistently better than a naive adaption of DOC to graphs. Specifically, in experiments using the smallest history size, the out-of-distribution detection score of gDOC is 0.09 compared to 0.01 for DOC. Furthermore, gDOC achieves an Open-F1 score, a combined measure of in-distribution classification and out-of-distribution detection, of 0.33 compared to 0.25 of DOC (32% increase).

Abstract

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

Abstract

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

Abstract

The current research investigated structural priming in Tagalog, a symmetrical voice language containing rich verbal morphology that results in changes in mapping between syntactic positions and thematic roles. This grammatically rare feature, which results in multiple transitive structures that are balanced in terms of the grammatical status of their arguments, provides the opportunity to test whether word order priming is sensitive to the voice morphology of the verb. In three sentence priming experiments (Ns = 64), we manipulated whether the target-verb prompt carried the same voice as the verb in the prime sentence. In all experiments, priming occurred only when the prime and target had the same voice morphology. Additionally, we found that the strength of word order priming depends on voice: stronger priming effects were found for the voice morpheme associated with a more flexible word order. The findings are consistent with learning-based accounts where language-specific representations for syntax emerge across developmental time. We discuss the implications of these results in the context of Tagalog's grammar. The results reveal the value of crosslinguistic data for theory-testing, and the value of structural priming in determining the representational nature of linguistic structure.

Abstract

In the target article, Cristia, Foushee, Aravena-Bravo, Cychosz, Scaff, and Casillas (2022) convincingly show the need to broaden the current language acquisition research base, not only in linguistic diversity, but also in terms of regions and cultural groups studied. In conducting acquisition research in understudied populations, such as in rural settings, the authors highlight the importance of using a multi-method approach. They present the challenges in adapting these methods to new settings and offer possible ways to promote this type of research. In this commentary, we extend the discussion to understudied urban communities, as we encounter several of the concerns raised in Cristia et al. when collecting observational and experimental language acquisition data from Metro Manila, Philippines. We first describe the community we study, the challenges and modifications needed for conducting research in this setting, and end with a discussion of possible strategies to promote research in communities with understudied populations.

Abstract

We present a visual world eye-tracking study on Tseltal (a Mayan language) and investigate whether verbal information can be used to anticipate an upcoming referent. Basic word order in transitive sentences in Tseltal is Verb-Object-Subject (VOS). The verb is usually encountered first, making argument structure and syntactic information available at the outset, which should facilitate anticipation of the post-verbal arguments. Tseltal speakers listened to verb-initial sentences with either an object-predictive verb (e.g., ‘eat’) or a general verb (e.g., ‘look for’) (e.g., “Ya slo’/sle ta stukel on te kereme”, Is eating/is looking (for) by himself the avocado the boy/ “The boy is eating/is looking (for) an avocado by himself”) while seeing a visual display showing one potential referent (e.g., avocado) and three distractors (e.g., bag, toy car, coffee grinder). We manipulated verb type (predictive vs. general) and recorded participants' eye-movements while they listened and inspected the visual scene. Participants’ fixations to the target referent were analysed using multilevel logistic regression models. Shortly after hearing the predictive verb, participants fixated the target object before it was mentioned. In contrast, when the verb was general, fixations to the target only started to increase once the object was heard. Our results suggest that Tseltal hearers pre-activate semantic features of the grammatical object prior to its linguistic expression. This provides evidence from a verb-initial language for online incremental semantic interpretation and anticipatory processing during language comprehension. These processes are comparable to the ones identified in subject-initial languages, which is consistent with the notion that different languages follow similar universal processing principles.

Abstract

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

Abstract

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

Abstract

Schizophrenia is a debilitating psychiatric disorder associated with a reduced fertility and decreased life expectancy, yet common predisposing variation substantially contributes to the onset of the disorder, which poses an evolutionary paradox. Previous research has suggested balanced selection, a mechanism by which schizophrenia risk alleles could also provide advantages under certain environments, as a reliable explanation. However, recent studies have shown strong evidence against a positive selection of predisposing loci. Furthermore, evolutionary pressures on schizophrenia risk alleles could have changed throughout human history as new environments emerged. Here in this study, we used 1000 Genomes Project data to explore the relationship between schizophrenia predisposing loci and recent natural selection (RNS) signatures after the human diaspora out of Africa around 100,000 years ago on a genome-wide scale. We found evidence for significant enrichment of RNS markers in derived alleles arisen during human evolution conferring protection to schizophrenia. Moreover, both partitioned heritability and gene set enrichment analyses of mapped genes from schizophrenia predisposing loci subject to RNS revealed a lower involvement in brain and neuronal related functions compared to those not subject to RNS. Taken together, our results suggest non-antagonistic pleiotropy as a likely mechanism behind RNS that could explain the persistence of schizophrenia common predisposing variation in human populations due to its association to other non-psychiatric phenotypes.

Abstract

The search for common characteristics between the musical abilities of humans and other animal species is still taking its first steps. One of the most promising aspects from a comparative point of view is the analysis of rhythmic components, which are crucial features of human communicative performance but also well-identifiable patterns in the vocal displays of other species. Therefore, the study of rhythm is becoming essential to understand the mechanisms of singing behavior and the evolution of human communication. Recent findings provided evidence that particular rhythmic structures occur in human music and some singing animal species, such as birds and rock hyraxes, but only 2 species of nonhuman primates have been investigated so far (Indri indri and Hylobates lar). Therefore, our study aims to consistently broaden the list of species studied regarding the presence of rhythmic categories. We investigated the temporal organization in the singing of 3 species of crested gibbons (Nomascus gabriellae, Nomascus leucogenys, and Nomascus siki) and found that the most prominent rhythmic category was isochrony. Moreover, we found slight variation in songs’ tempo among species, with N. gabriellae and N. siki singing with a temporal pattern involving a gradually increasing tempo (a musical accelerando), and N. leucogenys with a more regular pattern. Here, we show how the prominence of a peak at the isochrony establishes itself as a shared characteristic in the small apes considered so far.

Abstract

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

Abstract

In the cognitive, computational, and neuro-sciences, practitioners often reason about what computational models represent or learn, as well as what algorithm is instantiated. The putative goal of such reasoning is to generalize claims about the model in question, to claims about the mind and brain, and the neurocognitive capacities of those systems. Such inference is often based on a model’s performance on a task, and whether that performance approximates human behavior or brain activity. Here we demonstrate how such argumentation problematizes the relationship between models and their targets; we place emphasis on artificial neural networks (ANNs), though any theory-brain relationship that falls into the same schema of reasoning is at risk. In this paper, we model inferences from ANNs to brains and back within a formal framework — metatheoretical calculus — in order to initiate a dialogue on both how models are broadly understood and used, and on how to best formally characterize them and their functions. To these ends, we express claims from the published record about models’ successes and failures in first-order logic. Our proposed formalization describes the decision-making processes enacted by scientists to adjudicate over theories. We demonstrate that formalizing the argumentation in the literature can uncover potential deep issues about how theory is related to phenomena. We discuss what this means broadly for research in cognitive science, neuroscience, and psychology; what it means for models when they lose the ability to mediate between theory and data in a meaningful way; and what this means for the metatheoretical calculus our fields deploy when performing high-level scientific inference.

Abstract

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

Abstract

Gestures are often regarded as the most typical compensatory device used by language learners in communicative trouble. Yet gestural solutions to communicative problems have rarely been studied within any theory of second language use. The work pre­sented in this volume aims to account for second language learners’ strategic use of speech-associated gestures by combining a process-oriented framework for communi­cation strategies with a cognitive theory of gesture. Two empirical studies are presented. The production study investigates Swedish lear­ners of French and French learners of Swedish and their use of strategic gestures. The results, which are based on analyses of both individual and group behaviour, contradict popular opinion as well as theoretical assumptions from both fields. Gestures are not primarily used to replace speech, nor are they chiefly mimetic. Instead, learners use gestures with speech, and although they do exploit mimetic gestures to solve lexical problems, they also use more abstract gestures to handle discourse-related difficulties and metalinguistic commentary. The influence of factors such as proficiency, task, culture, and strategic competence on gesture use is discussed, and the oral and gestural strategic modes are compared. In the evaluation study, native speakers’ assessments of learners’ gestures, and the potential effect of gestures on evaluations of proficiency are analysed and discussed in terms of individual communicative style. Compensatory gestures function at multiple communicative levels. This has implica­tions for theories of communication strategies, and an expansion of the existing frameworks is discussed taking both cognitive and interactive aspects into account.

Abstract

This paper explores the linguistic encoding of placement and removal events in Swedish. Drawing on elicited spoken data, it provides a unified approach to caused motion descriptions. The results show uniform syntactic behaviour of placement and removal descriptions and a consistent asymmetry between placement and removal in the semantic specificity of verbs. The results also reveal three further semantic patterns, pertaining to the nature of the relationship between Figure and Ground, that appear to account for how these event types are characterised, viz. whether the Ground is represented by a body part of the Agent; whether the Figure is contained within the Ground; or whether it is supported by the Ground.

Abstract

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

Abstract

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

Abstract

INTRODUCTION
Comparative epigenomics is an emerging field that combines epigenetic signatures with phylogenetic relationships to elucidate species characteristics such as maximum life span. For this study, we generated cytosine DNA methylation (DNAm) profiles (n = 15,456) from 348 mammalian species using a methylation array platform that targets highly conserved cytosines.
RATIONALE
Nature has evolved mammalian species of greatly differing life spans. To resolve the relationship of DNAm with maximum life span and phylogeny, we performed a large-scale cross-species unsupervised analysis. Comparative studies in many species enables the identification of epigenetic correlates of maximum life span and other traits.
RESULTS
We first tested whether DNAm levels in highly conserved cytosines captured phylogenetic relationships among species. We constructed phyloepigenetic trees that paralleled the traditional phylogeny. To avoid potential confounding by different tissue types, we generated tissue-specific phyloepigenetic trees. The high phyloepigenetic-phylogenetic congruence is due to differences in methylation levels and is not confounded by sequence conservation.
We then interrogated the extent to which DNA methylation associates with specific biological traits. We used an unsupervised weighted correlation network analysis (WGCNA) to identify clusters of highly correlated CpGs (comethylation modules). WGCNA identified 55 distinct comethylation modules, of which 30 were significantly associated with traits including maximum life span, adult weight, age, sex, human mortality risk, or perturbations that modulate murine life span.
Both the epigenome-wide association analysis (EWAS) and eigengene-based analysis identified methylation signatures of maximum life span, and most of these were independent of aging, presumably set at birth, and could be stable predictors of life span at any point in life. Several CpGs that are more highly methylated in long-lived species are located near HOXL subclass homeoboxes and other genes that play a role in morphogenesis and development. Some of these life span–related CpGs are located next to genes that are also implicated in our analysis of upstream regulators (e.g., ASCL1 and SMAD6). CpGs with methylation levels that are inversely related to life span are enriched in transcriptional start site (TSS1) and promoter flanking (PromF4, PromF5) associated chromatin states. Genes located in chromatin state TSS1 are constitutively active and enriched for nucleic acid metabolic processes. This suggests that long-living species evolved mechanisms that maintain low methylation levels in these chromatin states that would favor higher expression levels of genes essential for an organism’s survival.
The upstream regulator analysis of the EWAS of life span identified the pluripotency transcription factors OCT4, SOX2, and NANOG. Other factors, such as POLII, CTCF, RAD21, YY1, and TAF1, showed the strongest enrichment for negatively life span–related CpGs.
CONCLUSION
The phyloepigenetic trees indicate that divergence of DNA methylation profiles closely parallels that of genetics through evolution. Our results demonstrate that DNA methylation is subjected to evolutionary pressures and selection. The publicly available data from our Mammalian Methylation Consortium are a rich source of information for different fields such as evolutionary biology, developmental biology, and aging.

Abstract

According to the language marker hypothesis language has provided homo sapiens with a rich symbolic system that plays a central role in interpreting signals delivered by our sensory apparatus, in shaping action goals, and in creating a powerful tool for reasoning and inferencing. This view provides an important correction on embodied accounts of language that reduce language to action, perception, emotion and mental simulation. The presence of a language system has, however, also important consequences for perception, action, emotion, and memory. Language stamps signals from perception, action, and emotional systems with rich cognitive markers that transform the role of these signals in the overall cognitive architecture of the human mind. This view does not deny that language is implemented by means of universal principles of neural organization. However, language creates the possibility to generate rich internal models of the world that are shaped and made accessible by the characteristics of a language system. This makes us less dependent on direct action-perception couplings and might even sometimes go at the expense of the veridicality of perception. In cognitive (neuro)science the pendulum has swung from language as the key to understand the organization of the human mind to the perspective that it is a byproduct of perception and action. It is time that it partly swings back again.

Abstract

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

Abstract

In a study by Milberg, Blumstein, and Dworetzky (1987), normal control subjects and Wernicke's and Broca's aphasics performed a lexical decision task on the third element of auditorily presented triplets of words with either a word or a nonword as target. In three of the four types of word triplets, the first and the third words were related to one or both meanings of the second word, which was semantically ambiguous. The fourth type of word triplet consisted of three unrelated, unambiguous words, functioning as baseline. Milberg et al. (1987) claim that the results for their control subjects are similar to those reported by Schvaneveldt, Meyer, and Becker's original study (1976) with the same prime types, and so interpret these as evidence for a selective lexical access of the different meanings of ambiguous words. It is argued here that Milberg et al. only partially replicate the Schvaneveldt et al. results. Moreover, the results of Milberg et al. are not fully in line with the selective access hypothesis adopted. Replication of the Milberg et al. (1987) study with Dutch materials, using both a design without and a design with repetition of the same target words for the same subjects led to the original pattern as reported by Schvaneveldt et al. (1976). In the design with four separate presentations of the same target word, a strong repetition effect was found. It is therefore argued that the discrepancy between the Milberg et al. results on the one hand, and the Schvaneveldt et al. results on the other, might be due to the absence of a control for repetition effects in the within-subject design used by Milberg et al. It is concluded that this makes the results for both normal and aphasic subjects in the latter study difficult to interpret in terms of a selective access model for normal processing.

Abstract

We review data and hypotheses dealing with the mental representations for perceived and produced speech that infants build and use over the course of learning a language. In the early stages of speech perception and vocal production, before the emergence of a receptive or a productive lexicon, the dominant picture emerging from the literature suggests rather non-analytic representations based on units of the size of the syllable: Young children seem to parse speech into syllable-sized units in spite of their ability to detect sound equivalence based on shared phonetic features. Once a productive lexicon has emerged, word form representations are initially rather underspecified phonetically but gradually become more specified with lexical growth, up to the phoneme level. The situation is different for the receptive lexicon, in which phonetic specification for consonants and vowels seem to follow different developmental paths. Consonants in stressed syllables are somewhat well specified already at the first signs of a receptive lexicon, and become even better specified with lexical growth. Vowels seem to follow a different developmental path, with increasing flexibility throughout lexical development. Thus, children come to exhibit a consonant vowel asymmetry in lexical representations, which is clear in adult representations.

Abstract

Face-to-face interaction is core to human sociality and its evolution, and provides the environment in which most of human communication occurs. Research into the full complexities that define face-to-face interaction requires a multi-disciplinary, multi-level approach, illuminating from different perspectives how we and other species interact. This special issue showcases a wide range of approaches, bringing together detailed studies of naturalistic social-interactional behaviour with larger scale analyses for generalization, and investigations of socially contextualized cognitive and neural processes that underpin the behaviour we observe. We suggest that this integrative approach will allow us to propel forwards the science of face-to-face interaction by leading us to new paradigms and novel, more ecologically grounded and comprehensive insights into how we interact with one another and with artificial agents, how differences in psychological profiles might affect interaction, and how the capacity to socially interact develops and has evolved in the human and other species. This theme issue makes a first step into this direction, with the aim to break down disciplinary boundaries and emphasizing the value of illuminating the many facets of face-to-face interaction.

Abstract

Originally published in Diachronica 27:2 (2010) One attempt at explaining why some language families are large (while others are small) is the hypothesis that the families that are now large became large because their ancestral speakers had a technological advantage, most often agriculture. Variants of this idea are referred to as the Language Farming Dispersal Hypothesis. Previously, detailed language family studies have uncovered various supporting examples and counterexamples to this idea. In the present paper I weigh the evidence from ALL attested language families. For each family, I use the number of member languages as a measure of cardinal size, member language coordinates to measure geospatial size and ethnographic evidence to assess subsistence status. This data shows that, although agricultural families tend to be larger in cardinal size, their size is hardly due to the simple presence of farming. If farming were responsible for language family expansions, we would expect a greater east-west geospatial spread of large families than is actually observed. The data, however, is compatible with weaker versions of the farming dispersal hypothesis as well with models where large families acquire farming because of their size, rather than the other way around.

Abstract

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

Abstract

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

Abstract

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

Abstract

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

Abstract

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

Abstract

Children with developmental language disorder (DLD) regularly use the bare form of verbs (e.g., dance) instead of inflected forms (e.g., danced). We propose an account of this behavior in which processing difficulties of children with DLD disproportionally affect processing novel inflected verbs in their input. Limited experience with inflection in novel contexts leads the inflection to face stronger competition from alternatives. Competition is resolved through a compensatory behavior that involves producing a more accessible alternative: in English, the bare form. We formalize this hypothesis within a probabilistic model that trades off context-dependent versus independent processing. Results show an over-reliance on preceding stem contexts when retrieving the inflection in a model that has difficulty with processing novel inflected forms. We further show that following the introduction of a bias to store and retrieve forms with preceding contexts, generalization in the typically developing (TD) models remains more or less stable, while the same bias in the DLD models exaggerates difficulties with generalization. Together, the results suggest that inconsistent use of inflectional morphemes by children with DLD could stem from inferences they make on the basis of data containing fewer novel inflected forms. Our account extends these findings to suggest that problems with detecting a form in novel contexts combined with a bias to rely on familiar contexts when retrieving a form could explain sequential planning difficulties in children with DLD.

Abstract

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

Abstract

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

Abstract

The search for molecular underpinnings of human vocal communication has focused on genes encoding forkhead-box transcription factors, as rare disruptions of FOXP1, FOXP2, and FOXP4 have been linked to disorders involving speech and language deficits. In male songbirds, an animal model for vocal learning, experimentally altered expression levels of these transcription factors impair song production learning. The relative contributions of auditory processing, motor function or auditory-motor integration to the deficits observed after different FoxP manipulations in songbirds are unknown. To examine the potential effects on auditory learning and development, we focused on female zebra finches (Taeniopygia guttata) that do not sing but develop song memories, which can be assayed in operant preference tests. We tested whether the relatively high levels of FoxP1 expression in forebrain areas implicated in female song preference learning are crucial for the development and/or maintenance of this behavior. Juvenile and adult female zebra finches received FoxP1 knockdowns targeted to HVC (proper name) or to the caudomedial mesopallium (CMM). Irrespective of target site and whether the knockdown took place before (juveniles) or after (adults) the sensitive phase for song memorization, all groups preferred their tutor’s song. However, adult females with FoxP1 knockdowns targeted at HVC showed weaker motivation to hear song and weaker song preferences than sham-treated controls, while no such differences were observed after knockdowns in CMM or in juveniles. In summary, FoxP1 knockdowns in the cortical song nucleus HVC were not associated with impaired tutor song memory but reduced motivation to actively request tutor songs.

Abstract

Neural oscillations are thought to support speech and language processing. They may not only inherit acoustic rhythms, but might also impose endogenous rhythms onto processing. In support of this, we here report that human (both male and female) eye movements during naturalistic reading exhibit rhythmic patterns that show frequency-selective coherence with the EEG, in the absence of any stimulation rhythm. Periodicity was observed in two distinct frequency bands: First, word-locked saccades at 4-5 Hz display coherence with whole-head theta-band activity. Second, fixation durations fluctuate rhythmically at ∼1 Hz, in coherence with occipital delta-band activity. This latter effect was additionally phase-locked to sentence endings, suggesting a relationship with the formation of multi-word chunks. Together, eye movements during reading contain rhythmic patterns that occur in synchrony with oscillatory brain activity. This suggests that linguistic processing imposes preferred processing time scales onto reading, largely independent of actual physical rhythms in the stimulus.

Abstract

Rhythmicity in the millisecond to second range is a fundamental building block of communication and coordinated movement. But how widespread are rhythmic capacities across species, and how did they evolve under different environmental pressures? Comparative research is necessary to answer these questions but has been hindered by limited crosstalk and comparability among results from different study species.
Most acoustics studies do not explicitly focus on characterising or quantifying rhythm, but many are just a few scrapes away from contributing to and advancing the field of comparative rhythm research. Here, we present an eight-level rhythm reporting framework which details actionable steps researchers can take to report rhythm-relevant metrics. Levels fall into two categories: metric reporting and data sharing. Metric reporting levels include defining rhythm-relevant metrics, providing point estimates of temporal interval variability, reporting interval distributions, and conducting rhythm analyses. Data sharing levels are: sharing audio recordings, sharing interval durations, sharing sound element start and end times, and sharing audio recordings with sound element start/end times.
Using sounds recorded from a sperm whale as a case study, we demonstrate how each reporting framework level can be implemented on real data. We also highlight existing best practice examples from recent research spanning multiple species. We clearly detail how engagement with our framework can be tailored case-by-case based on how much time and effort researchers are willing to contribute. Finally, we illustrate how reporting at any of the suggested levels will help advance comparative rhythm research.
This framework will actively facilitate a comparative approach to acoustic rhythms while also promoting cooperation and data sustainability. By quantifying and reporting rhythm metrics more consistently and broadly, new avenues of inquiry and several long-standing, big picture research questions become more tractable. These lines of research can inform not only about the behavioural ecology of animals but also about the evolution of rhythm-relevant phenomena and the behavioural neuroscience of rhythm production and perception. Rhythm is clearly an emergent feature of life; adopting our framework, researchers from different fields and with different study species can help understand why.

Abstract

We used functional magnetic resonance imaging (fMRI) to investigate the neural basis of comprehension and perceptual learning of artificially degraded [noise vocoded (NV)] speech. Fifteen participants were scanned while listening to 6-channel vocoded words, which are difficult for naive listeners to comprehend, but can be readily learned with appropriate feedback presentations. During three test blocks, we compared responses to potentially intelligible NV words, incomprehensible distorted words and clear speech. Training sessions were interleaved with the test sessions and included paired presentation of clear then noise-vocoded words: a type of feedback that enhances perceptual learning. Listeners' comprehension of NV words improved significantly as a consequence of training. Listening to NV compared to clear speech activated left insula, and prefrontal and motor cortices. These areas, which are implicated in speech production, may play an active role in supporting the comprehension of degraded speech. Elevated activation in the precentral gyrus during paired clear-then-distorted presentations that enhance learning further suggests a role for articulatory representations of speech in perceptual learning of degraded speech.

Abstract

In face-to-face discourse, listeners exploit cues in the input to generate predictions about upcoming words. Moreover, in addition to speech, speakers produce a multitude of visual signals, such as iconic gestures, which listeners readily integrate with incoming words. Previous studies have shown that processing of target words is facilitated when these are embedded in predictable compared to non-predictable discourses and when accompanied by iconic compared to meaningless gestures. In the present study, we investigated the interaction of both factors. We recorded electroencephalogram from 60 Dutch adults while they were watching videos of an actress producing short discourses. The stimuli consisted of an introductory and a target sentence; the latter contained a target noun. Depending on the preceding discourse, the target noun was either predictable or not. Each target noun was paired with an iconic gesture and a gesture that did not convey meaning. In both conditions, gesture presentation in the video was timed such that the gesture stroke slightly preceded the onset of the spoken target by 130 ms. Our ERP analyses revealed independent facilitatory effects for predictable discourses and iconic gestures. However, the interactive effect of both factors demonstrated that target processing (i.e., gesture-speech integration) was facilitated most when targets were part of predictable discourses and accompanied by an iconic gesture. Our results thus suggest a strong intertwinement of linguistic predictability and non-verbal gesture processing where listeners exploit predictive discourse cues to pre-activate verbal and non-verbal representations of upcoming target words.

Abstract

Listeners frequently recognize spoken words in the presence of background noise. Previous research has shown that noise reduces phoneme intelligibility and hampers spoken-word recognition—especially for non-native listeners. In the present study, we investigated how noise influences lexical competition in both the non-native and the native language, reflecting the degree to which both languages are co-activated. We recorded the eye movements of native Dutch participants as they listened to English sentences containing a target word while looking at displays containing four objects. On target-present trials, the visual referent depicting the target word was present, along with three unrelated distractors. On target-absent trials, the target object (e.g., wizard) was absent. Instead, the display contained an English competitor, overlapping with the English target in phonological onset (e.g., window), a Dutch competitor, overlapping with the English target in phonological onset (e.g., wimpel, pennant), and two unrelated distractors. Half of the sentences was masked by speech-shaped noise; the other half was presented in quiet. Compared to speech in quiet, noise delayed fixations to the target objects on target-present trials. For target-absent trials, we observed that the likelihood for fixation biases towards the English and Dutch onset competitors (over the unrelated distractors) was larger in noise than in quiet. Our data thus show that the presence of background noise increases lexical competition in the task-relevant non-native (English) and in the task-irrelevant native (Dutch) language. The latter reflects stronger interference of one’s native language during non-native spoken-word recognition under adverse conditions.

Abstract

Background Reduced total brain volume is a consistent finding in children with Attention Deficit/Hyperactivity Disorder (ADHD). In order to get a better understanding of the neurobiology of ADHD, we take the first step in studying the dimensionality of current self-reported adult ADHD symptoms, by looking at its relation with total brain volume. Methodology/Principal Findings In a sample of 652 highly educated adults, the association between total brain volume, assessed with magnetic resonance imaging, and current number of self-reported ADHD symptoms was studied. The results showed an association between these self-reported ADHD symptoms and total brain volume. Post-hoc analysis revealed that the symptom domain of inattention had the strongest association with total brain volume. In addition, the threshold for impairment coincides with the threshold for brain volume reduction. Conclusions/Significance This finding improves our understanding of the biological substrates of self-reported ADHD symptoms, and suggests total brain volume as a target intermediate phenotype for future gene-finding in ADHD.

Abstract

In an online experiment among native speakers of Dutch we measured addressees' responses to emails written in the informal pronoun T or the formal pronoun V in HR communication. 172 participants (61 male, mean age 37 years) read either the V-versions or the T-versions of two invitation emails and two rejection emails by four different fictitious recruiters. After each email, participants had to score their appreciation of the company and the recruiter on five different scales each, such as The recruiter who wrote this email seems … [scale from friendly to unfriendly]. We hypothesized that (i) the V-pronoun would be more appreciated in letters of rejection, and the T-pronoun in letters of invitation, and (ii) older people would appreciate the V-pronoun more than the T-pronoun, and the other way around for younger people. Although neither of these hypotheses was supported, we did find a small effect of pronoun: Emails written in V were more highly appreciated than emails in T, irrespective of type of email (invitation or rejection), and irrespective of the participant's age, gender, and level of education. At the same time, we observed differences in the strength of this effect across different scales.

Abstract

Purpose:
To our knowledge, there are no data examining the agreement between self-reported and clinician-rated stuttering severity. In the era of big data, self-reported ratings have great potential utility for large-scale data collection, where cost and time preclude in-depth assessment by a clinician. Equally, there is increasing emphasis on the need to recognize an individual's experience of their own condition. Here, we examined the agreement between self-reported stuttering severity compared to clinician ratings during a speech assessment. As a secondary objective, we determined whether self-reported stuttering severity correlated with an individual's subjective impact of stuttering.

Method:
Speech-language pathologists conducted face-to-face speech assessments with 195 participants (137 males) aged 5–84 years, recruited from a cohort of people with self-reported stuttering. Stuttering severity was rated on a 10-point scale by the participant and by two speech-language pathologists. Participants also completed the Overall Assessment of the Subjective Experience of Stuttering (OASES). Clinician and participant ratings were compared. The association between stuttering severity and the OASES scores was examined.

Results:
There was a strong positive correlation between speech-language pathologist and participant-reported ratings of stuttering severity. Participant-reported stuttering severity correlated weakly with the four OASES domains and with the OASES overall impact score.

Conclusions:
Participants were able to accurately rate their stuttering severity during a speech assessment using a simple one-item question. This finding indicates that self-report stuttering severity is a suitable method for large-scale data collection. Findings also support the collection of self-report subjective experience data using questionnaires, such as the OASES, which add vital information about the participants' experience of stuttering that is not captured by overt speech severity ratings alone.

Abstract

We investigated 4- and 5-year-old children’s mapping strategies in a spatial task. Children were required to find a picture in an array of three identical cups after observing another picture being hidden in another array of three cups. The arrays were either aligned one behind the other in two rows or placed side by side forming one line. Moreover, children were rewarded for two different mapping strategies. Half of the children needed to choose a cup that held the same relative position as the rewarded cup in the other array; they needed to map left–left, middle–middle, and right–right cups together (aligned mapping), which required encoding and mapping of two relations (e.g., the cup left of the middle cup and left of the right cup). The other half needed to map together the cups that held the same relation to the table’s spatial features—the cups at the edges, the middle cups, and the cups in the middle of the table (landmark mapping)—which required encoding and mapping of one relation (e.g., the cup at the table’s edge). Results showed that children’s success was constellation dependent; performance was higher when the arrays were aligned one behind the other in two rows than when they were placed side by side. Furthermore, children showed a preference for landmark mapping over aligned mapping.

Abstract

The experimental investigation of language-mediated visual attention is a promising way to study the interaction of the cognitive systems involved in language, vision, attention, and memory. Here we highlight four challenges for a mechanistic account of this oculomotor behavior: the levels of representation at which language-derived and vision-derived representations are integrated; attentional mechanisms; types of memory; and the degree of individual and group differences. Central points in our discussion are (a) the possibility that local microcircuitries involving feedforward and feedback loops instantiate a common representational substrate of linguistic and non-linguistic information and attention; and (b) that an explicit working memory may be central to explaining interactions between language and visual attention. We conclude that a synthesis of further experimental evidence from a variety of fields of inquiry and the testing of distinct, non-student, participant populations will prove to be critical.

Abstract

Prediction appears to be an important characteristic of the human mind. It has also been suggested that prediction is a core difference of autistic children. Past research exploring language-mediated anticipatory eye movements in autistic children, however, has been somewhat contradictory, with some studies finding normal anticipatory processing in autistic children with low levels of autistic traits but others observing weaker prediction effects in autistic children with less receptive language skills. Here we investigated language-mediated anticipatory eye movements in young children who differed in the severity of their level of autistic traits and were in professional institutional care in Hangzhou, China. We chose the same spoken sentences (translated into Mandarin Chinese) and visual stimuli as a previous study which observed robust prediction effects in young children (Mani & Huettig, 2012) and included a control group of typically-developing children. Typically developing but not autistic children showed robust prediction effects. Most interestingly, autistic children with lower communication, motor, and (adaptive) behavior scores exhibited both less predictive and non-predictive visual attention behavior. Our results raise the possibility that differences in language-mediated anticipatory eye movements in autistic children with higher levels of autistic traits may be differences in visual attention in disguise, a hypothesis that needs further investigation.

Abstract

We argue that the educational and psychological sciences must embrace the diversity of reading rather than chase the phantom of normal reading behavior. We critically discuss the research practice of asking participants in experiments to read “normally”. We then draw attention to the large cross-cultural and linguistic diversity around the world and consider the enormous diversity of reading situations and goals. Finally, we observe that people bring a huge diversity of brains and experiences to the reading task. This leads to certain implications. First, there are important lessons for how to conduct psycholinguistic experiments. Second, we need to move beyond Anglo-centric reading research and produce models of reading that reflect the large cross-cultural diversity of languages and types of writing systems. Third, we must acknowledge that there are multiple ways of reading and reasons for reading, and none of them is normal or better or a “gold standard”. Finally, we must stop stigmatizing individuals who read differently and for different reasons, and there should be increased focus on teaching the ability to extract information relevant to the person’s goals. What is important is not how well people decode written language and how fast people read but what people comprehend given their own stated goals.

Abstract

Semantic variation in the cutting and breaking domain has been shown to be constrained across languages in a previous typological study, but it was unclear whether Japanese was an outlier in this domain. Here we revisit cutting and breaking in the Japonic language area by collecting new naming data for 40 videoclips depicting cutting and breaking events in Standard Japanese, the highly divergent Tohoku dialects, as well as four related Ryukyuan languages (Amami, Okinawa, Miyako and Yaeyama). We find that the Japonic languages recapitulate the same semantic dimensions attested in the previous typological study, confirming that semantic variation in the domain of cutting and breaking is indeed cross-linguistically constrained. We then compare our new Japonic data to previously collected Germanic data and find that, in general, related languages resemble each other more than unrelated languages, and that the Japonic languages resemble each other more than the Germanic languages do. Nevertheless, English resembles all of the Japonic languages more than it resembles Swedish. Together, these findings show that the rate and extent of semantic change can differ between language families, indicating the existence of lineage-specific developments on top of universal cross-linguistic constraints.

Abstract

EEG and eye-tracking provide complementary information when investigating language comprehension. Evidence that speech processing may be facilitated by speech prediction comes from the observation that a listener's eye gaze moves towards a referent before it is mentioned if the remainder of the spoken sentence is predictable. However, changes to the trajectory of anticipatory fixations could result from a change in prediction or an attention shift. Conversely, N400 amplitudes and concurrent spectral power provide information about the ease of word processing the moment the word is perceived. In a proof-of-principle investigation, we combined EEG and eye-tracking to study linguistic prediction in naturalistic, virtual environments. We observed increased processing, reflected in theta band power, either during verb processing - when the verb was predictive of the noun - or during noun processing - when the verb was not predictive of the noun. Alpha power was higher in response to the predictive verb and unpredictable nouns. We replicated typical effects of noun congruence but not predictability on the N400 in response to the noun. Thus, the rich visual context that accompanied speech in virtual reality influenced language processing compared to previous reports, where the visual context may have facilitated processing of unpredictable nouns. Finally, anticipatory fixations were predictive of spectral power during noun processing and the length of time fixating the target could be predicted by spectral power at verb onset, conditional on the object having been fixated. Overall, we show that combining EEG and eye-tracking provides a promising new method to answer novel research questions about the prediction of upcoming linguistic input, for example, regarding the role of extralinguistic cues in prediction during language comprehension.

Abstract

n conversations, interlocutors concurrently perform two related processes: speech comprehension and speech planning. We investigated effects of speech planning on comprehension using EEG. Dutch speakers listened to sentences that ended with expected or unexpected target words. In addition, a picture was presented two seconds after target onset (Experiment 1) or 50 ms before target onset (Experiment 2). Participants’ task was to name the picture or to stay quiet depending on the picture category. In Experiment 1, we found a strong N400 effect in response to unexpected compared to expected target words. Importantly, this N400 effect was reduced in Experiment 2 compared to Experiment 1. Unexpectedly, the N400 effect was not smaller in the naming compared to categorization condition. This indicates that conceptual preparation or the decision whether to speak (taking place in both task conditions of Experiment 2) rather than processes specific to word planning interfere with comprehension.

Abstract

This paper examines how placement and removal events are lexicalised and conceptualised in Basque and Peninsular Spanish. After a brief description of the main linguistic devices employed for the coding of these types of events, the paper discusses how speakers of the two languages choose to talk about these events. Finally, the paper focuses on two aspects that seem to be crucial in the description of these events (1) the role of force dynamics: both languages distinguish between different degrees of force, causality, and intentionality, and (2) the influence of the verb-framed lexicalisation pattern. Data come from six Basque and ten Peninsular Spanish native speakers.

Abstract

Being ostracized or excluded, even briefly and by strangers, is painful and threatens fundamental needs. Recent work by Zhong and Leonardelli (2008) found that excluded individuals perceive the room as cooler and that they desire warmer drinks. A perspective that many rely on in embodiment is the theoretical idea that people use metaphorical associations to understand social exclusion (see Landau, Meier, & Keefer, 2010). We suggest that people feel colder because they are colder. The results strongly support the idea that more complex metaphorical understandings of social relations are scaffolded onto literal changes in bodily temperature: Being excluded in an online ball tossing game leads to lower finger temperatures (Study 1), while the negative affect typically experienced after such social exclusion is alleviated after holding a cup of warm tea (Study 2). The authors discuss further implications for the interaction between body and social relations specifically, and for basic and cognitive systems in general.

Abstract

During aging, intracranial volume remains unchanged and represents maximally attained brain size, while various interacting biological phenomena lead to brain volume loss. Consequently, intracranial volume and brain volume in late life reflect different genetic influences. Our genome-wide association study (GWAS) in 8,175 community-dwelling elderly persons did not reveal any associations at genome-wide significance (P < 5 × 10(-8)) for brain volume. In contrast, intracranial volume was significantly associated with two loci: rs4273712 (P = 3.4 × 10(-11)), a known height-associated locus on chromosome 6q22, and rs9915547 (P = 1.5 × 10(-12)), localized to the inversion on chromosome 17q21. We replicated the associations of these loci with intracranial volume in a separate sample of 1,752 elderly persons (P = 1.1 × 10(-3) for 6q22 and 1.2 × 10(-3) for 17q21). Furthermore, we also found suggestive associations of the 17q21 locus with head circumference in 10,768 children (mean age of 14.5 months). Our data identify two loci associated with head size, with the inversion at 17q21 also likely to be involved in attaining maximal brain size.

Abstract

Infectious diseases exert a constant evolutionary pressure on the innate immunity genes. TLR4, an important member of the Toll-like receptors family, specifically recognizes conserved structures of various infectious pathogens. Two functional TLR4 polymorphisms, Asp299Gly and Thr399Ile, modulate innate host defense against infections, and their prevalence between various populations has been proposed to be influenced by local infectious pressures. If this assumption is true, strong local infectious pressures would lead to a homogeneous pattern of these ancient TLR4 polymorphisms in geographically close populations, while a weak selection or genetic drift may result in a diverse pattern. We evaluated TLR4 polymorphisms in 15 ethnic groups of Iran, to assess whether infections exerted selective pressures on different haplotypes containing these variants. The Iranian subpopulations displayed a heterogeneous pattern of TLR4 polymorphisms, comprising various percentages of Asp299Gly and Thr399Ile alone or in combination. The Iranian sample as a whole showed an intermediate mixed pattern when compared with commonly found patterns in Africa, Europe, Eastern Asia and Americas. These findings suggest a weak or absent selection pressure on TLR4 polymorphisms in the Middle-East, that does not support the assumption of an important role of these polymorphisms in the host defence against local pathogens.

Abstract

Spanish can use dative as well as non-dative strategies to encode Possessors, Human Sources, Interestees (datives of interest) and Experiencers. In Dutch this optionality is virtually absent, restricting dative encoding mainly to the Recipient of a ditransitive. The present study examines whether this may lead to instability of the non-prototypical dative constructions in the Spanish of Dutch-Spanish bilinguals. Elicited data of 12 Chilean heritage informants from the Netherlands were analyzed. Whereas the evidence on the stability of dative Experiencers was not conclusive, the results indicate that the use of prototypical datives, dative External Possessors, dative Human Sources and datives of interest is fairly stable in bilinguals, except for those with limited childhood exposure to Spanish. It is argued that the consistent preference for non-dative strategies of this group was primarily attributable to instability of the dative clitic, which affected all constructions, even the encoding of prototypical indirect objects

Abstract

This study explores the expression of Source and Goal in describing placement and removal events in adult Japanese. Although placement and removal events a priori represent symmetry regarding the orientation of motion, their (c)overt expressions actually exhibit multiple asymmetries at various structural levels. The results show that the expression of the Source is less frequent than the expression of the Goal, but, if expressed, morphosyntactically more complex, suggesting that ‘taking’ events are more complex than ‘putting’ events in their construal. It is stressed that finer linguistic analysis is necessary before explaining linguistic asymmetries in terms of non-linguistic foundations of spatial language.

Abstract

To communicate, an animal's strategic timing of rhythmic signals is crucial. Evolutionary, game-theoretical, and dynamical systems models can shed light on the interaction between individuals and the associated costs and benefits of signalling at a specific time. Mathematical models that study rhythmic interactions from a strategic or evolutionary perspective are rare in animal communication research. But new inspiration may come from a recent game theory model of how group synchrony emerges from local interactions of oscillatory neurons. In the study, the authors analyse when the benefit of joint synchronization outweighs the cost of individual neurons sending electrical signals to each other. They postulate there is a benefit for pairs of neurons to fire together and a cost for a neuron to communicate. The resulting model delivers a variant of a classical dynamical system, the Kuramoto model. Here, we present an accessible overview of the Kuramoto model and evolutionary game theory, and of the 'oscillatory neurons' model. We interpret the model's results and discuss the advantages and limitations of using this particular model in the context of animal rhythmic communication. Finally, we sketch potential future directions and discuss the need to further combine evolutionary dynamics, game theory and rhythmic processes in animal communication studies.

Abstract

Objective

Researchers in animal cognition, psychophysics, and experimental psychology need to randomise the presentation order of trials in experimental sessions. In many paradigms, for each trial, one of two responses can be correct, and the trials need to be ordered such that the participant’s responses are a fair assessment of their performance. Specifically, in some cases, especially for low numbers of trials, randomised trial orders need to be excluded if they contain simple patterns which a participant could accidentally match and so succeed at the task without learning.
Results

We present and distribute a simple Python software package and tool to produce pseudorandom sequences following the Gellermann series. This series has been proposed to pre-empt simple heuristics and avoid inflated performance rates via false positive responses. Our tool allows users to choose the sequence length and outputs a .csv file with newly and randomly generated sequences. This allows behavioural researchers to produce, in a few seconds, a pseudorandom sequence for their specific experiment. PyGellermann is available at https://github.com/YannickJadoul/PyGellermann.

Abstract

Hereditary mixed polyposis syndrome (HMPS) is characterized by apparent autosomal dominant inheritance of multiple types of colorectal polyp, with colorectal carcinoma occurring in a high proportion of affected individuals. Here, we use genetic mapping, copy-number analysis, exclusion of mutations by high-throughput sequencing, gene expression analysis and functional assays to show that HMPS is caused by a duplication spanning the 3' end of the SCG5 gene and a region upstream of the GREM1 locus. This unusual mutation is associated with increased allele-specific GREM1 expression. Whereas GREM1 is expressed in intestinal subepithelial myofibroblasts in controls, GREM1 is predominantly expressed in the epithelium of the large bowel in individuals with HMPS. The HMPS duplication contains predicted enhancer elements; some of these interact with the GREM1 promoter and can drive gene expression in vitro. Increased GREM1 expression is predicted to cause reduced bone morphogenetic protein (BMP) pathway activity, a mechanism that also underlies tumorigenesis in juvenile polyposis of the large bowel.