Publications

Abstract

Individuals with attention deficit/hyperactivity disorder (ADHD) are at increased risk of developing substance use disorders (SUDs) and nicotine dependence. The co-occurrence of ADHD and SUDs/nicotine dependence may in part be mediated by shared genetic liability. Several neurobiological pathways have been implicated in both ADHD and SUDs, including dopamine and serotonin pathways. We hypothesized that variations in dopamine and serotonin neurotransmission genes were involved in the genetic liability to develop SUDs/nicotine dependence in ADHD. The current study included participants with ADHD (n = 280) who were originally part of the Dutch International Multicenter ADHD Genetics study. Participants were aged 5-15 years and attending outpatient clinics at enrollment in the study. Diagnoses of ADHD, SUDs, nicotine dependence, age of first nicotine and substance use, and alcohol use severity were based on semi-structured interviews and questionnaires. Genetic risk scores were created for both serotonergic and dopaminergic risk genes previously shown to be associated with ADHD and SUDs and/or nicotine dependence. The serotonin genetic risk score significantly predicted alcohol use severity. No significant serotonin x dopamine risk score or effect of stimulant medication was found. The current study adds to the literature by providing insight into genetic underpinnings of the co-morbidity of ADHD and SUDs. While the focus of the literature so far has been mostly on dopamine, our study suggests that serotonin may also play a role in the relationship between these disorders.

Abstract

When visual stimuli remain present during search, people spend more time fixating objects that are semantically or visually related to the target instruction than fixating unrelated objects. Are these semantic and visual biases also observable when participants search within memory? We removed the visual display prior to search while continuously measuring eye movements towards locations previously occupied by objects. The target absent trials contained objects that were either visually or semantically related to the target instruction. When the overall mean proportion of fixation time was considered, we found biases towards the location previously occupied by the target, but failed to find biases towards visually or semantically related objects. However, in two experiments, the pattern of biases towards the target over time provided a reliable predictor for biases towards the visually and semantically related objects. We therefore conclude that visual and semantic representations alone can guide eye movements in memory search, but that orienting biases are weak when the stimuli are no longer present.

Abstract

An important question is to what extent visual attention is driven by the semantics of individual objects, rather than by their visual appearance. This study investigates the hypothesis that timing is a crucial factor in the occurrence and strength of semantic influences on visual orienting. To assess the dynamics of such influences, the target instruction was presented either before or after visual stimulus onset, while eye movements were continuously recorded throughout the search. The results show a substantial but delayed bias in orienting towards semantically related objects compared to visually related objects when target instruction is presented before visual stimulus onset. However, this delay can be completely undone by presenting the visual information before the target instruction (Experiment 1). Moreover, the absence or presence of visual competition does not change the temporal dynamics of the semantic bias (Experiment 2). Visual orienting is thus driven by priority settings that dynamically shift between visual and semantic representations, with each of these types of bias operating largely independently. The findings bridge the divide between the visual attention and the psycholinguistic literature.

Abstract

Researchers in different fields of psychology have been interested in how vision and language interact, and what type of representations are involved in such interactions. We introduce a stimulus set that facilitates such research (available online). The set consists of 100 words each of which is paired with four pictures of objects: One semantically similar object (but visually dissimilar), one visually similar object (but semantically dissimilar), and two unrelated objects. Visual and semantic similarity ratings between corresponding items are provided for every picture for Dutch and for English. In addition, visual and linguistic parameters of each picture are reported. We thus present a stimulus set from which researchers can select, on the basis of various parameters, the items most optimal for their research question.

Abstract

Visual attention is biased by both visual and semantic representations activated by words. We investigated to what extent language-induced visual and semantic biases are subject to task demands. Participants memorized a spoken word for a verbal recognition task, and performed a visual search task during the retention period. Crucially, while the word had to be remembered in all conditions, it was either relevant for the search (as it also indicated the target) or irrelevant (as it only served the memory test afterwards). On critical trials, displays contained objects that were visually or semantically related to the memorized word. When the word was relevant for the search, eye movement biases towards visually related objects arose earlier and more strongly than biases towards semantically related objects. When the word was irrelevant, there was still evidence for visual and semantic biases, but these biases were substantially weaker, and similar in strength and temporal dynamics, without a visual advantage. We conclude that language-induced attentional biases are subject to task requirements.

Abstract

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

Abstract

The two hemispheres of the human brain differ functionally and structurally. Despite over a century of research, the extent to which brain asymmetry is influenced by sex, handedness, age, and genetic factors is still controversial. Here we present the largest ever analysis of subcortical brain asymmetries, in a harmonized multi-site study using meta-analysis methods. Volumetric asymmetry of seven subcortical structures was assessed in 15,847 MRI scans from 52 datasets worldwide. There were sex differences in the asymmetry of the globus pallidus and putamen. Heritability estimates, derived from 1170 subjects belonging to 71 extended pedigrees, revealed that additive genetic factors influenced the asymmetry of these two structures and that of the hippocampus and thalamus. Handedness had no detectable effect on subcortical asymmetries, even in this unprecedented sample size, but the asymmetry of the putamen varied with age. Genetic drivers of asymmetry in the hippocampus, thalamus and basal ganglia may affect variability in human cognition, including susceptibility to psychiatric disorders.

Abstract

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

Abstract

The success of fMRI places constraints on the nature of the neural code. The fact that researchers can infer similarities between neural representations, despite fMRI’s limitations, implies that certain neural coding schemes are more likely than others. For fMRI to succeed given its low temporal and spatial resolution, the neural code must be smooth at the voxel and functional level such that similar stimuli engender similar internal representations. Through proof and simulation, we determine which coding schemes are plausible given both fMRI’s successes and its limitations in measuring neural activity. Deep neural network approaches, which have been forwarded as computational accounts of the ventral stream, are consistent with the success of fMRI, though functional smoothness breaks down in the later network layers. These results have implications for the nature of the neural code and ventral stream, as well as what can be successfully investigated with fMRI.

Abstract

This paper outlines some reasons for why gestures are relevant to the study of SLA. First, given cross-cultural and cross-linguistic gestural repertoires, gestures can be treated as part of what learners can acquire in a target language. Gestures can therefore be studied as a developing system in their own right both in L2 production and comprehension. Second, because of the close link between gestures, language, and speech, learners' gestures as deployed in L2 usage and interaction can offer valuable insights into the processes of acquisition, such as the handling of expressive difficulties, the influence of the first language, interlanguage phenomena, and possibly even into planning and processing difficulties. As a form of input to learners and to their interlocutors alike, finally, gestures also play a potential role for comprehension and learning.

Abstract

This study investigates whether addressees visually attend to speakers’ gestures in interaction and whether attention is modulated by changes in social setting and display size. We compare a live face-to-face setting to two video conditions. In all conditions, the face dominates as a fixation target and only a minority of gestures draw fixations. The social and size parameters affect gaze mainly when combined and in the opposite direction from the predicted with fewer gestures fixated on video than live. Gestural holds and speakers’ gaze at their own gestures reliably attract addressees’ fixations in all conditions. The attraction force of holds is unaffected by changes in social and size parameters, suggesting a bottom-up response, whereas speaker-fixated gestures draw significantly less attention in both video conditions, suggesting a social effect for overt gaze-following and visual joint attention. The study provides and validates a video-based paradigm enabling further experimental but ecologically valid explorations of cross-modal information processing.

Abstract

The production of cohesive discourse, especially maintained reference, poses problems for early second language (L2) speakers. This paper considers a communicative account of overexplicit L2 discourse by focusing on the interdependence between spoken and gestural cohesion, the latter being expressed by anchoring of referents in gesture space. Specifically, this study investigates whether overexplicit maintained reference in speech (lexical noun phrases [NPs]) and gesture (anaphoric gestures) constitutes an interactional communication strategy. We examine L2 speech and gestures of 16 Dutch learners of French retelling stories to addressees under two visibility conditions. The results indicate that the overexplicit properties of L2 speech are not motivated by interactional strategic concerns. The results for anaphoric gestures are more complex. Although their presence is not interactionally

Abstract

Since listeners usually look at the speaker's face, gestural information has to be absorbed through peripheral visual perception. In the literature, it has been suggested that listeners look at gestures under certain circumstances: 1) when the articulation of the gesture is peripheral; 2) when the speech channel is insufficient for comprehension; and 3) when the speaker him- or herself indicates that the gesture is worthy of attention. The research here reported employs eye tracking techniques to study the perception of gestures in face-to-face interaction. The improved control over the listener's visual channel allows us to test the validity of the above claims. We present preliminary findings substantiating claims 1 and 3, and relate them to theoretical proposals in the literature and to the issue of how visual and cognitive attention are related.

Abstract

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

Abstract

Acceptability judgments are no longer acceptable as the holy grail for testing the nature of linguistic representations. Experimental and quantitative methods should be used to test theoretical claims in psycholinguistics. These methods should include not only behavior, but also the more recent possibilities to probe the neural codes for language-relevant representation

Abstract

In this study, event-related brain potential ffects of speech processing are obtained and compared to similar effects in sentence reading. In two experiments sentences were presented that contained three different types of grammatical violations. In one experiment sentences were presented word by word at a rate of four words per second. The grammatical violations elicited a Syntactic Positive Shift (P600/SPS), 500 ms after the onset of the word that rendered the sentence ungrammatical. The P600/SPS consisted of two phases, an early phase with a relatively equal anterior-posterior distribution and a later phase with a strong posterior distribution. We interpret the first phase as an indication of structural integration complexity, and the second phase as an indication of failing parsing operations and/or an attempt at reanalysis. In the second experiment the same syntactic violations were presented in sentences spoken at a normal rate and with normal intonation. These violations elicited a P600/SPS with the same onset as was observed for the reading of these sentences. In addition two of the three violations showed a preceding frontal negativity, most clearly over the left hemisphere.

Abstract

In this study, event-related brain potential effects of speech processing are obtained and compared to similar effects insentence reading. In two experiments spoken sentences were presented with semantic violations in sentence-signal or mid-sentence positions. For these violations N400 effects were obtained that were very similar to N400 effects obtained in reading. However, the N400 effects in speech were preceded by an earlier negativity (N250). This negativity is not commonly observed with written input. The early effect is explained as a manifestation of a mismatch between the word forms expected on the basis of the context, and the actual cohort of activated word candidates that is generated on the basis of the speech signal.

Abstract

The central issue of this study concerns the claim that the processing of gender agreement in online sentence comprehension is a syntactic rather than a conceptual/semantic process. This claim was tested for the grammatical gender agreement in Dutch between the definite article and the noun. Subjects read sentences in which the definite article and the noun had the same gender and sentences in which the gender agreement was violated, While subjects read these sentences, their electrophysiological activity was recorded via electrodes placed on the scalp. Earlier research has shown that semantic and syntactic processing events manifest themselves in different event-related brain potential (ERP) effects. Semantic integration modulates the amplitude of the so-called N400.The P600/SPS is an ERP effect that is more sensitive to syntactic processes. The violation of grammatical gender agreement was found to result in a P600/SPS. For violations in sentence-final position, an additional increase of the N400 amplitude was observed. This N400 effect is interpreted as resulting from the consequence of a syntactic violation for the sentence-final wrap-up. The overall pattern of results supports the claim that the on-line processing of gender agreement information is not a content driven but a syntactic-form driven process.

Abstract

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

Abstract

In this paper a general cognitive architecture of spoken language processing is specified. This is followed by an account of how this cognitive architecture is instantiated in the human brain. Both the spatial aspects of the networks for language are discussed, as well as the temporal dynamics and the underlying neurophysiology. A distinction is proposed between networks for coding/decoding linguistic information and additional networks for getting from coded meaning to speaker meaning, i.e. for making the inferences that enable the listener to understand the intentions of the speaker

Abstract

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

Abstract

Silent reading and reading aloud of German words and pseudowords were used in a PET study using (15O)butanol to examine the neural correlates of reading and of the phonological conversion of legal letter strings, with or without meaning.
The results of 11 healthy, right-handed volunteers in the age range of 25 to 30 years showed activation of the lingual gyri during silent reading in comparison with viewing a fixation cross. Comparisons between the reading of words and pseudowords suggest the involvement of the middle temporal gyri in retrieving both the phonological and semantic code for words. The reading of pseudowords activates the left inferior frontal gyrus, including the ventral part of Broca’s area, to a larger extent than the reading of words. This suggests that this area might be involved in the sublexical conversion of orthographic input strings into phonological output codes. (Pre)motor areas were found to be activated during both silent reading and reading aloud. On the basis of the obtained activation patterns, it is hypothesized that the articulation of high-frequency syllables requires the retrieval of their concomitant articulatory gestures from the SMA and that the articulation of lowfrequency syllables recruits the left medial premotor cortex.

Abstract

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

Abstract

We explore the nature of the oscillatory dynamics in the EEG of subjects reading sentences that contain a semantic violation. More specifically, we examine whether increases in theta (≈3–7 Hz) and gamma (around 40 Hz) band power occur in response to sentences that were either semantically correct or contained a semantically incongruent word (semantic violation). ERP results indicated a classical N400 effect. A wavelet-based time-frequency analysis revealed a theta band power increase during an interval of 300–800 ms after critical word onset, at temporal electrodes bilaterally for both sentence conditions, and over midfrontal areas for the semantic violations only. In the gamma frequency band, a predominantly frontal power increase was observed during the processing of correct sentences. This effect was absent following semantic violations. These results provide a characterization of the oscillatory brain dynamics, and notably of both theta and gamma oscillations, that occur during language comprehension.

Abstract

What would your ideas about language evolution be if there was only one language left on earth? Fortunately, our investigation need not be that impoverished. In the present article, we survey the state of knowledge regarding the kinds of language found among humans, the language inventory, population sizes, time depth, grammatical variation, and other relevant issues that a theory of language evolution should minimally take into account

Abstract

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

Abstract

The coordinate system has been proposed as a fundamental and cross-culturally used spatial representation, through which people code location and direction information in the environment. Here we provided direct evidence demonstrating that daily experience with the cardinal coordinate system (i.e., east, west, north, and south) contributed to the representation of cognitive maps. Behaviorally, we found that individuals who relied more on the cardinal coordinate system for daily navigation made smaller errors in an indoor pointing task, suggesting that the cardinal coordinate system is an important element of cognitive maps. Neurally, the extent to which individuals relied on the cardinal coordinate system was positively correlated with the gray matter volume of the entorhinal cortex, suggesting that the entorhinal cortex may serve as the neuroanatomical basis of coordinate-based navigation (the entorhinal coordinate area, ECA). Further analyses on the resting-state functional connectivity revealed that the intrinsic interaction between the ECA and two hippocampal sub-regions, the subiculum and cornu ammonis, might be linked with the representation precision of cognitive maps. In sum, our study reveals an association between daily experience with the cardinal coordinate system and cognitive maps, and suggests that the ECA works in collaboration with hippocampal sub-regions to represent cognitive maps.

Abstract

Introduction: Navigation is a fundamental and multidimensional cognitive function that individuals rely on to move around the environment. In this study, we investigated the neural basis of human spatial navigation ability. Methods: A large cohort of participants (N > 200) was examined on their navigation ability behaviorally and structural and functional magnetic resonance imaging (MRI) were then used to explore the corresponding neural basis of spatial navigation. Results: The gray matter volume (GMV) of the bilateral parahippocampus (PHG), retrosplenial complex (RSC), entorhinal cortex (EC), hippocampus (HPC), and thalamus (THAL) was correlated with the participants’ self-reported navigational ability in general, and their sense of direction in particular. Further fMRI studies showed that the PHG, RSC, and EC selectively responded to visually presented scenes, whereas the HPC and THAL showed no selectivity, suggesting a functional division of labor among these regions in spatial navigation. The resting-state functional connectivity analysis further revealed a hierarchical neural network for navigation constituted by these regions, which can be further categorized into three relatively independent components (i.e., scene recognition component, cognitive map component, and the component of heading direction for locomotion, respectively). Conclusions: Our study combined multi-modality imaging data to illustrate that multiple brain regions may work collaboratively to extract, integrate, store, and orientate spatial information to guide navigation behaviors.

Abstract

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

Abstract

An increase in frequency of a form has been argued to result in semantic extension (Bybee, 2003; Zipf, 1949). Yet, research on the acquisition of lexical semantics suggests that a form that frequently co-occurs with a meaning gets restricted to that meaning (Xu & Tenenbaum, 2007). The current work reconciles these positions by showing that – through its effect on form accessibility – frequency causes semantic extension in production, while at the same time causing entrenchment in comprehension. Repeatedly experiencing a form paired with a specific meaning makes one more likely to re-use the form to express related meanings, while also increasing one’s confidence that the form is never used to express those meanings. Recurrent pathways of semantic change are argued to result from a tug of war between the production-side pressure to reuse easily accessible forms and the comprehension-side confidence that one has seen all possible uses of a frequent form.

Abstract

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

Abstract

Perspective is a crucial feature for communicating about events. Yet it is unclear how linguistically encoded perspective relates to cognitive perspective taking. Here, we tested the effect of perspective taking with short literary stories. Participants listened to stories with 1st or 3rd person pronouns referring to the protagonist, while undergoing fMRI. When comparing action events with 1st and 3rd person pronouns, we found no evidence for a neural dissociation depending on the pronoun. A split sample approach based on the self-reported experience of perspective taking revealed 3 comprehension preferences. One group showed a strong 1st person preference, another a strong 3rd person preference, while a third group engaged in 1st and 3rd person perspective taking simultaneously. Comparing brain activations of the groups revealed different neural networks. Our results suggest that comprehension is perspective dependent, but not on the perspective suggested by the text, but on the reader’s (situational) preference

Abstract

Personal pronouns have been shown to influence cognitive perspective taking during comprehension. Studies using single sentences found that 3rd person pronouns facilitate the construction of a mental model from an observer’s perspective, whereas 2nd person pronouns support an actor’s perspective. The direction of the effect for 1st person pronouns seems to depend on the situational context. In the present study, we investigated how personal pronouns influence discourse comprehension when people read fiction stories and if this has consequences for affective components like emotion during reading or appreciation of the story. We wanted to find out if personal pronouns affect immersion and arousal, as well as appreciation of fiction. In a natural reading paradigm, we measured electrodermal activity and story immersion, while participants read literary stories with 1st and 3rd person pronouns referring to the protagonist. In addition, participants rated and ranked the stories for appreciation. Our results show that stories with 1st person pronouns lead to higher immersion. Two factors—transportation into the story world and mental imagery during reading—in particular showed higher scores for 1st person as compared to 3rd person pronoun stories. In contrast, arousal as measured by electrodermal activity seemed tentatively higher for 3rd person pronoun stories. The two measures of appreciation were not affected by the pronoun manipulation. Our findings underscore the importance of perspective for language processing, and additionally show which aspects of the narrative experience are influenced by a change in perspective.

Abstract

Experiments have shown that compared to fictional texts, readers read factual texts faster and have better memory for described situations. Reading fictional texts on the other hand seems to improve memory for exact wordings and expressions. Most of these studies used a ‘newspaper’ versus ‘literature’ comparison. In the present study, we investigated the effect of reader’s expectation to whether information is true or fictional with a subtler manipulation by labelling short stories as either based on true or fictional events. In addition, we tested whether narrative perspective or individual preference in perspective taking affects reading true or fictional stories differently. In an online experiment, participants (final N=1742) read one story which was introduced as based on true events or as fictional (factor fictionality). The story could be narrated in either 1st or 3rd person perspective (factor perspective). We measured immersion in and appreciation of the story, perspective taking, as well as memory for events. We found no evidence that knowing a story is fictional or based on true events influences reading behavior or experiential aspects of reading. We suggest that it is not whether a story is true or fictional, but rather expectations towards certain reading situations (e.g. reading newspaper or literature) which affect behavior by activating appropriate reading goals. Results further confirm that narrative perspective partially influences perspective taking and experiential aspects of reading

Abstract

Comparatively little is known about the inherited primate background underlying human cognition, the human cognitive “wild-type.” Yet it is possible to trace the evolution of human cognitive abilities and tendencies by contrasting the skills of our nearest cousins, not just chimpanzees, but all the extant great apes, thus showing what we are likely to have inherited from the common ancestor [1]. By looking at human infants early in cognitive development, we can also obtain insights into native cognitive biases in our species [2]. Here, we focus on spatial memory, a central cognitive domain. We show, first, that all nonhuman great apes and 1-year-old human infants exhibit a preference for place over feature strategies for spatial memory. This suggests the common ancestor of all great apes had the same preference. We then examine 3-year-old human children and find that this preference reverses. Thus, the continuity between our species and the other great apes is masked early in human ontogeny. These findings, based on both phylogenetic and ontogenetic contrasts, open up the prospect of a systematic evolutionary psychology resting upon the cladistics of cognitive preferences.

Abstract

Current approaches to human cognition often take a strong nativist stance based on Western adult performance, backed up where possible by neonate and infant research and almost never by comparative research across the Hominidae. Recent research suggests considerable cross-cultural differences in cognitive strategies, including relational thinking, a domain where infant research is impossible because of lack of cognitive maturation. Here, we apply the same paradigm across children and adults of different cultures and across all nonhuman great ape genera. We find that both child and adult spatial cognition systematically varies with language and culture but that, nevertheless, there is a clear inherited bias for one spatial strategy in the great apes. It is reasonable to conclude, we argue, that language and culture mask the native tendencies in our species. This cladistic approach suggests that the correct perspective on human cognition is neither nativist uniformitarian nor ‘‘blank slate’’ but recognizes the powerful impact that language and culture can have on our shared primate cognitive biases.

Abstract

Cranial growth and development is a complex process which affects the closely related traits of head circumference (HC) and intracranial volume (ICV). The underlying genetic influences affecting these traits during the transition from childhood to adulthood are little understood, but might include both age-specific genetic influences and low-frequency genetic variation. To understand these influences, we model the developmental genetic architecture of HC, showing this is genetically stable and correlated with genetic determinants of ICV. Investigating up to 46,000 children and adults of European descent, we identify association with final HC and/or final ICV+HC at 9 novel common and low-frequency loci, illustrating that genetic variation from a wide allele frequency spectrum contributes to cranial growth. The largest effects are reported for low-frequency variants within TP53, with 0.5 cm wider heads in increaser-allele carriers versus non-carriers during mid-childhood, suggesting a previously unrecognized role of TP53 transcripts in human cranial development.

Abstract

In the present electroencephalographical study, we asked to which extent executive control processes are shared by both the language and motor domain. The rationale was to examine whether executive control processes whose efficiency is reinforced by the frequent use of a second language can lead to a benefit in the control of eye movements, i.e. a non-linguistic activity. For this purpose, we administrated to 19 highly proficient late French-German bilingual participants and to a control group of 20 French monolingual participants an antisaccade task, i.e. a specific motor task involving control. In this task, an automatic saccade has to be suppressed while a voluntary eye movement in the opposite direction has to be carried out. Here, our main hypothesis is that an advantage in the antisaccade task should be observed in the bilinguals if some properties of the control processes are shared between linguistic and motor domains. ERP data revealed clear differences between bilinguals and monolinguals. Critically, we showed an increased N2 effect size in bilinguals, thought to reflect better efficiency to monitor conflict, combined with reduced effect sizes on markers reflecting inhibitory control, i.e. cue-locked positivity, the target-locked P3 and the saccade-locked presaccadic positivity (PSP). Moreover, effective connectivity analyses (dynamic causal modelling; DCM) on the neuronal source level indicated that bilinguals rely more strongly on ACC-driven control while monolinguals rely on PFC-driven control. Taken together, our combined ERP and effective connectivity findings may reflect a dynamic interplay between strengthened conflict monitoring, associated with subsequently more efficient inhibition in bilinguals. Finally, L2 proficiency and immersion experience constitute relevant factors of the language background that predict efficiency of inhibition. To conclude, the present study provided ERP and effective connectivity evidence for domain-general executive control involvement in handling multiple language use, leading to a control advantage in bilingualism.

Abstract

Interrogative structures such as ‘Could you pass the salt? and ‘Couldn’t you pass the salt?’ can be used for making requests. A study of such pairs within a conversation analytic framework suggests that these are not used interchangeably, and that they have different impacts on the interaction. Focusing on Danish interactions between elderly care recipients and their home help assistants, I demonstrate how the care recipient displays different degrees of stance towards whether she is entitled to make a request or not, depending on whether she formats her request as a positive or a negative interrogative. With a positive interrogative request, the care recipient orients to her request as one she is not entitled to make. This is underscored by other features, such as the use of mitigating devices and the choice of verb. When accounting for this type of request, the care recipient ties the request to the specific situation she is in, at the moment in which the request is produced. In turn, the home help assistant orients to the lack of entitlement by resisting the request. With a negative interrogative request, the care recipient, in contrast, orients to her request as one she is entitled to make. This is strengthened by the choice of verb and the lack of mitigating devices. When such requests are accounted for, the requested task is treated as something that should be routinely performed, and hence as something the home help assistant has neglected to do. In turn, the home help assistant orients to the display of entitlement by treating the request as unproblematic, and by complying with it immediately.

Abstract

Obesity is a genetically heterogeneous disorder. Using targeted and whole-exome sequencing, we studied 32 human and 87 rodent obesity genes in 2,548 severely obese children and 1,117 controls. We identified 52 variants contributing to obesity in 2% of cases including multiple novel variants in GNAS, which were sometimes found with accelerated growth rather than short stature as described previously. Nominally significant associations were found for rare functional variants in BBS1, BBS9, GNAS, MKKS, CLOCK and ANGPTL6. The p.S284X variant in ANGPTL6 drives the association signal (rs201622589, MAF~0.1%, odds ratio = 10.13, p-value = 0.042) and results in complete loss of secretion in cells. Further analysis including additional case-control studies and population controls (N = 260,642) did not support association of this variant with obesity (odds ratio = 2.34, p-value = 2.59 × 10−3), highlighting the challenges of testing rare variant associations and the need for very large sample sizes. Further validation in cohorts with severe obesity and engineering the variants in model organisms will be needed to explore whether human variants in ANGPTL6 and other genes that lead to obesity when deleted in mice, do contribute to obesity. Such studies may yield druggable targets for weight loss therapies.

Abstract

Simultaneous interpretation is a complex cognitive task that not only demands multilingual language processing, but also requires application of extreme levels of domain-general cognitive control. We used MRI to longitudinally measure cortical thickness in simultaneous interpretation trainees before and after a Master's program in conference interpreting. We compared them to multilingual control participants scanned at the same interval of time. Increases in cortical thickness were specific to trainee interpreters. Increases were observed in regions involved in lower-level, phonetic processing (left posterior superior temporal gyrus, anterior supramarginal gyrus and planum temporale), in the higher-level formulation of propositional speech (right angular gyrus) and in the conversion of items from working memory into a sequence (right dorsal premotor cortex), and finally, in domain-general executive control and attention (right parietal lobule). Findings are consistent with the linguistic requirements of simultaneous interpretation and also with the more general cognitive demands on attentional control for expert performance in simultaneous interpreting. Our findings may also reflect beneficial, potentially protective effects of simultaneous interpretation training, which has previously been shown to confer enhanced skills in certain executive and attentional domains over and above those conferred by bilingualism.

Abstract

Learning to read is associated with the appearance of an orthographically sensitive brain region known as the visual word form area. It has been claimed that development of this area proceeds by impinging upon territory otherwise available for the processing of culturally relevant stimuli such as faces and houses. In a large-scale functional magnetic resonance imaging study of a group of individuals of varying degrees of literacy (from completely illiterate to highly literate), we examined cortical responses to orthographic and nonorthographic visual stimuli. We found that literacy enhances responses to other visual input in early visual areas and enhances representational similarity between text and faces, without reducing the extent of response to nonorthographic input. Thus, acquisition of literacy in childhood recycles existing object representation mechanisms but without destructive competition.

Abstract

We investigate the type of attention (domain-general or language-specific) used during
syntactic processing. We focus on syntactic priming: In this task, participants listen to a
sentence that describes a picture (prime sentence), followed by a picture the participants need
to describe (target sentence). We measure the proportion of times participants use the
syntactic structure they heard in the prime sentence to describe the current target sentence as a
measure of syntactic processing. Participants simultaneously conducted a motion-object
tracking (MOT) task, a task commonly used to tax domain-general attentional resources. We
manipulated the number of objects the participant had to track; we thus measured
participants’ ability to process syntax while their attention is not-, slightly-, or overly-taxed.
Performance in the MOT task was significantly worse when conducted as a dual-task
compared to as a single task. We observed an inverted U-shaped curve on priming magnitude
when conducting the MOT task concurrently with prime sentences (i.e., memory encoding),
but no effect when conducted with target sentences (i.e., memory retrieval). Our results
illustrate how, during the encoding of syntactic information, domain-general attention
differentially affects syntactic processing, whereas during the retrieval of syntactic
information domain-general attention does not influence syntactic processing

Abstract

The use of virtual reality (VR) as a methodological tool is becoming increasingly popular in behavioral research as its flexibility allows for a wide range of applications. This new method has not been as widely accepted in the field of psycholinguistics, however, possibly due to the assumption that language processing during human-computer interactions does not accurately reflect human-human interactions. Yet at the same time there is a growing need to study human-human language interactions in a tightly controlled context, which has not been possible using existing methods. VR, however, offers experimental control over parameters that cannot be (as finely) controlled in the real world. As such, in this study we aim to show that human-computer language interaction is comparable to human-human language interaction in virtual reality. In the current study we compare participants’ language behavior in a syntactic priming task with human versus computer partners: we used a human partner, a human-like avatar with human-like facial expressions and verbal behavior, and a computer-like avatar which had this humanness removed. As predicted, our study shows comparable priming effects between the human and human-like avatar suggesting that participants attributed human-like agency to the human-like avatar. Indeed, when interacting with the computer-like avatar, the priming effect was significantly decreased. This suggests that when interacting with a human-like avatar, sentence processing is comparable to interacting with a human partner. Our study therefore shows that VR is a valid platform for conducting language research and studying dialogue interactions in an ecologically valid manner.

Abstract

Syntactic priming, the phenomenon in which participants adopt the linguistic behaviour of their partner, is widely used in psycholinguistics to investigate syntactic operations. Although the phenomenon of syntactic priming is well documented, the memory system that supports the retention of this syntactic information long enough to influence future utterances, is not as widely investigated. We aim to shed light on this issue by assessing patients with Korsakoff's amnesia on an active-passive syntactic priming task and compare their performance to controls matched in age, education, and premorbid intelligence. Patients with Korsakoff's syndrome display deficits in all subdomains of declarative memory, yet their nondeclarative memory remains intact, making them an ideal patient group to determine which memory system supports syntactic priming. In line with the hypothesis that syntactic priming relies on nondeclarative memory, the patient group shows strong priming tendencies (12.6% passive structure repetition). Our healthy control group did not show a priming tendency, presumably due to cognitive interference between declarative and nondeclarative memory. We discuss the results in relation to amnesia, aging, and compensatory mechanisms.

Abstract

The hippocampal formation is a brain structure integrally involved in episodic memory, spatial navigation, cognition and stress responsiveness. Structural abnormalities in hippocampal volume and shape are found in several common neuropsychiatric disorders. To identify the genetic underpinnings of hippocampal structure here we perform a genome-wide association study (GWAS) of 33,536 individuals and discover six independent loci significantly associated with hippocampal volume, four of them novel. Of the novel loci, three lie within genes (ASTN2, DPP4 and MAST4) and one is found 200 kb upstream of SHH. A hippocampal subfield analysis shows that a locus within the MSRB3 gene shows evidence of a localized effect along the dentate gyrus, subiculum, CA1 and fissure. Further, we show that genetic variants associated with decreased hippocampal volume are also associated with increased risk for Alzheimer’s disease (rg=−0.155). Our findings suggest novel biological pathways through which human genetic variation influences hippocampal volume and risk for neuropsychiatric illness.

Abstract

Many studies have demonstrated that listeners use information extracted from verbs to guide anticipatory eye movements to objects in the visual context that satisfy the selection restrictions of the verb. An important question is what underlies such verb-mediated anticipatory eye gaze. Based on empirical and theoretical suggestions, we investigated the influence of five potential predictors of this behavior: functional associations and general associations between verb and target object, as well as the listeners’ production fluency, receptive vocabulary knowledge, and non-verbal intelligence. In three eye-tracking experiments, participants looked at sets of four objects and listened to sentences where the final word was predictable or not predictable (e.g., “The man peels/draws an apple”). On predictable trials only the target object, but not the distractors, were functionally and associatively related to the verb. In Experiments 1 and 2, objects were presented before the verb was heard. In Experiment 3, participants were given a short preview of the display after the verb was heard. Functional associations and receptive vocabulary were found to be important predictors of verb-mediated anticipatory eye gaze independent of the amount of contextual visual input. General word associations did not and non-verbal intelligence was only a very weak predictor of anticipatory eye movements. Participants’ production fluency correlated positively with the likelihood of anticipatory eye movements when participants were given the long but not the short visual display preview. These findings fit best with a pluralistic approach to predictive language processing in which multiple mechanisms, mediating factors, and situational context dynamically interact. 

Abstract

Many studies have shown that a supportive context facilitates language comprehension. A currently influential view is that language production may support prediction in language comprehension. Experimental evidence for this, however, is relatively sparse. Here we explored whether encouraging prediction in a language production task encourages the use of predictive contexts in an interleaved comprehension task. In Experiment 1a, participants listened to the first part of a sentence and provided the final word by naming aloud a picture. The picture name was predictable or not predictable from the sentence context. Pictures were named faster when they could be predicted than when this was not the case. In Experiment 1b the same sentences, augmented by a final spill-over region, were presented in a self-paced reading task. No difference in reading times for predictive vs. non-predictive sentences was found. In Experiment 2, reading and naming trials were intermixed. In the naming task, the advantage for predictable picture names was replicated. More importantly, now reading times for the spill-over region were considerable faster for predictive vs. non-predictive sentences. We conjecture that these findings fit best with the notion that prediction in the service of language production encourages the use of predictive contexts in comprehension. Further research is required to identify the exact mechanisms by which production exerts its influence on comprehension.

Abstract

Objective: To investigate the possibility of tremor detection based on deep brain activity.
Methods: We re-analyzed recordings of local field potentials (LFPs) from the subthalamic nucleus in 10
PD patients (12 body sides) with spontaneously fluctuating rest tremor. Power in several frequency bands
was estimated and used as input to Hidden Markov Models (HMMs) which classified short data segments
as either tremor-free rest or rest tremor. HMMs were compared to direct threshold application to individual
power features.
Results: Applying a threshold directly to band-limited power was insufficient for tremor detection (mean
area under the curve [AUC] of receiver operating characteristic: 0.64, STD: 0.19). Multi-feature HMMs, in
contrast, allowed for accurate detection (mean AUC: 0.82, STD: 0.15), using four power features obtained
from a single contact pair. Within-patient training yielded better accuracy than across-patient training
(0.84 vs. 0.78, p = 0.03), yet tremor could often be detected accurately with either approach. High frequency
oscillations (>200 Hz) were the best performing individual feature.
Conclusions: LFP-based markers of tremor are robust enough to allow for accurate tremor detection in
short data segments, provided that appropriate statistical models are used.
Significance: LFP-based markers of tremor could be useful control signals for closed-loop deep brain
stimulation.

Abstract

In 2 experiments, we assessed the effects of response latency and task-induced goals on the onset and time course of semantic priming during rapid processing of visual words as revealed by ocular response
tasks. In Experiment 1 (ocular lexical decision task), participants performed a lexical decision task using eye movement responses on a sequence of 4 words. In Experiment 2, the same words were encoded for an episodic recognition memory task that did not require a metalinguistic judgment. For both tasks, survival analyses showed that the earliest observable effect (divergence point [DP]) of semantic priming on target-word reading times occurred at approximately 260 ms, and ex-Gaussian distribution fits revealed that the magnitude of the priming effect increased as a function of response time. Together, these
distributional effects of semantic priming suggest that the influence of the prime increases when target processing is more effortful. This effect does not require that the task include a metalinguistic judgment;
manipulation of the task goals across experiments affected the overall response speed but not the location of the DP or the overall distributional pattern of the priming effect. These results are more readily explained as the result of a retrospective, rather than a prospective, priming mechanism and are consistent with compound-cue models of semantic priming.

Abstract

This study assessed the effects of semantic context in the form of self-produced and other-produced words on subsequent language production. Pairs of participants performed a joint picture naming task, taking turns while naming a continuous series of pictures. In the single-speaker version of this paradigm, naming latencies have been found to increase for successive presentations of exemplars from the same category, a phenomenon known as Cumulative Semantic Interference (CSI). As expected, the joint-naming task showed a within-speaker CSI effect, such that naming latencies increased as a function of the number of category exemplars named previously by the participant (self-produced items). Crucially, we also observed an across-speaker CSI effect, such that naming latencies slowed as a function of the number of category members named by the participant's task partner (other-produced items). The magnitude of the across-speaker CSI effect did not vary as a function of whether or not the listening participant could see the pictures their partner was naming. The observation of across-speaker CSI suggests that the effect originates at the conceptual level of the language system, as proposed by Belke's (2013) Conceptual Accumulation account. Whereas self-produced and other-produced words both resulted in a CSI effect on naming latencies, post-experiment free recall rates were higher for self-produced than other-produced items. Together, these results suggest that both speaking and listening result in implicit learning at the conceptual level of the language system but that these effects are independent of explicit learning as indicated by item recall.

Abstract

Dialogue requires speakers to coordinate. According to the model of dialogue as joint action, interlocutors achieve this coordination by corepresenting their own and each other’s task share in a functionally equivalent manner. In two experiments, we investigated this corepresentation account using an interactive joint naming task in which pairs of participants took turns naming sets of objects on a shared display. Speaker A named the first, or the first and third object, and Speaker B named the second object. In control conditions, Speaker A named one, two, or all three objects and Speaker B remained silent. We recorded the timing of the speakers’ utterances and Speaker A’s eye movements. Interturn pause durations indicated that the speakers effectively coordinated their utterances in time. Speaker A’s speech onset latencies depended on the number of objects they named, but were unaffected by Speaker B’s naming task. This suggests speakers were not fully incorporating their partner’s task into their own speech planning. Moreover, Speaker A’s eye movements indicated that they were much less likely to attend to objects their partner named than to objects they named themselves. When speakers did inspect their partner’s objects, viewing times were too short to suggest that speakers were retrieving these object names as if they were planning to name the objects themselves. These results indicate that speakers prioritized planning their own responses over attending to their interlocutor’s task and suggest that effective coordination can be achieved without full corepresentation of the partner’s task.

Abstract

When faced with the noun phrase (NP) versus sentence (S) coordination ambiguity as in, for example, The thief shot the jeweller and the cop hellip, readers prefer the reading with NP-coordination (e.g., "The thief shot the jeweller and the cop yesterday") over one with two conjoined sentences (e.g., "The thief shot the jeweller and the cop panicked"). A corpus study is presented showing that NP-coordinations are produced far more often than S-coordinations, which in frequency-based accounts of parsing might be taken to explain the NP-coordination preference. In addition, we describe an eye-tracking experiment investigating S-coordinated sentences such as Jasper sanded the board and the carpenter laughed, where the poor thematic fit between carpenter and sanded argues against NP-coordination. Our results indicate that information regarding poor thematic fit was used rapidly, but not without leaving some residual processing difficulty. This is compatible with claims that thematic information can reduce but not completely eliminate garden-path effects.

Abstract

Conversational interaction occasionally lapses as topics become exhausted or as participants are left with no obvious thing to talk about next. In this article I look at episodes of ordinary conversation to examine how participants resolve issues of speakership and sequentiality in lapse environments. In particular, I examine one recurrent phenomenon—sequence recompletion—whereby participants bring to completion a sequence of talk that was already treated as complete. Using conversation analysis, I describe four methods for sequence recompletion: turn-exiting, action redoings, delayed replies, and post-sequence transitions. With this practice, participants use verbal and vocal resources to locally manage their participation framework when ending one course of action and potentially starting up a new one

Abstract

The importance of high quality teacher–student relationships for students' well-being has been long documented. Nonetheless, most studies focus either on teachers' perceptions of provided support or on students' perceptions of support. The degree to which teachers and students agree is often neither measured nor taken into account. In the current study, we will therefore use a dyadic analysis strategy called the one-with-many design. This design takes into account the nestedness of the data and looks at the importance of reciprocity when examining the influence of teacher support for students' academic and social functioning. Two samples of teachers and their students from Grade 4 (age 9–10 years) have been recruited in primary schools, located in Turkey and Romania. By using the one-with-many design we can first measure to what degree teachers' perceptions of support are in line with students' experiences. Second, this level of consensus is taken into account when examining the influence of teacher support for students' social well-being and academic functioning.

Abstract

Multiple layers of visual (and vocal) signals, plus their different onsets and offsets, represent a significant semantic and temporal binding problem during face-to-face conversation.
Despite this complex unification process, multimodal messages appear to be processed faster than unimodal messages.

Multimodal gestalt recognition and multilevel prediction are proposed to play a crucial role in facilitating multimodal language processing.

The basis of the processing mechanisms involved in multimodal language comprehension is hypothesized to be domain general, coopted for communication, and refined with domain-specific characteristics.
A new, situated framework for understanding human language processing is called for that takes into consideration the multilayered, multimodal nature of language and its production and comprehension in conversational interaction requiring fast processing.

Abstract

Does blinking function as a type of feedback in conversation? To address this question, we built a corpus of Dutch conversations, identified short and long addressee blinks during extended turns, and measured their occurrence relative to the end of turn constructional units (TCUs), the location
where feedback typically occurs. Addressee blinks were indeed timed to the
end of TCUs. Also, long blinks were more likely than short blinks to occur
during mutual gaze, with nods or continuers, and their occurrence was
restricted to sequential contexts in which signaling understanding was
particularly relevant, suggesting a special signaling capacity of long blinks.

Abstract

Dutch-learning and English-learning 9-month-olds were tested, using the Headturn Preference Procedure, for their ability to segment Dutch words with strong/weak stress patterns from fluent Dutch speech. This prosodic pattern is highly typical for words of both languages. The infants were familiarized with pairs of words and then tested on four passages, two that included the familiarized words and two that did not. Both the Dutch- and the English-learning infants gave evidence of segmenting the targets from the passages, to an equivalent degree. Thus, English-learning infants are able to extract words from fluent speech in a language that is phonetically different from English. We discuss the possibility that this cross-language segmentation ability is aided by the similarity of the typical rhythmic structure of Dutch and English words.

Abstract

Alcohol use is correlated within spouse-pairs, but it is difficult to disentangle effects of alcohol consumption on mate-selection from social factors or the shared spousal environment. We hypothesised that genetic variants related to alcohol consumption may, via their effect on alcohol behaviour, influence mate selection. Here, we find strong evidence that an individual’s self-reported alcohol consumption and their genotype at rs1229984, a missense variant in ADH1B, are associated with their partner’s self-reported alcohol use. Applying Mendelian randomization, we estimate that a unit increase in an individual’s weekly alcohol consumption increases partner’s alcohol consumption by 0.26 units (95% C.I. 0.15, 0.38; P = 8.20 × 10−6). Furthermore, we find evidence of spousal genotypic concordance for rs1229984, suggesting that spousal concordance for alcohol consumption existed prior to cohabitation. Although the SNP is strongly associated with ancestry, our results suggest some concordance independent of population stratification. Our findings suggest that alcohol behaviour directly influences mate selection.

Abstract

Aim: To determine if nonsyndromic cleft lip with or without cleft palate (nsCL/P) genetic risk variants influence liability to nsCL/P through gene regulation pathways, such as those involving DNA methylation. Materials & methods: nsCL/P genetic summary data and methylation data from four studies were used in conjunction with Mendelian randomization and joint likelihood mapping to investigate potential mediation of nsCL/P genetic variants. Results & conclusion: Evidence was found at VAX1 (10q25.3), LOC146880 (17q23.3) and NTN1 (17p13.1), that liability to nsCL/P and variation in DNA methylation might be driven by the same genetic variant, suggesting that genetic variation at these loci may increase liability to nsCL/P by influencing DNA methylation. Follow-up analyses using different tissues and gene expression data provided further insight into possible biological mechanisms.

Abstract

The functional region of interest (fROI) approach has increasingly become a favored methodology in functional magnetic resonance imaging (fMRI) because it can circumvent inter-subject anatomical and functional variability, and thus increase the sensitivity and functional resolution of fMRI analyses. The standard fROI method requires human experts to meticulously examine and identify subject-specific fROIs within activation clusters. This process is time-consuming and heavily dependent on experts’ knowledge. Several algorithmic approaches have been proposed for identifying subject-specific fROIs; however, these approaches cannot easily incorporate prior knowledge of inter-subject variability. In the present study, we improved the multi-atlas labeling approach for defining subject-specific fROIs. In particular, we used a classifier-based atlas-encoding scheme and an atlas selection procedure to account for the large spatial variability across subjects. Using a functional atlas database for face recognition, we showed that with these two features, our approach efficiently circumvented inter-subject anatomical and functional variability and thus improved labeling accuracy. Moreover, in comparison with a single-atlas approach, our multi-atlas labeling approach showed better performance in identifying subject-specific fROIs.

Abstract

When people process language, they can use context to predict upcoming information,
influencing processing and comprehension as seen in both behavioral and neural
measures. Although numerous studies have shown immediate facilitative effects
of confirmed predictions, the downstream consequences of prediction have been
less explored. In the current study, we examined those consequences by probing
participants’ recognition memory for words after they read sets of sentences.
Participants read strongly and weakly constraining sentences with expected or
unexpected endings (“I added my name to the list/basket”), and later were tested on
their memory for the sentence endings while EEG was recorded. Critically, the memory
test contained words that were predictable (“list”) but were never read (participants
saw “basket”). Behaviorally, participants showed successful discrimination between old
and new items, but false alarmed to the expected-item lures more often than to new
items, showing that predicted words or concepts can linger, even when predictions
are disconfirmed. Although false alarm rates did not differ by constraint, event-related
potentials (ERPs) differed between false alarms to strongly and weakly predictable words.
Additionally, previously unexpected (compared to previously expected) endings that
appeared on the memory test elicited larger N1 and LPC amplitudes, suggesting greater
attention and episodic recollection. In contrast, highly predictable sentence endings that
had been read elicited reduced LPC amplitudes during the memory test. Thus, prediction
can facilitate processing in the moment, but can also lead to false memory and reduced
recollection for predictable information.

Abstract

The processing of idiomatic expressions is a topical issue in empirical research. Various factors have been found to influence idiom processing, such as idiom familiarity and idiom transparency. Information on these variables is usually obtained through norming studies. Studies investigating the effect of various properties on idiom processing have led to ambiguous results. This may be due to the variability of operationalizations of the idiom properties across norming studies, which in turn may affect the reliability of the subjective judgements. However, not all studies that collected normative data on idiomatic expressions investigated their reliability, and studies that did address the reliability of subjective ratings used various measures and produced mixed results. In this study, we investigated the reliability of subjective judgements, the relation between subjective and objective idiom frequency, and the impact of these dimensions on the participants’ idiom knowledge by collecting normative data of five subjective idiom properties (Frequency of Exposure, Meaning Familiarity, Frequency of Usage, Transparency, and Imageability) from 390 native speakers and objective corpus frequency for 374 Dutch idiomatic expressions. For reliability, we compared measures calculated in previous studies, with the D-coefficient, a metric taken from Generalizability Theory. High reliability was found for all subjective dimensions. One reliability metric, Krippendorff’s alpha, generally produced lower values, while similar values were obtained for three other measures (Cronbach’s alpha, Intraclass Correlation Coefficient, and the D-coefficient). Advantages of the D-coefficient are that it can be applied to unbalanced research designs, and to estimate the minimum number of raters required to obtain reliable ratings. Slightly higher coefficients were observed for so-called experience-based dimensions (Frequency of Exposure, Meaning Familiarity, and Frequency of Usage) than for content-based dimensions (Transparency and Imageability). In addition, fewer raters were required to obtain reliable ratings for the experience-based dimensions. Subjective and objective frequency appeared to be poorly correlated, while all subjective idiom properties and objective frequency turned out to affect idiom knowledge. Meaning Familiarity, Subjective and Objective Frequency of Exposure, Frequency of Usage, and Transparency positively contributed to idiom knowledge, while a negative effect was found for Imageability. We discuss these relationships in more detail, and give methodological recommendations with respect to the procedures and the measure to calculate reliability.

Abstract

Native speakers of Dutch do not always adhere to prescriptive grammar rules in their daily speech. These grammatical norm violations can elicit emotional reactions in language purists, mostly high-educated people, who claim that for them these constructions are truly ungrammatical. However, linguists generally assume that grammatical norm violations are in fact truly grammatical, especially when they occur frequently in a language. In an fMRI study we investigated the processing of grammatical norm violations in the brains of language purists, and compared them with truly grammatical and truly ungrammatical sentences. Grammatical norm violations were found to be unique in that their processing resembled not only the processing of truly grammatical sentences (in left medial Superior Frontal Gyrus and Angular Gyrus), but also that of truly ungrammatical sentences (in Inferior Frontal Gyrus), despite what theories of grammar would usually lead us to believe

Abstract

Literacy has many obvious benefits—it exposes the reader to a wealth of new information and enhances syntactic knowledge. However, we argue that literacy has an additional, often overlooked, benefit: it enhances people’s ability to predict spoken language thereby aiding comprehension. Readers are under pressure to process information more quickly than listeners, and reading provides excellent conditions, in particular a stable environment, for training the predictive system. It also leads to increased awareness of words as linguistic units, and more fine-grained phonological and additional orthographic representations, which sharpen lexical representations and facilitate predicted representations to be retrieved. Thus, reading trains core processes and representations involved in language prediction that are common to both reading and listening.

Abstract

There is a consensus among language researchers that people can predict upcoming language. But do people always predict when comprehending language? Notions that “brains … are essentially prediction machines” certainly suggest so. In three eye-tracking experiments we tested this view. Participants listened to simple Dutch sentences (‘Look at the displayed bicycle’) while viewing four objects (a target, e.g. a bicycle, and three unrelated distractors). We used the identical visual stimuli and the same spoken sentences but varied speech rates, preview time, and participant instructions. Target nouns were preceded by definite gender-marked determiners, which allowed participants to predict the target object because only the targets but not the distractors agreed in gender with the determiner. In Experiment 1, participants had four seconds preview and sentences were presented either in a slow or a normal speech rate. Participants predicted the targets as soon as they heard the determiner in both conditions. Experiment 2 was identical except that participants were given only a one second preview. Participants predicted the targets only in the slow speech condition. Experiment 3 was identical to Experiment 2 except that participants were explicitly told to predict. This led only to a small prediction effect in the normal speech condition. Thus, a normal speech rate only afforded prediction if participants had an extensive preview. Even the explicit instruction to predict the target resulted in only a small anticipation effect with a normal speech rate and a short preview. These findings are problematic for theoretical proposals that assume that prediction pervades cognition.

Abstract

It is now well established that anticipation of up-coming input is a key characteristic of spoken language comprehension. Several mechanisms of predictive language processing have been proposed. The possible influence of mediating factors such as working memory and processing speed however has hardly been explored. We sought to find evidence for such an influence using an individual differences approach. 105 participants from 32 to 77 years of age received spoken instructions (e.g., "Kijk naar deCOM afgebeelde pianoCOM" - look at the displayed piano) while viewing four objects. Articles (Dutch “het” or “de”) were gender-marked such that the article agreed in gender only with the target. Participants could thus use gender information from the article to predict the upcoming target object. The average participant anticipated the target objects well in advance of the critical noun. Multiple regression analyses showed that working memory and processing speed had the largest mediating effects: Enhanced working memory abilities and faster processing speed supported anticipatory spoken language processing. These findings suggest that models of predictive language processing must take mediating factors such as working memory and processing speed into account. More generally, our results are consistent with the notion that working memory grounds language in space and time, linking linguistic and visual-spatial representations.

Abstract

Many psycholinguistic experiments suggest that prediction is an important characteristic of language processing. Some recent theoretical accounts in the cognitive sciences (e.g., Clark, 2013; Friston, 2010) and psycholinguistics (e.g., Dell & Chang, 2014) appear to suggest that prediction is even necessary to understand language. In the present opinion paper we evaluate this proposal. We first critically discuss several arguments that may appear to be in line with the notion that prediction is necessary for language processing. These arguments include that prediction provides a unified theoretical principle of the human mind and that it pervades cortical function. We discuss whether evidence of human abilities to detect statistical regularities is necessarily evidence for predictive processing and evaluate suggestions that prediction is necessary for language learning. Five arguments are then presented that question the claim that all language processing is predictive in nature. We point out that not all language users appear to predict language and that suboptimal input makes prediction often very challenging. Prediction, moreover, is strongly context-dependent and impeded by resource limitations. We also argue that it may be problematic that most experimental evidence for predictive language processing comes from 'prediction-encouraging' experimental set-ups. Finally, we discuss possible ways that may lead to a further resolution of this debate. We conclude that languages can be learned and understood in the absence of prediction. Claims that all language processing is predictive in nature are premature.

Abstract

In the visual world paradigm, participants are more likely to fixate a visual referent that has some semantic relationship with a heard word, than they are to fixate an unrelated referent [Cooper, R. M. (1974). The control of eye fixation by the meaning of spoken language. A new methodology for the real-time investigation of speech perception, memory, and language processing. Cognitive Psychology, 6, 813–839]. Here, this method is used to examine the psychological validity of models of high-dimensional semantic space. The data strongly suggest that these corpus-based measures of word semantics predict fixation behavior in the visual world and provide further evidence that language-mediated eye movements to objects in the concurrent visual environment are driven by semantic similarity rather than all-or-none categorical knowledge. The data suggest that the visual world paradigm can, together with other methodologies, converge on the evidence that may help adjudicate between different theoretical accounts of the psychological semantics.

Abstract

We examined whether assortative mating for educational attainment (“like marries like”) can be detected in the genomes of ~ 1600 UK spouse pairs of European descent. Assortative mating on heritable traits like educational attainment increases the genetic variance and heritability of the trait in the population, which may increase social inequalities. We test for genetic assortative mating in the UK on educational attainment, a phenotype that is indicative of socio-economic status and has shown substantial levels of assortative mating. We use genome-wide allelic effect sizes from a large genome-wide association study on educational attainment (N ~ 300 k) to create polygenic scores that are predictive of educational attainment in our independent sample (r = 0.23, p < 2 × 10− 16). The polygenic scores significantly predict partners' educational outcome (r = 0.14, p = 4 × 10− 8 and r = 0.19, p = 2 × 10− 14, for prediction from males to females and vice versa, respectively), and are themselves significantly correlated between spouses (r = 0.11, p = 7 × 10− 6). Our findings provide molecular genetic evidence for genetic assortative mating on education in the UK

Abstract

Like the transfer of genetic variation through gene flow, language changes constantly as a result of its use in human interaction. Contact between speakers is most likely to happen when they are close in space, time, and social setting. Here, we investigated the role of geographical configuration in this process by studying linguistic diversity in Japan, which comprises a large connected mainland (less isolation, more potential contact) and smaller island clusters of the Ryukyuan archipelago (more isolation, less potential contact). We quantified linguistic diversity using dialectometric methods, and performed regression analyses to assess the extent to which distance in space and time predict contemporary linguistic diversity. We found that language diversity in general increases as geographic distance increases and as time passes—as with biodiversity. Moreover, we found that (I) for mainland languages, linguistic diversity is most strongly related to geographic distance—a so-called isolation-by-distance pattern, and that (II) for island languages, linguistic diversity reflects the time since varieties separated and diverged—an isolation-by-colonisation pattern. Together, these results confirm previous findings that (linguistic) diversity is shaped by distance, but also goes beyond this by demonstrating the critical role of geographic configuration.

Abstract

Human language processing involves combinatorial operations that make human communication stand out in the animal kingdom. These operations rely on a dynamic interplay between the inferior frontal and the posterior temporal cortices. Using source reconstructed magnetoencephalography, we tracked language processing in the brain, in order to investigate how individual words are interpreted when part of sentence context. The large sample size in this study (n = 68) allowed us to assess how event-related activity is associated across distinct cortical areas, by means of inter-areal co-modulation within an individual. We showed that, within 500 ms of seeing a word, the word's lexical information has been retrieved and unified with the sentence context. This does not happen in a strictly feed-forward manner, but by means of co-modulation between the left posterior temporal cortex (LPTC) and left inferior frontal cortex (LIFC), for each individual word. The co-modulation of LIFC and LPTC occurs around 400 ms after the onset of each word, across the progression of a sentence. Moreover, these core language areas are supported early on by the attentional network. The results provide a detailed description of the temporal orchestration related to single word processing in the context of ongoing language.

Abstract

A combination of impaired motor and cognitive function in Parkinson’s disease (PD) can impact on language and communication, with patients exhibiting a particular difficulty processing action verbs. Co-speech gestures embody a link between action and language and contribute significantly to communication in healthy people. Here, we investigated how co-speech gestures depicting actions are affected in PD, in particular with respect to the visual perspective—or the viewpoint – they depict. Gestures are closely related to mental imagery and motor simulations, but people with PD may be impaired in the way they simulate actions from a first-person perspective and may compensate for this by relying more on third-person visual features. We analysed the action-depicting gestures produced by mild-moderate PD patients and age-matched controls on an action description task and examined the relationship between gesture viewpoint, action naming, and performance on an action observation task (weight judgement). Healthy controls produced the majority of their action gestures from a first-person perspective, whereas PD patients produced a greater proportion of gestures produced from a third-person perspective. We propose that this reflects a compensatory reliance on third-person visual features in the simulation of actions in PD. Performance was also impaired in action naming and weight judgement, although this was unrelated to gesture viewpoint. Our findings provide a more comprehensive understanding of how action-language impairments in PD impact on action communication, on the cognitive underpinnings of this impairment, as well as elucidating the role of action simulation in gesture production

Abstract

Recent studies have shown that the pupillary light response (PLR) is modulated by higher cognitive functions, presumably through activity in visual sensory brain areas. Here we use the PLR to test the involvement of sensory areas in visual working memory (VWM). In two experiments, participants memorized either bright or dark stimuli. We found that pupils were smaller when a prestimulus cue indicated that a bright stimulus should be memorized; this reflects a covert shift of attention during encoding of items into VWM. Crucially, we obtained the same result with a poststimulus cue, which shows that internal shifts of attention within VWM affect pupil size as well. Strikingly, the effect of VWM content on pupil size was most pronounced immediately after the poststimulus cue, and then dissipated. This suggests that a shift of attention within VWM momentarily activates an "active" memory representation, but that this representation quickly transforms into a "hidden" state that does not rely on sensory areas.

Abstract

This paper examines how gesturers and signers use their bodies to express concepts such as instrumentality and humanness. Comparing across eight sign languages (American, Japanese, German, Israeli, and Kenyan Sign Languages, Ha Noi Sign Language of Vietnam, Central Taurus Sign Language of Turkey, and Al-Sayyid Bedouin Sign Language of Israel) and the gestures of American non-signers, we find recurring patterns for naming entities in three semantic categories (tools, animals, and fruits & vegetables). These recurring patterns are captured in a classification system that identifies iconic strategies based on how the body is used together with the hands. Across all groups, tools are named with manipulation forms, where the head and torso represent those of a human agent. Animals tend to be identified with personification forms, where the body serves as a map for a comparable non-human body. Fruits & vegetables tend to be identified with object forms, where the hands act independently from the rest of the body to represent static features of the referent. We argue that these iconic patterns are rooted in using the body for communication, and provide a basis for understanding how meaningful communication emerges quickly in gesture and persists in emergent and established sign languages.

Abstract

Individuals rapidly extract information about others’ social identity, including whether or not they belong to their in-group. Group membership status has been shown to affect how attentively people encode information conveyed by those others. These findings are highly relevant for the field of psycholinguistics where there exists an open debate on how words are represented in the mental lexicon and how abstract or context-specific these representations are. Here, we used a novel word learning paradigm to test our proposal that the group membership status of speakers also affects how speaker-specific representations of novel words are. Participants learned new words from speakers who either attended their own university (in-group speakers) or did not (out-group speakers) and performed a task to measure their individual in-group bias. Then, their source memory of the new words was tested in a recognition test to probe the speaker-specific content of the novel lexical representations and assess how it related to individual in-group biases. We found that speaker group membership and participants’ in-group bias affected participants’ decision biases. The stronger the in-group bias, the more cautious participants were in their decisions. This was particularly applied to in-group related decisions. These findings indicate that social biases can influence recognition threshold. Taking a broader scope, defining how information is represented is a topic of great overlap between the fields of memory and psycholinguistics. Nevertheless, researchers from these fields tend to stay within the theoretical and methodological borders of their own field, missing the chance to deepen their understanding of phenomena that are of common interest. Here we show how methodologies developed in the memory field can be implemented in language research to shed light on an important theoretical issue that relates to the composition of lexical representations.

Abstract

Foreign languages are often learned in emotionally neutral academic environments which differ greatly from the familiar context where native languages are acquired. This difference in learning contexts has been argued to lead to reduced emotional resonance when confronted with a foreign language. In the current study, we investigated whether the reactivity of the sympathetic nervous system in response to emotionally-charged stimuli is reduced in a foreign language. To this end, pupil sizes were recorded while reading aloud emotional sentences in the native or foreign language. Additionally, subjective ratings of emotional impact were provided after reading each sentence, allowing us to further investigate foreign language effects on explicit emotional understanding. Pupillary responses showed a larger effect of emotion in the native than in the foreign language. However, such a difference was not present for explicit ratings of emotionality. These results reveal that the sympathetic nervous system reacts differently depending on the language context, which in turns suggests a deeper emotional processing when reading in a native compared to a foreign language.

Abstract

Background Peripartum depression is a common cause of pregnancy- and postpartum-related morbidity. The production of corticotropin-releasing hormone (CRH) from the placenta alters the profile of hypothalamus–pituitary–adrenal axis hormones and may be associated with postpartum depression. The purpose of this study was to assess, in nondepressed pregnant women, the possible association between CRH levels in pregnancy and depressive symptoms postpartum. Methods A questionnaire containing demographic data and the Edinburgh Postnatal Depression Scale (EPDS) was filled in gestational weeks 17 and 32, and 6 week postpartum. Blood samples were collected in week 17 for assessment of CRH. A logistic regression model was constructed, using postpartum EPDS score as the dependent variable and log-transformed CRH levels as the independent variable. Confounding factors were included in the model. Subanalyses after exclusion of study subjects with preterm birth, newborns small for gestational age (SGA), and women on corticosteroids were performed. Results Five hundred thirty-five women without depressive symptoms during pregnancy were included. Logistic regression showed an association between high CRH levels in gestational week 17 and postpartum depressive symptoms, before and after controlling for several confounders (unadjusted OR = 1.11, 95% CI 1.01–1.22; adjusted OR = 1.13, 95% CI 1.02–1.26; per 0.1 unit increase in log CRH). Exclusion of women with preterm birth and newborns SGA as well as women who used inhalation corticosteroids during pregnancy did not alter the results. Conclusions This study suggests an association between high CRH levels in gestational week 17 and the development of postpartum depressive symptoms, among women without depressive symptoms during pregnancy.

Abstract

This article presents the results of a meta-analysis of 30 hemodynamic experiments comparing first language (L1) and second language (L2) processing in a range of tasks. The results suggest that reliably stronger activation during L2 processing is found (a) only for task-specific subgroups of L2 speakers and (b) within some, but not all regions that are also typically activated in native language processing. A tentative interpretation based on the functional roles of frontal and temporal regions is suggested.

Abstract

This volume is a harvest of articles from the first conference in a series on the cognitive neuroscience of language. The first conference focused on the cognitive neuroscience of second language acquisition (henceforth SLA). It brought together experts from as diverse fields as second language acquisition, bilingualism, cognitive neuroscience, and neuroanatomy. The articles and discussion articles presented here illustrate state-of-the-art findings and represent a wide range of theoretical approaches to classic as well as newer SLA issues. The theoretical themes cover age effects in SLA related to the so-called Critical Period Hypothesis and issues of ultimate attainment and focus both on age effects pertaining to childhood and to aging. Other familiar SLA topics are the effects of proficiency and learning as well as issues concerning the difference between the end product and the process that yields that product, here discussed in terms of convergence and degeneracy. A topic more related to actual usage of a second language once acquired concerns how multilingual speakers control and regulate their two languages.

Abstract

We investigated how two groups of Turkish-Dutch bilinguals and two groups of monolingual speakers of the two languages described static topological relations. The bilingual groups differed with respect to their first (L1) and second (L2) language proficiencies and a number of sociolinguistic factors. Using an elicitation tool that covers a wide range of topological relations, we first assessed the extensions of different spatial expressions (topological relation markers, TRMs) in the Turkish and Dutch spoken by monolingual speakers. We then assessed differences in the use of TRMs between the two bilingual groups and monolingual speakers. In both bilingual groups, differences compared to monolingual speakers were mainly observed for Turkish. Dutch-dominant bilinguals showed enhanced congruence between translation-equivalent Turkish and Dutch TRMs. Turkish-dominant bilinguals extended the use of a topologically neutral locative marker. Our results can be interpreted as showing different bilingual optimization strategies (Muysken, 2013) in bilingual speakers who live in the same environment but differ with respect to L2 onset, L2 proficiency, and perceived importance of the L1.