Publications

Abstract

How can data be used to check theories’ explanatory adequacy? The two traditional and most widespread approaches use single studies and non-systematic narrative reviews to evaluate theories’ explanatory adequacy; more
recently, large-scale replications entered the picture. We argue here that none of these approaches fits in with
cumulative science tenets. We propose instead Community-Augmented Meta-Analyses (CAMAs), which, like metaanalyses and systematic reviews, are built using all available data; like meta-analyses but not systematic reviews, can
rely on sound statistical practices to model methodological effects; and like no other approach, are broad-scoped,
cumulative and open. We explain how CAMAs entail a conceptual shift from meta-analyses and systematic reviews, a
shift that is useful when evaluating theories’ explanatory adequacy. We then provide step-by-step recommendations
for how to implement this approach – and what it means when one cannot. This leads us to conclude that CAMAs
highlight areas of uncertainty better than alternative approaches that bring data to bear on theory evaluation, and
can trigger a much needed shift towards a cumulative mindset with respect to both theory and data, leading us to
do and view experiments and narrative reviews differently.

Abstract

Phonological patterns in languages often involve groups of sounds rather than individual sounds, which may be explained if phonology operates on the abstract features shared by those groups (Troubetzkoy, 193957. Troubetzkoy , N. 1939/1969 . Principles of phonology , Berkeley : University of California Press . View all references/1969; Chomsky & Halle, 19688. Chomsky , N. and Halle , M. 1968 . The sound pattern of English , New York : Harper and Row . View all references). Such abstract features may be present in the developing grammar either because they are part of a Universal Grammar included in the genetic endowment of humans (e.g., Hale, Kissock and Reiss, 200618. Hale , M. , Kissock , M. and Reiss , C. 2006 . Microvariation, variation, and the features of universal grammar . Lingua , 32 : 402 – 420 . View all references), or plausibly because infants induce features from their linguistic experience (e.g., Mielke, 200438. Mielke , J. 2004 . The emergence of distinctive features , Ohio State University : Unpublished doctoral dissertation . View all references). A first experiment tested 7-month-old infants' learning of an artificial grammar pattern involving either a set of sounds defined by a phonological feature, or a set of sounds that cannot be described with a single feature—an “arbitrary” set. Infants were able to induce the constraint and generalize it to a novel sound only for the set that shared the phonological feature. A second study showed that infants' inability to learn the arbitrary grouping was not due to their inability to encode a constraint on some of the sounds involved.

Abstract

Speaker diarization (answering 'who spoke when') is a widely researched subject within speech technology. Numerous experiments have been run on datasets built from broadcast news, meeting data, and call centers—the task sometimes appears close to being solved. Much less work has begun to tackle the hardest diarization task of all: spontaneous conversations in real-world settings. Such diarization would be particularly useful for studies of language acquisition, where researchers investigate the speech children produce and hear in their daily lives. In this paper, we study audio gathered with a recorder worn by small children as they went about their normal days. As a result, each child was exposed to different acoustic environments with a multitude of background noises and a varying number of adults and peers. The inconsistency of speech and noise within and across samples poses a challenging task for speaker diarization systems, which we tackled via retraining and data augmentation techniques. We further studied sources of structured variation across raw audio files, including the impact of speaker type distribution, proportion of speech from children, and child age on diarization performance. We discuss the extent to which these findings might generalize to other samples of speech in the wild.

Abstract

Cooperation among nonhuman animals has been the topic of much theoretical and empirical research, but few studies have examined systematically the effects of various reward payoffs on cooperative behaviour. Here, we presented heterosexual pairs of cooperatively breeding cottontop tamarins with a cooperative problem-solving task. In a series of four experiments, we examined how the tamarins’ cooperative performance changed under conditions in which (1) both actors were mutually rewarded, (2) both actors were rewarded reciprocally across days, (3) both actors competed for a monopolizable reward and (4) one actor repeatedly delivered a single reward to the other actor. The tamarins showed sensitivity to the reward structure, showing the greatest percentage of trials solved and shortest latency to solve the task in the mutual reward experiment and the lowest percentage of trials solved and longest latency to solve the task in the experiment in which one actor was repeatedly rewarded. However, even in the experiment in which the fewest trials were solved, the tamarins still solved 46 _ 12% of trials and little to no aggression was observed among partners following inequitable reward distributions. The tamarins did, however, show selfish motivation in each of the experiments. Nevertheless, in all experiments, unrewarded individuals continued to cooperate and procure rewards for their social partners.

Abstract

A large amount of variability exists across human brains; revealed initially on a small scale by postmortem studies and,
more recently, on a larger scale with the advent of neuroimaging. Here we compared structural variability between human
and macaque monkey brains using grey and white matter magnetic resonance imaging measures. The monkey brain was
overall structurally as variable as the human brain, but variability had a distinct distribution pattern, with some key areas
showing high variability. We also report the first evidence of a relationship between anatomical variability and evolutionary
expansion in the primate brain. This suggests a relationship between variability and stability, where areas of low variability
may have evolved less recently and have more stability, while areas of high variability may have evolved more recently and
be less similar across individuals. We showed specific differences between the species in key areas, including the amount of
hemispheric asymmetry in variability, which was left-lateralized in the human brain across several phylogenetically recent
regions. This suggests that cerebral variability may be another useful measure for comparison between species and may add
another dimension to our understanding of evolutionary mechanisms.

Abstract

Idiomatic expressions like hit the road or turn the tables are known to be problematic for L2 learners, but research indicates that learning L2 idiomatic language is important. Relatively few studies, most of them focusing on English idioms, have investigated how L2 idioms are actually acquired and how this process is affected by important idiom properties like transparency (the degree to which the figurative meaning of an idiom can be inferred from its literal analysis) and cross-language overlap (the degree to which L2 idioms correspond to L1 idioms). The present study employed a specially designed CALL system to investigate the effects of intensity of practice and the reading modality on learning Dutch L2 idioms, as well as the impact of idiom transparency and cross-language overlap. The results show that CALL practice with a focus on meaning and form is effective for learning L2 idioms and that the degree of practice needed depends on the properties of the idioms. L2 learners can achieve or even exceed native-like performance. Practicing reading idioms aloud does not lead to significantly higher performance than reading idioms silently.These findings have theoretical implications as they show that differences between native speakers and L2 learners are due to differences in exposure, rather than to different underlying acquisition mechanisms. For teaching practice, this study indicates that a properly designed CALL system is an effective and an ecologically sound environment for learning L2 idioms, a generally unattended area in L2 classes, and that teaching priorities should be based on degree of transparency and cross-language overlap of L2 idioms.

Abstract

Speech processing by human listeners derives meaning from acoustic input via intermediate steps involving abstract representations of what has been heard. Recent results from several lines of research are here brought together to shed light on the nature and role of these representations. In spoken-word recognition, representations of phonological form and of conceptual content are dissociable. This follows from the independence of patterns of priming for a word's form and its meaning. The nature of the phonological-form representations is determined not only by acoustic-phonetic input but also by other sources of information, including metalinguistic knowledge. This follows from evidence that listeners can store two forms as different without showing any evidence of being able to detect the difference in question when they listen to speech. The lexical representations are in turn separate from prelexical representations, which are also abstract in nature. This follows from evidence that perceptual learning about speaker-specific phoneme realization, induced on the basis of a few words, generalizes across the whole lexicon to inform the recognition of all words containing the same phoneme. The efficiency of human speech processing has its basis in the rapid execution of operations over abstract representations.

Abstract

Listeners heard an ambiguous /f-s/ in nonword contexts where only one of /f/ or /s/ was legal (e.g., frul/*srul or *fnud/snud). In later categorisation of a phonetic continuum from /f/ to /s/, their category boundaries had shifted; hearing -rul led to expanded /f/ categories, -nud expanded /s/. Thus phonotactic sequence information alone induces perceptual retuning of phoneme category boundaries; lexical access is not required.

Abstract

How do speakers of languages with different intonation systems produce and perceive prosodic junctures in sentences with identical structural ambiguity? Native speakers of English and of Mandarin produced potentially ambiguous sentences with a prosodic juncture either earlier in the utterance (e.g., “He gave her # dog biscuits,” “他给她#狗饼干 ”), or later (e.g., “He gave her dog # biscuits,” “他给她狗 #饼干 ”). These productiondata showed that prosodic disambiguation is realised very similarly in the two languages, despite some differences in the degree to which individual juncture cues (e.g., pausing) were favoured. In perception experiments with a new disambiguation task, requiring speeded responses to select the correct meaning for structurally ambiguous sentences, language differences in disambiguation response time appeared: Mandarin speakers correctly disambiguated sentences with earlier juncture faster than those with later juncture, while English speakers showed the reverse. Mandarin-speakers with L2 English did not show their native-language response time pattern when they heard the English ambiguous sentences. Thus even with identical structural ambiguity and identically cued production, prosodic juncture perception across languages can differ.

Abstract

In two experiments, Mandarin listeners resolved potential syntactic ambiguities in spoken utterances in (a) their native language (L1) and (b) English which they had learned as a second language (L2). A new disambiguation task was used, requiring speeded responses to select the correct meaning for structurally ambiguous sentences. Importantly, the ambiguities used in the study are identical in Mandarin and in English, and production data show that prosodic disambiguation of this type of ambiguity is also realised very similarly in the two languages. The perceptual results here showed however that listeners’ response patterns differed for L1 and L2, although there was a significant increase in similarity between the two response patterns with increasing exposure to the L2. Thus identical ambiguity and comparable disambiguation patterns in L1 and L2 do not lead to immediate application of the appropriate L1 listening strategy to L2; instead, it appears that such a strategy may have to be learned anew for the L2.

Abstract

Using a phoneme detection task, the present series of
experiments examines whether listeners can entrain to
different combinations of prosodic cues to predict where focus
will fall in an utterance. The stimuli were recorded by four
female native speakers of Australian English who happened to
have used different prosodic cues to produce sentences with
prosodic focus: a combination of duration cues, mean and
maximum F0, F0 range, and longer pre-target interval before
the focused word onset, only mean F0 cues, only pre-target
interval, and only duration cues. Results revealed that listeners
can entrain in almost every condition except for where
duration was the only reliable cue. Our findings suggest that
listeners are flexible in the cues they use for focus processing.

Abstract

Speech recognition in noise is harder in second (L2) than first languages (L1). This could be because noise disrupts speech processing more in L2 than L1, or because L1 listeners recover better though disruption is equivalent. Two similar prior studies produced discrepant results: Equivalent noise effects for L1 and L2 (Dutch) listeners, versus larger effects for L2 (Spanish) than L1. To explain this, the latter experiment was presented to listeners from the former population. Larger noise effects on consonant identification emerged for L2 (Dutch) than L1 listeners, suggesting that task factors rather than L2 population differences underlie the results discrepancy.

Abstract

Listeners adapt rapidly to previously unheard talkers by
adjusting phoneme categories using lexical knowledge, in a
process termed lexically-guided perceptual learning. Although
this is firmly established for listening in the native language
(L1), perceptual flexibility in second languages (L2) is as yet
less well understood. We report two experiments examining L1
and L2 perceptual learning, the first in Mandarin-English late
bilinguals, the second in Australian learners of Mandarin. Both
studies showed stronger learning in L1; in L2, however,
learning appeared for the English-L1 group but not for the
Mandarin-L1 group. Phonological mapping differences from
the L1 to the L2 are suggested as the reason for this result.

Abstract

In three experiments, the processing of lexical tone in Cantonese was examined. Cantonese listeners more often accepted a nonword as a word when the only difference between the nonword and the word was in tone, especially when the F0 onset difference between correct and erroneous tone was small. Same–different judgments by these listeners were also slower and less accurate when the only difference between two syllables was in tone, and this was true whether the F0 onset difference between the two tones was large or small. Listeners with no knowledge of Cantonese produced essentially the same same-different judgment pattern as that produced by the native listeners, suggesting that the results display the effects of simple perceptual processing rather than of linguistic knowledge. It is argued that the processing of lexical tone distinctions may be slowed, relative to the processing of segmental distinctions, and that, in speeded-response tasks, tone is thus more likely to be misprocessed than is segmental structure.

Abstract

Listeners' recognition of spoken language involves complex decoding processes: The continuous speech stream must be segmented into its component words, and words must be recognized despite great variability in their pronunciation (due to talker differences, or to influence of phonetic context, or to speech register) and despite competition from many spuriously present forms supported by the speech signal. L1 listeners deal more readily with all levels of this complexity than L2 listeners. Fortunately, the decoding processes necessary for competent L2 listening can be taught in the classroom. Evidence-based methodologies targeted at the development of efficient speech decoding include teaching of minimal pairs, of phonotactic constraints, and of reduction processes, as well as the use of dictation and L2 video captions.

Abstract

An acoustically invariant one-word segment occurred in two versions of one syntactic context. In one version, the preceding intonation contour indicated that a stress would fall at the point where this word occurred. In the other version, the preceding contour predicted reduced stress at that point. Reaction time to the initial phoneme of the word was faster in the former case, despite the fact that no acoustic correlates of stress were present. It is concluded that a part of the sentence comprehension process is the prediction of upcoming sentence accents.

Abstract

Research on the exploitation of prosodic information in the recognition of spoken language is reviewed. The research falls into three main areas: the use of prosody in the recognition of spoken words, in which most attention has been paid to the question of whether the prosodic structure of a word plays a role in initial contact with stored lexical representations; the use of prosody in the computation of syntactic structure, in which the resolution of global and local ambiguities has formed the central focus; and the role of prosody in the processing of discourse structure, in which there has been a preponderance of work on the contribution of accentuation and deaccentuation to integration of concepts with an existing discourse model. The review reveals that in each area progress has been made towards new conceptions of prosody's role in processing, and in particular this has involved abandonment of previously held deterministic views of the relationship between prosodic structure and other aspects of linguistic structure

Abstract

Psycholinguists strive to construct a model of human language processing in general. But this does not imply that they should confine their research to universal aspects of linguistic structure, and avoid research on language-specific phenomena. First, even universal characteristics of language structure can only be accurately observed cross-linguistically. This point is illustrated here by research on the role of the syllable in spoken-word recognition, on the perceptual processing of vowels versus consonants, and on the contribution of phonetic assimilation phonemena to phoneme identification. In each case, it is only by looking at the pattern of effects across languages that it is possible to understand the general principle. Second, language-specific processing can certainly shed light on the universal model of language comprehension. This second point is illustrated by studies of the exploitation of vowel harmony in the lexical segmentation of Finnish, of the recognition of Dutch words with and without vowel epenthesis, and of the contribution of different kinds of lexical prosodic structure (tone, pitch accent, stress) to the initial activation of candidate words in lexical access. In each case, aspects of the universal processing model are revealed by analysis of these language-specific effects. In short, the study of spoken-language processing by human listeners requires cross-linguistic comparison.

Abstract

Language production and comprehension are intimately interrelated; and models of production and comprehension should, we argue, be constrained by common architectural guidelines. Levelt et al.'s target article adopts as guiding principle Ockham's razor: the best model of production is the simplest one. We recommend adoption of the same principle in comprehension, with consequent simplification of some well-known types of models.

Abstract

Three experiments addressed the question of whether pitch-accent information may be exploited in the process of recognizing spoken words in Tokyo Japanese. In a two-choice classification task, listeners judged from which of two words, differing in accentual structure, isolated syllables had been extracted ~e.g., ka from baka HL or gaka LH!; most judgments were correct, and listeners’ decisions were correlated with the fundamental frequency characteristics of the syllables. In a gating experiment, listeners heard initial fragments of words and guessed what the words were; their guesses overwhelmingly had the same initial accent structure as the gated word even when only the beginning CV of the stimulus ~e.g., na- from nagasa HLL or nagashi LHH! was presented. In addition, listeners were more confident in guesses with the same initial accent structure as the stimulus than in guesses with different accent. In a lexical decision experiment, responses to spoken words ~e.g., ame HL! were speeded by previous presentation of the same word ~e.g., ame HL! but not by previous presentation of a word differing only in accent ~e.g., ame LH!. Together these findings provide strong evidence that accentual information constrains the activation and selection of candidates for spoken-word recognition.

Abstract

Two lexical decision studies examined the effects of single-phoneme mismatches on lexical activation in spoken-word recognition. One study was carried out in English, and involved spoken primes and visually presented lexical decision targets. The other study was carried out in Dutch, and primes and targets were both presented auditorily. Facilitation was found only for spoken targets preceded immediately by spoken primes; no facilitation occurred when targets were presented visually, or when intervening input occurred between prime and target. The effects of vowel mismatches and consonant mismatches were equivalent.

Abstract

Listening to speech is difficult in noisy environments, and is even harder when the interfering noise consists of intelligible speech as compared to unintelligible sounds. This suggests that the competing linguistic information interferes with the neural processing of target speech. Interference could either arise from a degradation of the neural representation of the target speech, or from increased representation of distracting speech that enters in competition with the target speech. We tested these alternative hypotheses using magnetoencephalography (MEG) while participants listened to a target clear speech in the presence of distracting noise-vocoded speech. Crucially, the distractors were initially unintelligible but became more intelligible after a short training session. Results showed that the comprehension of the target speech was poorer after training than before training. The neural tracking of target speech in the delta range (1–4 Hz) reduced in strength in the presence of a more intelligible distractor. In contrast, the neural tracking of distracting signals was not significantly modulated by intelligibility. These results suggest that the presence of distracting speech signals degrades the linguistic representation of target speech carried by delta oscillations.

Abstract

The neural mechanism for selectively tuning in to a target speaker while tuning out the others in a multi-speaker situation (i.e., the cocktail-party effect) remains elusive. Here we addressed this issue by measuring brain activity simultaneously from a listener and from multiple speakers while they were involved in naturalistic conversations. Results consistently show selectively enhanced interpersonal neural synchronization (INS) between the listener and the attended speaker at left temporal–parietal junction, compared with that between the listener and the unattended speaker across different multi-speaker situations. Moreover, INS increases significantly prior to the occurrence of verbal responses, and even when the listener’s brain activity precedes that of the speaker. The INS increase is independent of brain-to-speech synchronization in both the anatomical location and frequency range. These findings suggest that INS underlies the selective process in a multi-speaker situation through neural predictions at the content level but not the sensory level of speech.

Abstract

Background

Variation in the longitudinal course of childhood attention deficit/hyperactivity disorder (ADHD) coincides with neurodevelopmental maturation of brain structure and function. Prior work has attempted to determine how alterations in white matter (WM) relate to changes in symptom severity, but much of that work has been done in smaller cross-sectional samples using voxel-based analyses. Using standard diffusion-weighted imaging (DWI) methods, we previously showed WM alterations were associated with ADHD symptom remission over time in a longitudinal sample of probands, siblings, and unaffected individuals. Here, we extend this work by further assessing the nature of these changes in WM microstructure by including an additional follow-up measurement (aged 18 – 34 years), and using the more physiologically informative fixel-based analysis (FBA).
Methods

Data were obtained from 139 participants over 3 clinical and 2 follow-up DWI waves, and analyzed using FBA in regions-of-interest based on prior findings. We replicated previously reported significant models and extended them by adding another time-point, testing whether changes in combined ADHD and hyperactivity-impulsivity (HI) continuous symptom scores are associated with fixel metrics at follow-up.
Results

Clinical improvement in HI symptoms over time was associated with more fiber density at follow-up in the left corticospinal tract (lCST) (tmax = 1.092, standardized effect[SE] = 0.044, pFWE = 0.016). Improvement in combined ADHD symptoms over time was associated with more fiber cross-section at follow-up in the lCST (tmax = 3.775, SE = 0.051, pFWE = 0.019).
Conclusions

Aberrant white matter development involves both lCST micro- and macrostructural alterations, and its path may be moderated by preceding symptom trajectory.

Abstract

In the present study, we explore whether multiple data sources may be more effective than single sources at predicting the words that language learners are likely to know. Second language researchers have hypothesized that there is a relationship between word frequency and the likelihood that words will be encountered or used by second language learners, but it is not yet clear how this relationship should be effectively measured. An analysis of word frequency measures showed that spoken language frequency alone may predict the occurrence of words in learner textbooks, but that multiple corpora as well as textbook status can improve predictions of learner usage.

Abstract

The causal correlations between human genetic variants and linguistic (typological) features could represent the mechanism required for gradual, accretionary models of language evolution. The causal link is mediated by the process of cultural transmission of language across generations in a population of genetically biased individuals. The particular case of Tone, ASPM and Microcephalin is discussed as an illustration. It is proposed that this type of genetically-influenced linguistic bias, coupled with a fundamental role for genetic and linguistic diversities, provides a better explanation for the evolution of language and linguistic universals.

Abstract

One of the best-known types of non-independence between languages is caused by genealogical relationships due to descent from a common ancestor. These can be represented by (more or less resolved and controversial) language family trees. In theory, one can argue that language families should be built through the strict application of the comparative method of historical linguistics, but in practice this is not always the case, and there are several proposed classifications of languages into language families, each with its own advantages and disadvantages. A major stumbling block shared by most of them is that they are relatively difficult to use with computational methods, and in particular with phylogenetics. This is due to their lack of standardization, coupled with the general non-availability of branch length information, which encapsulates the amount of evolution taking place on the family tree. In this paper I introduce a method (and its implementation in R) that converts the language classifications provided by four widely-used databases (Ethnologue, WALS, AUTOTYP and Glottolog) intothe de facto Newick standard generally used in phylogenetics, aligns the four most used conventions for unique identifiers of linguistic entities (ISO 639-3, WALS, AUTOTYP and Glottocode), and adds branch length information from a variety of sources (the tree's own topology, an externally given numeric constant, or a distance matrix). The R scripts, input data and resulting Newick trees are available under liberal open-source licenses in a GitHub repository (https://github.com/ddediu/lgfam-newick), to encourage and promote the use of phylogenetic methods to investigate linguistic diversity and its temporal dynamics.

Abstract

Here we re-evaluate our 2013 paper on the antiquity of language (Dediu and Levinson, 2013) in the light of a surge of new information on human evolution in the last half million years. Although new genetic data suggest the existence of some cognitive differences between Neanderthals and modern humans — fully expected after hundreds of thousands of years of partially separate evolution, overall our claims that Neanderthals were fully articulate beings and that language evolution was gradual are further substantiated by the wealth of new genetic, paleontological and archeological evidence briefly reviewed here.

Abstract

It has recently been proposed (Dediu, D., Ladd, D.R., 2007. Linguistic tone is related to the population frequency of the adaptive haplogroups of two brain size genes, ASPM and Microcephalin. Proc Natl Acad Sci USA 104, 10944-10949) that genetically coded linguistic biases can influence the trajectory of language change. However, the nature of such biases and the conditions under which they can become manifest have remained vague. The present paper explores computationally two plausible types of linguistic acquisition biases in a population of agents implementing realistic genetic, linguistic and demographic processes. One type of bias represents an innate asymmetric initial state (Initial Expectation bias) while the other an innate asymmetric facility of acquisition (Rate of Learning bias). It was found that only the second type of bias produces detectable effects on language through cultural transmission across generations and that such effects are produced even by weak biases present at low frequencies in the population. This suggests that learning preference asymmetries, very small at the individual level and not very frequent at the population level, can bias the trajectory of language change through the process of cultural transmission.

Abstract

In this article we investigate the relation between discourse markers and turn-transition strategies in face-to-face conversations and Instant Messaging (IM), that is, unplanned, real-time, text-based, computer-mediated communication. By means of a quantitative corpus study of utterances containing a discourse marker, we show that utterance-final discourse markers are used more often in IM than in face-to-face conversations. Moreover, utterance-final discourse markers are shown to occur more often at points of turn-transition compared with points of turn-maintenance in both types of conversation. From our results we conclude that the discourse markers in utterance-final position can function as a turn-transition mechanism, signaling that the turn is over and the floor is open to the hearer. We argue that this linguistic turn-taking strategy is essentially similar in face-to-face and IM communication. Our results add to the evidence that communication in IM is more like speech than like writing.

Abstract

Recurrent de novo variants in the TBR1 transcription factor are implicated in the etiology of sporadic autism spectrum disorders (ASD). Disruptions include missense variants located in the T-box DNA-binding domain and previous work has demonstrated that they disrupt TBR1 protein function. Recent screens of thousands of simplex families with sporadic ASD cases uncovered additional T-box variants in TBR1 but their etiological relevance is unclear. We performed detailed functional analyses of de novo missense TBR1 variants found in the T-box of ASD cases, assessing many aspects of protein function, including subcellular localization, transcriptional activity and protein-interactions. Only two of the three tested variants severely disrupted TBR1 protein function, despite in silico predictions that all would be deleterious. Furthermore, we characterized a putative interaction with BCL11A, a transcription factor that was recently implicated in a neurodevelopmental syndrome involving developmental delay and language deficits. Our findings enhance understanding of molecular functions of TBR1, as well as highlighting the importance of functional testing of variants that emerge from next-generation sequencing, to decipher their contributions to neurodevelopmental disorders like ASD.

Abstract

Prion diseases are fatal neurodegenerative disorders that include Creutzfeldt-Jakob disease in humans and bovine spongiform encephalopathy in animals. They are unique in terms of their biology because they are caused by the conformational re-arrangement of a normal host-encoded prion protein, PrPC, to an abnormal infectious isoform, PrPSc. Currently the precise mechanism behind prion-mediated neurodegeneration remains unclear. It is hypothesised than an unknown toxic gain of function of PrPSc, or an intermediate oligomeric form, underlies neuronal death. Increasing evidence suggests a role for the ubiquitin proteasome system (UPS) in prion disease. Both wild-type PrPC and disease-associated PrP isoforms accumulate in cells after proteasome inhibition leading to increased cell death, and abnormal beta-sheet-rich PrP isoforms have been shown to inhibit the catalytic activity of the proteasome. Here we review potential interactions between prions and the proteasome outlining how the UPS may be implicated in prion-mediated neurodegeneration.

Abstract

Intellectual disability (ID) is a severe neurodevelopmental disorder with genetically heterogeneous causes. Large-scale sequencing has led to the identification of many gene-disrupting mutations; however, a substantial proportion of cases lack a molecular diagnosis. As such, there remains much to uncover for a complete understanding of the genetic underpinnings of ID. Genetic variants present in non-coding regions of the genome have been highlighted as potential contributors to neurodevelopmental disorders given their role in regulating gene expression. Nevertheless the functional characterization of non-coding variants remains challenging. We describe the identification and characterization of de novo non-coding variation in 3′UTR regulatory regions within an ID cohort of 50 patients. This cohort was previously screened for structural and coding pathogenic variants via CNV, whole exome and whole genome analysis. We identified 44 high-confidence single nucleotide non-coding variants within the 3′UTR regions of these 50 genomes. Four of these variants were located within predicted miRNA binding sites and were thus hypothesised to have regulatory consequences. Functional testing showed that two of the variants interfered with miRNA-mediated regulation of their target genes, AMD1 and FAIM. Both these variants were found in the same individual and their functional consequences may point to a potential role for such variants in intellectual disability.

Abstract

Understanding the genetic factors underlying neurodevelopmental and neuropsychiatric disorders is a major challenge given their prevalence and potential severity for quality of life. While large-scale genomic screens have made major advances in this area, for many disorders the genetic underpinnings are complex and poorly understood. To date the field has focused predominantly on protein coding variation, but given the importance of tightly controlled gene expression for normal brain development and disorder, variation that affects non-coding regulatory regions of the genome is likely to play an important role in these phenotypes. Herein we show the importance of 3 prime untranslated region (3'UTR) non-coding regulatory variants across neurodevelopmental and neuropsychiatric disorders. We devised a pipeline for identifying and functionally validating putatively pathogenic variants from next generation sequencing (NGS) data. We applied this pipeline to a cohort of children with severe specific language impairment (SLI) and identified a functional, SLI-associated variant affecting gene regulation in cells and post-mortem human brain. This variant and the affected gene (ARHGEF39) represent new putative risk factors for SLI. Furthermore, we identified 3′UTR regulatory variants across autism, schizophrenia and bipolar disorder NGS cohorts demonstrating their impact on neurodevelopmental and neuropsychiatric disorders. Our findings show the importance of investigating non-coding regulatory variants when determining risk factors contributing to neurodevelopmental and neuropsychiatric disorders. In the future, integration of such regulatory variation with protein coding changes will be essential for uncovering the genetic causes of complex neurological disorders and the fundamental mechanisms underlying health and disease

Abstract

This paper investigates when and how children figure out the force of modals: that possibility modals (e.g., can/might) express possibility, and necessity modals (e.g., must/have to) express necessity. Modals raise a classic subset problem: given that necessity entails possibility, what prevents learners from hypothesizing possibility meanings for necessity modals? Three solutions to such subset problems can be found in the literature: the first is for learners to rely on downward-entailing (DE) environments (Gualmini and Schwarz in J. Semant. 26(2):185–215, 2009); the second is a bias for strong (here, necessity) meanings; the third is for learners to rely on pragmatic cues stemming from the conversational context (Dieuleveut et al. in Proceedings of the 2019 Amsterdam colloqnium, pp. 111–122, 2019a; Rasin and Aravind in Nat. Lang. Semant. 29:339–375, 2020). This paper assesses the viability of each of these solutions by examining the modals used in speech to and by 2-year-old children, through a combination of corpus studies and experiments testing the guessability of modal force based on their context of use. Our results suggest that, given the way modals are used in speech to children, the first solution is not viable and the second is unnecessary. Instead, we argue that the conversational context in which modals occur is highly informative as to their force and sufficient, in principle, to sidestep the subset problem. Our child results further suggest an early mastery of possibility—but not necessity—modals and show no evidence for a necessity bias.

Abstract

Retrieval of autobiographical memories is facilitated by activation of perceptuo-motor aspects of the experience, for example a congruent body position at the time of the experiencing and the time of retelling (Dijkstra, Kaschak, & Zwaan, 2007). The present study examined whether similar retrieval facilitation occurs when the direction of motor action is congruent with the valence of emotional memories. Consistent with evidence that people mentally represent emotions spatially (Casasanto, in press), participants moved marbles between vertically stacked boxes at a higher rate when the direction of movement was congruent with the valence of the memory they retrieved (e.g., upward for positive memories, downward for negative memories) than when direction and valence were incongruent (t(22)=4.24, p<.001). In addition, valence-congruent movements facilitated access to these memories, resulting in shorter retrieval times (t(22)=2.43, p<.05). Results demonstrate bidirectional influences between the emotional content of autobiographical memories and irrelevant motor actions.

Abstract

To investigate how orthography and semantics interact during bilingual visual word recognition, Dutch–English bilinguals made lexical decisions in two masked priming experiments. Dutch primes and English targets were presented that were either neighbour cognates (boek – BOOK), noncognate translations (kooi – CAGE), orthographically related neighbours (neus – NEWS), or unrelated words (huid - COAT). Prime durations of 50 ms (Experiment 1) and 83 ms (Experiment 2) led to similar result patterns. Both experiments reported a large cognate facilitation effect, a smaller facilitatory noncognate translation effect, and the absence of inhibitory orthographic neighbour effects. These results indicate that cognate facilitation is in large part due to orthographic-semantic resonance. Priming results for each condition were simulated well (all r's >.50) by Multilink+, a recent computational model for word retrieval. Limitations to the role of lateral inhibition in bilingual word recognition are discussed.

Abstract

Age has a major effect on brain volume. However, the normative studies available are constrained by small sample sizes, restricted age coverage and significant methodological variability. These limitations introduce inconsistencies and may obscure or distort the lifespan trajectories of brain morphometry. In response, we capitalized on the resources of the Enhancing Neuroimaging Genetics through Meta‐Analysis (ENIGMA) Consortium to examine age‐related trajectories inferred from cross‐sectional measures of the ventricles, the basal ganglia (caudate, putamen, pallidum, and nucleus accumbens), the thalamus, hippocampus and amygdala using magnetic resonance imaging data obtained from 18,605 individuals aged 3–90 years. All subcortical structure volumes were at their maximum value early in life. The volume of the basal ganglia showed a monotonic negative association with age thereafter; there was no significant association between age and the volumes of the thalamus, amygdala and the hippocampus (with some degree of decline in thalamus) until the sixth decade of life after which they also showed a steep negative association with age. The lateral ventricles showed continuous enlargement throughout the lifespan. Age was positively associated with inter‐individual variability in the hippocampus and amygdala and the lateral ventricles. These results were robust to potential confounders and could be used to examine the functional significance of deviations from typical age‐related morphometric patterns.

Abstract

In this paper we discuss the influence of semantically unexpected information on the prosodic realization of contrast.
For this purpose, we examine the interplay between unexpectedness and various discourse factors that have been claimed to enhance the accentuation of contrastive
information: contrast direction, syntactic status, and discourse distance. We conducted a production experiment in Dutch in which speakers described scenes consisting of moving fruits with unnatural colors. We found that a general cognitive factor such as the unexpectedness of a property has a strong impact on the intonational marking of contrast, over and above the influence of the immediate discourse context.

Abstract

In this paper, we discuss the interplay of factors that influence the intonational marking of contrast in Dutch. In particular, we examine how prominence is expressed at the prosodic level when semantically abnormal information conflicts with contrastive information. For this purpose, we conducted a production experiment in Dutch in which speakers described scenes containing fruits with unnatural colors. We found that semantically abnormal information invokes cognitive prominence which corresponds to intonational prominence. Moreover, the results show that abnormality may overrule the accentual marking of information structural categories such as contrastive focus. If semantically abnormal information becomes integrated into the larger discourse context, its prosodic prominence decreases in favor of the signaling of information structural categories such as contrastive focus.

Abstract

Empirical studies addressing the age factor in second language acquisition have mainly been concerned with a comparison of end state data (from learners before and after the closure of a putative Critical Period for language acquisition) to the native speaker norm. Based on longitudinal corpus data, this paper investigates the affect of age on end state, rate and the process of acquisition and addresses the question of whether different grammatical domains are equally affected. To this end, the paper presents summarized findings from the acquisition of word order and inflectional morphology in L2 German by Russian learners of different ages and discusses theoretical implications that can be drawn from this evidence.

Abstract

It is widely assumed that ultimate attainment in adult second language (L2) learners often differs quite radically from ultimate attainment in child L2 learners. This article addresses the question of whether learners at different ages also show qualitative differences in the process of L2 acquisition. Longitudinal production data from two untutored Russian beginners (ages 8 and 14) acquiring German under roughly similar conditions are compared to published results on the acquisition of German by adult immigrants. The study focuses on the acquisition of negation and finiteness as core domains of German sentence grammar. Adult learners have been shown to produce an early nonfinite learner variety in which utterance organization relies on principles of information structure rather than on target language grammar. They then go through a couple of intermediate steps in which, first, semantically empty verbs (auxiliaries) serve as isolated carriers of finiteness before lexical verbs become finite. Whereas the 14-year-old learner of this case study basically shows a developmental pattern similar to that of adults, the 8-year-old child produces a different order of acquisition: Not only is the development of finite morphology faster, but finite lexical verbs are acquired before auxiliary constructions (Perfekt). Results suggest a stronger tendency for young learners to incrementally assimilate input patterns without relying on analytic steps guided by principles of information organization to the same extent as older learners.

Abstract

Continuers —words like mm, mmhm, uhum and the like— are among the most frequent types of responses in conversation. They play a key role in joint action coordination by showing positive evidence of understanding and scaffolding narrative delivery. Here we investigate the hypothesis that their functional importance along with their conversational ecology places selective pressures on their form and may lead to cross-linguistic similarities through convergent cultural evolution. We compare continuer tokens in linguistically diverse conversational corpora and find languages make available highly similar forms. We then approach the causal mechanism of convergent cultural evolution using exemplar modelling, simulating the process by which a combination of effort minimization and functional specialization may push continuers to a particular region of phonological possibility space. By combining comparative linguistics and computational modelling we shed new light on the question of how language structure is shaped by and for social interaction.

Abstract

Informal social interaction is the primordial home of human language. Linguistically diverse conversational corpora are an important and largely untapped resource for computational linguistics and language technology. Through the efforts of a worldwide language documentation movement, such corpora are increasingly becoming available. We show how interactional data from 63 languages (26 families) harbours insights about turn-taking, timing, sequential structure and social action, with implications for language technology, natural language understanding, and the design of conversational interfaces. Harnessing linguistically diverse conversational corpora will provide the empirical foundations for flexible, localizable, humane language technologies of the future.

Abstract

This entry provides some orientation and task suggestions on how to explore the perceptual world of your field site and the interaction between the cultural world and the sensory lexicon in your community. The material consists of procedural texts; soundscapes; other documentary and observational tasks. The goal of this task is to explore the perceptual world of your field site and the interaction between the cultural world and the sensory lexicon in your community.

Abstract

In conversation, people regularly deal with problems of speaking, hearing, and understanding. We report on a cross-linguistic investigation of the conversational structure of other-initiated repair (also known as collaborative repair, feedback, requests for clarification, or grounding sequences). We take stock of formats for initiating repair across languages (comparable to English huh?, who?, y’mean X?, etc.) and find that different languages make available a wide but remarkably similar range of linguistic resources for this function. We exploit the patterned variation as evidence for several underlying concerns addressed by repair initiation: characterising trouble, managing responsibility, and handling knowledge. The concerns do not always point in the same direction and thus provide participants in interaction with alternative principles for selecting one format over possible others. By comparing conversational structures across languages, this paper contributes to pragmatic typology: the typology of systems of language use and the principles that shape them.

Abstract

Ideophones (also known as expressives or mimetics, and including onomatopoeia) have been systematically studied in linguistics since the 1850s, when they were first described as a lexical class of vivid sensory words in West-African languages. This paper surveys the research history of ideophones, from its roots in African linguistics to its fruits in general linguistics and typology around the globe. It shows that despite a recurrent narrative of marginalisation, work on ideophones has made an impact in many areas of linguistics, from theories of phonological features to typologies of manner and motion, and from sound symbolism to sensory language. Due to their hybrid nature as gradient vocal gestures that grow roots in discrete linguistic systems, ideophones provide opportunities to reframe typological questions, reconsider the role of language ideology in linguistic scholarship, and rethink the margins of language. With ideophones increasingly being brought into the fold of the language sciences, this review synthesises past theoretical insights and empirical findings in order to enable future work to build on them.

Abstract

This thesis examines the semantic structures underlying the encoding of space in Chintang, a Kiranti (Sino-Tibetan) language of Nepal. It provides a short general introduction to the history of thinking and speaking about space as well as to the notions of deixis and transposition, and sketches a state-of-the-art theory for categorizing spatial semantics (Levinson 2003). Drawing on targeted elicitation with native speakers, the empirical part then relates linguistic items of Chintang to the theoretical framework, with a focus on the nominal domain. After an analysis of deictic, topological, intrinsic and absolute spatial relations and their reflections in the language, the investigation concludes by comparing sets of Chintang deictics to those found in neighbouring Belhare (Bickel 2001). Despite striking formal resemblances, the semantic differences found indicate that even across closely related languages, meaning does not generalize easily.

Abstract

Relationships among laurasiatherian clades represent one of the most highly disputed topics in mammalian phylogeny. In this study, we attempt to disentangle laurasiatherian interordinal relationships using two independent genome-level approaches: (1) quantifying retrotransposon presence/absence patterns, and (2) comparisons of exon datasets at the levels of nucleotides and amino acids. The two approaches revealed contradictory phylogenetic signals, possibly due to a high level of ancestral incomplete lineage sorting. The positions of Eulipotyphla and Chiroptera as the first and second earliest divergences were consistent across the approaches. However, the phylogenetic relationships of Perissodactyla, Cetartiodactyla, and Ferae, were contradictory. While retrotransposon insertion analyses suggest a clade with Cetartiodactyla and Ferae, the exon dataset favoured Cetartiodactyla and Perissodactyla. Future analyses of hitherto unsampled laurasiatherian lineages and synergistic analyses of retrotransposon insertions, exon and conserved intron/intergenic sequences might unravel the conflicting patterns of relationships in this major mammalian clade.

Abstract

People readily generalize knowledge to novel domains and stimuli. We present a theory, instantiated in a computational model, based on the idea that cross-domain generalization in humans is a case of analogical inference over structured (i.e., symbolic) relational representations. The model is an extension of the Learning and Inference with Schemas and Analogy (LISA; Hummel & Holyoak, 1997, 2003) and Discovery of Relations by Analogy (DORA; Doumas et al., 2008) models of relational inference and learning. The resulting model learns both the content and format (i.e., structure) of relational representations from nonrelational inputs without supervision, when augmented with the capacity for reinforcement learning it leverages these representations to learn about individual domains, and then generalizes to new domains on the first exposure (i.e., zero-shot learning) via analogical inference. We demonstrate the capacity of the model to learn structured relational representations from a variety of simple visual stimuli, and to perform cross-domain generalization between video games (Breakout and Pong) and between several psychological tasks. We demonstrate that the model’s trajectory closely mirrors the trajectory of children as they learn about relations, accounting for phenomena from the literature on the development of children’s reasoning and analogy making. The model’s ability to generalize between domains demonstrates the flexibility afforded by representing domains in terms of their underlying relational structure, rather than simply in terms of the statistical relations between their inputs and outputs.

Abstract

How a system represents information tightly constrains the kinds of problems it can solve. Humans routinely solve problems that appear to require structured representations of stimulus properties and the relations between them. An account of how we might acquire such representations has central importance for theories of human cognition. We describe how a system can learn structured relational representations from initially unstructured inputs using comparison, sensitivity to time, and a modified Hebbian learning algorithm. We summarize how the model DORA (Discovery of Relations by Analogy) instantiates this approach, which we call predicate learning, as well as how the model captures several phenomena from cognitive development, relational reasoning, and language processing in the human brain. Predicate learning offers a link between models based on formal languages and models which learn from experience and provides an existence proof for how structured representations might be learned in the first place.

Abstract

Reading and writing are crucial life skills but roughly one in ten children are affected by dyslexia, which can persist into adulthood. Family studies of dyslexia suggest heritability up to 70%, yet few convincing genetic markers have been found. Here we performed a genome-wide association study of 51,800 adults self-reporting a dyslexia diagnosis and 1,087,070 controls and identified 42 independent genome-wide significant loci: 15 in genes linked to cognitive ability/educational attainment, and 27 new and potentially more specific to dyslexia. We validated 23 loci (13 new) in independent cohorts of Chinese and European ancestry. Genetic etiology of dyslexia was similar between sexes, and genetic covariance with many traits was found, including ambidexterity, but not neuroanatomical measures of language-related circuitry. Dyslexia polygenic scores explained up to 6% of variance in reading traits, and might in future contribute to earlier identification and remediation of dyslexia.

Abstract

We here demonstrate that face-to-face spatial orientation induces a special ‘social mode’ for neurocognitive processing during conversation, even in the absence of visibility. Participants conversed face-to-face, face-to-face but visually occluded, and back-to-back to tease apart effects caused by seeing visual communicative signals and by spatial orientation. Using dual-EEG, we found that 1) listeners’ brains engaged more strongly while conversing in face-to-face than back-to-back, irrespective of the visibility of communicative signals, 2) listeners attended to speech more strongly in a back-to-back compared to a face-to-face spatial orientation without visibility; visual signals further reduced the attention needed; 3) the brains of interlocutors were more in sync in a face-to-face compared to a back-to-back spatial orientation, even when they could not see each other; visual signals further enhanced this pattern. Communicating in face-to-face spatial orientation is thus sufficient to induce a special ‘social mode’ which fine-tunes the brain for neurocognitive processing in conversation.

Abstract

A commentary on
Transcranial Magnetic Stimulation over Left Inferior Frontal and Posterior Temporal Cortex Disrupts Gesture-Speech Integration

by Zhao, W., Riggs, K., Schindler, I., and Holle, H. (2018). J. Neurosci. 10, 1748–1717. doi: 10.1523/JNEUROSCI.1748-17.2017

Abstract

Previous work revealed that visual semantic information conveyed by gestures can enhance degraded speech comprehension, but the mechanisms underlying these integration processes under adverse listening conditions remain poorly understood. We used MEG to investigate how oscillatory dynamics support speech–gesture integration when integration load is manipulated by auditory (e.g., speech degradation) and visual semantic (e.g., gesture congruency) factors. Participants were presented with videos of an actress uttering an action verb in clear or degraded speech, accompanied by a matching (mixing gesture + “mixing”) or mismatching (drinking gesture + “walking”) gesture. In clear speech, alpha/beta power was more suppressed in the left inferior frontal gyrus and motor and visual cortices when integration load increased in response to mismatching versus matching gestures. In degraded speech, beta power was less suppressed over posterior STS and medial temporal lobe for mismatching compared with matching gestures, showing that integration load was lowest when speech was degraded and mismatching gestures could not be integrated and disambiguate the degraded signal. Our results thus provide novel insights on how low-frequency oscillatory modulations in different parts of the cortex support the semantic audiovisual integration of gestures in clear and degraded speech: When speech is clear, the left inferior frontal gyrus and motor and visual cortices engage because higher-level semantic information increases semantic integration load. When speech is degraded, posterior STS/middle temporal gyrus and medial temporal lobe are less engaged because integration load is lowest when visual semantic information does not aid lexical retrieval and speech and gestures cannot be integrated.

Abstract

During face-to-face communication, listeners integrate speech with gestures. The semantic information conveyed by iconic gestures (e.g., a drinking gesture) can aid speech comprehension in adverse listening conditions. In this magnetoencephalography (MEG) study, we investigated the spatiotemporal neural oscillatory activity associated with gestural enhancement of degraded speech comprehension. Participants watched videos of an actress uttering clear or degraded speech, accompanied by a gesture or not and completed a cued-recall task after watching every video. When gestures semantically disambiguated degraded speech comprehension, an alpha and beta power suppression and a gamma power increase revealed engagement and active processing in the hand-area of the motor cortex, the extended language network (LIFG/pSTS/STG/MTG), medial temporal lobe, and occipital regions. These observed low- and high-frequency oscillatory modulations in these areas support general unification, integration and lexical access processes during online language comprehension, and simulation of and increased visual attention to manual gestures over time. All individual oscillatory power modulations associated with gestural enhancement of degraded speech comprehension predicted a listener's correct disambiguation of the degraded verb after watching the videos. Our results thus go beyond the previously proposed role of oscillatory dynamics in unimodal degraded speech comprehension and provide first evidence for the role of low- and high-frequency oscillations in predicting the integration of auditory and visual information at a semantic level.

Abstract

Native listeners neurally integrate iconic gestures with speech, which can enhance degraded speech comprehension. However, it is unknown how non-native listeners neurally integrate speech and gestures, as they might process visual semantic context differently than natives. We recorded EEG while native and highly-proficient non-native listeners watched videos of an actress uttering an action verb in clear or degraded speech, accompanied by a matching ('to drive'+driving gesture) or mismatching gesture ('to drink'+mixing gesture). Degraded speech elicited an enhanced N400 amplitude compared to clear speech in both groups, revealing an increase in neural resources needed to resolve the spoken input. A larger N400 effect was found in clear speech for non-natives compared to natives, but in degraded speech only for natives. Non-native listeners might thus process gesture more strongly than natives when speech is clear, but need more auditory cues to facilitate access to gestural semantic information when speech is degraded.

Abstract

Der vorliegende Beitrag zum Kieler Symposium1 stellt die Resultate eines Teilbereichs meiner Arbeit zum Guarani vor, nämlich einen Vorschlag zur Analyse der Personenpräfixe dieser Sprache und der mit ihnen verbundenen grammatischen Kategorien. Die im Titel angedeutete lexikographische Fragestellung bedarf einer näheren Erläuterung, die ich im Zusammenhang mit einer kurzen Darstellung der Motivation für meine Untersuchungen geben will

Abstract

With the present essay I pursue a threefold aim as will be explained in the following paragraphs. Since I cannot expect my readers to be familiar with the language studied, Guaran´ı, more information about this language will be given in the next subsection.

Abstract

1. Object: Awetí and the ‘Mawetí-Guaraní’ subfamily “Mawetí-Guaraní” is a shorter designation of a branch of the large Tupí language family, alongside with eight other branches or subfamilies. This branch in turn consists internally of the languages (Sateré-) Mawé and Awetí and the large Tupí-Guaraní subfamily, and so its explicit but longish name could be “Mawé-Awetí-Tupí-Guaraní” (MTAG). This genetic grouping has already been suggested (without any specific designation) by A. D. Rodrigues (e.g., 1984/85; Rodrigues and Dietrich 1997), and, more recently, it has been confirmed by comparative studies (Corrêa da Silva 2007; Drude 2006; Meira and Drude in prep.), which also more reliably establish the most probable internal ramification, according to which Mawé separated first, whereas the differentiation between Awetí, on the one hand, and the precursor of the Tupí-Guaraní (TG) subfamily, proto-Tupí-Guaraní (pTG), on the other, would have been more recent. The intermediate branch could be named “Awetí-Tupí-Guaraní” (“Awetí-TG” or “ATG”). Figure 1 shows the internal grouping of the Tupí family according to results of the Tupí Comparative Project under D. Moore at the Museu Goeldi (2000–2006).

Abstract

This paper describes the verbal Tense-Aspect-Mood system of Awetí (Tupian, Central Brazil) in a Word-and-Paradigm approach. One classification of Awetí verb forms contains clear aspect categories. A second set of independent classifications renders at least four moods and contains a third major TAM classification, factuality, that has one mainly temporal category Future, while others are partially or wholly modal. Structural categories reflect the formal composition of the forms. Some forms are synthetic, ‘marked’ only by means of affixes, but many are analytic, containing auxiliary particles. With selected sample forms we demonstrate in detail the interplay of structural and functional categories in Awetí verb paradigms.

Abstract

Biologically inspired spiking networks are an important tool to study the nature of computation and cognition in neural systems. In this work, we investigate the representational capacity of spiking networks engaged in an identity mapping task. We compare two schemes for encoding symbolic input, one in which input is injected as a direct current and one where input is delivered as a spatio-temporal spike pattern. We test the ability of networks to discriminate their input as a function of the number of distinct input symbols. We also compare performance using either membrane potentials or filtered spike trains as state variable. Furthermore, we investigate how the circuit behavior depends on the balance between excitation and inhibition, and the degree of synchrony and regularity in its internal dynamics. Finally, we compare different linear methods of decoding population activity onto desired target labels. Overall, our results suggest that even this simple mapping task is strongly influenced by design choices on input encoding, state-variables, circuit characteristics and decoding methods, and these factors can interact in complex ways. This work highlights the importance of constraining computational network models of behavior by available neurobiological evidence.

Abstract

The number of individuals affected by traumatic brain injury (TBI) is growing globally. TBIs may cause a range of physical, cognitive, and psychiatric deficits that can negatively impact employment, academic attainment, community independence, and interpersonal relationships. Although there has been a significant decrease in the number of injury related deaths over the past several decades, there has been no corresponding reduction in injury related disability over the same time period. We propose that patient registries with large, representative samples and rich multidimensional and longitudinal data have tremendous value in advancing basic and translational research and in capturing, characterizing, and predicting individual differences in deficit profile and outcomes. Patient registries, together with recent theoretical and methodological advances in analytic approaches and neuroscience, provide powerful tools for brain injury research and for leveraging the heterogeneity that has traditionally been cited as a barrier inhibiting progress in treatment research and clinical practice. We report on our experiences, and challenges, in developing and maintaining our own patient registry. We conclude by pointing to some future opportunities for discovery that are afforded by a registry model.

Abstract

Motricity is the most commonly affected ability after a stroke. While many clinical studies attempt to predict motor symptoms at different chronic time points after a stroke, longitudinal acute-to-chronic studies remain scarce. Taking advantage of recent advances in mapping brain disconnections, we predict motor outcomes in 62 patients assessed longitudinally two weeks, three months, and one year after their stroke. Results indicate that brain disconnection patterns accurately predict motor impairments. However, disconnection patterns leading to impairment differ between the three-time points and between left and right motor impairments. These results were cross-validated using resampling techniques. In sum, we demonstrated that while some neuroplasticity mechanisms exist changing the structure–function relationship, disconnection patterns prevail when predicting motor impairment at different time points after stroke.

Abstract

Numerous studies in psychology, cognitive neuroscience and psycholinguistics have used pictures of objects as stimulus materials. Currently, authors engaged in cross-linguistic work or wishing to run parallel studies at multiple sites where different languages are spoken must rely on rather small sets of black-and-white or colored line drawings. These sets are increasingly experienced as being too limited. Therefore, we constructed a new set of 750 colored pictures of concrete concepts. This set, MultiPic, constitutes a new valuable tool for cognitive scientists investigating language, visual perception, memory and/or attention in monolingual or multilingual populations. Importantly, the MultiPic databank has been normed in six different European languages (British English, Spanish, French, Dutch, Italian and German). All stimuli and norms are freely available at http://www.bcbl.eu/databases/multipic

Abstract

Understanding cetacean distribution is essential for conservation planning and decision-making, particularly in regions subject to rapid environmental changes. Nevertheless, information on their spatiotemporal distribution is commonly limited, especially from remote areas. Species distribution models (SDMs) are powerful tools, relating species occurrences to environmental variables to predict the species' potential distribution. This study aims at using presence-only SDMs (MaxEnt) to identify suitable habitats for fin whales (Balaenoptera physalus) on their Nordic and Barents Seas feeding grounds. We used spatial-block cross-validation to tune MaxEnt parameters and evaluate model performance using spatially independent testing data. We considered spatial sampling bias correction using four methods. Important environmental variables were distance to shore and sea ice edge, variability of sea surface temperature and sea surface salinity, and depth. Suitable fin whale habitats were predicted along the west coast of Svalbard, between Svalbard and the eastern Norwegian Sea, coastal areas off Iceland and southern East Greenland, and along the Knipovich Ridge to Jan Mayen. Results support that presence-only SDMs are effective tools to predict cetacean habitat suitability, particularly in remote areas like the Arctic Ocean. SDMs constitute a cost-effective method for targeting future surveys and identifying top priority sites for conservation measures.

Abstract

Using various methods derived from evolutionary biology, including maximum parsimony and Bayesian phylogenetic analysis, we tackle the question of the relationships among a group of Papuan isolate languages that have hitherto resisted accepted attempts at demonstration of interrelatedness. Instead of using existing vocabulary-based methods, which cannot be applied to these languages due to the paucity of shared lexemes, we created a database of STRUCTURAL FEATURES—abstract phonological and grammatical features apart from their form. The methods are first tested on the closely related Oceanic languages spoken in the same region as the Papuan languages in question. We find that using biological methods on structural features can recapitulate the results of the comparative method tree for the Oceanic languages, thus showing that structural features can be a valid way of extracting linguistic history. Application of the same methods to the otherwise unrelatable Papuan languages is therefore likely to be similarly valid. Because languages that have been in contact for protracted periods may also converge, we outline additional methods for distinguishing convergence from inherited relatedness.

Abstract

It is often argued that narratives improve social cognition, either by appealing to social-cognitive abilities as we engage with the story world and its characters, or by conveying social knowledge. Empirical studies have found support for both a correlational and a causal link between exposure to (literary, fictional) narratives and social cognition. However, a series of failed replications has cast doubt on the robustness of these claims. Here, we review the existing empirical literature and identify open questions and challenges. An important conclusion of the review is that previous research has given too little consideration to the diversity of narratives, readers, and social-cognitive processes involved in the social-cognitive potential of narratives. We therefore establish a research agenda, proposing that future research should focus on (1) the specific text characteristics that drive the social-cognitive potential of narratives, (2) the individual differences between readers with respect to their sensitivity to this potential, and (3) the various aspects of social cognition that are potentially affected by reading narratives. Our recommendations can guide the design of future studies that will help us understand how, for whom, and in what respect exposure to narratives can advantage social cognition.

Abstract

While the importance of mental simulation during literary reading has long been recognized, we know little about the factors that determine when, what, and how much readers mentally simulate. Here we investigate the influence of a specific text characteristic, namely verb tense (present vs. past), on mental simulation during literary reading. Verbs usually denote the actions and events that take place in narratives and hence it is hypothesized that verb tense will influence the amount of mental simulation elicited in readers. Although the present tense is traditionally considered to be more “vivid”, this study is one of the first to experimentally assess this claim. We recorded eye-movements while subjects read stories in the past or present tense and collected data regarding self-reported levels of mental simulation, transportation and appreciation. We found no influence of tense on any of the offline measures. The eye-tracking data showed a slightly more complex pattern. Although we did not find a main effect of sensorimotor simulation content on reading times, we were able to link the degree to which subjects slowed down when reading simulation eliciting content to offline measures of attention and transportation, but this effect did not interact with the tense of the story. Unexpectedly, we found a main effect of tense on reading times per word, with past tense stories eliciting longer first fixation durations and gaze durations. However, we were unable to link this effect to any of the offline measures. In sum, this study suggests that tense does not play a substantial role in the process of mental simulation elicited by literary stories.

Abstract

Predictive language processing is often studied by measuring eye movements as participants look at objects on a computer screen while they listen to spoken sentences. The use of this variant of the visual world paradigm has shown that information encountered by a listener at a spoken verb can give rise to anticipatory eye movements to a target object, which is taken to indicate that people predict upcoming words. The ecological validity of such findings remains questionable, however, because these computer experiments used two-dimensional (2D) stimuli that are mere abstractions of real world objects. Here we present a visual world paradigm study in a three-dimensional (3D) immersive virtual reality environment. Despite significant changes in the stimulus material and the different mode of stimulus presentation, language-mediated anticipatory eye movements were observed. These findings thus indicate prediction of upcoming words in language comprehension in a more naturalistic setting where natural depth cues are preserved. Moreover, the results confirm the feasibility of using eye-tracking in rich and multimodal 3D virtual environments.

Abstract

We present a dataset of behavioural and fMRI observations acquired in the context of humans involved in multimodal referential communication. The dataset contains audio/video and motion-tracking recordings of face-to-face, task-based communicative interactions in Dutch, as well as behavioural and neural correlates of participants’ representations of dialogue referents. Seventy-one pairs of unacquainted participants performed two interleaved interactional tasks in which they described and located 16 novel geometrical objects (i.e., Fribbles) yielding spontaneous interactions of about one hour. We share high-quality video (from three cameras), audio (from head-mounted microphones), and motion-tracking (Kinect) data, as well as speech transcripts of the interactions. Before and after engaging in the face-to-face communicative interactions, participants’ individual representations of the 16 Fribbles were estimated. Behaviourally, participants provided a written description (one to three words) for each Fribble and positioned them along 29 independent conceptual dimensions (e.g., rounded, human, audible). Neurally, fMRI signal evoked by each Fribble was measured during a one-back working-memory task. To enable functional hyperalignment across participants, the dataset also includes fMRI measurements obtained during visual presentation of eight animated movies (35 minutes total). We present analyses for the various types of data demonstrating their quality and consistency with earlier research. Besides high-resolution multimodal interactional data, this dataset includes different correlates of communicative referents, obtained before and after face-to-face dialogue, allowing for novel investigations into the relation between communicative behaviours and the representational space shared by communicators. This unique combination of data can be used for research in neuroscience, psychology, linguistics, and beyond.

Abstract

How involved in an event is a person that possesses one of the event participants? Some languages can treat such “external possessors” as very closely involved, even marking them on the verb along with core roles such as subject and object. Other languages only allow possessors to be expressed as non-core participants. This task explores possibilities for the encoding of possessors and other related roles such as beneficiaries. The materials consist of a sequence of thirty drawings designed to elicit target construction types.