Publications

Abstract

Individuals with heterozygous 16p11.2 deletions reportedly suffer from a variety of difficulties with speech and language. Indeed, recent copy-number variant screens of children with childhood apraxia of speech (CAS), a specific and rare motor speech disorder, have identified three unrelated individuals with 16p11.2 deletions. However, the nature and prevalence of speech and language disorders in general, and CAS in particular, is unknown for individuals with 16p11.2 deletions. Here we took a genotype-first approach, conducting detailed and systematic characterization of speech abilities in a group of 11 unrelated children ascertained on the basis of 16p11.2 deletions. To obtain the most precise and replicable phenotyping, we included tasks that are highly diagnostic for CAS, and we tested children under the age of 18 years, an age group where CAS has been best characterized. Two individuals were largely nonverbal, preventing detailed speech analysis, whereas the remaining nine met the standard accepted diagnostic criteria for CAS. These results link 16p11.2 deletions to a highly penetrant form of CAS. Our findings underline the need for further precise characterization of speech and language profiles in larger groups of affected individuals, which will also enhance our understanding of how genetic pathways contribute to human communication disorders.

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 long-standing debate in cognitive neurosciences concerns the effect of music on verbal learning and memory. Research in this field has largely provided conflicting results in both clinical as well as non-clinical populations. Although several studies have shown a positive effect of music on the encoding and retrieval of verbal stimuli, music has also been suggested to hinder mnemonic performance by dividing attention. In an attempt to explain this conflict, we review the most relevant literature on the effects of music on verbal learning and memory. Furthermore, we specify several mechanisms through which music may modulate these cognitive functions. We suggest that the extent to which music boosts these cognitive functions relies on experimental factors, such as the relative complexity of musical and verbal stimuli employed. These factors should be carefully considered in further studies, in order to reliably establish how and when music boosts verbal memory and learning. The answers to these questions are not only crucial for our knowledge of how music influences cognitive and brain functions, but may have important clinical implications. Considering the increasing number of approaches using music as a therapeutic tool, the importance of understanding exactly how music works can no longer be underestimated.

Abstract

This article focuses on “perceptual syntax”, the faculty to process patterns in sensory stimuli. Specifically, this study addresses the ability to perceptually connect elements that are: (1) of the same sensory modality; (2) spatially and temporally non-adjacent; or (3) within multiple sensorial domains. The underlying hypothesis is that in each animal species, this core cognitive faculty enables the perception of the environment-world (Umwelt) and consequently the possibility to survive within it. Importantly, it is suggested that in doing so, perceptual syntax determines (and guides) each species’ ontological access to the world. In support of this hypothesis, research on perceptual syntax in nonverbal individuals (preverbal infants and nonhuman animals) and humans is reviewed. This comparative approach results in theoretical remarks on human cognition and ontology, pointing to the conclusion that the ability to map cross-modal connections through verbal language is what makes humans’ form of life species-typical.

Abstract

Across a wide range of animal taxa, prosodic modulation of the voice can express emotional information and is used to coordinate vocal interactions between multiple individuals. Within a comparative approach to animal communication systems, I hypothesize that the ability for emotional and interactional prosody (EIP) paved the way for the evolution of linguistic prosody – and perhaps also of music, continuing to play a vital role in the acquisition of language. In support of this hypothesis, I review three research fields: (i) empirical studies on the adaptive value of EIP in non-human primates, mammals, songbirds, anurans, and insects; (ii) the beneficial effects of EIP in scaffolding language learning and social development in human infants; (iii) the cognitive relationship between linguistic prosody and the ability for music, which has often been identified as the evolutionary precursor of language.

Abstract

The perception of danger in the environment can induce physiological responses (such as a heightened state of arousal) in animals, which may cause measurable changes in the prosodic modulation of the voice (Briefer, 2012). The ability to interpret the prosodic features of animal calls as an indicator of emotional arousal may have provided the first hominins with an adaptive advantage, enabling, for instance, the recognition of a threat in the surroundings. This ability might have paved the ability to process meaningful prosodic modulations in the emerging linguistic utterances.

Abstract

Humans combine multiple sources of information to comprehend meanings. These sources can be characterized as linguistic (i.e., lexical units and/or sentences) or paralinguistic (e.g. body posture, facial expression, voice intonation, pragmatic context). Emotion communication is a special case in which linguistic and paralinguistic dimensions can simultaneously denote the same, or multiple incongruous referential meanings. Think, for instance, about when someone says “I’m sad!”, but does so with happy intonation and a happy facial expression. Here, the communicative channels express very specific (although conflicting) emotional states as denotations. In such cases of intermodal incongruence, are we involuntarily biased to respond to information in one channel over the other? We hypothesize that humans are involuntary biased to respond to prosody over verbal content and facial expression, since the ability to communicate socially relevant information such as basic emotional states through prosodic modulation of the voice might have provided early hominins with an adaptive advantage that preceded the emergence of segmental speech (Darwin 1871; Mithen, 2005). To address this hypothesis, we examined the interaction between multiple communicative channels in recruiting attentional resources, within a Stroop interference task (i.e. a task in which different channels give conflicting information; Stroop, 1935). In experiment 1, we used synonyms of “happy” and “sad” spoken with happy and sad prosody. Participants were asked to identify the emotion expressed by the verbal content while ignoring prosody (Word task) or vice versa (Prosody task). Participants responded faster and more accurately in the Prosody task. Within the Word task, incongruent stimuli were responded to more slowly and less accurately than congruent stimuli. In experiment 2, we adopted synonyms of “happy” and “sad” spoken in happy and sad prosody, while a happy or sad face was displayed. Participants were asked to identify the emotion expressed by the verbal content while ignoring prosody and face (Word task), to identify the emotion expressed by prosody while ignoring verbal content and face (Prosody task), or to identify the emotion expressed by the face while ignoring prosody and verbal content (Face task). Participants responded faster in the Face task and less accurately when the two non-focused channels were expressing an emotion that was incongruent with the focused one, as compared with the condition where all the channels were congruent. In addition, in the Word task, accuracy was lower when prosody was incongruent to verbal content and face, as compared with the condition where all the channels were congruent. Our data suggest that prosody interferes with emotion word processing, eliciting automatic responses even when conflicting with both verbal content and facial expressions at the same time. In contrast, although processed significantly faster than prosody and verbal content, faces alone are not sufficient to interfere in emotion processing within a three-dimensional Stroop task. Our findings align with the hypothesis that the ability to communicate emotions through prosodic modulation of the voice – which seems to be dominant over verbal content - is evolutionary older than the emergence of segmental articulation (Mithen, 2005; Fitch, 2010). This hypothesis fits with quantitative data suggesting that prosody has a vital role in the perception of well-formed words (Johnson & Jusczyk, 2001), in the ability to map sounds to referential meanings (Filippi et al., 2014), and in syntactic disambiguation (Soderstrom et al., 2003). This research could complement studies on iconic communication within visual and auditory domains, providing new insights for models of language evolution. Further work aimed at how emotional cues from different modalities are simultaneously integrated will improve our understanding of how humans interpret multimodal emotional meanings in real life interactions.

Abstract

The aim of this paper is to help refine the definition of humans as “linguistic animals” in light of a comparative approach on nonhuman animals’ cognitive systems. As Uexküll & Kriszat (1934/1992) have theorized, the epistemic access to each species-specific environment (Umwelt) is driven by different biocognitive processes. Within this conceptual framework, I identify the salient cognitive process that distinguishes each species typical perception of the world as the faculty of language meant in the following operational definition: the ability to connect different elements according to structural rules. In order to draw some conclusions about humans’ specific faculty of language, I review different empirical studies on nonhuman animals’ ability to recognize formal patterns of tokens. I suggest that what differentiates human language from other animals’ cognitive systems is the ability to categorize the units of a pattern, going beyond its perceptual aspects. In fact, humans are the only species known to be able to combine semantic units within a network of combinatorial logical relationships (Deacon 1997) that can be linked to the state of affairs in the external world (Wittgenstein 1922). I assume that this ability is the core cognitive process underlying a) the capacity to speak (or to reason) in verbal propositions and b) the general human faculty of language expressed, for instance, in the ability to draw visual conceptual maps or to compute mathematical expressions. In light of these considerations, I conclude providing some research questions that could lead to a more detailed comparative exploration of the faculty of language.

Abstract

Temporal regularities in speech, such as interdependencies in the timing of speech events, are thought to scaffold early acquisition of the building blocks in speech. By providing on-line clues to the location and duration of upcoming syllables, temporal structure may aid segmentation and clustering of continuous speech into separable units. This hypothesis tacitly assumes that learners exploit predictability in the temporal structure of speech. Existing measures of speech timing tend to focus on first-order regularities among adjacent units, and are overly sensitive to idiosyncrasies in the data they describe. Here, we compare several statistical methods on a sample of 18 languages, testing whether syllable occurrence is predictable over time. Rather than looking for differences between languages, we aim to find across languages (using clearly defined acoustic, rather than orthographic, measures), temporal predictability in the speech signal which could be exploited by a language learner. First, we analyse distributional regularities using two novel techniques: a Bayesian ideal learner analysis, and a simple distributional measure. Second, we model higher-order temporal structure—regularities arising in an ordered series of syllable timings—testing the hypothesis that non-adjacent temporal structures may explain the gap between subjectively-perceived temporal regularities, and the absence of universally-accepted lower-order objective measures. Together, our analyses provide limited evidence for predictability at different time scales, though higher-order predictability is difficult to reliably infer. We conclude that temporal predictability in speech may well arise from a combination of individually weak perceptual cues at multiple structural levels, but is challenging to pinpoint.

Abstract

The rise of genomic technologies has yielded exciting new routes for studying the biological foundations of language. Researchers have begun to identify genes implicated in neurodevelopmental disorders that disrupt speech and language skills. This chapter illustrates how such work can provide powerful entry points into the critical neural pathways using FOXP2 as an example. Rare mutations of this gene cause problems with learning to sequence mouth movements during speech, accompanied by wide-ranging impairments in language production and comprehension. FOXP2 encodes a regulatory protein, a hub in a network of other genes, several of which have also been associated with language-related impairments. Versions of FOXP2 are found in similar form in many vertebrate species; indeed, studies of animals and birds suggest conserved roles in the development and plasticity of certain sets of neural circuits. Thus, the contributions of this gene to human speech and language involve modifications of evolutionarily ancient functions.

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

State-of-the-art DNA sequencing is providing ever more detailed insights into the genomes of humans, extant apes, and even extinct hominins (1–3), offering unprecedented opportunities to uncover the molecular variants that make us human. A common assumption is that the emergence of behaviorally modern humans after 200,000 years ago required—and followed—a specific biological change triggered by one or more genetic mutations. For example, Klein has argued that the dawn of human culture stemmed from a single genetic change that “fostered the uniquely modern ability to adapt to a remarkable range of natural and social circumstance” (4). But are evolutionary changes in our genome a cause or a consequence of cultural innovation (see the figure)?

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

The testimony of others and direct experience play a major role in the development of children's knowledge. Children actively use questions to seek others' testimony and explore the environment. It is unclear though whether children distinguish when it is better to ask from when it is better to try to find an answer by oneself. In 2 experiments, we examined the ability of 4- and 6-year-olds to select between looking and asking to determine visible and invisible properties of entities (e.g., hair color vs. knowledge of French). All children chose to look more often for visible than invisible properties. However, only 6-year-olds chose above chance to look for visible properties and to ask for invisible properties. Four-year-olds showed a preference for looking in one experiment and asking in the other. The results suggest substantial development in the efficacy of children's learning in early childhood.

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

Systematic investigations into the role of semantics in the speech production process have remained elusive. This special issue aims at moving forward toward a more detailed account of how precisely conceptual information is used to access the lexicon in speaking and what corresponding format of conceptual representations needs to be assumed. The studies presented in this volume investigated effects of conceptual processing on different processing stages of language production, including sentence formulation, lemma selection, and word form access.

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

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

In the Cha’palaa language of Ecuador the main-clause use of the otherwise non-finite morpheme -ba can be accounted for by a specific interactive practice: the ‘counter-assertion’ of statement or implicature of a previous conversational turn. Attention to the ways in which different constructions are deployed in such recurrent conversational contexts reveals a plausible account for how this type of dependent clause has come to be one of the options for finite clauses. After giving some background on Cha’palaa and placing ba clauses within a larger ecology of insubordination constructions in the language, this chapter uses examples from a video corpus of informal conversation to illustrate how interactive data provides answers that may otherwise be elusive for understanding how the different grammatical options for Cha’palaa finite verb constructions have been structured by insubordination

Abstract

From the study of sign languages we know that the visual modality robustly supports the encoding of conventionalized linguistic elements, yet while the same possibility exists for the visual bodily behavior of speakers of spoken languages, such practices are often referred to as ‘gestural’ and are not usually described in linguistic terms. This article describes a practice of speakers of the Brazilian indigenous language Nheengatú of pointing to positions along the east-west axis of the sun’s arc for time-of-day reference, and illustrates how it satisfies any of the common criteria for linguistic elements, as a system of standardized and productive form-meaning pairings whose contributions to propositional meaning remain stable across contexts. First, examples from a video corpus of natural speech demonstrate these conventionalized properties of Nheengatú time reference across multiple speakers. Second, a series of video-based elicitation stimuli test several dimensions of its conventionalization for nine participants. The results illustrate why modality is not an a priori reason that linguistic properties cannot develop in the visual practices that accompany spoken language. The conclusion discusses different possible morphosyntactic and pragmatic analyses for such conventionalized visual elements and asks whether they might be more crosslinguistically common than we presently know.

Abstract

The ethnographic literature has sometimes described parts of the northwest Amazon as areas of shared culture across linguistic groups. This paper illustrates how a principle of semantic transparency across languages is a key means of establishing elements of a common regional culture through practices like the calquing of ethnonyms and toponyms so that they are semantically, but not phonologically, equivalent across languages. It places the upper Rio Negro area of the northwest Amazon in a general discussion of cross-linguistic naming practices in South America and considers the extent to which a preference for semantic transparency can be linked to cases of widespread cultural ‘calquing’, in which culturally-important meanings are kept similar across different linguistic systems. It also addresses the principle of semantic transparency beyond specific referential phrases and into larger discourse structures. It concludes that an attention to semiotic practices in multilingual settings can provide new and more complex ways of thinking about the idea of shared culture.

Abstract

This chapter surveys the available data on Barbacoan languages and their neighbors to explore a case study of switch reference within a single language family and in a situation of areal contact. To the extent possible given the available data, we weigh accounts appealing to common inheritance and areal convergence to ask what combination of factors led to the current state of these languages. We discuss the areal distribution of switch reference systems in the northwest Andean region, the different types of systems and degrees of complexity observed, and scenarios of contact and convergence, particularly in the case of Barbacoan and Ecuadorian Quechua. We then covers each of the Barbacoan languages’ systems (with the exception of Totoró, represented by its close relative Guambiano), identifying limited formal cognates, primarily between closely-related Tsafiki and Cha’palaa, as well as broader functional similarities, particularly in terms of interactions with topic/focus markers. n accounts for the current state of affairs with a complex scenario of areal prevalence of switch reference combined with deep structural family inheritance and formal re-structuring of the systems over time

Abstract

This article expands the study of other-initiated repair in conversation—when one party
signals a problemwith producing or perceiving another’s turn at talk—into the domain
of visual bodily behavior. It presents one primary cross-linguistic finding about the
timing of visual bodily behavior in repair sequences: if the party who initiates repair
accompanies their turn with a “hold”—when relatively dynamic movements are
temporarily andmeaningfully held static—this positionwill not be disengaged until the
problem is resolved and the sequence closed. We base this finding on qualitative and
quantitative analysis of corpora of conversational interaction from three unrelated languages representing two different modalities: Northern Italian, the Cha’palaa language of Ecuador, and Argentine Sign Language. The cross-linguistic similarities
uncovered by this comparison suggest that visual bodily practices have been
semiotized for similar interactive functions across different languages and modalities
due to common pressures in face-to-face interaction.

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

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

Prior language input is not lost but integrated with the current input. This principle is demonstrated by “reservoir computing”: Untrained recurrent neural networks project input sequences onto a random point in high-dimensional state space. Earlier inputs can be retrieved from this projection, albeit less reliably so as more input is received. The bottleneck is therefore not “Now-or-Never” but “Sooner-is-Better.

Abstract

Schizophrenia is a devastating psychiatric illness with high heritability. Brain structure and function differ, on average, between people with schizophrenia and healthy individuals. As common genetic associations are emerging for both schizophrenia and brain imaging phenotypes, we can now use genome-wide data to investigate genetic overlap. Here we integrated results from common variant studies of schizophrenia (33,636 cases, 43,008 controls) and volumes of several (mainly subcortical) brain structures (11,840 subjects). We did not find evidence of genetic overlap between schizophrenia risk and subcortical volume measures either at the level of common variant genetic architecture or for single genetic markers. These results provide a proof of concept (albeit based on a limited set of structural brain measures) and define a roadmap for future studies investigating the genetic covariance between structural or functional brain phenotypes and risk for psychiatric disorders

Abstract

Do people incrementally incorporate the meaning of quantifier expressions to understand an unfolding sentence? Most previous studies concluded that quantifiers do not immediately influence how a sentence is understood based on the observation that online N400-effects differed from offline plausibility judgments. Those studies, however, used serial visual presentation (SVP), which involves unnatural reading. In the current ERP-experiment, we presented spoken positive and negative quantifier sentences (“Practically all/practically no postmen prefer delivering mail, when the weather is good/bad during the day”). Different from results obtained in a previously reported SVP-study (Nieuwland, 2016) sentence truth-value N400 effects occurred in positive and negative quantifier sentences alike, reflecting fully incremental quantifier comprehension. This suggests that the prosodic information available during spoken language comprehension supports the generation of online predictions for upcoming words and that, at least for quantifier sentences, comprehension of spoken language may proceed more incrementally than comprehension during SVP reading.

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

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

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

Language learning requires mastering multiple tasks, including segmenting speech to identify words, and learning the syntactic role of these words within sentences. A key question in language acquisition research is the extent to which these tasks are sequential or successive, and consequently whether they may be driven by distinct or similar computations. We explored a classic artificial language learning paradigm, where the language structure is defined in terms of non-adjacent dependencies. We show that participants are able to use the same statistical information at the same time to segment continuous speech to both identify words and to generalise over the structure, when the generalisations were over novel speech that the participants had not previously experienced. We suggest that, in the absence of evidence to the contrary, the most economical explanation for the effects is that speech segmentation and grammatical generalisation are dependent on similar statistical processing mechanisms.

Abstract

Recent studies suggest that high-frequency words may benefit speech segmentation (Bortfeld, Morgan, Golinkoff, & Rathbun, 2005) and grammatical categorisation (Monaghan, Christiansen, & Chater, 2007). To date, these tasks have been examined separately, but not together. We familiarised adults with continuous speech comprising repetitions of target words, and compared learning to a language in which targets appeared alongside high-frequency marker words. Marker words reliably preceded targets, and distinguished them into two otherwise unidentifiable categories. Participants completed a 2AFC segmentation test, and a similarity judgement categorisation test. We tested transfer to a word-picture mapping task, where words from each category were used either consistently or inconsistently to label actions/objects. Participants segmented the speech successfully, but only demonstrated effective categorisation when speech contained high-frequency marker words. The advantage of marker words extended to the early stages of the transfer task. Findings indicate the same high-frequency words may assist speech segmentation and grammatical categorisation.

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

In list learning paradigms with free recall, written recall has been found to be less susceptible to intrusions of related concepts than spoken recall when the list items had been visually presented. This effect has been ascribed to the use of stored orthographic representations from the study phase during written recall (Kellogg, 2001). In other memory retrieval paradigms, by contrast, either better recall for modality-congruent items or an input-independent writing superiority effect have been found (Grabowski, 2005). In a series of four experiments using a paired associate learning paradigm we tested (a) whether output modality effects on verbal recall can be replicated in a paradigm that does not involve the rejection of semantically related intrusion words, (b) whether a possible superior performance for written recall was due to a slower response onset for writing as compared to speaking in immediate recall, and (c) whether the performance in paired associate word recall was correlated with performance in an additional episodic memory recall task. We observed better written recall in the first half of the recall phase, irrespective of the modality in which the material was presented upon encoding. An explanation for this effect based on longer response latencies for writing and hence more time for memory retrieval could be ruled out by showing that the effect persisted in delayed response versions of the task. Although there was some evidence that stored additional episodic information may contribute to the successful retrieval of associate words, this evidence was only found in the immediate response experiments and hence is most likely independent from the observed output modality effect. In sum, our results from a paired associate learning paradigm suggest that superior performance for written vs. spoken recall cannot be (solely) explained in terms of additional access to stored orthographic representations from the encoding phase. Our findings rather suggest a general writing-superiority effect at the time of memory retrieval.

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

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

Reading with Rapid Serial Visual Presentation (RSVP) has shown promise for optimizing screen space and increasing reading speed without compromising comprehension. Given the wide use of small-screen devices, the present study compared RSVP and traditional reading on three types of reading comprehension, reading speed, and subjective measures on a smart watch. Results confirm previous studies that show faster reading speed with RSVP without detracting from comprehension. Subjective data indicate that Traditional is strongly preferred to RSVP as a primary reading method. Given the optimal use of screen space, increased speed and comparable comprehension, future studies should focus on making RSVP a more comfortable format.

Abstract

The present study investigated whether Short Message Service shortcuts are more difficult to process in sentence context than the spelled-out word equivalent and, if so, how any additional processing difficulty arises. Twenty-four student participants read 37 Short Message Service shortcuts and word equivalents embedded in semantically plausible and implausible contexts (e.g., He left/drank u/you a note) while their eye movements were recorded. There were effects of plausibility and spelling on early measures of processing difficulty (first fixation durations, gaze durations, skipping, and first-pass regression rates for the targets), but there were no interactions of plausibility and spelling. Late measures of processing difficulty (second run gaze duration and total fixation duration) were only affected by plausibility but not by spelling. These results suggest that shortcuts are harder to recognize, but that, once recognized, they are integrated into the sentence context as easily as ordinary words.

Abstract

We investigated whether Tagalog-speaking children incrementally interpret the first noun
as the agent, even if verbal and nominal markers for assigning thematic roles are given
early in Tagalog sentences. We asked five- and seven-year-old children and adult
controls to select which of two pictures of reversible actions matched the sentence they
heard, while their looks to the pictures were tracked. Accuracy and eye-tracking data
showed that agent-initial sentences were easier to comprehend than patient-initial
sentences, but the effect of word order was modulated by voice. Moreover, our eyetracking
data provided evidence that, by the first noun phrase, seven-year-old children
looked more to the target in the agent-initial compared to the patient-initial conditions,
but this word order advantage was no longer observed by the second noun phrase. The
findings support language processing and acquisition models which emphasize the role
of frequency in developing heuristic strategies (e.g., Chang, Dell, & Bock, 2006).

Abstract

We report on two experiments that investigated the acquisition of the Tagalog symmetrical voice system, a typologically rare feature of Western Austronesian languages in which there are more than one basic transitive construction and no preference for agents to be syntactic subjects. In the experiments, 3-, 5-, and 7-year-old Tagalog-speaking children and adults completed a structural priming task that manipulated voice and word order, with the uniqueness of Tagalog allowing us to tease apart priming of thematic role order from that of syntactic roles. Participants heard a description of a picture showing a transitive action, and were then asked to complete a sentence of an unrelated picture using a voice-marked verb provided by the experimenter. Our results show that children gradually acquire an agent-before-patient preference, instead of having a default mapping of the agent to the first noun position. We also found an earlier mastery of the patient voice verbal and nominal marker configuration (patient is the subject), suggesting that children do not initially map the agent to the subject. Children were primed by thematic role but not syntactic role order, suggesting that they prioritize mapping of the thematic roles to sentence positions.

Abstract

Acoustic allometry is the study of how animal vocalisations reflect their body size. A key aim of this research is to identify outliers to acoustic allometry principles and pinpoint the evolutionary origins of such outliers. A parallel strand of research investigates species capable of vocal learning, the experience-driven ability to produce novel vocal signals through imitation or modification of existing vocalisations. Modification of vocalizations is a common feature found when studying both acoustic allometry and vocal learning. Yet, these two fields have only been investigated separately to date. Here, we review and connect acoustic allometry and vocal learning across mammalian clades, combining perspectives from bioacoustics, anatomy and evolutionary biology. Based on this, we hypothesize that, as a precursor to vocal learning, some species might have evolved the capacity for volitional vocal modulation via sexual selection for ‘dishonest’ signalling. We provide preliminary support for our hypothesis by showing significant associations between allometric deviation and vocal learning in a dataset of 164 mammals. Our work offers a testable framework for future empirical research linking allometric principles with the evolution of vocal learning.

Abstract

Communicating species identity is a key component of many animal signals. However, whether selection for species recognition systematically increases signal diversity during clade radiation remains debated. Here we show that in woodpecker drumming, a rhythmic signal used during mating and territorial defense, the amount of species identity information encoded remained stable during woodpeckers’ radiation. Acoustic analyses and evolutionary reconstructions show interchange among six main drumming types despite strong phylogenetic contingencies, suggesting evolutionary tinkering of drumming structure within a constrained acoustic space. Playback experiments and quantification of species discriminability demonstrate sufficient signal differentiation to support species recognition in local communities. Finally, we only find character displacement in the rare cases where sympatric species are also closely related. Overall, our results illustrate how historical contingencies and ecological interactions can promote conservatism in signals during a clade radiation without impairing the effectiveness of information transfer relevant to inter-specific discrimination.

Abstract

Adult mouse ultrasonic vocalizations (USVs) occur in multiple behavioral and stimulus contexts associated with various levels of arousal, emotion, and social interaction. Here, in three experiments of increasing stimulus intensity (water; female urine; male interacting with adult female), we tested the hypothesis that USVs of adult males express the strength of arousal and emotion via different USV parameters (18 parameters analyzed). Furthermore, we analyzed two mouse lines with heterozygous Foxp2 mutations (R552H missense, S321X nonsense), known to produce severe speech and language disorders in humans. These experiments allowed us to test whether intact Foxp2 function is necessary for developing full adult USV repertoires, and whether mutations of this gene influence instinctive vocal expressions based on arousal and emotion. The results suggest that USV calling rate characterizes the arousal level, while sound pressure and spectro-temporal call complexity (overtones/harmonics, type of frequency jumps) may provide indices of levels of positive emotion. The presence of Foxp2 mutations did not qualitatively affect the USVs; all USV types that were found in wild-type animals also occurred in heterozygous mutants. However, mice with Foxp2 mutations displayed quantitative differences in USVs as compared to wild-types, and these changes were context dependent. Compared to wild-type animals, heterozygous mutants emitted mainly longer and louder USVs at higher minimum frequencies with a higher occurrence rate of overtones/harmonics and complex frequency jump types. We discuss possible hypotheses about Foxp2 influence on emotional vocal expressions, which can be investigated in future experiments using selective knockdown of Foxp2 in specific brain circuits.

Abstract

The Perceptual Loop Theory of speech monitoring assumes that speakers routinely inspect their inner speech. In contrast, Huettig and Hartsuiker (2010) observed that listening to one’s own speech during language production drives eye-movements to phonologically related printed words with a similar time-course as listening to someone else’s speech does in speech perception experiments. This suggests that speakers listen to their own overt speech, but not to their inner speech. However, a direct comparison between production and perception with the same stimuli and participants is lacking so far. The current printed word eye-tracking experiment therefore used a within-subjects design, combining production and perception. Displays showed four words, of which one, the target, either had to be named or was presented auditorily. Accompanying words were phonologically related, semantically related, or unrelated to the target. There were small increases in looks to phonological competitors with a similar time-course in both production and perception. Phonological effects in perception however lasted longer and had a much larger magnitude. We conjecture that this difference is related to a difference in predictability of one’s own and someone else’s speech, which in turn has consequences for lexical competition in other-perception and possibly suppression of activation in self-perception.

Abstract

Our species displays remarkable linguistic diversity. While the uneven distribution of this diversity demands explanation, the drivers of these patterns have not been conclusively determined. We address this issue in two steps. First, we review previous empirical studies that have suggested environmental, geographical, and socio-cultural drivers of linguistic diversification. However, contradictory results and methodological variation make it difficult to draw general conclusions. Second, we outline a program for future research. We suggest that future analyses should account for interactions among causal factors, lack of spatial and phylogenetic independence of data, and transitory patterns. Recent analytical advances in biogeography and evolutionary biology, such as simulation modeling of diversity patterns, hold promise for testing four key mechanisms of language diversification proposed here: neutral change, population movement, contact, and selection. Future modeling approaches should also evaluate how the outcomes of these processes are influenced by demography, environmental heterogeneity, and time.

Abstract

Processing of recursion has been proposed as the foundation of human linguistic ability. Yet this ability may be shared with other domains, such as the musical or rhythmic domain. Lindenmayer grammars (L-systems) have been proposed as a recursive grammar for use in artificial grammar experiments to test recursive processing abilities, and previous work had shown that participants are able to learn such a grammar using linguistic stimuli (syllables). In the present work, we used two experimental paradigms (a yes/no task and a two-alternative forced choice) to test whether adult participants are able to learn a recursive Lindenmayer grammar composed of drum sounds. After a brief exposure phase, we found that participants at the group level were sensitive to the exposure grammar and capable of distinguishing the grammatical and ungrammatical test strings above chance level in both tasks. While we found evidence of participants’ sensitivity to a very complex L-system grammar in a non-linguistic, potentially musical domain, the results were not robust. We discuss the discrepancy within our results and with the previous literature using L-systems in the linguistic domain. Furthermore, we propose directions for future music cognition research using L-system grammars.

Abstract

We present the first rhythm detection experiment using a Lindenmayer grammar, a self-similar recursive grammar shown previously to be learnable by adults using speech stimuli. Results show that learners were unable to correctly accept or reject grammatical and ungrammatical strings at the group level, although five (of 40) participants were able to do so with detailed instructions before the exposure phase.

Abstract

We propose a Random-Forest based sign language identification system. The system uses low-level visual features and is based on the hypothesis that sign languages have varying distributions of phonemes (hand-shapes, locations and movements). We evaluated the system on two sign languages -- British SL and Greek SL, both taken from a publicly available corpus, called Dicta Sign Corpus. Achieved average F1 scores are about 95% - indicating that sign languages can be identified with high accuracy using only low-level visual features.

Abstract

We present a vision-based method for signer diarization -- the task of automatically determining "who signed when?" in a video. This task has similar motivations and applications as speaker diarization but has received little attention in the literature. In this paper, we motivate the problem and propose a method for solving it. The method is based on the hypothesis that signers make more movements than their interlocutors. Experiments on four videos (a total of 1.4 hours and each consisting of two signers) show the applicability of the method. The best diarization error rate (DER) obtained is 0.16.

Abstract

This paper presents a Native Language Identification (NLI) system based on TF-IDF weighting schemes and using linear classifiers - support vector machines, logistic regressions and perceptrons. The system was one of the participants of the 2013 NLI Shared Task in the closed-training track, achieving 0.814 overall accuracy for a set of 11 native languages. This accuracy was only 2.2 percentage points lower than the winner's performance. Furthermore, with subsequent evaluations using 10-fold cross-validation (as given by the organizers) on the combined training and development data, the best average accuracy obtained is 0.8455 and the features that contributed to this accuracy are the TF-IDF of the combined unigrams and bigrams of words.

Abstract

We present and solve the speaker diarization problem in a novel way. We hypothesize that the gesturer is the speaker and that identifying the gesturer can be taken as identifying the active speaker. We provide evidence in support of the hypothesis from gesture literature and audio-visual synchrony studies. We also present a vision-only diarization algorithm that relies on gestures (i.e. upper body movements). Experiments carried out on 8.9 hours of a publicly available dataset (the AMI meeting data) show that diarization error rates as low as 15% can be achieved.

Abstract

Does spatial language influence how people think about space? To address this question, we observed children who did not know a conventional language, and tested their performance on nonlinguistic spatial tasks. We studied deaf children living in Istanbul whose hearing losses prevented them from acquiring speech and whose hearing parents had not exposed them to sign. Lacking a conventional language, the children used gestures, called homesigns, to communicate. In Study 1, we asked whether homesigners used gesture to convey spatial relations, and found that they did not. In Study 2, we tested a new group of homesigners on a Spatial Mapping Task, and found that they performed significantly worse than hearing Turkish children who were matched to the deaf children on another cognitive task. The absence of spatial language thus went hand-in-hand with poor performance on the nonlinguistic spatial task, pointing to the importance of spatial language in thinking about space.

Abstract

Not much is known about event apprehension, the earliest stage of information processing in elicited language production studies, using pictorial stimuli. A reason for our lack of knowledge on this process is that apprehension happens very rapidly (<350 ms after stimulus onset, Griffin & Bock 2000), making it difficult to measure the process directly. To broaden our understanding of apprehension, we analyzed landing positions and onset latencies of first fixations on visual stimuli (pictures of real-world events) given short stimulus presentation times, presupposing that the first fixation directly results from information processing during apprehension

Abstract

Wilson disease (WD) is an autosomal recessive disorder resulting in pathological progressive copper accumulation in liver and other tissues. The worldwide prevalence (P) is about 30/million, while in Sardinia it is in the order of 1/10 000. However, all of these estimates are likely to suffer from an underdiagnosis bias. Indeed, a recent molecular neonatal screening in Sardinia reported a WD prevalence of 1:2707. In this study, we used a new approach that makes it possible to estimate the allelic frequency (q) of an autosomal recessive disorder if one knows the proportion between homozygous and compound heterozygous patients (the homozygosity index or HI) and the inbreeding coefficient (F) in a sample of affected individuals. We applied the method to a set of 178 Sardinian individuals (3 of whom born to consanguineous parents), each with a clinical and molecular diagnosis of WD. Taking into account the geographical provenance of the parents of every patient within Sardinia (to make F computation more precise), we obtained a q=0.0191 (F=7.8 × 10-4, HI=0.476) and a corresponding prevalence P=1:2732. This result confirms that the prevalence of WD is largely underestimated in Sardinia. On the other hand, the general reliability and applicability of the HI approach to other autosomal recessive disorders is confirmed, especially if one is interested in the genetic epidemiology of populations with high frequency of consanguineous marriages.

Abstract

Background

Reading and language skills have overlapping genetic bases, most of which are still unknown. Part of the missing heritability may be caused by copy number variants (CNVs).
Methods

In a dataset of children recruited for a history of reading disability (RD, also known as dyslexia) or attention deficit hyperactivity disorder (ADHD) and their siblings, we investigated the effects of CNVs on reading and language performance. First, we called CNVs with PennCNV using signal intensity data from Illumina OmniExpress arrays (~723,000 probes). Then, we computed the correlation between measures of CNV genomic burden and the first principal component (PC) score derived from several continuous reading and language traits, both before and after adjustment for performance IQ. Finally, we screened the genome, probe-by-probe, for association with the PC scores, through two complementary analyses: we tested a binary CNV state assigned for the location of each probe (i.e., CNV+ or CNV−), and we analyzed continuous probe intensity data using FamCNV.
Results

No significant correlation was found between measures of CNV burden and PC scores, and no genome-wide significant associations were detected in probe-by-probe screening. Nominally significant associations were detected (p~10−2–10−3) within CNTN4 (contactin 4) and CTNNA3 (catenin alpha 3). These genes encode cell adhesion molecules with a likely role in neuronal development, and they have been previously implicated in autism and other neurodevelopmental disorders. A further, targeted assessment of candidate CNV regions revealed associations with the PC score (p~0.026–0.045) within CHRNA7 (cholinergic nicotinic receptor alpha 7), which encodes a ligand-gated ion channel and has also been implicated in neurodevelopmental conditions and language impairment. FamCNV analysis detected a region of association (p~10−2–10−4) within a frequent deletion ~6 kb downstream of ZNF737 (zinc finger protein 737, uncharacterized protein), which was also observed in the association analysis using CNV calls.
Conclusions

These data suggest that CNVs do not underlie a substantial proportion of variance in reading and language skills. Analysis of additional, larger datasets is warranted to further assess the potential effects that we found and to increase the power to detect CNV effects on reading and language.

Abstract

First paragraph: The study of the transmission of sign languages can give novel insights into the transmission of spoken languages1 and, more generally, into gene–culture coevolution. Over the years, several papers related to the persistence of sign language have been
reported.2–6 All of these studies have emphasized the role of assortative (non-random) mating by deafness state (ie, a tendency for deaf individuals to partner together) for increasing the frequency of recessive deafness, and hence for the persistence of sign language in a population.

Abstract

How are space and time related in the brain? This study contrasts two proposals that make different predictions about the interaction between spatial and temporal magnitudes. Whereas ATOM implies that space and time are symmetrically related, Metaphor Theory claims they are asymmetrically related. Here we investigated whether space and time activate the same neural structures in the inferior parietal cortex (IPC) and whether the activation is symmetric or asymmetric across domains. We measured participants’ neural activity while they made temporal and spatial judgments on the same visual stimuli. The behavioral results replicated earlier observations of a space-time asymmetry: Temporal judgments were more strongly influenced by irrelevant spatial information than vice versa. The BOLD fMRI data indicated that space and time activated overlapping clusters in the IPC and that, consistent with Metaphor Theory, this activation was asymmetric: The shared region of IPC was activated more strongly during temporal judgments than during spatial judgments. We consider three possible interpretations of this neural asymmetry, based on 3 possible functions of IPC.

Abstract

People often accommodate to each other's speech by aligning their linguistic production with their partner's. According to an influential theory, the Interactive Alignment Model (Pickering & Garrod, 2004), alignment is the result of priming. When people perceive an utterance, the corresponding linguistic representations are primed, and become easier to produce. Here we tested this theory by investigating whether pitch (F0) alignment shows two characteristic signatures of priming: dose dependence and persistence. In a virtual reality experiment, we manipulated the pitch of a virtual interlocutor's speech to find out (a.) whether participants accommodated to the agent's F0, (b.) whether the amount of accommodation increased with increasing exposure to the agent's speech, and (c.) whether changes to participants' F0 persisted beyond the conversation. Participants accommodated to the virtual interlocutor, but accommodation did not increase in strength over the conversation, and it disappeared immediately after the conversation ended. Results argue against a priming-based account of F0 accommodation, and indicate that an alternative mechanism is needed to explain alignment along continuous dimensions of language such as speech rate and pitch.

Abstract

Regional variation in African-American English (AAE) is especially salient to its speakers involved with hip-hop culture, as hip-hop assigns great importance to regional identity and regional accents are a key means of expressing regional identity. However, little is known about AAE regional variation regarding prosodic rhythm and melody. In hip-hop music, regional variation can also be observed, with different regions’ rap performances being characterized by distinct “flows” (i.e., rhythmic and melodic delivery), an observation which has not been quantitatively investigated yet. This study concerns regional variation in AAE speech and rap, specifically regarding the United States’ East and West Coasts. It investigates how East Coast and West Coast AAE prosody are distinct, how East Coast and West Coast rap flows differ, and whether the two domains follow a similar pattern: more rhythmic and melodic variation on the West Coast compared to the East Coast for both speech and rap. To this end, free speech and rap recordings of 16 prominent African-American members of the East Coast and West Coast hip-hop communities were phonetically analyzed regarding rhythm (e.g., syllable isochrony and musical timing) and melody (i.e., pitch fluctuation) using a combination of existing and novel methodological approaches. The results mostly confirm the hypotheses that East Coast AAE speech and rap are less rhythmically diverse and more monotone than West Coast AAE speech and rap, respectively. They also show that regional variation in AAE prosody and rap flows pattern in similar ways, suggesting a connection between rhythm and melody in language and music.

Abstract

According to the cue-based parsing approach (Lewis, Vasishth, & Van Dyke, 2006), sentence comprehension difficulty derives from interference from material that partially matches syntactic and semantic retrieval cues. In a 2 (low vs. high semantic interference) × 2 (low vs. high syntactic interference) fMRI study, greater activation was observed in left BA44/45 for high versus low syntactic interference conditions following sentences and in left BA45/47 for high versus low semantic interference conditions following comprehension questions. A conjunction analysis showed BA45 associated with both types of interference, while BA47 was associated with only semantic interference. Greater activation was also observed in the left STG in the high interference conditions. Importantly, the results for the LIFG could not be attributed to greater working memory capacity demands for high interference conditions. The results favor a fractionation of the LIFG wherein BA45 is associated with post-retrieval selection and BA47 with controlled retrieval of semantic information.

Abstract

Comparative thanatology encompasses the study of death-related responses in non-human animals and aspires to elucidate the evolutionary origins of human behavior in the context of death. Many reports have revealed that humans are not the only species affected by the death of group members. Non-human primates in particular show behaviors such as congregating around the deceased, carrying the corpse for prolonged periods of time (predominantly mothers carrying dead infants), and inspecting the corpse for signs of life. Here, we extend the focus on death-related responses in non-human animals by exploring whether chimpanzees are inclined to console the bereaved: the individual(s) most closely associated with the deceased. We report a case in which a chimpanzee (Pan troglodytes) mother experienced the loss of her fully developed infant (presumed stillborn). Using observational data to compare the group members’ behavior before and after the death, we found that a substantial number of group members selectively increased their affiliative expressions toward the bereaved mother. Moreover, on the day of the death, we observed heightened expressions of species-typical reassurance behaviors toward the bereaved mother. After ruling out several alternative explanations, we propose that many of the chimpanzees consoled the bereaved mother by means of affiliative and selective empathetic expressions.

Abstract

Native listeners make use of higher-level, context-driven semantic and linguistic information during the perception of speech-in-noise. In a recent behavioral study, using a new paradigm that isolated the semantic level of speech by using words, we showed that this native-language benefit is at least partly driven by semantic context (Golestani et al., 2009). Here, we used the same paradigm in a functional magnetic resonance imaging (fMRI) experiment to study the neural bases of speech intelligibility, as well as to study the neural bases of this semantic context effect in the native language. A forced-choice recognition task on the first of two auditorily presented semantically related or unrelated words was employed, where the first, 'target' word was embedded in different noise levels. Results showed that activation in components of the brain language network, including Broca's area and the left posterior superior temporal sulcus, as well as brain regions known to be functionally related to attention and task difficulty, was modulated by stimulus intelligibility. In line with several previous studies examining the role of linguistic context in the intelligibility of degraded speech at the sentence level, we found that activation in the angular gyrus of the left inferior parietal cortex was modulated by the presence of semantic context, and further, that this modulation depended on the intelligibility of the speech stimuli. Our findings help to further elucidate neural mechanisms underlying the interaction of context-driven and signal-driven factors during the perception of degraded speech, and this specifically at the semantic level. (c) 2013 Elsevier Inc. All rights reserved.

Abstract

The present article examines the proposal that typology is a major factor guiding transfer selectivity in L3/Ln acquisition. We tested first exposure in L3/Ln using two artificial languages (ALs) lexically based in English and Spanish, focusing on gender agreement between determiners and nouns, and between nouns and adjectives. 50 L1 Spanish-L2 English speakers took part in the experiment. After receiving implicit training in one of the ALs (Mini-Spanish, N = 26; Mini-English, N = 24), gender violations elicited a fronto-lateral negativity in Mini-English in the earliest time window (200–500 ms), although this was not followed by any other differences in subsequent periods. This effect was highly localized, surfacing only in electrodes of the right-anterior region. In contrast, gender violations in Mini-Spanish elicited a broadly distributed positivity in the 300–600 ms time window. While we do not find typical indices of grammatical processing such as the P600 component, we believe that the between-groups differential appearance of the positivity for gender violations in the 300–600 ms time window reflects differential allocation of attentional resources as a function of the ALs’ lexical similarity to English or Spanish. We take these differences in attention to be precursors of the processes involved in transfer source selection in L3/Ln.

Abstract

Humans associate abstract words with physical stimulus dimensions, such as linking upward locations with positive concepts (e.g., happy = up). These associations manifest both via subjective reports of associations and on objective performance metrics. Humans also report subjective associations between colours and abstract words (e.g., joy is linked to yellow). Here we tested whether such associations manifest on objective task performance, even when not task-relevant. Across three experiments, participants were presented with abstract words in physical colours that were either congruent with previously-reported subjective word-colour associations (e.g., victory in red and unhappy in blue), or were incongruent (e.g., victory in blue and unhappy in red). In Experiment 1, participants' task was to identify the valence of words. This congruency manipulation systematically affected objective task performance. In Experiment 2, participants completed two blocks, a valence-identification and a colour-identification task block. Both tasks produced congruency effects on performance, however, the results of the colour identification block could have reflected learning effects (i.e., associating the more common congruent colour with the word). This issue was rectified in Experiment 3, whereby participants completed the same two tasks as Experiment 2, but now matched congruent and incongruent pairs were used for both tasks. Again, both tasks produced reliable congruency effects. Item analyses in each experiment revealed that these effects demonstrated a degree of item specificity. Overall, there was clear evidence that at least some abstract word-colour pairings can systematically affect behaviour.

Abstract

Humans appear to rely on spatial mappings to describe and represent concepts. In particular, conceptual cueing refers to the effect whereby after reading or hearing a particular word, the location of observers’ visual attention in space can be systematically shifted in a particular direction. For example, words such as “sun” and “happy” orient attention upwards, whereas words such as “basement” and “bitter” orient attention downwards. This area of research has garnered much interest, particularly within the embodied cognition framework, for its potential to enhance our understanding of the interaction between abstract cognitive processes such as language and basic visual processes such as attention and stimulus processing. To date, however, this area has relied on subjective classification criteria to determine whether words ought to be classified as having a meaning that implies “up” or “down.” The present study, therefore, provides a set of 498 items that have each been systematically rated by over 90 participants, providing refined, continuous measures of the extent to which people associate given words with particular spatial dimensions. The resulting database provides an objective means to aid item-selection for future research in this area.

Abstract

Rapid automatized naming (RAN) is strongly related to literacy gains in developing readers, reading disabilities, and reading ability in children and adults. Because successful RAN performance depends on the close coordination of a number of abilities, it is unclear what specific skills drive this RAN-reading relationship. The current study used concurrent recordings of young adult participants' vocalizations and eye movements during the RAN task to assess how individual variation in RAN performance depends on the coordination of visual and vocal processes. Results showed that fast RAN times are facilitated by having the eyes 1 or more items ahead of the current vocalization, as long as the eyes do not get so far ahead of the voice as to require a regressive eye movement to an earlier item. These data suggest that optimizing RAN performance is a problem of scheduling eye movements and vocalization given memory constraints and the efficiency of encoding and articulatory control. Both RAN completion time (conventionally used to indicate RAN performance) and eye-voice relations predicted some aspects of participants' eye movements on a separate sentence reading task. However, eye-voice relations predicted additional features of first-pass reading that were not predicted by RAN completion time. This shows that measurement of eye-voice patterns can identify important aspects of individual variation in reading that are not identified by the standard measure of RAN performance. We argue that RAN performance predicts reading ability because both tasks entail challenges of scheduling cognitive and linguistic processes that operate simultaneously on multiple linguistic inputs

Abstract

The activity of reading raises fundamental theoretical and practical questions about healthy cognitive aging. Reading relies greatly on knowledge of patterns of language and of meaning at the level of words and topics of text. Further, this knowledge must be rapidly accessed so that it can be coordinated with processes of perception, attention, memory and motor control that sustain skilled reading at rates of four-to-five words a second. As such, reading depends both on crystallized semantic intelligence which grows or is maintained through healthy aging, and on components of fluid intelligence which decline with age. Reading is important to older adults because it facilitates completion of everyday tasks that are essential to independent living. In addition, it entails the kind of active mental engagement that can preserve and deepen the cognitive reserve that may mitigate the negative consequences of age-related changes in the brain. This chapter reviews research on the front end of reading (word recognition) and on the back end of reading (text memory) because both of these abilities are surprisingly robust to declines associated with cognitive aging. For word recognition, that robustness is surprising because rapid processing of the sort found in reading is usually impaired by aging; for text memory, it is surprising because other types of episodic memory performance (e.g., paired associates) substantially decline in aging. These two otherwise quite different levels of reading comprehension remain robust because they draw on the knowledge of language that older adults gain through a life-time of experience with language.

Abstract

Background: While persons with aphasia (PwA) are often dichotomised as fluent or nonfluent, agreement that fluency is not an all-or-nothing construct has led to the use of continuous variables as a way to quantify fluency, such as multi-dimensional rating scales, speech rate, and utterance length. Though these measures are often used in research, they provide little information about the underlying fluency deficit.
Aim: The aim of the study was to identify how well commonly used continuous measures of fluency capture variability in spontaneous speech variables at lexical, grammatical, and speech production levels. Methods & Procedures: Speech samples of 254 English-speaking PwA from the AphasiaBank database were analyzed to examine the distributions of four continuous measures of fluency: the WAB-R fluency scale, utterance length, retracing, and speech rate. Linear regression was used to identify spontaneous speech predictors contributing to each fluency outcome measure.
Outcomes & Results: All the outcome measures reflected the influence of multiple underlying dimensions, although the predictors varied. The WAB-R fluency scale, speech rate, and retracing were influenced by measures of grammatical competence, lexical retrieval, and speech production, whereas utterance length was influenced only by measures of grammatical competence and lexical retrieval. The strongest predictor of WAB-R fluency was aphasia severity, whereas the strongest predictor for all other fluency proxy measures was grammatical complexity.
Conclusions: Continuous measures allow a variety of ways to objectively quantify speech fluency; however, they reflect superficial manifestations of fluency that may be affected by multiple underlying deficits. Furthermore, the deficits underlying different measures vary, which may reduce the reliability of fluency diagnoses. Capturing these differences at the individual level is critical to accurate diagnosis and appropriately targeted therapy.

Abstract

Our aim in the present study is to measure neural correlates during spontaneous interactive sentence production. We present a novel approach using the word-by-word technique from improvisational theatre, in which two speakers jointly produce one sentence. This paradigm allows the assessment of behavioural aspects, such as turn-times, and electrophysiological responses, such as event-related-potentials (ERPs). Twenty-five participants constructed a cued but spontaneous four-word German sentence together with a confederate, taking turns for each word of the sentence. In 30% of the trials, the confederate uttered an unexpected gender-marked article. To complete the sentence in a meaningful way, the participant had to detect the violation and retrieve and utter a new fitting response. We found significant increases in response times after unexpected words and – despite allowing unscripted language production and naturally varying speech material – successfully detected significant N400 and P600 ERP effects for the unexpected word. The N400 EEG activity further significantly predicted the response time of the subsequent turn. Our results show that combining behavioural and neuroscientific measures of verbal interactions while retaining sufficient experimental control is possible, and that this combination provides promising insights into the mechanisms of spontaneous spoken dialogue.

Abstract

The aim of this study was to investigate whether early-English education benefits the perception
of English phonetic contrasts that are known to be perceptually confusable for Dutch
native speakers, comparing Dutch pupils who were enrolled in an early-English programme
at school from the age of four with pupils in a mainstream programme with English instruction
from the age of 11, and English-Dutch early bilingual children. Children were 4-5-yearolds
(start of primary school), 8-9-year-olds, or 11-12-year-olds (end of primary school).
Children were tested on four contrasts that varied in difficulty: /b/-/s/ (easy), /k/-/ɡ/ (intermediate),
/f/-/θ/ (difficult), /ε/-/æ/ (very difficult). Bilingual children outperformed the two other
groups on all contrasts except /b/-/s/. Early-English pupils did not outperform mainstream
pupils on any of the contrasts. This shows that early-English education as it is currently
implemented is not beneficial for pupils’ perception of non-native contrasts.

Abstract

Aims: We aimed to investigate whether bilingual pupil’s perceptions of teachers’ appreciation of their home language were of influence on bilingual cognitive advantages.
Design: We examined whether Dutch bilingual primary school pupils who speak either German or Turkish at home differed in perceptions of their teacher’s appreciation of their HL, and whether these differences could explain differences between the two groups in executive functioning.
Data and analysis: Executive functioning was measured through computer tasks, and perceived home language appreciation through orally administered questionnaires. The relationship between the two was assessed with regression analyses.
Findings: German-Dutch pupils perceived there to be more appreciation of their home language from their teacher than Turkish-Dutch pupils. This difference did partly explain differences in executive functioning. Besides, we replicated bilingual advantages in nonverbal working memory and switching, but not in verbal working memory or inhibition.
Originality and significance: This study demonstrates that bilingual advantages cannot be dissociated from the influence of the sociolinguistic context of the classroom. Thereby, it stresses the importance of culturally responsive teaching.

Abstract

Benefits of being bilingual? The relationship between pupils’ perceptions of
teachers’ appreciation of their home language and executive functioning
We aimed to investigate whether bilingual pupils’ perceptions of their
teachers’ appreciation of their Home Language (HL) were of influence on
bilingual cognitive advantages. We examined whether Dutch bilingual primary
school pupils who speak either German or Turkish at home differed in
perceptions of their teacher’s appreciation of their HL, and whether these
differences could explain differences between the two groups in executive
functioning. Executive functioning was measured through computer tasks,
and perceived HL appreciation through orally administered questionnaires.
The relationship between the two was assessed with regression analyses.
German-Dutch pupils perceived more appreciation of their home language
from their teacher than Turkish-Dutch pupils did. This difference partly
explained differences in executive functioning. Besides, we replicated bilingual
advantages in nonverbal working memory and switching, but not in
verbal working memory or inhibition. This study demonstrates that bilingual
advantages cannot be dissociated from the influence of the sociolinguistic
context of the classroom. Thereby, it stresses the importance of culturally
responsive teaching.

Abstract

In recent years, the influence of alpha (7–13 Hz) phase on visual processing has received a lot of attention. Magneto‐/encephalography (M/EEG) studies showed that alpha phase indexes visual excitability and task performance. Studies with transcranial alternating current stimulation (tACS) aim to modulate oscillations and causally impact task performance. Here, we applied right occipital tACS (O2 location) to assess the functional role of alpha phase in a series of experiments. We presented visual stimuli at different pre‐determined, experimentally controlled, phases of the entraining tACS signal, hypothesizing that this should result in an oscillatory pattern of visual performance in specifically left hemifield detection tasks. In experiment 1, we applied 10 Hz tACS and used separate psychophysical staircases for six equidistant tACS‐phase conditions, obtaining contrast thresholds for detection of visual gratings in left or right hemifield. In experiments 2 and 3, tACS was at EEG‐based individual peak alpha frequency. In experiment 2, we measured detection rates for gratings with (pseudo‐)fixed contrast. In experiment 3, participants detected brief luminance changes in a custom‐built LED device, at eight equidistant alpha phases. In none of the experiments did the primary outcome measure over phase conditions consistently reflect a one‐cycle sinusoid. However, post hoc analyses of reaction times (RT) suggested that tACS alpha phase did modulate RT for specifically left hemifield targets in both experiments 1 and 2 (not measured in experiment 3). This observation requires future confirmation, but is in line with the idea that alpha phase causally gates visual inputs through cortical excitability modulation.

Abstract

Researchers are beginning to uncover the neurogenetic pathways that underlie our unparalleled capacity for spoken language. Initial clues come from identification of genetic risk factors implicated in developmental language disorders. The underlying genetic architecture is complex, involving a range of molecular mechanisms. For example, rare protein-coding mutations of the FOXP2 transcription factor cause severe problems with sequencing of speech sounds, while common genetic risk variants of small effect size in genes like CNTNAP2, ATP2C2 and CMIP are associated with typical forms of language impairment. In this article, we describe how investigations of these and other candidate genes, in humans, animals and cellular models, are unravelling the connections between genes and cognition. This depends on interdisciplinary research at multiple levels, from determining molecular interactions and functional roles in neural cell-biology all the way through to effects on brain structure and activity.

Abstract

The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson’s disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder.

Abstract

Absolute pitch and synesthesia are two uncommon cognitive traits that reflect increased neuronal connectivity and have been anecdotally reported to occur together in a same individual. Here we systematically evaluate the occurrence of syesthesia in a population of 768 subjects with documented absolute pitch. Out of these 768 subjects, 151(20.1%) reported synesthesia, most commonly with color. These self-reports of synesthesia were validated in a subset of 21 study subjects using an established methodology. We further carried out combined linkage analysis of 53 multiplex families with absolute pitch and 36 multiplex families with synesthesia. We observed a peak NPL LOD=4.68 on chromosome 6q, as well as evidence of linkage on chromosome 2 using a dominant model. These data establish the close phenotypic and genetic relationship between absolute pitch and synesthesia. The chromosome 6 linkage region contains 73 genes; several leading candidate genes involved in neurodevelopment were investigated by exon resequencing. However, further studies will be required to definitively establish the identity of the causative gene(s) in the region.

Abstract

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

Abstract

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

Abstract

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

Abstract

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

Abstract

Magnetoencephalographic (MEG) recordings are a rich source of information about the neural dynamics underlying cognitive processes in the brain, with excellent temporal and good spatial resolution. In recent years there have been considerable advances in MEG hardware developments as well as methodological developments. Sophisticated analysis techniques are now routinely applied and continuously improved, leading to fascinating insights into the intricate dynamics of neural processes. However, the rapidly increasing level of complexity of the different steps in a MEG study make it difficult for novices, and sometimes even for experts, to stay aware of possible limitations and caveats. Furthermore, the complexity of MEG data acquisition and data analysis requires special attention when describing MEG studies in publications, in order to facilitate interpretation and reproduction of the results. This manuscript aims at making recommendations for a number of important data acquisition and data analysis steps and suggests details that should be specified in manuscripts reporting MEG studies. These recommendations will hopefully serve as guidelines that help to strengthen the position of the MEG research community within the field of neuroscience, and may foster discussion within the community in order to further enhance the quality and impact of MEG research.