Publications

Abstract

In natural situations, speech perception often takes place during the concurrent execution of other cognitive tasks, such as listening while viewing a visual scene. The execution of a dual task typically has detrimental effects on concurrent speech perception, but how exactly cognitive load disrupts speech encoding is still unclear. The detrimental effect on speech representations may consist of either a general reduction in the robustness of processing of the speech signal (‘noisy encoding’), or, alternatively it may specifically influence the temporal sampling of the sensory input, with listeners missing temporal pulses, thus underestimating segmental durations (‘shrinking of time’). The present study investigated whether and how spectral and temporal cues in a precursor sentence that has been processed under high vs. low cognitive load influence the perception of a subsequent target word. If cognitive load effects are implemented through ‘noisy encoding’, increasing cognitive load during the precursor should attenuate the encoding of both its temporal and spectral cues, and hence reduce the contextual effect that these cues can have on subsequent target sound perception. However, if cognitive load effects are expressed as ‘shrinking of time’, context effects should not be modulated by load, but a main effect would be expected on the perceived duration of the speech signal. Results from two experiments indicate that increasing cognitive load (manipulated through a secondary visual search task) did not modulate temporal (Experiment 1) or spectral context effects (Experiment 2). However, a consistent main effect of cognitive load was found: increasing cognitive load during the precursor induced a perceptual increase in its perceived speech rate, biasing the perception of a following target word towards longer durations. This finding suggests that cognitive load effects in speech perception are implemented via ‘shrinking of time’, in line with a temporal sampling framework. In addition, we argue that our results align with a model in which early (spectral and temporal) normalization is unaffected by attention but later adjustments may be attention-dependent.

Abstract

Anecdotal evidence suggests that unfamiliar languages sound faster than one’s native language. Empirical evidence for this impression has, so far, come from explicit rate judgments. The aim of the present study was to test whether such perceived rate differences between native and foreign languages have effects on implicit speech processing. Our measure of implicit rate perception was “normalization for speaking rate”: an ambiguous vowel between short /a/ and long /a:/ is interpreted as /a:/ following a fast but as /a/ following a slow carrier sentence. That is, listeners did not judge speech rate itself; instead, they categorized ambiguous vowels whose perception was implicitly affected by the rate of the context. We asked whether a bias towards long /a:/ might be observed when the context is not actually faster but simply spoken in a foreign language. A fully symmetrical experimental design was used: Dutch and German participants listened to rate matched (fast and slow) sentences in both languages spoken by the same bilingual speaker. Sentences were followed by nonwords that contained vowels from an /a-a:/ duration continuum. Results from Experiments 1 and 2 showed a consistent effect of rate normalization for both listener groups. Moreover, for German listeners, across the two experiments, foreign sentences triggered more /a:/ responses than (rate matched) native sentences, suggesting that foreign sentences were indeed perceived as faster. Moreover, this Foreign Language effect was modulated by participants’ ability to understand the foreign language: those participants that scored higher on a foreign language translation task showed less of a Foreign Language effect. However, opposite effects were found for the Dutch listeners. For them, their native rather than the foreign language induced more /a:/ responses. Nevertheless, this reversed effect could be reduced when additional spectral properties of the context were controlled for. Experiment 3, using explicit rate judgments, replicated the effect for German but not Dutch listeners. We therefore conclude that the subjective impression that foreign languages sound fast may have an effect on implicit speech processing, with implications for how language learners perceive spoken segments in a foreign language.

Abstract

In conversation, our own speech and that of others follow each other in rapid succession. Effects of the surrounding context on speech perception are well documented but, despite the ubiquity of the sound of our own voice, it is unknown whether our own speech also influences our perception of other talkers. This study investigated context effects induced by our own speech through six experiments, specifically targeting rate normalization (i.e., perceiving phonetic segments relative to surrounding speech rate). Experiment 1 revealed that hearing pre-recorded fast or slow context sentences altered the perception of ambiguous vowels, replicating earlier work. Experiment 2 demonstrated that talking at a fast or slow rate prior to target presentation also altered target perception, though the effect of preceding speech rate was reduced. Experiment 3 showed that silent talking (i.e., inner speech) at fast or slow rates did not modulate the perception of others, suggesting that the effect of self-produced speech rate in Experiment 2 arose through monitoring of the external speech signal. Experiment 4 demonstrated that, when participants were played back their own (fast/slow) speech, no reduction of the effect of preceding speech rate was observed, suggesting that the additional task of speech production may be responsible for the reduced effect in Experiment 2. Finally, Experiments 5 and 6 replicate Experiments 2 and 3 with new participant samples. Taken together, these results suggest that variation in speech production may induce variation in speech perception, thus carrying implications for our understanding of spoken communication in dialogue settings.

Abstract

Speech comprehension involves extensive use of prediction. Linguistic prediction may be guided by the semantics or syntax, but also by the performance characteristics of the speech signal, such as disfluency. Previous studies have shown that listeners, when presented with the filler uh, exhibit a disfluency bias for discourse-new or unknown referents, drawing inferences about the source of the disfluency. The goal of the present study is to study the contrast between native and non-native disfluencies in speech comprehension. Experiment 1 presented listeners with pictures of high-frequency (e.g., a hand) and low-frequency objects (e.g., a sewing machine) and with fluent and disfluent instructions. Listeners were found to anticipate reference to low-frequency objects when encountering disfluency, thus attributing disfluency to speaker trouble in lexical retrieval. Experiment 2 showed that, when participants listened to disfluent non-native speech, no anticipation of low-frequency referents was observed. We conclude that listeners can adapt their predictive strategies to the (non-native) speaker at hand, extending our understanding of the role of speaker identity in speech comprehension.

Abstract

Where native speakers supposedly are fluent by default, non-native speakers often have to strive hard to achieve a native-like fluency level. However, disfluencies (such as pauses, fillers, repairs, etc.) occur in both native and non-native speech and it is as yet unclear ow luency raters weigh the fluency characteristics of native and non-native speech. Two rating experiments compared the way raters assess the luency of native and non-native speech. The fluency characteristics of native and non- native speech were controlled by using phonetic anipulations in pause (Experiment 1) and speed characteristics (Experiment 2). The results show that the ratings on manipulated native and on-native speech were affected in a similar fashion. This suggests that there is no difference in the way listeners weigh the fluency haracteristics of native and non-native speakers.

Abstract

Electrically stimulating early visual cortex results in a visual percept known as a phosphene. Although phosphenes can be evoked by a wide range of electrode sizes and current amplitudes, they are invariably described as small. To better understand this observation, we electrically stimulated 93 electrodes implanted in the visual cortex of 13 human subjects who reported phosphene size while stimulation current was varied. Phosphene size increased as the stimulation current was initially raised above threshold, but then rapidly reached saturation. Phosphene size also depended on the location of the stimulated site, with size increasing with distance from the foveal representation. We developed a model relating phosphene size to the amount of activated cortex and its location within the retinotopic map. First, a sigmoidal curve was used to predict the amount of activated cortex at a given current. Second, the amount of active cortex was converted to degrees of visual angle by multiplying by the inverse cortical magnification factor for that retinotopic location. This simple model accurately predicted phosphene size for a broad range of stimulation currents and cortical locations. The unexpected saturation in phosphene sizes suggests that the functional architecture of cerebral cortex may impose fundamental restrictions on the spread of artificially evoked activity and this may be an important consideration in the design of cortical prosthetic devices.

Abstract

The primary aim of this paper is to assess patterns of morphological variation in the mandible to investigate changes during the last 500 years in the Netherlands. Three-dimensional geometric morphometrics is used on data collected from adults from three populations living in the Netherlands during three time-periods. Two of these samples come from Dutch archaeological sites (Alkmaar, 1484-1574, n = 37; and Middenbeemster, 1829-1866, n = 51) and were digitized using a 3D laser scanner. The third is a modern sample obtained from MRI scans of 34 modern Dutch individuals. Differences between mandibles are dominated by size. Significant differences in size are found among samples, with on average, males from Alkmaar having the largest mandibles and females from Middenbeemster having the smallest. The results are possibly linked to a softening of the diet, due to a combination of differences in food types and food processing that occurred between these time-periods. Differences in shape are most noticeable between males from Alkmaar and Middenbeemster. Shape differences between males and females are concentrated in the symphysis and ramus, which is mostly the consequence of sexual dimorphism. The relevance of this research is a better understanding of the anatomical variation of the mandible that can occur over an evolutionarily short time, as well as supporting research that has shown plasticity of the mandibular form related to diet and food processing. This plasticity of form must be taken into account in phylogenetic research and when the mandible is used in sex estimation of skeletons.

Abstract

Relational grammar was proposed in Suppes (1976) as a semantical grammar for natural language. Fragments considered so far are restricted to distributive notions. In this article, relational grammar is extended to collective notions.

Abstract

The acquisition of literacy has a profound impact on the functional specialization and lateralization of the visual cortex. Due to the overall lateralization of the language network, specialization for printed words develops in the left occipitotemporal cortex, allegedly inducing a secondary shift of visual face processing to the right, in literate as compared to illiterate subjects. Applying the same logic to the acquisition of high-level musical literacy, we predicted that, in musicians as compared to non-musicians, occipitotemporal activations should show a leftward shift for music reading, and an additional rightward push for face perception. To test these predictions, professional musicians and non-musicians viewed pictures of musical notation, faces, words, tools and houses in the MRI, and laterality was assessed in the ventral stream combining ROI and voxel-based approaches. The results supported both predictions, and allowed to locate the leftward shift to the inferior temporal gyrus and the rightward shift to the fusiform cortex. Moreover, these laterality shifts generalized to categories other than music and faces. Finally, correlation measures across subjects did not support a causal link between the leftward and rightward shifts. Thus the acquisition of an additional perceptual expertise extensively modifies the laterality pattern in the visual system

Abstract

This study reports three experiments on how children learning Mandarin Chinese comprehend and use aspect markers. These experiments examine the role of lexical aspect in children's acquisition of grammatical aspect. Results provide converging evidence for children's early sensitivity to (1) the association between atelic verbs and the imperfective aspect markers zai, -zhe, and -ne, and (2) the association between telic verbs and the perfective aspect marker -le. Children did not show a sensitivity in their use or understanding of aspect markers to the difference between stative and activity verbs or between semelfactive and activity verbs. These results are consistent with Slobin's (1985) basic child grammar hypothesis that the contrast between process and result is important in children's early acquisition of temporal morphology. In contrast, they are inconsistent with Bickerton's (1981, 1984) language bioprogram hypothesis that the distinctions between state and process and between punctual and nonpunctual are preprogrammed into language learners. We suggest new ways of looking at the results in the light of recent probabilistic hypotheses that emphasize the role of input, prototypes and connectionist representations.

Abstract

To clarify whether the neural pathways concerning color processing are the same for natural objects, for artifacts objects and for non-sense objects we examined functional magnetic resonance imaging (FMRI) responses during a covert naming task including the factors color (color vs. black&white (B&W)) and stimulus type (natural vs. artifacts vs. non-sense objects). Our results indicate that the superior parietal lobule and precuneus (BA 7) bilaterally, the right hippocampus and the right fusifom gyrus (V4) make part of a network responsible for color processing both for natural and artifacts objects, but not for non-sense objects. The recognition of non-sense colored objects compared to the recognition of color objects activated the posterior cingulate/precuneus (BA 7/23/31), suggesting that color attribute induces the mental operation of trying to associate a non-sense composition with a familiar objects. When color objects (both natural and artifacts) were contrasted with color nonobjects we observed activations in the right parahippocampal gyrus (BA 35/36), the superior parietal lobule (BA 7) bilaterally, the left inferior middle temporal region (BA 20/21) and the inferior and superior frontal regions (BA 10/11/47). These additional activations suggest that colored objects recruit brain regions that are related to visual semantic information/retrieval and brain regions related to visuo-spatial processing. Overall, the results suggest that color information is an attribute that improve object recognition (based on behavioral results) and activate a specific neural network related to visual semantic information that is more extensive than for B&W objects during object recognition

Abstract

In order to clarify whether the influence of color knowledge information in object recognition depends on the presence of the appropriate surface color, we designed a name—object verification task. The relationship between color and shape information provided by the name and by the object photo was manipulated in order to assess color interference independently of shape interference. We tested three different versions for each object: typically colored, black and white, and nontypically colored. The response times on the nonmatching trials were used to measure the interference between the name and the photo. We predicted that the more similar the name and the photo are, the longer it would take to respond. Overall, the color similarity effect disappeared in the black-and-white and nontypical color conditions, suggesting that the influence of color knowledge on object recognition depends on the presence of the appropriate surface color information.

Abstract

Structural priming is a useful laboratory-based technique for investigating how children respond to temporary changes in the distribution of structures in their input. In the current study we investigated whether increasing the number of object relative clauses (RCs) in German-speaking children’s input changes their processing preferences for ambiguous RCs. Fifty-one 6-year-olds and 54 9-year-olds participated in a priming task that (i) gauged their baseline interpretations for ambiguous RC structures, (ii) primed an object-RC interpretation of ambiguous RCs, and (iii) determined whether priming persevered beyond immediate prime-target pairs. The 6-year old children showed no priming effect, whereas the 9-year-old group showed robust priming that was long lasting. Unlike in studies of priming in production, priming did not increase in magnitude when there was lexical overlap between prime and target. Overall, the results suggest that increased exposure to object RCs facilitates children’s interpretation of this otherwise infrequent structure, but only in older children. The implications for acquisition theory are discussed.

Abstract

It has been fifty years since Levelt’s monograph On Binocular Rivalry (1965) was published, but its four propositions that describe the relation between stimulus strength and the phenomenology of binocular rivalry remain a benchmark for theorists and experimentalists even today. In this review, we will revisit the original conception of the four propositions and the scientific landscape in which this happened. We will also provide a brief update concerning distributions of dominance durations, another aspect of Levelt’s monograph that has maintained a prominent presence in the field. In a critical evaluation of Levelt’s propositions against current knowledge of binocular rivalry we will then demonstrate that the original propositions are not completely compatible with what is known today, but that they can, in a straightforward way, be modified to encapsulate the progress that has been made over the past fifty years. The resulting modified, propositions are shown to apply to a broad range of bistable perceptual phenomena, not just binocular rivalry, and they allow important inferences about the underlying neural systems. We argue that these inferences reflect canonical neural properties that play a role in visual perception in general, and we discuss ways in which future research can build on the work reviewed here to attain a better understanding of these properties

Abstract

The adverb now in English (nu in Dutch) can draw listeners’ attention to an upcoming contrast (e.g., ‘Put X in Y. Now put X in Z’). In Dutch, but not English, the position of this sequential adverb may disambiguate which constituent is contrasted. We investigated whether and how the intonational realization of now/nu is varied to signal different scopes and whether it interacts with word order. Three contrast conditions (contrast in object, location, or both) were produced by eight Dutch and eight English speakers. Results showed no consistent use of word order for scope disambiguation in Dutch. Importantly, independent of language, an unaccented now/nu signaled a contrasting object while an accented now/nu signaled a contrast in the location. Since these intonational patterns were independent of word order, we interpreted the results in the framework of grammatical saliency: now/nu appears to be unmarked when the contrast lies in a salient constituent (the object) but marked with a prominent rise when a less salient constituent is contrasted (the location).

Abstract

Sentences with a contrastive intonation contour are usually produced when the speaker entertains alternatives to the accented words. However, such contrastive sentences are frequently produced without making the alternatives explicit for the listener. In two cross-modal associative priming experiments we tested in Dutch whether such contextual alternatives become available to listeners upon hearing a sentence with a contrastive intonation contour compared with a sentence with a non-contrastive one. The first experiment tested the recognition of contrastive associates (contextual alternatives to the sentence-final primes), the second one the recognition of non-contrastive associates (generic associates which are not alternatives). Results showed that contrastive associates were facilitated when the primes occurred in sentences with a contrastive intonation contour but not in sentences with a non-contrastive intonation. Non-contrastive associates were weakly facilitated independent of intonation. Possibly, contrastive contours trigger an accommodation mechanism by which listeners retrieve the contrast available for the speaker.

Abstract

The current work uses memory errors to examine the mental representation of verb-particle constructions (VPCs; e.g., make up the story, cut up the meat). Some evidence suggests that VPCs are represented by a cline in which the relationship between the VPC and its component elements ranges from highly transparent (cut up) to highly idiosyncratic (make up). Other evidence supports a multiple class representation, characterizing VPCs as belonging to discretely separated classes differing in semantic and syntactic structure. We outline a novel paradigm to investigate the representation of VPCs in which we elicit illusory conjunctions, or memory errors sensitive to syntactic structure. We then use a novel application of piecewise regression to demonstrate that the resulting error pattern follows a cline rather than discrete classes. A preregistered replication verifies these findings, and a final preregistered study verifies that these errors reflect syntactic structure. This provides evidence for gradient rather than discrete representations across levels of representation in language processing.

Abstract

In work on grammatical agreement in sentence production, there are accounts of verb number formulation that emphasise the role of whole-structure properties and accounts that emphasise the role of word-driven properties. To evaluate these alternatives, we carried out two experiments that examined a referential (wholistic) contributor to agreement along with two lexical-semantic (local) factors. Both experiments gauged the accuracy and latency of inflected-verb production in order to assess how variations in grammatical number interacted with the other factors. The accuracy of verb production was modulated both by the referential effect of notional number and by the lexical-semantic effects of relatedness and category membership. As an index of agreement difficulty, latencies were little affected by either factor. The findings suggest that agreement is sensitive to referential as well as lexical forces and highlight the importance of lexical-structural integration in the process of sentence production.

Abstract

Automated processing of large amounts of scientific data, especially across domains, requires that the data can be selected and parsed without human intervention. Precise characterization of that data, as in typing, is needed once the processing goes beyond the realm of domain specific or local research group assumptions. The Research Data Alliance (RDA) Data Type Registries Working Group (DTR-WG) was assembled to address this issue through the creation of a Data Type Registry methodology, data model, and prototype. The WG was approved by the RDA Council during March of 2013 and will complete its work in mid-2014, in between the third and fourth RDA Plenaries.

Abstract

This paper shows that the effect of different types of noise on recognition of different phonemes by native versus non-native listeners is highly variable, even within classes of phonemes with the same manner or place of articulation. In a phoneme identification experiment, English and Dutch listeners heard all 24 English consonants in VCV stimuli in quiet and in three types of noise: competing talker, speech-shaped noise, and modulated speech-shaped noise (all with SNRs of −6 dB). Differential effects of noise type for English and Dutch listeners were found for eight consonants (/p t k g m n ŋ r/) but not for the other 16 consonants. For those eight consonants, effects were again highly variable: each noise type hindered non-native listeners more than native listeners for some of the target sounds, but none of the noise types did so for all of the target sounds, not even for phonemes with the same manner or place of articulation. The results imply that the noise types employed will strongly affect the outcomes of any study of native and non-native speech perception in noise.

Abstract

This study examined whether listeners align to reduced speech. Participants were asked to shadow sentences from a casual speech corpus containing canonical and reduced targets. Participants' productions showed alignment: durations of canonical targets were longer than durations of reduced targets; and participants often imitated the segment types (canonical versus reduced) in both targets. The effect sizes were similar to previous work on alignment. In addition, shadowed productions were overall longer in duration than the original stimuli and this effect was larger for reduced than canonical targets. A possible explanation for this finding is that listeners reconstruct canonical forms from reduced forms.

Abstract

This study examined the influence of background language variation on speech recognition. English listeners performed an English sentence recognition task in either “pure” background conditions in which all trials had either English or Dutch background babble or in mixed background conditions in which the background language varied across trials (i.e., a mix of English and Dutch or one of these background languages mixed with quiet trials). This design allowed the authors to compare performance on identical trials across pure and mixed conditions. The data reveal that speech-in-speech recognition is sensitive to contextual variation in terms of the target-background language (mis)match depending on the relative ease/difficulty of the test trials in relation to the surrounding trials.

Abstract

This study examined the temporal dynamics of spoken word recognition in noise and background speech. In two visual-world experiments, English participants listened to target words while looking at four pictures on the screen: a target (e.g. candle), an onset competitor (e.g. candy), a rhyme competitor (e.g. sandal), and an unrelated distractor (e.g. lemon). Target words were presented in quiet, mixed with broadband noise, or mixed with background speech. Results showed that lexical competition changes throughout the observation window as a function of what is presented in the background. These findings suggest that, rather than being strictly sequential, stream segregation and lexical competition interact during spoken word recognition

Abstract

Languages vary typologically in their lexicalization of Path of motion (Talmy 1991). Furthermore, lexicalization patterns are argued to affect syntactic packaging at the level of the clause (e.g. Slobin 1996b) and tend to transfer from a first (L1) to a second language (L2) in second language acquisition (e.g. Cadierno 2004). From this crosslinguistic and developmental evidence, typological preferences for Path expression appear highly robust features of a first language. The current study examines the extent to which preferences for Path encoding really are as enduring as they seem by investigating (1) whether Japanese follows patterns identified for other verb-framed languages like Spanish, and (2) whether patterns established in one’s first language can change after acquisition of a second language. L1 performance of native speakers of Japanese with intermediate-level knowledge of English was compared to that of monolingual speakers of Japanese and English. Results showed that monolingual Japanese speakers followed basic lexicalization patterns typical of other verb-framed languages, but with different realizations of Path packaging within the clause. Moreover, non-monolingual Japanese speakers displayed both English- and Japanese-like patterns for lexicalization with significantly more Path information per clause than either group of monolinguals. Implications for typology and second language acquisition are discussed.

Abstract

A major finding in studies of early vocabulary acquisition has been that children tend to learn a lot of nouns early but make do with relatively few verbs, among which semantically general-purpose verbs like do, make, get, have, give, come, go, and be play a prominent role. The preponderance of nouns is explained in terms of nouns labelling concrete objects beings “easier” to learn than verbs, which label relational categories. Nouns label “natural categories” observable in the world, verbs label more linguistically and culturally specific categories of events linking objects belonging to such natural categories (Gentner 1978, 1982; Clark 1993). This view has been challenged recently by data from children learning certain non-Indo-European languges like Korean, where children have an early verb explosion and verbs dominate in early child utterances. Children learning the Mayan language Tzeltal also acquire verbs early, prior to any noun explosion as measured by production. Verb types are roughly equivalent to noun types in children’s beginning production vocabulary and soon outnumber them. At the one-word stage children’s verbs mostly have the form of a root stripped of affixes, correctly segmented despite structural difficulties. Quite early (before the MLU 2.0 point) there is evidence of productivity of some grammatical markers (although they are not always present): the person-marking affixes cross-referencing core arguments, and the completive/incompletive aspectual distinctions. The Tzeltal facts argue against a natural-categories explanation for childre’s early vocabulary, in favor of a view emphasizing the early effects of language-specific properties of the input. They suggest that when and how a child acquires a “verb” category is centrally influenced by the structural properties of the input, and that the semantic structure of the language - where the referential load is concentrated - plays a fundamental role in addition to distributional facts.

Abstract

When Tzeltal children in the Mayan community of Tenejapa, in southern Mexico, begin speaking, their production vocabulary consists predominantly of verb roots, in contrast to the dominance of nouns in the initial vocabulary of first‐language learners of Indo‐European languages. This article proposes that a particular Tzeltal conversational feature—known in the Mayanist literature as "dialogic repetition"—provides a context that facilitates the early analysis and use of verbs. Although Tzeltal babies are not treated by adults as genuine interlocutors worthy of sustained interaction, dialogic repetition in the speech the children are exposed to may have an important role in revealing to them the structural properties of the language, as well as in socializing the collaborative style of verbal interaction adults favor in this community.

Abstract

This is a Spanish translation of Brown 1997.

Abstract

This paper reports the results of a study of Tzeltal questions and their responses, based on a collection of 419 question/response sequences drawn from video recordings of ‘maximally casual’ naturally occurring face-to-face interactions in a Tzeltal (Mayan) community. I describe the lexical and grammatical resources for formulating content and polar questions in Tzeltal, the different kinds of social actions that questions can be used to perform and their relative frequency in the data, and the characteristic properties of responses to questions. This is part of a large-scale comparative study of questions in 10 different languages, and we find that Tzeltal is like most others in making much more use of polar than of content questions, and in the strong tendency for confirming answers to polar questions. Tzeltal is however unusual in three respects: in the comparatively minimal use of gaze to select next speaker, in the frequency with which answers take the form of repeats, and in the complete absence of visible-only responses (e.g., nods or head-shakes). There are also some language-specific properties of question–answer sequences that reveal cultural shaping of sequencing in conversation.

Abstract

Speaking begins with the formulation of an intended preverbal message and linguistic encoding of this information. The transition from thought to speech occurs incrementally, with cascading planning at subsequent levels of production. In this article, we aim to specify the mechanisms that support incremental message preparation. We contrast two hypotheses about the mechanisms responsible for incorporating message-level information into a linguistic plan. According to the Initial Preparation view, messages can be encoded as fluent utterances if all information is ready before speaking begins. By contrast, on the Continuous Incrementality view, messages can be continually prepared and updated throughout the production process, allowing for fluent production even if new information is added to the message while speaking is underway. Testing these hypotheses, eye-tracked speakers in two experiments produced unscripted, conjoined noun phrases with modifiers. Both experiments showed that new message elements can be incrementally incorporated into the utterance even after articulation begins, consistent with a Continuous Incrementality view of message planning, in which messages percolate to linguistic encoding immediately as that information becomes available in the mind of the speaker. We conclude by discussing the functional role of incremental message planning in conversational speech and the situations in which this continuous incremental planning would be most likely to be observed

Abstract

Genes of the Major Histocompatibility Complex (MHC) have recently been shown to have neuronal functions in the thalamus and hippocampus. Common genetic variants in the Human Leukocyte Antigens (HLA) region, human homologue of the MHC locus, are associated with small effects on susceptibility to schizophrenia, while volumetric changes of the thalamus and hippocampus have also been linked to schizophrenia. We therefore investigated whether common variants of the HLA would affect volumetric variation of the thalamus and hippocampus. We analyzed thalamus and hippocampus volumes, as measured using structural magnetic resonance imaging, in 1.265 healthy participants. These participants had also been genotyped using genome-wide single nucleotide polymorphism (SNP) arrays. We imputed genotypes for single nucleotide polymorphisms at high density across the HLA locus, as well as HLA allotypes and HLA amino acids, by use of a reference population dataset that was specifically targeted to the HLA region. We detected a significant association of the SNP rs17194174 with thalamus volume (nominal P=0.0000017, corrected P=0.0039), as well as additional SNPs within the same region of linkage disequilibrium. This effect was largely lateralized to the left thalamus and is localized within a genomic region previously associated with schizophrenia. The associated SNPs are also clustered within a potential regulatory element, and a region of linkage disequilibrium that spans genes expressed in the thalamus, including HLA-A. Our data indicate that genetic variation within the HLA region influences the volume and asymmetry of the human thalamus. The molecular mechanisms underlying this association may relate to HLA influences on susceptibility to schizophrenia

Abstract

Epigenetic effects on psychiatric traits remain relatively under-studied, and it remains unclear what the sizes of individual epigenetic effects may be, or how they vary between different clinical populations. The gene LRRTM1 (chromosome 2p12) has previously been linked and associated with schizophrenia in a parent-of-origin manner in a set of affected siblings (LOD = 4.72), indirectly suggesting a disruption of paternal imprinting at this locus in these families. From the same set of siblings that originally showed strong linkage at this locus, we analyzed 99 individuals using 454-bisulfite sequencing, from whole blood DNA, to measure the level of DNA methylation in the promoter region of LRRTM1. We also assessed seven additional loci that would be informative to compare. Paternal identity-by-descent sharing at LRRTM1, within sibling pairs, was linked to their similarity of methylation at the gene's promoter. Reduced methylation at the promoter showed a significant association with schizophrenia. Sibling pairs concordant for schizophrenia showed more similar methylation levels at the LRRTM1 promoter than diagnostically discordant pairs. The alleles of common SNPs spanning the locus did not explain this epigenetic linkage, which can therefore be considered as largely independent of DNA sequence variation and would not be detected in standard genetic association analysis. Our data suggest that hypomethylation at the LRRTM1 promoter, particularly of the paternally inherited allele, was a risk factor for the development of schizophrenia in this set of siblings affected with familial schizophrenia, and that had previously showed linkage at this locus in an affected-sib-pair context.

Abstract

Background Retracing the genetic histories of the descendant populations of the Slave Trade (16th-19th centuries) is particularly challenging due to the diversity of African ethnic groups involved and the different hybridisation processes with Europeans and Amerindians, which have blurred their original genetic inheritances. The Noir Marron in French Guiana are the direct descendants of maroons who escaped from Dutch plantations in the current day Surinam. They represent an original ethnic group with a highly blended culture. Uniparental markers (mtDNA and NRY) coupled with HTLV-1 sequences (env and LTR) were studied to establish the genetic relationships linking them to African American and African populations. Results All genetic systems presented a high conservation of the African gene pool (African ancestry: mtDNA = 99.3%; NRY = 97.6%; HTLV-1 env = 20/23; HTLV-1 LTR = 6/8). Neither founder effect nor genetic drift was detected and the genetic diversity is within a range commonly observed in Africa. Higher genetic similarities were observed with the populations inhabiting the Bight of Benin (from Ivory Coast to Benin). Other ancestries were identified but they presented an interesting sex-bias. Whilst male origins spread throughout the north of the bight (from Benin to Senegal), female origins were spread throughout the south (from the Ivory Coast to Angola). Conclusions The Noir Marron are unique in having conserved their African genetic ancestry, despite major cultural exchanges with Amerindians and Europeans through inhabiting the same region for four centuries. Their maroon identity and the important number of slaves deported in this region have maintained the original African diversity. All these characteristics permit to identify a major origin located in the former region of the Gold Coast and the Bight of Benin; regions highly impacted by slavery, from which goes a sex-biased longitudinal gradient of ancestry.

Abstract

Several neurodevelopmental disorders are associated with preference for routine and challenging behavior following changes to routines. We examine individuals with Prader–Willi syndrome, who show elevated levels of this behavior, to better understand how previous experience of a routine can affect challenging behavior elicited by disruption to that routine. Play based challenges exposed 16 participants to routines, which were either adhered to or changed. Temper outburst behaviors, heart rate and movement were measured. As participants were exposed to routines for longer before a change (between 10 and 80 min; within participants), more temper outburst behaviors were elicited by changes. Increased emotional arousal was also elicited, which was indexed by heart rate increases not driven by movement. Further study will be important to understand whether current intervention approaches that limit exposure to changes, may benefit from the structured integration of flexibility to ensure that the opportunity for routine establishment is also limited.

Abstract

The recently disclosed plasticity properties of adult-derived stem cells, their ability to be reprogrammed by defined factors into pluripotent stem cells and the comprehension of “epi”-genetic mechanisms underlying stem cells differentiation process has opened unexpected avenues to attempt regeneration of tissues affected by degenerative disorders and prompted the birth of the new “regenerative medicine” concept. Regeneration of the vascular and myocardial tissues is considered a primary endpoint to limit the consequences of acute and chronic ischemic heart disorders. Cellular therapy of the ischemic heart has been attempted in more than 1000 patients worldwide and the results of the first meta-analysis studies have been recently made available. In several cases, the results did not fulfill the expectations. In fact, they unpredictably indicated modest, yet significant, clinical benefits in patients compared to the outstanding results using stem cells in animal models of ischemic heart and peripheral disease. Several interpretations have been raised to explain these discrepancies. These include lifestyle and risk factor-associated modifications of the stem cell biological activity, but also procedural problems in the translation of cells from bench to bedside. The present review will cover light and shaded areas in the cardiovascular cellular therapy field, and will discuss about recent advances and related patents designed to enhance efficiency of stem cell therapy in patients with cardiovascular disease. These advancements will be discussed in the light of the most advanced issues that have been introduced worldwide by Regulatory Agencies. - See more at: http://www.eurekaselect.com/85525/article#sthash.lEuaE1A5.dpuf

Abstract

Do all humans perceive, think, and talk about tree cover ("forests") in more or less the same way? International forestry programs frequently seem to operate on the assumption that they do. However, recent advances in the language sciences show that languages vary greatly as to how the landscape domain is lexicalized and grammaticalized. Different languages segment and label the large-scale environment and its features according to astonishingly different semantic principles, often in tandem with highly culture-specific practices and ideologies. Presumed basic concepts like mountain, valley, and river cannot in fact be straightforwardly translated across languages. In this paper we describe, compare, and evaluate some of the semantic diversity observed in relation to forests. We do so on the basis of first-hand linguistic field data from a global sample of indigenous categorization systems as they are manifested in the following languages: Avatime (Ghana), Duna (Papua New Guinea), Jahai (Malay Peninsula), Lokono (the Guianas), Makalero (East Timor), and Umpila/Kuuku Ya'u (Cape York Peninsula). We show that basic linguistic categories relating to tree cover vary considerably in their principles of semantic encoding across languages, and that forest is a challenging category from the point of view of intercultural translatability. This has consequences for current global policies and programs aimed at standardizing forest definitions and measurements. It calls for greater attention to categorial diversity in designing and implementing such agendas, and for receptiveness to and understanding of local indigenous classification systems in communicating those agendas on the ground.

Abstract

This study examines whether the production of words with two phonological variants involves single or multiple lexical phonological representations. Three production experiments investigated the roles of the relative frequencies of the two pronunciation variants of French words with schwa: the schwa variant (e.g., Image ) and the reduced variant (e.g., Image ). In two naming tasks and in a symbol–word association learning task, variants with higher relative frequencies were produced faster. This suggests that the production lexicon keeps a frequency count for each variant and hence that schwa words are represented in the production lexicon with two different lexemes. In addition, the advantage for schwa variants over reduced variants in the naming tasks but not in the learning task and the absence of a variant relative frequency effect for schwa variants produced in isolation support the hypothesis that context affects the variants’ lexical activation and modulates the effect of variant relative frequency.

Abstract

Heschl's gyrus (HG) is a core region of the auditory cortex whose morphology is highly variable across individuals. This variability has been linked to sound perception ability in both speech and music domains. Previous studies show that variations in morphological features of HG, such as cortical surface area and thickness, are heritable. To identify genetic variants that affect HG morphology, we conducted a genome-wide association scan (GWAS) meta-analysis in 3054 healthy individuals using HG surface area and thickness as quantitative traits. None of the single nucleotide polymorphisms (SNPs) showed association P values that would survive correction for multiple testing over the genome. The most significant association was found between right HG area and SNP rs72932726 close to gene DCBLD2 (3q12.1; P=2.77x10(-7)). This SNP was also associated with other regions involved in speech processing. The SNP rs333332 within gene KALRN (3q21.2; P=2.27x10(-6)) and rs143000161 near gene COBLL1 (2q24.3; P=2.40x10(-6)) were associated with the area and thickness of left HG, respectively. Both genes are involved in the development of the nervous system. The SNP rs7062395 close to the X-linked deafness gene POU3F4 was associated with right HG thickness (Xq21.1; P=2.38x10(-6)). This is the first molecular genetic analysis of variability in HG morphology

Abstract

This study examined whether musical training, ethnicity, and experience with a natural tone language influenced sensitivity to tone while listening to an artificial tone language. The language was designed with three tones, modeled after level-tone African languages. Participants listened to a 15-min random concatenation of six 3-syllable words. Sensitivity to tone was assessed using minimal pairs differing only in one syllable (nonword task: e.g., to-kà-su compared to ca-fí-to) or only in tone (tone task: e.g., to-kà-su compared to to-ká-su). Proficiency in an East Asian heritage language was the strongest predictor of success on the tone task. Asians without tone language experience were no better than other ethnic groups. We conclude by considering implications for research on second language learning, especially as approached through artificial language learning.

Abstract

Pediatric myelodysplastic syndrome (MDS) is a heterogeneous disease covering a spectrum ranging from aplasia (RCC) to myeloproliferation (RAEB(t)). In adult-type MDS there is increasing evidence for abnormal function of the bone-marrow microenvironment. Here, we extensively studied the mesenchymal stromal cells (MSCs) derived from children with MDS. MSCs were expanded from the bone-marrow of 17 MDS patients (RCC: n = 10 and advanced MDS: n = 7) and pediatric controls (n = 10). No differences were observed with respect to phenotype, differentiation capacity, immunomodulatory capacity or hematopoietic support. mRNA expression analysis by Deep-SAGE revealed increased IL-6 expression in RCC- and RAEB(t)-MDS. RCC-MDS MSC expressed increased levels of DKK3, a protein associated with decreased apoptosis. RAEB(t)-MDS revealed increased CRLF1 and decreased DAPK1 expressions. This pattern has been associated with transformation in hematopoietic malignancies. Genes reported to be differentially expressed in adult MDS-MSC did not differ between MSC of pediatric MDS and controls. An altered mRNA expression profile, associated with cell survival and malignant transformation, of MSC derived from children with MDS strengthens the hypothesis that the micro-environment is of importance in this disease. Our data support the understanding that pediatric and adult MDS are two different diseases. Further evaluation of the pathways involved might reveal additional therapy targets.

Abstract

An aberrant interaction between hematopoietic stem cells and mesenchymal stromal cells has been linked to disease and shown to contribute to the pathophysiology of hematologic malignancies in murine models. Juvenile myelomonocytic leukemia is an aggressive malignant disease affecting young infants. Here we investigated the impact of juvenile myelomonocytic leukemia on mesenchymal stromal cells. Mesenchymal stromal cells were expanded from bone marrow samples of patients at diagnosis (n=9) and after hematopoietic stem cell transplantation (n=7; from 5 patients) and from healthy children (n=10). Cells were characterized by phenotyping, differentiation, gene expression analysis (of controls and samples obtained at diagnosis) and in vitro functional studies assessing immunomodulation and hematopoietic support. Mesenchymal stromal cells from patients did not differ from controls in differentiation capacity nor did they differ in their capacity to support in vitro hematopoiesis. Deep-SAGE sequencing revealed differential mRNA expression in patient-derived samples, including genes encoding proteins involved in immunomodulation and cell-cell interaction. Selected gene expression normalized during remission after successful hematopoietic stem cell transplantation. Whereas natural killer cell activation and peripheral blood mononuclear cell proliferation were not differentially affected, the suppressive effect on monocyte to dendritic cell differentiation was increased by mesenchymal stromal cells obtained at diagnosis, but not at time of remission. This study shows that active juvenile myelomonocytic leukemia affects the immune response-related gene expression and function of mesenchymal stromal cells. In contrast, the differential gene expression of hematopoiesis-related genes could not be supported by functional data. Decreased immune surveillance might contribute to the therapy resistance and progression in juvenile myelomonocytic leukemia.

Abstract

Background: Identifying age-related changes in cognition that contribute towards reduced driving performance is important for the development of interventions to improve older adults' driving and prolong the time that they can continue to drive. While driving, one is often required to switch from attending to events changing in time, to distribute attention spatially. Although there is extensive research into both spatial attention and temporal attention and how these change with age, the literature on switching between these modalities of attention is limited within any age group. Methods: Age groups (21-30, 40-49, 50-59, 60-69 and 70+ years) were compared on their ability to switch between detecting a target in a rapid serial visual presentation (RSVP) stream and detecting a target in a visual search display. To manipulate the cost of switching, the target in the RSVP stream was either the first item in the stream (Target 1st), towards the end of the stream (Target Mid), or absent from the stream (Distractor Only). Visual search response times and accuracy were recorded. Target 1st trials behaved as no-switch trials, as attending to the remaining stream was not necessary. Target Mid and Distractor Only trials behaved as switch trials, as attending to the stream to the end was required. Results: Visual search response times (RTs) were longer on "Target Mid" and "Distractor Only" trials in comparison to "Target 1st" trials, reflecting switch-costs. Larger switch-costs were found in both the 40-49 and 60-69 years group in comparison to the 21-30 years group when switching from the Target Mid condition. Discussion: Findings warrant further exploration as to whether there are age-related changes in the ability to switch between these modalities of attention while driving. If older adults display poor performance when switching between temporal and spatial attention while driving, then the development of an intervention to preserve and improve this ability would be beneficial. © 2017 Callaghan, Holland and Kessler.

Abstract

Modulations of occipito-parietal α-band (8–14 Hz) power that are opposite in direction (α-enhancement vs. α-suppression) and origin of generation (ipsilateral vs. contralateral to the locus of attention) are a robust correlate of anticipatory visuospatial attention. Yet, the neural generators of these α-band modulations, their interdependence across homotopic areas, and their respective contribution to subsequent perception remain unclear. To shed light on these questions, we employed magnetoencephalography, while human volunteers performed a spatially cued detection task. Replicating previous findings, we found α-power enhancement ipsilateral to the attended hemifield and contralateral α-suppression over occipitoparietal sensors. Source localization (beamforming) analysis showed that α-enhancement and suppression were generated in 2 distinct brain regions, located in the dorsal and ventral visual streams, respectively. Moreover, α-enhancement and suppression showed different dynamics and contribution to perception. In contrast to the initial and transient dorsal α-enhancement, α-suppression in ventro-lateral occipital cortex was sustained and influenced subsequent target detection. This anticipatory biasing of ventrolateral extrastriate α-activity probably reflects increased receptivity in the brain region specialized in processing upcoming target features. Our results add to current models on the role of α-oscillations in attention orienting by showing that α-enhancement and suppression can be dissociated in time, space, and perceptual relevance.

Abstract

Eyetracking facilities are typically restricted to monitoring a single person viewing static images or pre-recorded video. In the present article, we describe a system that makes it possible to study visual attention in coordination with other activity during joint action. The software links two eyetracking systems in parallel and provides an on-screen task. By locating eye movements against dynamic screen regions, it permits automatic tracking of moving on-screen objects. Using existing SR technology, the system can also cross-project each participant's eyetrack and mouse location onto the other's on-screen work space. Keeping a complete record of eyetrack and on-screen events in the same format as subsequent human coding, the system permits the analysis of multiple modalities. The software offers new approaches to spontaneous multimodal communication: joint action and joint attention. These capacities are demonstrated using an experimental paradigm for cooperative on-screen assembly of a two-dimensional model. The software is available under an open source license.

Abstract

Rapid response to danger holds an evolutionary advantage. In this positron emission tomography study, phobics were exposed to masked visual stimuli with timings that either allowed awareness or not of either phobic, fear-relevant (e.g., spiders to snake phobics), or neutral images. When the timing did not permit awareness, the amygdala responded to both phobic and fear-relevant stimuli. With time for more elaborate processing, phobic stimuli resulted in an addition of an affective processing network to the amygdala activity, whereas no activity was found in response to fear-relevant stimuli. Also, right prefrontal areas appeared deactivated, comparing aware phobic and fear-relevant conditions. Thus, a shift from top-down control to an affectively driven system optimized for speed was observed in phobic relative to fear-relevant aware processing.

Abstract

When we talk we communicate our intentions. Although the origin of intentional action is debated in cognitive neuroscience, the question of how the brain generates the intention in speech remains still open. Using magnetoencephalography, we investigated the cortical dynamics engaged when healthy subjects attended to either their intention to speak or their actual speech. We found that activity in the right and left parietal cortex increased before subjects became aware of intending to speak. Within the time window of parietal activation, we also observed a transient left frontal activity in Broca's area, a crucial region for inner speech. During attention to speech, neural activity was detected in left prefrontal and temporal areas and in the temporoparietal junction. In agreement with previous results, our findings suggest that the parietal cortex plays a multimodal role in monitoring intentional mechanisms in both action and language. The coactivation of parietal regions and Broca's area may constitute the cortical circuit specific for controlling intentional processes during speech.

Abstract

Language comprehension engages a distributed network of frontotemporal, parietal, and sensorimotor regions, but it is still unclear how meaning of words and their semantic relationships are represented and processed within these regions and to which degrees lexico-semantic representations differ between regions and semantic types. We used fMRI and representational similarity analysis to relate word-elicited multivoxel patterns to semantic similarity between action and object words. In left inferior frontal (BA 44-45-47), left posterior middle temporal and left precentral cortex, the similarity of brain response patterns reflected semantic similarity among action-related verbs, as well as across lexical classes-between action verbs and tool-related nouns and, to a degree, between action verbs and food nouns, but not between action verbs and animal nouns. Instead, posterior inferior temporal cortex exhibited a reverse response pattern, which reflected the semantic similarity among object-related nouns, but not action-related words. These results show that semantic similarity is encoded by a range of cortical areas, including multimodal association (e.g., anterior inferior frontal, posterior middle temporal) and modality-preferential (premotor) cortex and that the representational geometries in these regions are partly dependent on semantic type, with semantic similarity among action-related words crossing lexical-semantic category boundaries.

Abstract

Dyslexia is a common specific learning disability with a substantive genetic component. Several candidate genes have been proposed to be implicated in dyslexia susceptibility, such as DYX1C1, ROBO1, KIAA0319, and DCDC2. Associations with variants in these genes have also been reported with a variety of psychometric measures tapping into the underlying processes that might be impaired in dyslexic people. In this study, we first conducted a literature review to select single nucleotide polymorphisms (SNPs) in dyslexia candidate genes that had been repeatedly implicated across studies. We then assessed the SNPs for association in the richly phenotyped longitudinal data set from the Dutch Dyslexia Program. We tested for association with several quantitative traits, including word and nonword reading fluency, rapid naming, phoneme deletion, and nonword repetition. In this, we took advantage of the longitudinal nature of the sample to examine if associations were stable across four educational time-points (from 7 to 12 years). Two SNPs in the KIAA0319 gene were nominally associated with rapid naming, and these associations were stable across different ages. Genetic association analysis with complex cognitive traits can be enriched through the use of longitudinal information on trait development.

Abstract

Can simple motor actions affect how efficiently people retrieve emotional memories, and influence what they choose to remember? In Experiment 1, participants were prompted to retell autobiographical memories with either positive or negative valence, while moving marbles either upward or downward. They retrieved memories faster when the direction of movement was congruent with the valence of the memory (upward for positive, downward for negative memories). Given neutral-valence prompts in Experiment 2, participants retrieved more positive memories when instructed to move marbles up, and more negative memories when instructed to move them down, demonstrating a causal link from motion to emotion. Results suggest that positive and negative life experiences are implicitly associated with schematic representations of upward and downward motion, consistent with theories of metaphorical mental representation. Beyond influencing the efficiency of memory retrieval, the direction of irrelevant, repetitive motor actions can also partly determine the emotional content of the memories people retrieve: moving marbles upward (an ostensibly meaningless action) can cause people to think more positive thoughts.

Abstract

According to the body-specificity hypothesis, people with different bodily characteristics should form correspondingly different mental representations, even in highly abstract conceptual domains. In a previous test of this proposal, right- and left-handers were found to associate positive ideas like intelligence, attractiveness, and honesty with their dominant side and negative ideas with their non-dominant side. The goal of the present study was to determine whether ‘body-specific’ associations of space and valence can be observed beyond the laboratory in spontaneous behavior, and whether these implicit associations have visible consequences.

Abstract

What is the relationship between space and time in the human mind? Studies in adults show an asymmetric relationship between mental representations of these basic dimensions of experience: Representations of time depend on space more than representations of space depend on time. Here we investigated the relationship between space and time in the developing mind. Native Greek-speaking children watched movies of two animals traveling along parallel paths for different distances or durations and judged the spatial and temporal aspects of these events (e.g., Which animal went for a longer distance, or a longer time?). Results showed a reliable cross-dimensional asymmetry. For the same stimuli, spatial information influenced temporal judgments more than temporal information influenced spatial judgments. This pattern was robust to variations in the age of the participants and the type of linguistic framing used to elicit responses. This finding demonstrates a continuity between space-time representations in children and adults, and informs theories of analog magnitude representation.

Abstract

Children begin developing turn-taking skills in infancy but take several years to fluidly integrate their growing knowledge of language into their turn-taking behavior. In two eye-tracking experiments, we measured children’s anticipatory gaze to upcoming responders while controlling linguistic cues to turn structure. In Experiment 1, we showed English and non-English conversations to English-speaking adults and children. In Experiment 2, we phonetically controlled lexicosyntactic and prosodic cues in English-only speech. Children spontaneously made anticipatory gaze switches by age two and continued improving through age six. In both experiments, children and adults made more anticipatory switches after hearing questions. Consistent with prior findings on adult turn prediction, prosodic information alone did not increase children’s anticipatory gaze shifts. But, unlike prior work with adults, lexical information alone was not sucient either—children’s performance was best overall with lexicosyntax and prosody together. Our findings support an account in which turn tracking and turn prediction emerge in infancy and then gradually become integrated with children’s online linguistic processing.

Abstract

Learning a specific skill during childhood may partly determine the functional organization of the adult brain. This hypothesis led us to study oral language processing in illiterate subjects who, for social reasons, had never entered school and had no knowledge of reading or writing. In a brain activation study using PET and statistical parametric mapping, we compared word and pseudoword repetition in literate and illiterate subjects. Our study confirms behavioural evidence of different phonological processing in illiterate subjects. During repetition of real words, the two groups performed similarly and activated similar areas of the brain. In contrast, illiterate subjects had more difficulty repeating pseudowords correctly and did not activate the same neural structures as literates. These results are consistent with the hypothesis that learning the written form of language (orthography) interacts with the function of oral language. Our results indicate that learning to read and write during childhood influences the functional organization of the adult human brain.

Abstract

The parietal lobe has a unique place in the human brain. Anatomically, it is at the crossroad between the frontal, occipital, and temporal lobes, thus providing a middle ground for multimodal sensory integration. Functionally, it supports higher cognitive functions that are characteristic of the human species, such as mathematical cognition, semantic and pragmatic aspects of language, and abstract thinking. Despite its importance, a comprehensive comparison of human and simian intraparietal networks is missing.

In this study, we used diffusion imaging tractography to reconstruct the major intralobar parietal tracts in twenty-one datasets acquired in vivo from healthy human subjects and eleven ex vivo datasets from five vervet and six macaque monkeys. Three regions of interest (postcentral gyrus, superior parietal lobule and inferior parietal lobule) were used to identify the tracts. Surface projections were reconstructed for both species and results compared to identify similarities or differences in tract anatomy (i.e., trajectories and cortical projections). In addition, post-mortem dissections were performed in a human brain.

The largest tract identified in both human and monkey brains is a vertical pathway between the superior and inferior parietal lobules. This tract can be divided into an anterior (supramarginal gyrus) and a posterior (angular gyrus) component in both humans and monkey brains. The second prominent intraparietal tract connects the postcentral gyrus to both supramarginal and angular gyri of the inferior parietal lobule in humans but only to the supramarginal gyrus in the monkey brain. The third tract connects the postcentral gyrus to the anterior region of the superior parietal lobule and is more prominent in monkeys compared to humans. Finally, short U-shaped fibres in the medial and lateral aspects of the parietal lobe were identified in both species. A tract connecting the medial parietal cortex to the lateral inferior parietal cortex was observed in the monkey brain only.

Our findings suggest a consistent pattern of intralobar parietal connections between humans and monkeys with some differences for those areas that have cytoarchitectonically distinct features in humans. The overall pattern of intraparietal connectivity supports the special role of the inferior parietal lobule in cognitive functions characteristic of humans.

Abstract

Specific language impairment (SLI), an unexpected failure to develop appropriate language skills despite adequate non-verbal intelligence, is a heterogeneous multifactorial disorder with a complex genetic basis. We identified a homozygous microdeletion of 21,379 bp in the ZNF277 gene (NM_021994.2), encompassing exon 5, in an individual with severe receptive and expressive language impairment. The microdeletion was not found in the proband’s affected sister or her brother who had mild language impairment. However, it was inherited from both parents, each of whom carries a heterozygous microdeletion and has a history of language problems. The microdeletion falls within the AUTS1 locus, a region linked to autistic spectrum disorders (ASDs). Moreover, ZNF277 is adjacent to the DOCK4 and IMMP2L genes, which have been implicated in ASD. We screened for the presence of ZNF277 microdeletions in cohorts of children with SLI or ASD and panels of control subjects. ZNF277 microdeletions were at an increased allelic frequency in SLI probands (1.1%) compared with both ASD family members (0.3%) and independent controls (0.4%). We performed quantitative RT-PCR analyses of the expression of IMMP2L, DOCK4 and ZNF277 in individuals carrying either an IMMP2L_DOCK4 microdeletion or a ZNF277 microdeletion. Although ZNF277 microdeletions reduce the expression of ZNF277, they do not alter the levels of DOCK4 or IMMP2L transcripts. Conversely, IMMP2L_DOCK4 microdeletions do not affect the expression levels of ZNF277. We postulate that ZNF277 microdeletions may contribute to the risk of language impairments in a manner that is independent of the autism risk loci previously described in this region.

Abstract

Lexicalized theories of syntax often assume that verb-structure regularities are mediated by lemmas, which abstract over variation in verb tense and aspect. German syntax seems to challenge this assumption, because verb position depends on tense and aspect. To examine how German speakers link these elements, a structural priming study was performed which varied syntactic structure, verb position (encoded by tense and aspect), and verb overlap. Abstract structural priming was found, both within and across verb position, but priming was larger when the verb position was the same between prime and target. Priming was boosted by verb overlap, but there was no interaction with verb position. The results can be explained by a lemma model where tense and aspect are linked to structural choices in German. Since the architecture of this lemma model is not consistent with results from English, a connectionist model was developed which could explain the cross-linguistic variation in the production system. Together, these findings support the view that language learning plays an important role in determining the nature of structural priming in different languages

Abstract

Theories from the psychology of communication may be applicable in understanding why hand-off communication is inherently problematic. The purpose of this study was to assess whether postcall pediatric interns can correctly estimate the patient care information and rationale received by on-call interns during hand-off communication. METHODS: Pediatric interns at the University of Chicago were interviewed about the hand-off. Postcall interns were asked to predict what on-call interns would report as the important pieces of information communicated during the hand-off about each patient, with accompanying rationale. Postcall interns also guessed on-call interns' rating of how well the hand-offs went. Then, on-call interns were asked to list the most important pieces of information for each patient that postcall interns communicated during the hand-off, with accompanying rationale. On-call interns also rated how well the hand-offs went. Interns had access to written hand-offs during the interviews. RESULTS: We conducted 52 interviews, which constituted 59% of eligible interviews. Seventy-two patients were discussed. The most important piece of information about a patient was not successfully communicated 60% of the time, despite the postcall intern's believing that it was communicated. Postcall and on-call interns did not agree on the rationales provided for 60% of items. In addition, an item was more likely to be effectively communicated when it was a to-do item (65%) or an item related to anticipatory guidance (69%) compared with a knowledge item (38%). Despite the lack of agreement on content and rationale of information communicated during hand-offs, peer ratings of hand-off quality were high. CONCLUSIONS: Pediatric interns overestimated the effectiveness of their hand-off communication. Theories from communication psychology suggest that miscommunication is caused by egocentric thought processes and a tendency for the speaker to overestimate the receiver's understanding. This study demonstrates that systematic causes of miscommunication may play a role in hand-off quality.

Abstract

This study examines the perception of paralinguistic intonational meanings deriving from Ohala’s Frequency Code (Experiment 1) and Gussenhoven’s Effort Code (Experiment 2) in British English and Dutch. Native speakers of British English and Dutch listened to a number of stimuli in their native language and judged each stimulus on four semantic scales deriving from these two codes: SELF-CONFIDENT versus NOT SELF-CONFIDENT, FRIENDLY versus NOT FRIENDLY (Frequency Code); SURPRISED versus NOT SURPRISED, and EMPHATIC versus NOT EMPHATIC (Effort Code). The stimuli, which were lexically equivalent across the two languages, differed in pitch contour, pitch register and pitch span in Experiment 1, and in pitch register, peak height, peak alignment and end pitch in Experiment 2. Contrary to the traditional view that the paralinguistic usage of intonation is similar across languages, it was found that British English and Dutch listeners differed considerably in the perception of “confident,” “friendly,” “emphatic,” and “surprised.” The present findings support a theory of paralinguistic meaning based on the universality of biological codes, which however acknowledges a languagespecific component in the implementation of these codes.

Abstract

While detecting genetic variations underlying brain structures helps reveal mechanisms of neural disorders, high data dimensionality poses a major challenge for imaging genomic association studies. In this work, we present the application of a recently proposed approach, parallel independent component analysis with reference (pICA-R), to investigate genomic factors potentially regulating gray matter variation in a healthy population. This approach simultaneously assesses many variables for an aggregate effect and helps to elicit particular features in the data. We applied pICA-R to analyze gray matter density (GMD) images (274,131 voxels) in conjunction with single nucleotide polymorphism (SNP) data (666,019 markers) collected from 1,256 healthy individuals of the Brain Imaging Genetics (BIG) study. Guided by a genetic reference derived from the gene GNA14, pICA-R identified a significant SNP-GMD association (r = −0.16, P = 2.34 × 10−8), implying that subjects with specific genotypes have lower localized GMD. The identified components were then projected to an independent dataset from the Mind Clinical Imaging Consortium (MCIC) including 89 healthy individuals, and the obtained loadings again yielded a significant SNP-GMD association (r = −0.25, P = 0.02). The imaging component reflected GMD variations in frontal, precuneus, and cingulate regions. The SNP component was enriched in genes with neuronal functions, including synaptic plasticity, axon guidance, molecular signal transduction via PKA and CREB, highlighting the GRM1, PRKCH, GNA12, and CAMK2B genes. Collectively, our findings suggest that GNA12 and GNA14 play a key role in the genetic architecture underlying normal GMD variation in frontal and parietal regions

Abstract

This article aims to clarify misunderstandings over the relation between production and comprehension in the acquisition of the focus-to-accentuation mapping and shed new light on this issue on the basis of experimental data obtained from Dutch-speaking children. The reanalysis of recent production data on children's and adult's intonational marking of focus reveals that 4- to 5-year-olds can use accentuation to mark non-contrastive narrow focus in question–answer dialogues, although they accent the focal noun slightly less frequently than adults in both sentence-initial and sentence-final positions and tend to accent the noun in sentence-final position to seek confirmation. Regarding comprehension, the processing of accentuation as a cue to non-contrastive narrow focus was examined in question–answer dialogues by means of the RT technique. It was found that 4- to 5-year-olds can process the mapping of non-contrastive narrow focus to accentuation although they need longer processing time than adults. Based on these results, it is argued that children's comprehension is similar to their production at the age of 4 or 5, contra the earlier claim that production precedes comprehension in the acquisition of the focus-to-accentuation mapping. In both production and comprehension, children exhibit similar patterns to adults but are not yet fully adult-like. However, the difference between adults and children is mainly of a gradient nature.

Abstract

A significant proportion of children have unexplained problems acquiring proficient linguistic skills despite adequate intelligence and opportunity. Developmental language disorders are highly heritable with substantial societal impact. Molecular studies have begun to identify candidate loci, but much of the underlying genetic architecture remains undetermined. We performed whole-exome sequencing of 43 unrelated probands affected by severe specific language impairment, followed by independent validations with Sanger sequencing, and analyses of segregation patterns in parents and siblings, to shed new light on aetiology. By first focusing on a pre-defined set of known candidates from the literature, we identified potentially pathogenic variants in genes already implicated in diverse language-related syndromes, including ERC1, GRIN2A, and SRPX2. Complementary analyses suggested novel putative candidates carrying validated variants which were predicted to have functional effects, such as OXR1, SCN9A and KMT2D. We also searched for potential “multiple-hit” cases; one proband carried a rare AUTS2 variant in combination with a rare inherited haplotype affecting STARD9, while another carried a novel nonsynonymous variant in SEMA6D together with a rare stop-gain in SYNPR. On broadening scope to all rare and novel variants throughout the exomes, we identified biological themes that were enriched for such variants, including microtubule transport and cytoskeletal regulation.

Abstract

The goal of this study is to examine how the degree of vowel-to-vowel coarticulation varies as a function of prosodic factors such as nuclear-pitch accent (accented vs. unaccented), level of prosodic boundary (Prosodic Word vs. Intermediate Phrase vs. Intonational Phrase), and position-in-prosodic-domain (initial vs. final). It is hypothesized that vowels in prosodically stronger locations (e.g., in accented syllables and at a higher prosodic boundary) are not only coarticulated less with their neighboring vowels, but they also exert a stronger influence on their neighbors. Measurements of tongue position for English /a i/ over time were obtained with Carsten’s electromagnetic articulography. Results showed that vowels in prosodically stronger locations are coarticulated less with neighboring vowels, but do not exert a stronger influence on the articulation of neighboring vowels. An examination of the relationship between coarticulation and duration revealed that (a) accent-induced coarticulatory variation cannot be attributed to a duration factor and (b) some of the data with respect to boundary effects may be accounted for by the duration factor. This suggests that to the extent that prosodically conditioned coarticulatory variation is duration-independent, there is no absolute causal relationship from duration to coarticulation. It is proposed that prosodically conditioned V-to-V coarticulatory reduction is another type of strengthening that occurs in prosodically strong locations. The prosodically driven coarticulatory patterning is taken to be part of the phonetic signatures of the hierarchically nested structure of prosody.

Abstract

Children adopted early in life into another linguistic community typically forget their birth language but retain, unaware, relevant linguistic knowledge that may facilitate (re)learning of birth-language patterns. Understanding the nature of this knowledge can shed light on how language is acquired. Here, international adoptees from Korea with Dutch as their current language, and matched Dutch-native controls, provided speech production data on a Korean consonantal distinction unlike any Dutch distinctions, at the outset and end of an intensive perceptual training. The productions, elicited in a repetition task, were identified and rated by Korean listeners. Adoptees' production scores improved significantly more across the training period than control participants' scores, and, for adoptees only, relative production success correlated significantly with the rate of learning in perception (which had, as predicted, also surpassed that of the controls). Of the adoptee group, half had been adopted at 17 months or older (when talking would have begun), while half had been prelinguistic (under six months). The former group, with production experience, showed no advantage over the group without. Thus the adoptees' retained knowledge of Korean transferred from perception to production and appears to be abstract in nature rather than dependent on the amount of experience.

Abstract

Until at least 6 mo of age, infants show good discrimination for familiar phonetic contrasts (i.e., those heard in the environmental language) and contrasts that are unfamiliar. Adult-like discrimination (significantly worse for nonnative than for native contrasts) appears only later, by 9–10 mo. This has been interpreted as indicating that infants have no knowledge of phonology until vocabulary development begins, after 6 mo of age. Recently, however, word recognition has been observed before age 6 mo, apparently decoupling the vocabulary and phonology acquisition processes. Here we show that phonological acquisition is also in progress before 6 mo of age. The evidence comes from retention of birth-language knowledge in international adoptees. In the largest ever such study, we recruited 29 adult Dutch speakers who had been adopted from Korea when young and had no conscious knowledge of Korean language at all. Half were adopted at age 3–5 mo (before native-specific discrimination develops) and half at 17 mo or older (after word learning has begun). In a short intensive training program, we observe that adoptees (compared with 29 matched controls) more rapidly learn tripartite Korean consonant distinctions without counterparts in their later-acquired Dutch, suggesting that the adoptees retained phonological knowledge about the Korean distinction. The advantage is equivalent for the younger-adopted and the older-adopted groups, and both groups not only acquire the tripartite distinction for the trained consonants but also generalize it to untrained consonants. Although infants younger than 6 mo can still discriminate unfamiliar phonetic distinctions, this finding indicates that native-language phonological knowledge is nonetheless being acquired at that age.

Abstract

English and Korean differ in how they lexicalize the components of motionevents. English characteristically conflates Motion with Manner, Cause, or Deixis, and expresses Path separately. Korean, in contrast, conflates Motion with Path and elements of Figure and Ground in transitive clauses for caused Motion, but conflates motion with Deixis and spells out Path and Manner separately in intransitive clauses for spontaneous motion. Children learningEnglish and Korean show sensitivity to language-specific patterns in the way they talk about motion from as early as 17–20 months. For example, learners of English quickly generalize their earliest spatial words — Path particles like up, down, and in — to both spontaneous and caused changes of location and, for up and down, to posture changes, while learners of Korean keep words for spontaneous and caused motion strictly separate and use different words for vertical changes of location and posture changes. These findings challenge the widespread view that children initially map spatial words directly to nonlinguistic spatial concepts, and suggest that they are influenced by the semantic organization of their language virtually from the beginning. We discuss how input and cognition may interact in the early phases of learning to talk about space.

Abstract

Models of speech production assume that syllables play a functional role in the process of word-form encoding in speech production. In this study, we investigate this claim and specifically provide evidence about the level at which syllables come into play. We report two studies using an odd-man-out variant of the implicit priming paradigm to examine the role of the syllable during the process of word formation. Our results show that this modified version of the implicit priming paradigm can trace the emergence of syllabic structure during spoken word generation. Comparing these results to prior syllable priming studies, we conclude that syllables emerge at the interface between phonological and phonetic encoding. The results are discussed in terms of the WEAVER++ model of lexical access.

Abstract

The present study concerns individual differences in gesture production. We used correlational and multiple regression analyses to examine the relationship between individuals’ cognitive abilities and empathy levels and their gesture frequency and saliency. We chose predictor variables according to experimental evidence of the functions of gesture in speech production and communication. We examined 3 types of gestures: representational gestures, conduit gestures, and palm-revealing gestures. Higher frequency of representational gestures was related to poorer visual and spatial working memory, spatial transformation ability, and conceptualization ability; higher frequency of conduit gestures was related to poorer visual working memory, conceptualization ability, and higher levels of empathy; and higher frequency of palm-revealing gestures was related to higher levels of empathy. The saliency of all gestures was positively related to level of empathy. These results demonstrate that cognitive abilities and empathy levels are related to individual differences in gesture frequency and saliency

Abstract

Language and action systems are highly interlinked. A critical piece of evidence is that speech and its accompanying gestures are tightly synchronized. Five experiments were conducted to test 2 hypotheses about the synchronization of speech and gesture. According to the interactive view, there is continuous information exchange between the gesture and speech systems, during both their planning and execution phases. According to the ballistic view, information exchange occurs only during the planning phases of gesture and speech, but the 2 systems become independent once their execution has been initiated. In all experiments, participants were required to point to and/or name a light that had just lit up. Virtual reality and motion tracking technologies were used to disrupt their gesture or speech execution. Participants delayed their speech onset when their gesture was disrupted. They did so even when their gesture was disrupted at its late phase and even when they received only the kinesthetic feedback of their gesture. Also, participants prolonged their gestures when their speech was disrupted. These findings support the interactive view and add new constraints on models of speech and gesture production

Abstract

Koriat (1981) demonstrated that an association from the target to a preceding prime, in the absence of an association from the prime to the target, facilitates lexical decision and referred to this effect as "backward priming". Backward priming is of relevance, because it can provide information about the mechanism underlying semantic priming effects. Following Neely (1991), we distinguish three mechanisms of priming: spreading activation, expectancy, and semantic matching/integration. The goal was to determine which of these mechanisms causes backward priming, by assessing effects of backward priming on a language-relevant ERP component, the N400, and reaction time (RT). Based on previous work, we propose that the N400 priming effect reflects expectancy and semantic matching/integration, but in contrast with RT does not reflect spreading activation. Experiment 1 shows a backward priming effect that is qualitatively similar for the N400 and RT in a lexical decision task. This effect was not modulated by an ISI manipulation. Experiment 2 clarifies that the N400 backward priming effect reflects genuine changes in N400 amplitude and cannot be ascribed to other factors. We will argue that these backward priming effects cannot be due to expectancy but are best accounted for in terms of semantic matching/integration.

Abstract

Some Trobriand Islands string figures by Stephan Claassen, Best, the Netherlands, and Joseph D'Antoni, Queens, New York, USA, in cooperation with Gunter Senft, Max Planck Institute for Psycholinguistics, Nijmegen, Netherlands (pages 72-128) - The construction and execution of fourteen string figures from the Trobriand Islands is given, along with accompanying chants (in the original, and in translation) and comparative notes. The figures were made during a 1984 string figure performance by two ladies in the village of Tauwema, on the island of Kaile’una. The performance was filmed by a team of German researchers. One of the figures appears to be not recorded before, and the construction method of another figure was hitherto unknown. Some of the other figures have their own peculiarities.

Abstract

Expectancy mechanisms are routinely used by the cognitive system in stimulus processing and in anticipation of appropriate responses. Electrophysiology research has documented negative shifts of brain activity when expectancies are violated within a local stimulus context (e.g., reading an implausible word in a sentence) or more globally between consecutive stimuli (e.g., a narrative of images with an incongruent end). In this EEG study, we examine the interaction between expectancies operating at the level of stimulus plausibility and at more global level of contextual congruency to provide evidence for, or against, a disassociation of the underlying processing mechanisms. We asked participants to verify the congruency of pairs of cross-modal stimuli (a sentence and a scene), which varied in plausibility. ANOVAs on ERP amplitudes in selected windows of interest show that congruency violation has longer-lasting (from 100 to 500 ms) and more widespread effects than plausibility violation (from 200 to 400 ms). We also observed critical interactions between these factors, whereby incongruent and implausible pairs elicited stronger negative shifts than their congruent counterpart, both early on (100–200 ms) and between 400–500 ms. Our results suggest that the integration mechanisms are sensitive to both global and local effects of expectancy in a modality independent manner. Overall, we provide novel insights into the interdependence of expectancy during meaning integration of cross-modal stimuli in a verification task

Abstract

Explanatory accounts of the emergence, spread, storage, persistence, and transformation of knowledge face numerous theoretical and methodological challenges. This paper argues that although anthropologists are uniquely positioned to address some of these challenges, joint engagement with relevant research in neighbouring disciplines holds considerable promise for advancement in the area. Researchers across the human and social sciences are increasingly recognizing the importance of conjointly operative and mutually contingent bodily, cognitive, neural, and social mechanisms informing the generation and communication of knowledge. Selected cognitive scientific work, in particular, is reviewed here and used to illustrate how anthropology may potentially richly contribute not only to descriptive and interpretive endeavours, but to the development and substantiation of explanatory accounts also. Résumé Les comptes-rendus portant sur l'émergence, la diffusion, la conservation, la persistance et la transformation des connaissances se heurtent à de nombreuses difficultés théoriques et méthodologiques. Bien que les anthropologues soient particulièrement bien placés pour affronter ces défis, des progrès considérables pourraient être réalisés en la matière dans le cadre d'une approche conjointe avec des disciplines voisines menant des recherches connexes. Les adeptes du décloisonnement des sciences humaines et sociales reconnaissent de plus en plus l'importance des interactions et interdépendances entre mécanismes physiques, cognitifs, neurologiques et sociaux dans la production et la communication des connaissances. Des travaux scientifiques choisis, en matière de cognition en particulier, sont examinés et utilisés pour illustrer la manière dont l'anthropologie pourrait apporter une riche contribution non seulement aux tâches descriptives et interprétatives, mais aussi à l'élaboration et la mise à l'épreuve de comptes-rendus explicatifs.

Abstract

Physical exercise is known to stimulate the release of endorphins, creating a mild sense of euphoria that has rewarding properties. Using pain tolerance (a conventional non-invasive
assay for endorphin release), we show that synchronized training in a college rowing crew creates a heightened endorphin surge compared
with a similar training regime carried out alone. This heightened effect from synchronized activity may explain the sense of euphoria experienced
during other social activities (such as
laughter, music-making and dancing) that are involved in social bonding in humans and possibly other vertebrates

Abstract

Processing speech in a non-native language requires listeners to cope with influences from their first language and to overcome the effects of limited exposure and experience. These factors may be particularly important when listening in adverse conditions. However,native listeners also suffer in noise, and the intelligibility of speech in noise clearly depends on factors which are independent of a listener’s first language. The current study explored the issue of language-independence by comparing the responses of eight listener groups differing in native language when confronted with the task of identifying English intervocalic consonants in three masker backgrounds, viz.stationary speech-shaped noise, temporally-modulated speech-shaped noise and competing English speech. The study analysed the effects of (i) noise type, (ii) speaker, (iii) vowel context, (iv) consonant, (v) phonetic feature classes, (vi) stress position, (vii) gender and (viii) stimulus onset relative to noise onset. A significant degree of similarity in the response to many of these factors was evident across all eight language groups, suggesting that acoustic and auditory considerations play a large role in determining intelligibility. Language- specific influences were observed in the rankings of individual consonants and in the masking effect of competing speech relative to speech-modulated noise.

Abstract

Contemporary methods of computational cognitive modeling have recently been criticized by Addyman and French (2012) on the grounds that they have not kept up with developments in computer technology and human–computer interaction. They present a manifesto for change according to which, it is argued, modelers should devote more effort to making their models accessible, both to non-modelers (with an appropriate easy-to-use user interface) and modelers alike. We agree that models, like data, should be freely available according to the normal standards of science, but caution against confusing implementations with specifications. Models may embody theories, but they generally also include implementation assumptions. Cognitive modeling methodology needs to be sensitive to this. We argue that specification, replication and experimentation are methodological approaches that can address this issue.

Abstract

Speech processing can often take place in adverse listening conditions that involve the mixing of speech and background noise. In this study, we investigated processing dependencies between background noise and indexical speech features, using a speeded classification paradigm (Garner, 1974; Exp. 1), and whether background noise is encoded and represented in memory for spoken words in a continuous recognition memory paradigm (Exp. 2). Whether or not the noise spectrally overlapped with the speech signal was also manipulated. The results of Experiment 1 indicated that background noise and indexical features of speech (gender, talker identity) cannot be completely segregated during processing, even when the two auditory streams are spectrally nonoverlapping. Perceptual interference was asymmetric, whereby irrelevant indexical feature variation in the speech signal slowed noise classification to a greater extent than irrelevant noise variation slowed speech classification. This asymmetry may stem from the fact that speech features have greater functional relevance to listeners, and are thus more difficult to selectively ignore than background noise. Experiment 2 revealed that a recognition cost for words embedded in different types of background noise on the first and second occurrences only emerged when the noise and the speech signal were spectrally overlapping. Together, these data suggest integral processing of speech and background noise, modulated by the level of processing and the spectral separation of the speech and noise.

Abstract

Past events like fluctuations in population size and post-glacial colonization processes may influence the relative importance of genetic drift, migration and selection when determining the present day patterns of genetic variation. We disentangle how drift, selection and migration shape neutral and adaptive genetic variation in 12 moor frog populations along a 1700 km latitudinal gradient. We studied genetic differentiation and variation at a MHC exon II locus and a set of 18 microsatellites.
Results

Using outlier analyses, we identified the MHC II exon 2 (corresponding to the β-2 domain) locus and one microsatellite locus (RCO8640) to be subject to diversifying selection, while five microsatellite loci showed signals of stabilizing selection among populations. STRUCTURE and DAPC analyses on the neutral microsatellites assigned populations to a northern and a southern cluster, reflecting two different post-glacial colonization routes found in previous studies. Genetic variation overall was lower in the northern cluster. The signature of selection on MHC exon II was weaker in the northern cluster, possibly as a consequence of smaller and more fragmented populations.
Conclusion

Our results show that historical demographic processes combined with selection and drift have led to a complex pattern of differentiation along the gradient where some loci are more divergent among populations than predicted from drift expectations due to diversifying selection, while other loci are more uniform among populations due to stabilizing selection. Importantly, both overall and MHC genetic variation are lower at northern latitudes. Due to lower evolutionary potential, the low genetic variation in northern populations may increase the risk of extinction when confronted with emerging pathogens and climate change.

Abstract

In three experiments, listeners detected vowel or consonant targets in lists of CV syllables constructed from five vowels and five consonants. Responses were faster in a predictable context (e.g., listening for a vowel target in a list of syllables all beginning with the same consonant) than in an unpredictable context (e.g., listening for a vowel target in a list of syllables beginning with different consonants). In Experiment 1, the listeners’ native language was Dutch, in which vowel and consonant repertoires are similar in size. The difference between predictable and unpredictable contexts was comparable for vowel and consonant targets. In Experiments 2 and 3, the listeners’ native language was Spanish, which has four times as many consonants as vowels; here effects of an unpredictable consonant context on vowel detection were significantly greater than effects of an unpredictable vowel context on consonant detection. This finding suggests that listeners’ processing of phonemes takes into account the constitution of their language’s phonemic repertoire and the implications that this has for contextual variability.

Abstract

Single nucleotide polymorphisms (SNPs) within the MIR137, TCF4, and ZNF804A genes show genome-wide association to schizophrenia. However, the biological basis for the associations is unknown. Here, we tested the effects of these genes on brain structure in 1300 healthy adults. Using volumetry and voxel-based morphometry, neither gene-wide effects—including the combined effect of the genes—nor single SNP effects—including specific psychosis risk SNPs—were found on total brain volume, grey matter, white matter, or hippocampal volume. These results suggest that the associations between these risk genes and schizophrenia are unlikely to be mediated via effects on macroscopic brain structure.

Abstract

The present study investigated the neural correlates of infant discrimination of very similar linguistic varieties (Quebecois and Parisian French) using functional Near InfraRed Spectroscopy. In line with previous behavioral and electrophysiological data, there was no evidence that 3-month-olds discriminated the two regional accents, whereas 5-month-olds did, with the locus of discrimination in left anterior perisylvian regions. These neuroimaging results suggest that a developing language network relying crucially on left perisylvian cortices sustains infants' discrimination of similar linguistic varieties within this early period of infancy.