Publications

Abstract

Although previous work on viewpoint techniques has shown that viewpoint is ubiquitous in narrative discourse, approaches to identify and analyze the linguistic manifestations of viewpoint are currently scattered over different disciplines and dominated by qualitative methods. This article presents the ViewPoint Identification Procedure (VPIP), the first systematic method for the lexical identification of markers of perceptual, cognitive and emotional viewpoint in narrative discourse. Use of this step-wise procedure is facilitated by a large appendix of Dutch viewpoint markers. After the introduction of the procedure and discussion of some special cases, we demonstrate its application by discussing three types of narrative excerpts: a literary narrative, a news narrative, and an oral narrative. Applying the identification procedure to the full news narrative, we show that the VPIP can be reliably used to detect viewpoint markers in long stretches of narrative discourse. As such, the systematic identification of viewpoint has the potential to benefit both established viewpoint scholars and researchers from other fields interested in the analytical and experimental study of narrative and viewpoint. Such experimental studies could complement qualitative studies, ultimately advancing our theoretical understanding of the relation between the linguistic presentation and cognitive processing of viewpoint. Suggestions for elaboration of the VPIP, particularly in the realm of pragmatic viewpoint marking, are formulated in the final part of the paper.

Abstract

Visual reaction times to target pictures after naming events are an informative measurement in language acquisition research, because gaze shifts measured in looking-while-listening paradigms are an indicator of infants’ lexical speed of processing. This measure is very useful, as it can be applied from a young age onwards and has been linked to later language development. However, to obtain valid reaction times, the infant is required to switch the fixation of their eyes from a distractor to a target object. This means that usually at least half the trials have to be discarded—those where the participant is already fixating the target at the onset of the target word—so that no reaction time can be measured. With few trials, reliability suffers, which is especially problematic when studying individual differences. In order to solve this problem, we developed a gaze-triggered looking-while-listening paradigm. The trials do not differ from the original paradigm apart from the fact that the target object is chosen depending on the infant’s eye fixation before naming. The object the infant is looking at becomes the distractor and the other object is used as the target, requiring a fixation switch, and thus providing a reaction time. We tested our paradigm with forty-three 18-month-old infants, comparing the results to those from the original paradigm. The Gaze-triggered paradigm yielded more valid reaction time trials, as anticipated. The results of a ranked correlation between the conditions confirmed that the manipulated paradigm measures the same concept as the original paradigm.

Abstract

During silent problem solving, hand gestures arise that have no communicative intent. The role of such co-thought gestures in
cognition has been understudied in cognitive research as compared to co-speech gestures. We investigated whether gesticulation
during silent problem solving supported subsequent performance in a Tower of Hanoi problem-solving task, in relation
to visual working-memory capacity and task complexity. Seventy-six participants were assigned to either an instructed gesture
condition or a condition that allowed them to gesture, but without explicit instructions to do so. This resulted in three
gesture groups: (1) non-gesturing; (2) spontaneous gesturing; (3) instructed gesturing. In line with the embedded/extended
cognition perspective on gesture, gesturing benefited complex problem-solving performance for participants with a lower
visual working-memory capacity, but not for participants with a lower spatial working-memory capacity.

Abstract

Purpose

In healthy speakers, the more frequent and probable a word is in its context, the shorter the word tends to be. This study investigated whether these probabilistic effects were similarly sized for speakers with dysarthria of different severities.
Method

Fifty-six speakers of New Zealand English (42 speakers with dysarthria and 14 healthy speakers) were recorded reading the Grandfather Passage. Measurements of word duration, frequency, and transitional word probability were taken.
Results

As hypothesized, words with a higher frequency and probability tended to be shorter in duration. There was also a significant interaction between word frequency and speech severity. This indicated that the more severe the dysarthria, the smaller the effects of word frequency on speakers' word durations. Transitional word probability also interacted with speech severity, but did not account for significant unique variance in the full model.
Conclusions

These results suggest that, as the severity of dysarthria increases, the duration of words is less affected by probabilistic variables. These findings may be due to reductions in the control and execution of muscle movement exhibited by speakers with dysarthria.

Abstract

Previous studies have shown that speakers align their speech to each other at multiple linguistic levels. This study investigates whether alignment is mostly the result of priming from the immediately preceding
speech materials, focussing on pitch and articulation rate (AR). Native Dutch speakers completed sentences, first by themselves (pre-test), then in alternation with Confederate 1 (Round 1), with Confederate 2 (Round 2), with Confederate 1 again
(Round 3), and lastly by themselves again (post-test). Results indicate that participants aligned to the confederates and that this alignment lasted during the post-test. The confederates’ directly preceding sentences were not good predictors for the participants’ pitch and AR. Overall, the results indicate that alignment is more of a global effect than a local priming effect.

Abstract

Genetic investigations of people with impaired development of spoken language provide windows into key aspects of human biology. Over 15 years after FOXP2 was identified, most speech and language impairments remain unexplained at the molecular level. We sequenced whole genomes of nineteen unrelated individuals diagnosed with childhood apraxia of speech, a rare disorder enriched for causative mutations of large effect. Where DNA was available from unaffected parents, we discovered de novo mutations, implicating genes, including CHD3, SETD1A and WDR5. In other probands, we identified novel loss-of-function variants affecting KAT6A, SETBP1, ZFHX4, TNRC6B and MKL2, regulatory genes with links to neurodevelopment. Several of the new candidates interact with each other or with known speech-related genes. Moreover, they show significant clustering within a single co-expression module of genes highly expressed during early human brain development. This study highlights gene regulatory pathways in the developing brain that may contribute to acquisition of proficient speech.

Abstract

Predictions of our sensory environment facilitate perception across domains. During speech perception, formal and temporal predictions may be made for phonotactic probability and syllable stress patterns, respectively, contributing to the efficient processing of speech input. The current experiment employed a passive EEG oddball paradigm to probe the neurophysiological processes underlying temporal and formal predictions simultaneously. The component of interest, the mismatch negativity (MMN), is considered a marker for experience-dependent change detection, where its timing and amplitude are indicative of the perceptual system’s sensitivity to presented stimuli. We hypothesized that more predictable stimuli (i.e. high phonotactic probability and first syllable stress) would facilitate change detection, indexed by shorter peak latencies or greater peak amplitudes of the MMN. This hypothesis was confirmed for phonotactic probability: high phonotactic probability deviants elicited an earlier MMN than low phonotactic probability deviants. We do not observe a significant modulation of the MMN to variations in syllable stress. Our findings confirm that speech perception is shaped by formal and temporal predictability. This paradigm may be useful to investigate the contribution of implicit processing of statistical regularities during (a)typical language development.

Abstract

This chapter discusses some of the elements of human sociality that serve as the social and cognitive infrastructure or preconditions for the use of requests and other kinds of recruitments in interaction. The notion of an agent with goals is a canonical starting point, though importantly agency tends not to be wholly located in individuals, but rather is socially distributed. This is well illustrated in the case of requests, in which the person or group that has a certain goal is not necessarily the one who carries out the behavior towards that goal. The chapter focuses on the role of semiotic (mostly linguistic) resources in negotiating the distribution of agency with request-like actions, with examples from video-recorded interaction in Lao, a language spoken in Laos and nearby countries. The examples illustrate five hallmarks of requesting in human interaction, which show some ways in which our ‘manipulation’ of other people is quite unlike our manipulation of tools: (1) that even though B is being manipulated, B wants to help, (2) that while A is manipulating B now, A may be manipulated in return later; (3) that the goal of the behavior may be shared between A and B, (4) that B may not comply, or may comply differently than requested, due to actual or potential contingencies, and (5) that A and B are accountable to one another; reasons may be asked for, and/or given, for the request. These hallmarks of requesting are grounded in a prosocial framework of human agency.

Abstract

What causes a language to be the way it is? Some features are universal, some are inherited, others are borrowed, and yet others are internally innovated. But no matter where a bit of language is from, it will only exist if it has been diffused and kept in circulation through social interaction in the history of a community. This book makes the case that a proper understanding of the ontology of language systems has to be grounded in the causal mechanisms by which linguistic items are socially transmitted, in communicative contexts. A biased transmission model provides a basis for understanding why certain things and not others are likely to develop, spread, and stick in languages. Because bits of language are always parts of systems, we also need to show how it is that items of knowledge and behavior become structured wholes. The book argues that to achieve this, we need to see how causal processes apply in multiple frames or 'time scales' simultaneously, and we need to understand and address each and all of these frames in our work on language. This forces us to confront implications that are not always comfortable: for example, that "a language" is not a real thing but a convenient fiction, that language-internal and language-external processes have a lot in common, and that tree diagrams are poor conceptual tools for understanding the history of languages. By exploring avenues for clear solutions to these problems, this book suggests a conceptual framework for ultimately explaining, in causal terms, what languages are like and why they are like that.

Abstract

How do people answer polar questions? In this fourteen-language study of answers to questions in conversation, we compare the two main strategies; first, interjection-type answers such as uh-huh (or equivalents yes, mm, head nods, etc.), and second, repetition-type answers that repeat some or all of the question. We find that all languages offer both options, but that there is a strong asymmetry in their frequency of use, with a global preference for interjection-type answers. We propose that this preference is motivated by the fact that the two options are not equivalent in meaning. We argue that interjection-type answers are intrinsically suited to be the pragmatically unmarked, and thus more frequent, strategy for confirming polar questions, regardless of the language spoken. Our analysis is based on the semantic-pragmatic profile of the interjection-type and repetition-type answer strategies, in the context of certain asymmetries inherent to the dialogic speech act structure of question–answer sequences, including sequential agency and thematic agency. This allows us to see possible explanations for the outlier distributions found in ǂĀkhoe Haiǁom and Tzeltal.

Abstract

Over the decades, high-intensity language learners scattered over the globe referred to as “hyperpolyglots” have undertaken a natural experiment into the limits of learning and acquiring proficiencies in multiple languages. This chapter details several ways in which hyperpolyglots are relevant to research on aptitude. First, historical hyperpolyglots Cardinal Giuseppe Mezzofanti, Emil Krebs, Elihu Burritt, and Lomb Kató are described in terms of how they viewed their own exceptional outcomes. Next, I draw on results from an online survey with 390 individuals to explore how contemporary hyperpolyglots consider the explanatory value of aptitude. Third, the challenges involved in studying the genetic basis of hyperpolyglottism (and by extension of language aptitude) are discussed. This mosaic of data is meant to inform the direction of future aptitude research that takes hyperpolyglots, one type of exceptional language learner and user, into account.

Abstract

Acoustic reduction refers to the frequent phenomenon in conversational speech that words are produced with fewer or lenited segments compared to their citation forms. The few published studies on the production and comprehension of acoustic reduction have important implications for the debate on the relevance of abstractions and exemplars in speech processing. This article discusses these implications. It first briefly introduces the key assumptions of simple abstractionist and simple exemplar-based models. It then discusses the literature on acoustic reduction and draws the conclusion that both types of models need to be extended to explain all findings. The ultimate model should allow for the storage of different pronunciation variants, but also reserve an important role for phonetic implementation. Furthermore, the recognition of a highly reduced pronunciation variant requires top down information and leads to activation of the corresponding unreduced variant, the variant that reaches listeners’ consciousness. These findings are best accounted for in hybrids models, assuming both abstract representations and exemplars. None of the hybrid models formulated so far can account for all data on reduced speech and we need further research for obtaining detailed insight into how speakers produce and listeners comprehend reduced speech.

Abstract

This article introduces a new speech corpus, the Nijmegen Corpus of Casual Czech (NCCCz), which contains more than 30 hours of high-quality recordings of casual conversations in Common Czech, among ten groups of three male and ten groups of three female friends. All speakers were native speakers of Czech, raised in Prague or in the region of Central Bohemia, and were between 19 and 26 years old. Every group of speakers consisted of one confederate, who was instructed to keep the conversations lively, and two speakers naive to the purposes of the recordings. The naive speakers were engaged in conversations for approximately 90 minutes, while the confederate joined them for approximately the last 72 minutes. The corpus was orthographically annotated by experienced transcribers and this orthographic transcription was aligned with the speech signal. In addition, the conversations were videotaped. This corpus can form the basis for all types of research on casual conversations in Czech, including phonetic research and research on how to improve automatic speech recognition. The corpus will be freely available

Abstract

When we have spoken conversations, it is usually in the context of competing sounds within our environment. Speech can be masked by many different kinds of sounds, for example, machinery noise and the speech of others, and these different sounds place differing demands on cognitive resources. In this talk, I will present data from a series of functional magnetic resonance imaging (fMRI) studies in which the informational properties of background sounds have been manipulated to make them more or less similar to speech. I will demonstrate the neural effects associated with speaking over and listening to these sounds, and demonstrate how in perception these effects are modulated by the age of the listener. The results will be interpreted within a framework of auditory processing developed from primate neurophysiology and human functional imaging work (Rauschecker and Scott 2009).

Abstract

A principal components analysis of the ten scales of the Worry Questionnaire revealed the existence of major worry factors or domains of social evaluation and physical threat, and these factors were confirmed in a subsequent item analysis. Those high in trait anxiety had much higher scores on the Worry Questionnaire than those low in trait anxiety, especially on those scales relating to social evaluation. Scores on the Marlowe-Crowne Social Desirability Scale were negatively related to worry frequency. However, groups of low-anxious and repressed individucores did not differ in worry. It was concluded that worry, especals formed on the basis of their trait anxiety and social desirability sially in the social evaluation domain, is of fundamental importance to trait anxiety.

Abstract

Decades of research have established that the content of language (e.g. lexical characteristics of words) predicts eye movements during reading. Here we investigate whether there exist individual differences in ‘stable’ eye movement patterns during narrative reading. We computed Euclidean distances from correlations between gaze durations time courses (word level) across 102 participants who each read three literary narratives in Dutch. The resulting distance matrices were compared between narratives using a Mantel test. The results show that correlations between the scaling matrices of different narratives are relatively weak (r ≤ .11) when missing data points are ignored. However, when including these data points as zero durations (i.e. skipped words), we found significant correlations between stories (r > .51). Word skipping was significantly positively associated with print exposure but not with self-rated attention and story-world absorption, suggesting that more experienced readers are more likely to skip words, and do so in a comparable fashion. We interpret this finding as suggesting that word skipping might be a stable individual eye movement pattern.

Abstract

The oldest of the Celtic language family, Irish differs considerably from English, notably with respect to word order and case marking. In spite of differences in surface constituent structure, less restricted accounts of bilingual shared syntax predict that processing datives and passives in Irish should prime the production of their English equivalents. Furthermore, this cross-linguistic influence should be sensitive to L2 proficiency, if shared structural representations are assumed to develop over time. In Experiment 1, we investigated cross-linguistic structural priming from Irish to English in 47 bilingual adolescents who are educated through Irish. Testing took place in a classroom setting, using written primes and written sentence generation. We found that priming for prepositional-object (PO) datives was predicted by self-rated Irish (L2) proficiency, in line with previous studies. In Experiment 2, we presented translations of the materials to an English-educated control group (n=54). We found a within-language priming effect for PO datives, which was not modulated by English (L1) proficiency. Our findings are compatible with current theories of bilingual language processing and L2 syntactic acquisition.

Abstract

Error-based theories of language acquisition suggest that children, like adults, continuously make and evaluate predictions in order to reach an adult-like state of language use. However, while these theories have become extremely influential, their central claim - that unpredictable
input leads to higher rates of lasting change in linguistic representations – has scarcely been
tested. We designed a prime surprisal-based intervention study to assess this claim.
As predicted, both 5- to 6-year-old children (n=72) and adults (n=72) showed a pre- to post-test shift towards producing the dative syntactic structure they were exposed to in surprising sentences. The effect was significant in both age groups together, and in the child group separately when participants with ceiling performance in the pre-test were excluded. Secondary
predictions were not upheld: we found no verb-based learning effects and there was only reliable evidence for immediate prime surprisal effects in the adult, but not in the child group. To our knowledge this is the first published study demonstrating enhanced learning rates for the same syntactic structure when it appeared in surprising as opposed to predictable contexts, thus
providing crucial support for error-based theories of language acquisition.

Abstract

Strong and weak syllables in English can be distinguished on the basis of vowel quality, of stress, or of both factors. Critical for deciding between these factors are syllables containing unstressed unreduced vowels, such as the first syllable of automata. In this study 12 speakers produced sentences containing matched sets of words with initial vowels ranging from stressed to reduced, at normal and at fast speech rates. Measurements of the duration, intensity, F0, and spectral characteristics of the word-initial vowels showed that unstressed unreduced vowels differed significantly from both stressed and reduced vowels. This result held true across speaker sex and dialect. The vowels produced by one speaker were then cross-spliced across the words within each set, and the resulting words' acceptability was rated by listeners. In general, cross-spliced words were only rated significantly less acceptable than unspliced words when reduced vowels interchanged with any other vowel. Correlations between rated acceptability and acoustic characteristics of the cross-spliced words demonstrated that listeners were attending to duration, intensity, and spectral characteristics. Together these results suggest that unstressed unreduced vowels in English pattern differently from both stressed and reduced vowels, so that no acoustic support for a binary categorical distinction exists; nevertheless, listeners make such a distinction, grouping unstressed unreduced vowels by preference with stressed vowels

Abstract

This paper shows that the dictation task, a well-
known testing instrument in language education, has
untapped potential as a research tool for studying
speech perception. We describe how transcriptions
can be scored on measures of lexical, orthographic,
phonological, and semantic similarity to target
phrases to provide comprehensive information about
accuracy at different processing levels. The former
three measures are automatically extractable,
increasing objectivity, and the middle two are
gradient, providing finer-grained information than
traditionally used. We evaluate the measures in an
English dictation task featuring phonetically reduced
continuous speech. Whereas the lexical and
orthographic measures emphasize listeners’ word
identification difficulties, the phonological measure
demonstrates that listeners can often still recover
phonological features, and the semantic measure
captures their ability to get the gist of the utterances.
Correlational analyses and a discussion of practical
and theoretical considerations show that combining
multiple measures improves the dictation task’s
utility as a research tool.

Abstract

Lexically guided perceptual learning has traditionally been studied with ambiguous consonant sounds to which native listeners are exposed in a purely receptive listening context. To extend previous research, we investigate whether lexically guided learning applies to a vowel shift encountered by non-native listeners in an interactive dialogue. Dutch participants played a two-player game in English in either a control condition, which contained no evidence for a vowel shift, or a lexically constraining condition, in which onscreen lexical information required them to re-interpret their interlocutor’s /ɪ/ pronunciations as representing /ε/. A phonetic categorization pre-test and post-test were used to assess whether the game shifted listeners’ phonemic boundaries such that more of the /ε/-/ɪ/ continuum came to be perceived as /ε/. Both listener groups showed an overall post-test shift toward /ɪ/, suggesting that vowel perception may be sensitive to directional biases related to properties of the speaker’s vowel space. Importantly, listeners in the lexically constraining condition made relatively more post-test /ε/ responses than the control group, thereby exhibiting an effect of lexically guided adaptation. The results thus demonstrate that non-native listeners can adjust their phonemic boundaries on the basis of lexical information to accommodate a vowel shift learned in interactive conversation.

Abstract

When speaking in any language, speakers must conceptualize what they want to say before they can formulate and articulate their message. We present two experiments employing a novel experimental paradigm in which the formulating and articulating stages of speech production were kept identical across conditions of differing conceptualizing difficulty. We tracked the effect of difficulty in conceptualizing during the generation of speech (Experiment 1) and during the abandonment and regeneration of speech (Experiment 2) on speaking fluency by Dutch native speakers in their first (L1) and second (L2) language (English). The results showed that abandoning and especially regenerating a speech plan taxes the speaker, leading to disfluencies. For most fluency measures, the increases in disfluency were similar across L1 and L2. However, a significant interaction revealed that abandoning and regenerating a speech plan increases the time needed to solve conceptual difficulties while speaking in the L2 to a greater degree than in the L1. This finding supports theories in which cognitive resources for conceptualizing are shared with those used for later stages of speech planning. Furthermore, a practical implication for language assessment is that increasing the conceptual difficulty of speaking tasks should be considered with caution.

Abstract

The impact of language impairment on the clinical assessment of patients suffering from disorders of consciousness (DOC) is unknown or underestimated, and may mask the presence of conscious behavior. In a group of DOC patients (n=11; time post-injury range:5-252 months), we investigated the main neural functional and structural underpinnings of linguistic processing, and their relationship with the behavioral measures of the auditory function, using the Coma Recovery Scale-Revised (CRS-R). We assessed the integrity of the brainstem auditory pathways, of the left superior temporal gyrus and arcuate fasciculus, the neural activity elicited by passive listening of an auditory language task and the mean hemispheric glucose metabolism.
Our results support the hypothesis of a relationship between the level of preservation of the investigated structures/functions and the CRS-R auditory subscale scores.
Moreover, our findings indicate that patients in minimally conscious state minus (MCS-): 1) when presenting the \emph{auditory startle} (at the CRS-R auditory subscale) might be aphasic in the receptive domain, being severely impaired in the core language structures/functions; 2) when presenting the \emph{localization to sound} might retain language processing, being almost intact or intact in the core language structures/functions. Despite the small group of investigated patients, our findings provide a grounding of the clinical measures of the CRS-R auditory subscale in the integrity of the underlying auditory structures/functions. Future studies are needed to confirm our results that might have important consequences for the clinical practice.

Abstract

A large literature in social neuroscience has associated the medial prefrontal cortex (mPFC) with the processing of self-related information. However, only recently have social neuroscience studies begun to consider the large behavioral literature showing a strong self-positivity bias, and these studies have mostly focused on its correlates during self-related judgments and decision making. We carried out a functional MRI (fMRI) study to ask whether the mPFC would show effects of the self-positivity bias in a paradigm that probed participants’ self-concept without any requirement of explicit self-judgment. We presented social vignettes that were either self-relevant or non-self-relevant with a neutral, positive, or negative outcome described in the second sentence. In previous work using event-related potentials, this paradigm has shown evidence of a self-positivity bias that influences early stages of semantically processing incoming stimuli. In the present fMRI study, we found evidence for this bias within the mPFC: an interaction between self-relevance and valence, with only positive scenarios showing a self vs other effect within the mPFC. We suggest that the mPFC may play a role in maintaining a positively-biased self-concept and discuss the implications of these findings for the social neuroscience of the self and the role of the mPFC.

Abstract

With the aim to clarify the definition of humans as “linguistic animals”, in the present paper I functionally distinguish three types of language competences: i) language as a general biological tool for communication, ii) “perceptual syntax”, iii) propositional language. Following this terminological distinction, I review pivotal findings on animals' communication systems, which constitute useful evidence for the investigation of the nature of three core components of humans' faculty of language: semantics, syntax, and theory of mind. In fact, despite the capacity to process and share utterances with an open-ended structure is uniquely human, some isolated components of our linguistic competence are in common with nonhuman animals. Therefore, as I argue in the present paper, the investigation of animals' communicative competence provide crucial insights into the range of cognitive constraints underlying humans' ability of language, enabling at the same time the analysis of its phylogenetic path as well as of the selective pressures that have led to its emergence.

Abstract

The aim of this study is to investigate the word-learning phenomenon utilizing a new model that integrates three processes: a) extracting a word out of a continuous sounds sequence, b) inducing referential meanings, c) mapping a word onto its intended referent, with the possibility to extend the acquired word over a potentially infinite sets of objects of the same semantic category, and over not-previously-heard utterances. Previous work has examined the role of statistical learning and/or of prosody in each of these processes separately. In order to examine the multilayered word-learning task, we integrate these two strands of investigation into a single approach. We have conducted the study on adults and included six different experimental conditions, each including specific perceptual manipulations of the signal. In condition 1, the only cue to word-meaning mapping was the co-occurrence between words and referents (“statistical cue”). This cue was present in all the conditions. In condition 2, we added infant-directed-speech (IDS) typical pitch enhancement as a marker of the target word and of the statistical cue. In condition 3 we placed IDS typical pitch enhancement on random words of the utterances, i.e. inconsistently matching the statistical cue. In conditions 4, 5 and 6 we manipulated respectively duration, a non-prosodic acoustic cue and a visual cue as markers of the target word and of the statistical cue. Systematic comparisons between learning performance in condition 1 with the other conditions revealed that the word-learning process is facilitated only when pitch prominence consistently marks the target word and the statistical cue…

Abstract

This study investigates word-learning using a new experimental paradigm that integrates three processes: (a) extracting a word out of a continuous sound sequence, (b) inferring its referential meanings in context, (c) mapping the segmented word onto its broader intended referent, such as other objects of the same semantic category, and to novel utterances. Previous work has examined the role of statistical learning and/or of prosody in each of these processes separately. Here, we combine these strands of investigation into a single experimental approach, in which participants viewed a photograph belonging to one of three semantic categories while hearing a complex, five-word utterance containing a target word. Six between-subjects conditions were tested with 20 adult participants each. In condition 1, the only cue to word-meaning mapping was the co-occurrence of word and referents. This statistical cue was present in all conditions. In condition 2, the target word was sounded at a higher pitch. In condition 3, random words were sounded at a higher pitch, creating an inconsistent cue. In condition 4, the duration of the target word was lengthened. In conditions 5 and 6, an extraneous acoustic cue and a visual cue were associated with the target word, respectively. Performance in this word-learning task was significantly higher than that observed with simple co-occurrence only when pitch prominence consistently marked the target word. We discuss implications for the pragmatic value of pitch marking as well as the relevance of our findings to language acquisition and language evolution.

Abstract

We have constructed two YAC contigs in the Xp11.23-p11.22 interval of the human X chromosome, a region that was previously poorly characterized. One contig, of at least 1.4 Mb, links the pseudogene OATL1 to the genes GATA1, TFE3, and SYP and also contains loci implicated in Wiskott-Aldrich syndrome and synovial sarcoma. A second contig, mapping proximal to the first, is estimated to be over 2.1 Mb and links the hypervariable locus DXS255 to DXS146, and also contains a chloride channel gene that is responsible for hereditary nephrolithiasis. We have used plasmid rescue, inverse PCR, and Alu-PCR to generate 20 novel markers from this region, 1 of which is polymorphic, and have positioned these relative to one another on the basis of YAC analysis. The order of previously known markers within our contigs, Xpter-OATL1-GATA-TFE3-SYP-DXS255146- Xcen, agrees with genomic pulsed-field maps of the region. In addition, we have constructed a rare-cutter restriction map for a 710-kb region of the DXS255-DXS146 contig and have identified three CPG islands. These contigs and new markers will provide a useful resource for more detailed analysis of Xp11.23-p11.22, a region implicated in several genetic diseases.

Abstract

Dent disease, an X-linked familial renal tubular disorder, is a form of Fanconi syndrome associated with proteinuria, hypercalciuria, nephrocalcinosis, kidney stones, and eventual renal failure. We have previously used positional cloning to identify the 3' part of a novel kidney-specific gene (initially termed hClC-K2, but now referred to as CLCN5), which is deleted in patients from one pedigree segregating Dent disease. Mutations that disrupt this gene have been identified in other patients with this disorder. Here we describe the isolation and characterization of the complete open reading frame of the human CLCN5 gene, which is predicted to encode a protein of 746 amino acids, with significant homology to all known members of the ClC family of voltage-gated chloride channels. CLCN5 belongs to a distinct branch of this family, which also includes the recently identified genes CLCN3 and CLCN4. We have shown that the coding region of CLCN5 is organized into 12 exons, spanning 25-30 kb of genomic DNA, and have determined the sequence of each exon-intron boundary. The elucidation of the coding sequence and exon-intron organization of CLCN5 will both expedite the evaluation of structure/function relationships of these ion channels and facilitate the screening of other patients with renal tubular dysfunction for mutations at this locus.

Abstract

FOXP2 mutations cause a speech and language disorder, raising interest in potential roles of this gene in human evolution. A new study re-evaluates genomic variation at the human FOXP2 locus but finds no evidence of recent adaptive evolution.

Abstract

Relative clauses are a syntactic device to create complex sentences and they make language structurally productive. Despite a considerable number of experimental studies, it is still largely unclear how children learn relative clauses and how these are processed in the language system. Researchers at the MPI for Psycholinguistics used a computational learning model to gain novel insights into these issues. The model explains the differential development of relative clauses in English as well as cross-linguistic differences

Abstract

Event-related potentials (ERPs) provide a window into how the brain is processing language. Here, we propose a theory that argues that ERPs such as the N400 and P600 arise as side effects of an error-based learning mechanism that explains linguistic adaptation and language learning. We instantiated this theory in a connectionist model that can simulate data from three studies on the N400 (amplitude modulation by expectancy, contextual constraint, and sentence position), five studies on the P600 (agreement, tense, word category, subcategorization and garden-path sentences), and a study on the semantic P600 in role reversal anomalies. Since ERPs are learning signals, this account explains adaptation of ERP amplitude to within-experiment frequency manipulations and the way ERP effects are shaped by word predictability in earlier sentences. Moreover, it predicts that ERPs can change over language development. The model provides an account of the sensitivity of ERPs to expectation mismatch, the relative timing of the N400 and P600, the semantic nature of the N400, the syntactic nature of the P600, and the fact that ERPs can change with experience. This approach suggests that comprehension ERPs are related to sentence production and language acquisition mechanisms

Abstract

Language processing involves the ability to store and integrate pieces of
information in working memory over short periods of time. According to
the dominant view, information is maintained through sustained, elevated
neural activity. Other work has argued that short-term synaptic facilitation
can serve as a substrate of memory. Here, we propose an account where
memory is supported by intrinsic plasticity that downregulates neuronal
firing rates. Single neuron responses are dependent on experience and we
show through simulations that these adaptive changes in excitability pro-
vide memory on timescales ranging from milliseconds to seconds. On this
account, spiking activity writes information into coupled dynamic variables
that control adaptation and move at slower timescales than the membrane
potential. From these variables, information is continuously read back into
the active membrane state for processing. This neuronal memory mech-
anism does not rely on persistent activity, excitatory feedback, or synap-
tic plasticity for storage. Instead, information is maintained in adaptive
conductances that reduce firing rates and can be accessed directly with-
out cued retrieval. Memory span is systematically related to both the time
constant of adaptation and baseline levels of neuronal excitability. Inter-
ference effects within memory arise when adaptation is long-lasting. We
demonstrate that this mechanism is sensitive to context and serial order
which makes it suitable for temporal integration in sequence processing
within the language domain. We also show that it enables the binding of
linguistic features over time within dynamic memory registers. This work
provides a step towards a computational neurobiology of language.

Abstract

In this study we investigated the availability of non-target language semantic features in bilingual speech processing. We recorded EEG from Dutch-English bilinguals who listened to spoken sentences in their L2 (English) or L1 (Dutch). In Experiments 1 and 3 the sentences contained an interlingual homophone. The sentence context was either biased towards the target language meaning of the homophone (target biased), the non-target language meaning (non-target biased), or neither meaning of the homophone (fully incongruent). These conditions were each compared to a semantically congruent control condition. In L2 sentences we observed an N400 in the non-target biased condition that had an earlier offset than the N400 to fully incongruent homophones. In the target biased condition, a negativity emerged that was later than the N400 to fully incongruent homophones. In L1 contexts, neither target biased nor non-target biased homophones yielded significant N400 effects (compared to the control condition). In Experiments 2 and 4 the sentences contained a language switch to a non-target language word that could be semantically congruent or incongruent. Semantically incongruent words (switched, and non-switched) elicited an N400 effect. The N400 to semantically congruent language-switched words had an earlier offset than the N400 to incongruent words. Both congruent and incongruent language switches elicited a Late Positive Component (LPC). These findings show that bilinguals activate both meanings of interlingual homophones irrespective of their contextual fit. In L2 contexts, the target-language meaning of the homophone has a head start over the non-target language meaning. The target-language head start is also evident for language switches from both L2-to-L1 and L1-to-L2

Abstract

Does language influence how we perceive the world? This study examines how linguistic encoding of relational information by means of verbs implicitly affects visual processing, by measuring perceptual judgements behaviourally, and visual perception and attention in EEG. Verbal systems can vary cross-linguistically: Dutch uses posture verbs to describe inanimate object configurations (the bottle stands/lies on the table). In English, however, such use of posture verbs is rare (the bottle is on the table). Using this test case, we ask (1) whether previously attested language-perception interactions extend to more complex domains, and (2) whether differences in linguistic usage probabilities affect perception. We report three nonverbal experiments in which Dutch and English participants performed a picture-matching task. Prime and target pictures contained object configurations (e.g., a bottle on a table); in the critical condition, prime and target showed a mismatch in object position (standing/lying). In both language groups, we found similar responses, suggesting that probabilistic differences in linguistic encoding of relational information do not affect perception.

Abstract

Using eye-tracking as a window on cognitive processing, this study investigates language effects on attention to motion events in a non-verbal task. We compare gaze allocation patterns by native speakers of German and Modern Standard Arabic (MSA), two languages that differ with regard to the grammaticalization of temporal concepts. Findings of the non-verbal task, in which speakers watch dynamic event scenes while performing an auditory distracter task, are compared to gaze allocation patterns which were obtained in an event description task, using the same stimuli. We investigate whether differences in the grammatical aspectual systems of German and MSA affect the extent to which endpoints of motion events are linguistically encoded and visually processed in the two tasks. In the linguistic task, we find clear language differences in endpoint encoding and in the eye-tracking data (attention to event endpoints) as well: German speakers attend to and linguistically encode endpoints more frequently than speakers of MSA. The fixation data in the non-verbal task show similar language effects, providing relevant insights with regard to the language-and-thought debate. The present study is one of the few studies that focus explicitly on language effects related to grammatical concepts, as opposed to lexical concepts.

Abstract

In well-known demonstrations of lexical prediction during language comprehension, pre-nominal articles that mismatch a likely upcoming noun's gender elicit different neural activity than matching articles. However, theories differ on what this pre-nominal prediction effect means and on what is being predicted. Does it reflect mismatch with a predicted article, or ‘merely’ revision of the noun prediction? We contrasted the ‘article prediction mismatch’ hypothesis and the ‘noun prediction revision’ hypothesis in two ERP experiments on Dutch mini-story comprehension, with pre-registered data collection and analyses. We capitalized on the Dutch gender system, which marks gender on definite articles (‘de/het’) but not on indefinite articles (‘een’). If articles themselves are predicted, mismatching gender should have little effect when readers expected an indefinite article without gender marking. Participants read contexts that strongly suggested either a definite or indefinite noun phrase as its best continuation, followed by a definite noun phrase with the expected noun or an unexpected, different gender noun phrase (‘het boek/de roman’, the book/the novel). Experiment 1 (N = 48) showed a pre-nominal prediction effect, but evidence for the article prediction mismatch hypothesis was inconclusive. Informed by exploratory analyses and power analyses, direct replication Experiment 2 (N = 80) yielded evidence for article prediction mismatch at a newly pre-registered occipital region-of-interest. However, at frontal and posterior channels, unexpectedly definite articles also elicited a gender-mismatch effect, and this support for the noun prediction revision hypothesis was further strengthened by exploratory analyses: ERPs elicited by gender-mismatching articles correlated with incurred constraint towards a new noun (next-word entropy), and N400s for initially unpredictable nouns decreased when articles made them more predictable. By demonstrating its dual nature, our results reconcile two prevalent explanations of the pre-nominal prediction effect.

Abstract

This chapter connects the grammar of the first person collective pronoun in the Cha’palaa language of Ecuador with its use in interaction for collective reference and social category membership attribution, addressing the problem posed by the fact that non-singular pronouns do not have distributional semantics (“speakers”) but are rather associational (“speaker and relevant associates”). It advocates a cross-disciplinary approach that jointly considers elements of linguistic form, situated usages of those forms in instances of interaction, and the broader ethnographic context of those instances. Focusing on large-scale and relatively stable categories such as racial and ethnic groups, it argues that looking at how speakers categorize themselves and others in the speech situation by using pronouns provides empirical data on the status of macro-social categories for members of a society

Abstract

In this event-related FMRI study we investigated the effect of five days of implicit acquisition on preference classification by means of an artificial grammar learning (AGL) paradigm based on the structural mere-exposure effect and preference classification using a simple right-linear unification grammar. This allowed us to investigate implicit AGL in a proper learning design by including baseline measurements prior to grammar exposure. After 5 days of implicit acquisition, the FMRI results showed activations in a network of brain regions including the inferior frontal (centered on BA 44/45) and the medial prefrontal regions (centered on BA 8/32). Importantly, and central to this study, the inclusion of a naive preference FMRI baseline measurement allowed us to conclude that these FMRI findings were the intrinsic outcomes of the learning process itself and not a reflection of a preexisting functionality recruited during classification, independent of acquisition. Support for the implicit nature of the knowledge utilized during preference classification on day 5 come from the fact that the basal ganglia, associated with implicit procedural learning, were activated during classification, while the medial temporal lobe system, associated with explicit declarative memory, was consistently deactivated. Thus, preference classification in combination with structural mere-exposure can be used to investigate structural sequence processing (syntax) in unsupervised AGL paradigms with proper learning designs.

Abstract

Objective: To combine MRI-based cortical morphometry and diffusion white matter tractography to describe the anatomical correlates of repetition deficits in patients with primary progressive aphasia (PPA).

Methods: The traditional anatomical model of language identifies a network for word repetition that includes Wernicke and Broca regions directly connected via the arcuate fasciculus. Recent tractography findings of an indirect pathway between Wernicke and Broca regions suggest a critical role of the inferior parietal lobe for repetition. To test whether repetition deficits are associated with damage to the direct or indirect pathway between both regions, tractography analysis was performed in 30 patients with PPA (64.27 ± 8.51 years) and 22 healthy controls. Cortical volume measurements were also extracted from 8 perisylvian language areas connected by the direct and indirect pathways.

Results: Compared to healthy controls, patients with PPA presented with reduced performance in repetition tasks and increased damage to most of the perisylvian cortical regions and their connections through the indirect pathway. Repetition deficits were prominent in patients with cortical atrophy of the temporo-parietal region with volumetric reductions of the indirect pathway.

Conclusions: The results suggest that in PPA, deficits in repetition are due to damage to the temporo-parietal cortex and its connections to Wernicke and Broca regions. We therefore propose a revised language model that also includes an indirect pathway for repetition, which has important clinical implications for the functional mapping and treatment of neurologic patients.

Abstract

Stroke-induced aphasia is associated with adverse effects on quality of life and the ability to return to work. For patients and clinicians the possibility of relying on valid predictors of recovery is an important asset in the clinical management of stroke-related impairment. Age, level of education, type and severity of initial symptoms are established predictors of recovery. However, anatomical predictors are still poorly understood. In this prospective longitudinal study, we intended to assess anatomical predictors of recovery derived from diffusion tractography of the perisylvian language networks. Our study focused on the arcuate fasciculus, a language pathway composed of three segments connecting Wernicke’s to Broca’s region (i.e. long segment), Wernicke’s to Geschwind’s region (i.e. posterior segment) and Broca’s to Geschwind’s region (i.e. anterior segment). In our study we were particularly interested in understanding how lateralization of the arcuate fasciculus impacts on severity of symptoms and their recovery. Sixteen patients (10 males; mean age 60 ± 17 years, range 28–87 years) underwent post stroke language assessment with the Revised Western Aphasia Battery and neuroimaging scanning within a fortnight from symptoms onset. Language assessment was repeated at 6 months. Backward elimination analysis identified a subset of predictor variables (age, sex, lesion size) to be introduced to further regression analyses. A hierarchical regression was conducted with the longitudinal aphasia severity as the dependent variable. The first model included the subset of variables as previously defined. The second model additionally introduced the left and right arcuate fasciculus (separate analysis for each segment). Lesion size was identified as the only independent predictor of longitudinal aphasia severity in the left hemisphere [beta = −0.630, t(−3.129), P = 0.011]. For the right hemisphere, age [beta = −0.678, t(–3.087), P = 0.010] and volume of the long segment of the arcuate fasciculus [beta = 0.730, t(2.732), P = 0.020] were predictors of longitudinal aphasia severity. Adding the volume of the right long segment to the first-level model increased the overall predictive power of the model from 28% to 57% [F(1,11) = 7.46, P = 0.02]. These findings suggest that different predictors of recovery are at play in the left and right hemisphere. The right hemisphere language network seems to be important in aphasia recovery after left hemispheric stroke.

Abstract

Background Stroke-induced aphasia is associated with adverse effects on quality of life and the ability to return to work. However, the predictors of recovery are still poorly understood. Anatomical variability of the arcuate fasciculus, connecting Broca’s and Wernicke’s areas, has been reported in the healthy population using diffusion tensor imaging tractography. In about 40% of the population the arcuate fasciculus is bilateral and this pattern is advantageous for certain language related functions, such as auditory verbal learning (Catani et al. 2007). Methods In this prospective longitudinal study, anatomical predictors of post-stroke aphasia recovery were investigated using diffusion tractography and arterial spin labelling. Patients An 18-subject strong aphasia cohort with first-ever unilateral left hemispheric middle cerebral artery infarcts underwent post stroke language (mean 5±5 days) and neuroimaging (mean 10±6 days) assessments and neuropsychological follow-up at six months. Ten of these patients were available for reassessment one year after symptom onset. Aphasia was assessed with the Western Aphasia Battery, which provides a global measure of severity (Aphasia Quotient, AQ). Results Better recover from aphasia was observed in patients with a right arcuate fasciculus [beta=.730, t(2.732), p=.020] (tractography) and increased fractional anisotropy in the right hemisphere (p<0.05) (Tract-based spatial statistics). Further, an increase in left hemisphere perfusion was observed after one year (p<0.01) (perfusion). Lesion analysis identified maximal overlay in the periinsular white matter (WM). Lesion-symptom mapping identified damage to periinsular structure as predictive for overall aphasia severity and damage to frontal lobe white matter as predictive of repetition deficits. Conclusion These findings suggest an important role for the right hemisphere language network in recovery from aphasia after left hemispheric stroke.

Abstract

The occipital and frontal lobes are anatomically distant yet functionally highly integrated to generate some of the most complex behaviour. A series of long associative fibres, such as the fronto-occipital networks, mediate this integration via rapid feed-forward propagation of visual input to anterior frontal regions and direct top–down modulation of early visual processing.

Despite the vast number of anatomical investigations a general consensus on the anatomy of fronto-occipital connections is not forthcoming. For example, in the monkey the existence of a human equivalent of the ‘inferior fronto-occipital fasciculus’ (iFOF) has not been demonstrated. Conversely, a ‘superior fronto-occipital fasciculus’ (sFOF), also referred to as ‘subcallosal bundle’ by some authors, is reported in monkey axonal tracing studies but not in human dissections.

In this study our aim is twofold. First, we use diffusion tractography to delineate the in vivo anatomy of the sFOF and the iFOF in 30 healthy subjects and three acallosal brains. Second, we provide a comprehensive review of the post-mortem and neuroimaging studies of the fronto-occipital connections published over the last two centuries, together with the first integral translation of Onufrowicz's original description of a human fronto-occipital fasciculus (1887) and Muratoff's report of the ‘subcallosal bundle’ in animals (1893).

Our tractography dissections suggest that in the human brain (i) the iFOF is a bilateral association pathway connecting ventro-medial occipital cortex to orbital and polar frontal cortex, (ii) the sFOF overlaps with branches of the superior longitudinal fasciculus (SLF) and probably represents an ‘occipital extension’ of the SLF, (iii) the subcallosal bundle of Muratoff is probably a complex tract encompassing ascending thalamo-frontal and descending fronto-caudate connections and is therefore a projection rather than an associative tract.

In conclusion, our experimental findings and review of the literature suggest that a ventral pathway in humans, namely the iFOF, mediates a direct communication between occipital and frontal lobes. Whether the iFOF represents a unique human pathway awaits further ad hoc investigations in animals.

Abstract

This scientific commentary refers to ‘Metabolic lesion-deficit mapping of human cognition’ by Jha etal.

Abstract

In speech, listeners extract continuously-varying spectrotemporal cues from the acoustic signal to perceive discrete phonetic categories. Spectral cues are spatially encoded in the amplitude of responses in phonetically-tuned neural populations in auditory cortex. It remains unknown whether similar neurophysiological mechanisms encode temporal cues like voice-onset time (VOT), which distinguishes sounds like /b/ and/p/. We used direct brain recordings in humans to investigate the neural encoding of temporal speech cues with a VOT continuum from /ba/ to /pa/. We found that distinct neural populations respond preferentially to VOTs from one phonetic category, and are also sensitive to sub-phonetic VOT differences within a population’s preferred category. In a simple neural network model, simulated populations tuned to detect either temporal gaps or coincidences between spectral cues captured encoding patterns observed in real neural data. These results demonstrate that a spatial/amplitude neural code underlies the cortical representation of both spectral and temporal speech cues.

Abstract

Vocabulary learning occurs throughout the lifespan, often implicitly. For foreign language learners,
this is particularly challenging as they must acquire a large number of new words with little exposure.
In the present study, we explore the effects of contextual diversity—namely, the number of texts a
word appears in—on native and foreign language word learning. Participants read several texts that
had novel pseudowords replacing high-frequency words. The total number of encounters with the
novel words was held constant, but they appeared in 1, 2, 4, or 8 texts. In addition, some participants
read the texts in Spanish (their native language) and others in English (their foreign language). We
found that increasing contextual diversity improved recall and recognition of the word, as well as the
ability to match the word with its meaning while keeping comprehension unimpaired. Using a foreign
language only affected performance in the matching task, where participants had to quickly identify
the meaning of the word. Results are discussed in the greater context of the word learning and foreign
language literature as well as their importance as a teaching tool.

Abstract

The current study focuses on how different scales with varying demands can
affect our subjective assessments. We carried out 2 experiments in which we
asked participants to rate how happy or sad morphed images of faces looked.
The two extremes were the original happy and original sad faces with 4
morphs in between. We manipulated language of the task—namely, half of
the participants carried it out in their native language, Spanish, and the other
half in their foreign language, English—and type of scale. Within type of
scale, we compared verbal and brightness scales. We found that, while
language did not have an effect on the assessment, type of scale did. The
brightness scale led to overall higher ratings, i.e., assessing all faces as
somewhat happier. This provides a limitation on the foreign language effect,
as well as evidence for the influence of the cognitive demands of a scale on
emotionality assessments.

Abstract

Learning new content and vocabulary in a foreign language can be particularly difficult. Yet,
there are educational programs that require people to study in a language they are not
native speakers of. For this reason, it is important to understand how these learning processes work and possibly differ from native language learning, as well as to develop strategies to ease this process. The current study takes advantage of emotionality—operationally
defined as positive valence and high arousal—to improve memory. In two experiments, the
present paper addresses whether participants have more difficulty learning the names of
objects they have never seen before in their foreign language and whether embedding them
in a positive semantic context can help make learning easier. With this in mind, we had participants (with a minimum of a B2 level of English) in two experiments (43 participants in
Experiment 1 and 54 in Experiment 2) read descriptions of made-up objects—either positive
or neutral and either in their native or a foreign language. The effects of language varied
with the difficulty of the task and measure used. In both cases, learning the words in a positive context improved learning. Importantly, the effect of emotionality was not modulated by
language, suggesting that the effects of emotionality are independent of language and could
potentially be a useful tool for improving foreign language vocabulary learning.

Abstract

Reading is an audiovisual process that requires the learning of systematic links between graphemes and phonemes. It is thus possible that reading impairments reflect an audiovisual processing deficit. In this study, we compared audiovisual processing in adults with developmental dyslexia and adults without reading difficulties. We focused on differences in cross-modal temporal sensitivity both for speech and for non-speech events. When compared to adults without reading difficulties, adults with developmental dyslexia presented a wider temporal window in which unsynchronized speech events were perceived as synchronized. No differences were found between groups for the non-speech events. These results suggests a deficit in dyslexia in the perception of cross-modal temporal synchrony for speech events.

Abstract

Previous research on the effect of perturbed auditory feedback in speech production has focused on two types of responses. In the short term, speakers generate compensatory motor commands in response to unexpected perturbations. In the longer term, speakers adapt feedforward motor programmes in response to feedback perturbations, to avoid future errors. The current study investigated the relation between these two types of responses to altered auditory feedback. Specifically, it was hypothesised that consistency in previous feedback perturbations would influence whether speakers adapt their feedforward motor programmes. In an altered auditory feedback paradigm, formant perturbations were applied either across all trials (the consistent condition) or only to some trials, whereas the others remained unperturbed (the inconsistent condition). The results showed that speakers’ responses were affected by feedback consistency, with stronger speech changes in the consistent condition compared with the inconsistent condition. Current models of speech-motor control can explain this consistency effect. However, the data also suggest that compensation and adaptation are distinct processes, which are not in line with all current models.

Abstract

Kleefstra syndrome (KS) is a neurodevelopmental disorder caused by mutations in the histone methyltransferase EHMT1. To study the impact of decreased EHMT1 function in human cells, we generated excitatory cortical neurons from induced pluripotent stem (iPS) cells derived from KS patients. Neuronal networks of patient-derived cells exhibit network bursting with a reduced rate, longer duration, and increased temporal irregularity compared to control networks. We show that these changes are mediated by upregulation of NMDA receptor (NMDAR) subunit 1 correlating with reduced deposition of the repressive H3K9me2 mark, the catalytic product of EHMT1, at the GRIN1 promoter. In mice EHMT1 deficiency leads to similar neuronal network impairments with increased NMDAR function. Finally, we rescue the KS patient-derived neuronal network phenotypes by pharmacological inhibition of NMDARs. Summarized, we demonstrate a direct link between EHMT1 deficiency and NMDAR hyperfunction in human neurons, providing a potential basis for more targeted therapeutic approaches for KS.

Abstract

Disruptions of the FOXP2 gene cause a speech and language disorder involving difficulties in sequencing orofacial movements. FOXP2 is expressed in cortico-striatal and cortico-cerebellar circuits important for fine motor skills, and affected individuals show abnormalities in these brain regions. We selectively disrupted Foxp2 in the cerebellar Purkinje cells, striatum or cortex of mice and assessed the effects on skilled motor behaviour using an operant lever-pressing task. Foxp2 loss in each region impacted behaviour differently, with striatal and Purkinje cell disruptions affecting the variability and the speed of lever-press sequences, respectively. Mice lacking Foxp2 in Purkinje cells showed a prominent phenotype involving slowed lever pressing as well as deficits in skilled locomotion. In vivo recordings from Purkinje cells uncovered an increased simple spike firing rate and decreased modulation of firing during limb movements. This was caused by increased intrinsic excitability rather than changes in excitatory or inhibitory inputs. Our findings show that Foxp2 can modulate different aspects of motor behaviour in distinct brain regions, and uncover an unknown role for Foxp2 in the modulation of Purkinje cell activity that severely impacts skilled movements.

Abstract

Disruptions of the FOXP2 gene cause a rare speech and language disorder, a discovery that has opened up novel avenues for investigating the relevant neural pathways. FOXP2 shows remarkably high conservation of sequence and neural expression in diverse vertebrates, suggesting that studies in other species are useful in elucidating its functions. Here we describe how investigations of mice that carry disruptions of Foxp2 provide insights at multiple levels: molecules, cells, circuits and behaviour. Work thus far has implicated the gene in key processes including neurite outgrowth, synaptic plasticity, sensorimotor integration and motor-skill learning.

Abstract

Gradients capture some of the variance of the resting-state functional magnetic resonance imaging (rsfMRI) signal. Amongst these, the principal gradient depicts a functional processing hierarchy that spans from sensory-motor cortices to regions of the default-mode network. While the cortex has been well characterised in terms of gradients little is known about its underlying white matter. For instance, comprehensive mapping of the principal gradient on the largest white matter tract, the corpus callosum, is still missing. Here, we mapped the principal gradient onto the midsection of the corpus callosum using the 7T human connectome project dataset. We further explored how quantitative measures and variability in callosal midsection connectivity relate to the principal gradient values. In so doing, we demonstrated that the extreme values of the principal gradient are located within the callosal genu and the posterior body, have lower connectivity variability but a larger spatial extent along the midsection of the corpus callosum than mid-range values. Our results shed light on the relationship between the brain's functional hierarchy and the corpus callosum. We further speculate about how these results may bridge the gap between functional hierarchy, brain asymmetries, and evolution.

Abstract

Human behavioral asymmetries are commonly studied in the context of structural cortical and connectional asymmetries. Within this framework, Sreenivasan and Sridharan (1) provide intriguing evidence of a relationship between visual asymmetries and the lateralization of superior colliculi connections—a phylogenetically older mesencephalic structure. Specifically, response facilitation for cued locations (i.e., choice bias) in the contralateral hemifield was associated with differences in the connectivity of the superior colliculus. Given that the superior colliculus has a structural homolog—the optic tectum—which can be traced across all Vertebrata, these results may have meaningful evolutionary ramifications.

Abstract

Achieving linguistic proficiency requires identifying words from speech, and discovering the constraints that govern the way those words are used. In a recent study of non-adjacent dependency learning, Frost and Monaghan (2016) demonstrated that learners may perform these tasks together, using similar statistical processes - contrary to prior suggestions. However, in their study, non-adjacent dependencies were marked by phonological cues (plosive-continuant-plosive structure), which may have influenced learning. Here, we test the necessity of these cues by comparing learning across three conditions; fixed phonology, which contains these cues, varied phonology, which omits them, and shapes, which uses visual shape sequences to assess the generality of statistical processing for these tasks. Participants segmented the sequences and generalized the structure in both auditory conditions, but learning was best when phonological cues were present. Learning was around chance on both tasks for the visual shapes group, indicating statistical processing may critically differ across domains.

Abstract

High frequency words have been suggested to benefit both speech segmentation and grammatical categorization of the words around them. Despite utilizing similar information, these tasks are usually investigated separately in studies examining learning. We determined whether including high frequency words in continuous speech could support categorization when words are being segmented for the first time. We familiarized learners with continuous artificial speech comprising repetitions of target words, which were preceded by high-frequency marker words. Crucially, marker words distinguished targets into 2 distributionally defined categories. We measured learning with segmentation and categorization tests and compared performance against a control group that heard the artificial speech without these marker words (i.e., just the targets, with no cues for categorization). Participants segmented the target words from speech in both conditions, but critically when the marker words were present, they influenced acquisition of word-referent mappings in a subsequent transfer task, with participants demonstrating better early learning for mappings that were consistent (rather than inconsistent) with the distributional categories. We propose that high-frequency words may assist early grammatical categorization, while speech segmentation is still being learned.

Abstract

High frequency words play a key role in language acquisition, with recent work suggesting they may serve both speech segmentation and lexical categorisation. However, it is not yet known whether infants can detect novel high frequency words in continuous speech, nor whether they can use them to help learning for segmentation and categorisation at the same time. For instance, when hearing “you eat the biscuit”, can children use the high-frequency words “you” and “the” to segment out “eat” and “biscuit”, and determine their respective lexical categories? We tested this in two experiments. In Experiment 1, we familiarised 12-month-old infants with continuous artificial speech comprising repetitions of target words, which were preceded by high-frequency marker words that distinguished the targets into two distributional categories. In Experiment 2, we repeated the task using the same language but with additional phonological cues to word and category structure. In both studies, we measured learning with head-turn preference tests of segmentation and categorisation, and compared performance against a control group that heard the artificial speech without the marker words (i.e., just the targets). There was no evidence that high frequency words helped either speech segmentation or grammatical categorisation. However, segmentation was seen to improve when the distributional information was supplemented with phonological cues (Experiment 2). In both experiments, exploratory analysis indicated that infants’ looking behaviour was related to their linguistic maturity (indexed by infants’ vocabulary scores) with infants with high versus low vocabulary scores displaying novelty and familiarity preferences, respectively. We propose that high-frequency words must reach a critical threshold of familiarity before they can be of significant benefit to learning.

Abstract

To acquire language, infants must learn how to identify words and linguistic structure in speech. Statistical learning has been suggested to assist both of these tasks. However, infants’ capacity to use statistics to discover words and structure together remains unclear. Further, it is not yet known how infants’ statistical learning ability relates to their language development. We trained 17-month-old infants on an artificial language comprising non-adjacent dependencies, and examined their looking times on tasks assessing sensitivity to words and structure using an eye-tracked head-turn-preference paradigm. We measured infants’ vocabulary size using a Communicative Development Inventory (CDI) concurrently and at 19, 21, 24, 25, 27, and 30 months to relate performance to language development. Infants could segment the words from speech, demonstrated by a significant difference in looking times to words versus part-words. Infants’ segmentation performance was significantly related to their vocabulary size (receptive and expressive) both currently, and over time (receptive until 24 months, expressive until 30 months), but was not related to the rate of vocabulary growth. The data also suggest infants may have developed sensitivity to generalised structure, indicating similar statistical learning mechanisms may contribute to the discovery of words and structure in speech, but this was not related to vocabulary size.

Abstract

Acquiring language is notoriously complex, yet for the majority of children this feat is accomplished with remarkable ease. Usage-based accounts of language acquisition suggest that this success can be largely attributed to the wealth of experience with language that children accumulate over the course of language acquisition. One field of research that is heavily underpinned by this principle of experience is statistical learning, which posits that learners can perform powerful computations over the distribution of information in a given input, which can help them to discern precisely how that input is structured, and how it operates. A growing body of work brings this notion to bear in the field of language acquisition, due to a developing understanding of the richness of the statistical information contained in speech. In this chapter we discuss the role that statistical learning plays in language acquisition, emphasising the importance of both the distribution of information within language, and the situation in which language is being learnt. First, we address the types of statistical learning that apply to a range of language learning tasks, asking whether the statistical processes purported to support language learning are the same or distinct across different tasks in language acquisition. Second, we expand the perspective on what counts as environmental input, by determining how statistical learning operates over the situated learning environment, and not just sequences of sounds in utterances. Finally, we address the role of variability in children’s input, and examine how statistical learning can accommodate (and perhaps even exploit) this during language acquisition.

Abstract

Cumulative tool-based culture underwrote our species' evolutionary success and tool-based nut-cracking is one of the strongest candidates for cultural transmission in our closest relatives, chimpanzees. However the social learning processes that may explain both the similarities and differences between the species remain unclear. A previous study of nut-cracking by initially naïve chimpanzees suggested that a learning chimpanzee holding no hammer nevertheless replicated hammering actions it witnessed. This observation has potentially important implications for the nature of the social learning processes and underlying motor coding involved. In the present study, model and observer actions were quantified frame-by-frame and analysed with stringent statistical methods, demonstrating synchrony between the observer's and model's movements, cross-correlation of these movements above chance level and a unidirectional transmission process from model to observer. These results provide the first quantitative evidence for motor mimicking underlain by motor coding in apes, with implications for mirror neuron function.

Abstract

Previous research on language development shows that children are tuned early on to the language-specific semantic and syntactic encoding of events in their native language. Here we ask whether language-specificity is also evident in children's early representations in gesture accompanying speech. In a longitudinal study, we examined the spontaneous speech and cospeech gestures of eight Turkish-speaking children aged one to three and focused on their caused motion event expressions. In Turkish, unlike in English, the main semantic elements of caused motion such as Action and Path can be encoded in the verb (e.g. sok- ‘put in’) and the arguments of a verb can be easily omitted. We found that Turkish-speaking children's speech indeed displayed these language-specific features and focused on verbs to encode caused motion. More interestingly, we found that their early gestures also manifested specificity. Children used iconic cospeech gestures (from 19 months onwards) as often as pointing gestures and represented semantic elements such as Action with Figure and/or Path that reinforced or supplemented speech in language-specific ways until the age of three. In the light of previous reports on the scarcity of iconic gestures in English-speaking children's early productions, we argue that the language children learn shapes gestures and how they get integrated with speech in the first three years of life.

Abstract

Background: Two distinct insomnia disorder (ID) phenotypes have been proposed, distinguished on the basis of an objective total sleep time less or more than 6 hr. In particular, it has been recently reported that patients with objective short sleep duration have a blunted response to cognitive behavioral therapy for insomnia (CBT-I). The aim of this study was to investigate the differences of CBT-I response in two groups of ID patients subdivided according to total sleep time. Methods: Two hundred forty-six ID patients were subdivided into two groups, depending on their reported total sleep time (TST) assessed by sleep diaries. Patients with a TST greater than 6 hr were classified as “normal sleepers” (NS), while those with a total sleep time less than 6 hr were classified as “short sleepers” (SS). Results: The delta between Insomnia Severity Index scores and sleep efficiency at the beginning as compared to the end of the treatment was significantly higher for SS in comparison to NS, even if they still exhibit more insomnia symptoms. No difference was found between groups in terms of remitters; however, more responders were observed in the SS group in comparison to the NS group. Conclusions: Our results demonstrate that ID patients with reported short total sleep time had a beneficial response to CBT-I of greater magnitude in comparison to NS. However, these patients may still experience the presence of residual insomnia symptoms after treatment.

Abstract

Several studies report an association between REM Sleep Behavior Disorder (RBD) and neurodegenerative diseases, in particular synucleinopathies. Interestingly, the onset of RBD precedes the development of neurodegeneration by several years. This review and meta-analysis aims to establish the rate of conversion of RBD into neurodegenerative diseases. Longitudinal studies were searched from the PubMed, Web of Science, and SCOPUS databases. Using random-effect modeling, we performed a meta-analysis on the rate of RBD conversions into neurodegeneration. Furthermore, we fitted a Kaplan-Meier analysis and compared the differences between survival curves of different diseases with log-rank tests. The risk for developing neurodegenerative diseases was 33.5% at five years follow-up, 82.4% at 10.5 years and 96.6% at 14 years. The average conversion rate was 31.95% after a mean duration of follow-up of 4.75 ± 2.43 years. The majority of RBD patients converted to Parkinson's Disease (43%), followed by Dementia with Lewy Bodies (25%). The estimated risk for RBD patients to develop a neurodegenerative disease over a long-term follow-up is more than 90%. Future studies should include control group for the evaluation of REM sleep without atonia as marker for neurodegeneration also in non-clinical population and target RBD as precursor of neurodegeneration to develop protective trials.

Abstract

Large-scale graph data in real-world applications is often not static but dynamic,
i. e., new nodes and edges appear over time. Current graph convolution approaches
are promising, especially, when all the graph’s nodes and edges are available dur-
ing training. When unseen nodes and edges are inserted after training, it is not
yet evaluated whether up-training or re-training from scratch is preferable. We
construct an experimental setup, in which we insert previously unseen nodes and
edges after training and conduct a limited amount of inference epochs. In this
setup, we compare adapting pretrained graph neural networks against retraining
from scratch. Our results show that pretrained models yield high accuracy scores
on the unseen nodes and that pretraining is preferable over retraining from scratch.
Our experiments represent a first step to evaluate and develop truly online variants
of graph neural networks.

Abstract

Visuospatial attention theories often propose hemispheric asymmetries underlying the control of attention. In general support of these theories, previous EEG/MEG studies have shown that spatial attention is associated with hemispheric modulation of posterior alpha power (gating by inhibition). However, since measures of alpha power are typically expressed as lateralization scores, or collapsed across left and right attention shifts, the individual hemispheric contribution to the attentional control mechanism remains unclear. This is, however, the most crucial and decisive aspect in which the currently competing attention theories continue to disagree. To resolve this long-standing conflict, we derived predictions regarding alpha power modulations from Heilman's hemispatial theory and Kinsbourne's interhemispheric competition theory and tested them empirically in an EEG experiment. We used an attention paradigm capable of isolating alpha power modulation in two attentional states, namely attentional bias in a neutral cue condition and spatial orienting following directional cues. Differential alpha modulations were found for both hemispheres across conditions. When anticipating peripheral visual targets without preceding directional cues (neutral condition), posterior alpha power in the left hemisphere was generally lower and more strongly modulated than in the right hemisphere, in line with the interhemispheric competition theory. Intriguingly, however, while alpha power in the right hemisphere was modulated by both, cue-directed leftward and rightward attention shifts, the left hemisphere only showed modulations by rightward shifts of spatial attention, in line with the hemispatial theory. This suggests that the two theories may not be mutually exclusive, but rather apply to different attentional states.

Abstract

This study investigated how sentence formulation is influenced by a preceding discourse context. In two eye-tracking experiments, participants described pictures of two-character transitive events in Dutch (Experiment 1) and Chinese (Experiment 2). Focus was manipulated by presenting questions before each picture. In the Neutral condition, participants first heard ‘What is happening here?’ In the Object or Subject Focus conditions, the questions asked about the Object or Subject character (What is the policeman stopping? Who is stopping the truck?). The target response was the same in all conditions (The policeman is stopping the truck). In both experiments, sentence formulation in the Neutral condition showed the expected pattern of speakers fixating the subject character (policeman) before the object character (truck). In contrast, in the focus conditions speakers rapidly directed their gaze preferentially only to the character they needed to encode to answer the question (the new, or focused, character). The timing of gaze shifts to the new character varied by language group (Dutch vs. Chinese): shifts to the new character occurred earlier when information in the question can be repeated in the response with the same syntactic structure (in Chinese but not in Dutch). The results show that discourse affects the timecourse of linguistic formulation in simple sentences and that these effects can be modulated by language-specific linguistic structures such as parallels in the syntax of questions and declarative sentences.

Abstract

Researchers have long avoided neurophysiological experiments of overt speech production due to the suspicion that artifacts caused by muscle activity may lead to a bad signal-to-noise ratio in the measurements. However, the need to actually produce speech may influence earlier processing and qualitatively change speech production processes and what we can infer from neurophysiological measures thereof. Recently, however, overt speech has been successfully investigated using EEG, MEG, and fMRI. The aim of this Research Topic is to draw together recent research on the neurophysiological basis of language production, with the aim of developing and extending theoretical accounts of the language production process. In this Research Topic of Frontiers in Language Sciences, we invite both experimental and review papers, as well as those about the latest methods in acquisition and analysis of overt language production data. All aspects of language production are welcome: i.e., from conceptualization to articulation during native as well as multilingual language production. Focus should be placed on using the neurophysiological data to inform questions about the processing stages of language production. In addition, emphasis should be placed on the extent to which the identified components of the electrophysiological signal (e.g., ERP/ERF, neuronal oscillations, etc.), brain areas or networks are related to language comprehension and other cognitive domains. By bringing together electrophysiological and neuroimaging evidence on language production mechanisms, a more complete picture of the locus of language production processes and their temporal and neurophysiological signatures will emerge.