Publications

Abstract

Based on an analysis of 350 questions and their responses in a corpus of ordinary interactions, this paper gives a descriptive overview of the ways Dutch interactants formulate their utterances to make them recognizable as doing questioning and the options they rely on to respond to these questions. I describe the formal options for formulating questions and responses in Dutch and the range of social actions (e.g. requests for information, requests for confirmation) that are implemented through questions in the corpus. Finally, I focus on answer design and discuss some of the coherence relations between questions, answers, and social actions. Questions that are asked to elicit information are associated with the more prototypical, lexico-morpho-syntactically defined question type such as polar interrogatives and, mainly, content questions. Most polar questions with declarative syntax are not primarily concerned with obtaining information but with doing other kinds of social actions

Abstract

One of the fundamental issues for a language is its capacity to express
argument structure unambiguously. This study presents evidence
for the emergence and the incremental development of these
basic mechanisms in a newly developing language, Central Taurus
Sign Language. Our analyses identify universal patterns in both the
emergence and development of these mechanisms and in languagespecific
trajectories.

Abstract

Among the most fascinating data for phonology are those showing how speakers incorporate new words and foreign words into their language system, since these data provide cues to the actual principles underlying language. In this article, we address how speakers deal with neutralized obstruents in new words. We formulate four hypotheses and test them on the basis of Dutch word-final obstruents, which are neutral for [voice]. Our experiments show that speakers predict the characteristics ofneutralized segments on the basis ofphonologically similar morphemes stored in the mental lexicon. This effect of the similar morphemes can be modeled in several ways. We compare five models, among them STOCHASTIC OPTIMALITY THEORY and ANALOGICAL MODELING OF LANGUAGE; all perform approximately equally well, but they differ in their complexity, with analogical modeling oflanguage providing the most economical explanation.

Abstract

This paper discusses four experiments on Dutch which show that distinctive phonological features differ in their relevance for word recognition. The relevance of a feature for word recognition depends on its phonological stability, that is, the extent to which that feature is generally realized in accordance with its lexical specification in the relevant word position. If one feature value is uninformative, all values of that feature are less relevant for word recognition, with the least informative feature being the least relevant. Features differ in their relevance both in spoken and written word recognition, though the differences are more pronounced in auditory lexical decision than in self-paced reading.

Abstract

This study addresses the question to what extent the production of regular past tense forms in Dutch is a¤ected by analogical processes. We report an experiment in which native speakers of Dutch listened to existing regular verbs over headphones, and had to indicate which of the past tense allomorphs, te or de, was appropriate for these verbs. According to generative analyses, the choice between the two su‰xes is completely regular and governed by the underlying [voice]-specification of the stem-final segment. In this approach, no analogical e¤ects are expected. In connectionist and analogical approaches, by contrast, the phonological similarity structure in the lexicon is expected to a¤ect lexical processing. Our experimental results support the latter approach: all participants created more nonstandard past tense forms, produced more inconsistency errors, and responded more slowly for verbs with stronger analogical support for the nonstandard form.

Abstract

Amsterdam klinkt in informele gesprekken vaak als Amsdam en Rotterdam als Rodam, zonder dat de meeste moedertaalsprekers zich daar bewust van zijn. In alledaagse situaties valt een aanzienlijk deel van de klanken weg. Daarnaast worden veel klanken zwakker gearticuleerd (bijvoorbeeld een d als een j, als de mond niet helemaal afgesloten wordt). Het lijkt waarschijnlijk dat deze half uitgesproken woorden een probleem vormen voor tweedetaalleerders. Gereduceerde vormen kunnen immers sterk afwijken van de vormen die deze leerders geleerd hebben. Of dit werkelijk zo is, hebben de auteurs onderzocht in twee studies. Voordat ze deze twee studies bespreken, vertellen ze eerst kort iets over de verschillende typen reducties die voorkomen.

Abstract

Manganese (Mn2+)-enhanced magnetic resonance imaging (MEMRI) offers the possibility to generate longitudinal maps of brain activity in unrestrained and behaving animals. However, Mn2+ is a metabolic toxin and a competitive inhibitor for Ca2+, and therefore, a yet unsolved question in MEMRI studies is whether the concentrations of metal ion used may alter brain physiology. In the present work we have investigated the behavioral, electrophysiological and histopathological consequences of MnCl2 administration at concentrations and dosage protocols regularly used in MEMRI. Three groups of animals were sc injected with saline, 0.1 and 0.5 mmol/kg MnCl2, respectively. In vivo electrophysiological recordings in the hippocampal formation revealed a mild but detectable decrease in both excitatory postsynaptic potentials (EPSP) and population spike (PS) amplitude under the highest MnCl2 dose. The EPSP to PS ratio was preserved at control levels, indicating that neuronal excitability was not affected. Experiments of pair pulse facilitation demonstrated a dose dependent increase in the potentiation of the second pulse, suggesting presynaptic Ca2+ competition as the mechanism for the decreased neuronal response. Tetanization of the perforant path induced a long-term potentiation of synaptic transmission that was comparable in all groups, regardless of treatment. Accordingly, the choice accuracy tested on a hippocampal-dependent learning task was not affected. However, the response latency in the same task was largely increased in the group receiving 0.5 mmol/kg of MnCl2. Immunohistological examination of the hippocampus at the end of the experiments revealed no sign of neuronal toxicity or glial reaction. Although we show that MEMRI at 0.1 mmol/Kg MnCl2 may be safely applied to the study of cognitive networks, a detailed assessment of toxicity is strongly recommended for each particular study and Mn2+ administration protocol.

Abstract

Magnetic resonance imaging (MRI) is widely used in basic and clinical research to map the structural and functional organization of the brain. An important need of MR research is for contrast agents that improve soft-tissue contrast, enable visualization of neuronal tracks, and enhance the capacity of MRI to provide functional information at different temporal scales. Unchelated manganese can be such an agent, and manganese-enhanced MRI (MEMRI) can potentially be an excellent technique for localization of brain activity (for review see Silva et al., 2004). Yet, the toxicity of manganese presents a major limitation for employing MEMRI in behavioral paradigms. We have tested systematically the voluntary wheel running behavior of rats after systemic application of MnCl2 in a dose range of 16–80 mg/kg, which is commonly used in MEMRI studies. The results show a robust dose-dependent decrease in motor performance, which was accompanied by weight loss and decrease in food intake. The adverse effects lasted for up to 7 post-injection days. The lowest dose of MnCl2 (16 mg/kg) produced minimal adverse effects, but was not sufficient for functional mapping. We have therefore evaluated an alternative method of manganese delivery via osmotic pumps, which provide a continuous and slow release of manganese. In contrast to a single systemic injection, the pump method did not produce any adverse locomotor effects, while achieving a cumulative concentration of manganese (80 mg/kg) sufficient for functional mapping. Thus, MEMRI with such an optimized manganese delivery that avoids toxic effects can be safely applied for longitudinal studies in behaving animals.

Abstract

FOXP transcription factors play important roles in neurodevelopment, but little is known about how their transcriptional activity is regulated. FOXP proteins cooperatively regulate gene expression by forming homo- and hetero-dimers with each other. Physical associations with other transcription factors might also modulate the functions of FOXP proteins. However, few FOXP-interacting transcription factors have been identified so far. Therefore, we sought to discover additional transcription factors that interact with the brain-expressed FOXP proteins, FOXP1, FOXP2 and FOXP4, through affinity-purifications of protein complexes followed by mass spectrometry. We identified seven novel FOXP-interacting transcription factors (NR2F1, NR2F2, SATB1, SATB2, SOX5, YY1 and ZMYM2), five of which have well-established roles in cortical development. Accordingly, we found that these transcription factors are co-expressed with FoxP2 in the deep layers of the cerebral cortex and also in the Purkinje cells of the cerebellum, suggesting that they may cooperate with the FoxPs to regulate neural gene expression in vivo. Moreover, we demonstrated that etiological mutations of FOXP1 and FOXP2, known to cause neurodevelopmental disorders, severely disrupted the interactions with FOXP-interacting transcription factors. Additionally, we pinpointed specific regions within FOXP2 sequence involved in mediating these interactions. Thus, by expanding the FOXP interactome we have uncovered part of a broader neural transcription factor network involved in cortical development, providing novel molecular insights into the transcriptional architecture underlying brain development and neurodevelopmental disorders.

Abstract

Mutations affecting the transcription factor FOXP2 cause a rare form of severe speech and language disorder. Although it is clear that sufficient FOXP2 expression is crucial for normal brain development, little is known about how this transcription factor is regulated. To investigate post-translational mechanisms for FOXP2 regulation, we searched for protein interaction partners of FOXP2, and identified members of the PIAS family as novel FOXP2 interactors. PIAS proteins mediate post-translational modification of a range of target proteins with small ubiquitin-like modifiers (SUMOs). We found that FOXP2 can be modified with all three human SUMO proteins and that PIAS1 promotes this process. An aetiological FOXP2 mutation found in a family with speech and language disorder markedly reduced FOXP2 SUMOylation. We demonstrate that FOXP2 is SUMOylated at a single major site, which is conserved in all FOXP2 vertebrate orthologues and in the paralogues FOXP1 and FOXP4. Abolishing this site did not lead to detectable changes in FOXP2 subcellular localization, stability, dimerization or transcriptional repression in cellular assays, but the conservation of this site suggests a potential role for SUMOylation in regulating FOXP2 activity in vivo.

Abstract

Human language offers rich ways to track, compare, and engage the attentional and epistemic states of interlocutors. While this task is central to everyday communication, our knowledge of the cross-linguistic grammatical means that target such intersubjective coordination has remained basic. In two serialised papers, we introduce the term ‘engagement’ to refer to grammaticalised means for encoding the relative mental directedness of speaker and addressee towards an entity or state of affairs, and describe examples of engagement systems from around the world. Engagement systems express the speaker’s assumptions about the degree to which their attention or knowledge is shared (or not shared) by the addressee. Engagement categories can operate at the level of entities in the here-and-now (deixis), in the unfolding discourse (definiteness vs indefiniteness), entire event-depicting propositions (through markers with clausal scope), and even metapropositions (potentially scoping over evidential values). In this first paper, we introduce engagement and situate it with respect to existing work on intersubjectivity in language. We then explore the key role of deixis in coordinating attention and expressing engagement, moving through increasingly intercognitive deictic systems from those that focus on the the location of the speaker, to those that encode the attentional state of the addressee.

Abstract

Engagement systems encode the relative accessibility of an entity or state of affairs to the speaker and addressee, and are thus underpinned by our social cognitive capacities. In our first foray into engagement (Part 1), we focused on specialised semantic contrasts as found in entity-level deictic systems, tailored to the primal scenario for establishing joint attention. This second paper broadens out to an exploration of engagement at the level of events and even metapropositions, and comments on how such systems may evolve. The languages Andoke and Kogi demonstrate what a canonical system of engagement with clausal scope looks like, symmetrically assigning ‘knowing’ and ‘unknowing’ values to speaker and addressee. Engagement is also found cross-cutting other epistemic categories such as evidentiality, for example where a complex assessment of relative speaker and addressee awareness concerns the source of information rather than the proposition itself. Data from the language Abui reveal that one way in which engagement systems can develop is by upscoping demonstratives, which normally denote entities, to apply at the level of events. We conclude by stressing the need for studies that focus on what difference it makes, in terms of communicative behaviour, for intersubjective coordination to be managed by engagement systems as opposed to other, non-grammaticalised means.

Abstract

Childhood adversity (CA) has been associated with long-term structural brain alterations and an increased risk for psychiatric disorders. Evidence is emerging that subtypes of CA, varying in the dimensions of threat and deprivation, lead to distinct neural and behavioral outcomes. However, these specific associations have yet to be established without potential confounders such as psychopathology. Moreover, differences in neural development and psychopathology necessitate the exploration of sexual dimorphism. Young healthy adult subjects were selected based on history of CA from a large database to assess gray matter (GM) differences associated with specific subtypes of adversity. We compared voxel-based morphometry data of subjects reporting specific childhood exposure to abuse (n = 127) or deprivation (n = 126) and a similar sized group of controls (n = 129) without reported CA. Subjects were matched on age, gender, and educational level. Differences between CA subtypes were found in the fusiform gyrus and middle occipital gyms, where subjects with a history of deprivation showed reduced GM compared with subjects with a history of abuse. An interaction between sex and CA subtype was found. Women showed less GM in the visual posterior precuneal region after both subtypes of CA than controls. Men had less GM in the postcentral gyms after childhood deprivation compared with abuse. Our results suggest that even in a healthy population, CA subtypes are related to specific alterations in brain structure, which are modulated by sex. These findings may help understand neurodevelopmental consequences related to CA

Abstract

We make the case that, contra standard assumption in linguistic theory, the sound systems of human languages are adapted to their environment. While not conclusive, this plausible case rests on several points discussed in this work: First, human behavior is generally adaptive and the assumption that this characteristic does not extend to linguistic structure is empirically unsubstantiated. Second, animal communication systems are well known to be adaptive within species across a variety of phyla and taxa. Third, research in laryngology demonstrates clearly that ambient desiccation impacts the performance of the human vocal cords. The latter point motivates a clear, testable hypothesis with respect to the synchronic global distribution of language types. Fourth, this hypothesis is supported in our own previous work, and here we discuss new approaches being developed to further explore the hypothesis. We conclude by suggesting that the time has come to more substantively examine the possibility that linguistic sound systems are adapted to their physical ecology

Abstract

We begin by thanking the respondents for their thoughtful comments and insightful leads. The overall impression we are left with by this exchange is one of progress, even if no consensus remains about the particular hypothesis we raise. To date, there has been a failure to seriously engage with the possibility that humans might adapt their communication to ecological factors. In these exchanges, we see signs of serious engagement with that possibility. Most respondents expressed agreement with the notion that our central premise—that language is ecologically adaptive—requires further exploration and may in fact be operative. We are pleased to see this shift in discourse, and to witness a heightening appreciation of possible ecological constraints on language evolution. It is that shift in discourse that represents progress in our view. Our hope is that future work will continue to explore these issues, paying careful attention to the fact that the human larynx is clearly sensitive to characteristics of ambient air. More generally, we think this exchange is indicative of the growing realization that inquiries into language development must consider potential external factors (see Dediu 2015)...

Abstract

In contrast to the large amount of dual-task research investigating the coordination of a linguistic and a nonlinguistic
task, little research has investigated how two linguistic tasks are coordinated. However, such research
would greatly contribute to our understanding of how interlocutors combine speech planning and listening in
conversation. In three dual-task experiments we studied how participants coordinated the processing of an
auditory stimulus (S1), which was either a syllable or a tone, with selecting a name for a picture (S2). Two SOAs,
of 0 ms and 1000 ms, were used. To vary the time required for lexical selection and to determine when lexical
selection took place, the pictures were presented with categorically related or unrelated distractor words. In
Experiment 1 participants responded overtly to both stimuli. In Experiments 2 and 3, S1 was not responded to
overtly, but determined how to respond to S2, by naming the picture or reading the distractor aloud. Experiment
1 yielded additive effects of SOA and distractor type on the picture naming latencies. The presence of semantic
interference at both SOAs indicated that lexical selection occurred after response selection for S1. With respect to
the coordination of S1 and S2 processing, Experiments 2 and 3 yielded inconclusive results. In all experiments,
syllables interfered more with picture naming than tones. This is likely because the syllables activated phonological
representations also implicated in picture naming. The theoretical and methodological implications of the
findings are discussed.

Abstract

Myopia, currently at epidemic levels in East Asia, is a leading cause of untreatable visual impairment. Genome-wide association studies (GWAS) in adults have identified 39 loci associated with refractive error and myopia. Here, the age-of-onset of association between genetic variants at these 39 loci and refractive error was investigated in 5200 children assessed longitudinally across ages 7-15 years, along with gene-environment interactions involving the major environmental risk-factors, nearwork and time outdoors. Specific variants could be categorized as showing evidence of: (a) early-onset effects remaining stable through childhood, (b) early-onset effects that progressed further with increasing age, or (c) onset later in childhood (N = 10, 5 and 11 variants, respectively). A genetic risk score (GRS) for all 39 variants explained 0.6% (P = 6.6E-08) and 2.3% (P = 6.9E-21) of the variance in refractive error at ages 7 and 15, respectively, supporting increased effects from these genetic variants at older ages. Replication in multi-ancestry samples (combined N = 5599) yielded evidence of childhood onset for 6 of 12 variants present in both Asians and Europeans. There was no indication that variant or GRS effects altered depending on time outdoors, however 5 variants showed nominal evidence of interactions with nearwork (top variant, rs7829127 in ZMAT4; P = 6.3E-04).

Abstract

Myopia is the most common human eye disorder and it results from complex genetic and environmental causes. The rapidly increasing prevalence of myopia poses a major public health challenge. Here, the CREAM consortium performs a joint meta-analysis to test single-nucleotide polymorphism (SNP) main effects and SNP × education interaction effects on refractive error in 40,036 adults from 25 studies of European ancestry and 10,315 adults from 9 studies of Asian ancestry. In European ancestry individuals, we identify six novel loci (FAM150B-ACP1, LINC00340, FBN1, DIS3L-MAP2K1, ARID2-SNAT1 and SLC14A2) associated with refractive error. In Asian populations, three genome-wide significant loci AREG, GABRR1 and PDE10A also exhibit strong interactions with education (P<8.5 × 10−5), whereas the interactions are less evident in Europeans. The discovery of these loci represents an important advance in understanding how gene and environment interactions contribute to the heterogeneity of myopia

Abstract

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

Abstract

Two-year-old children’s reasoning about the relation between their own and others’ preferences was investigated across two studies. In Experiment 1, children first observed 2 actors display their individual preferences for various toys. Children were then asked to make inferences about new, visually inaccessible toys and books that were described as being the favorite of each actor, unfamiliar to each actor, or disliked by each actor. Children tended to select the favorite toys and books from the actor who shared their own preference but chose randomly when the new items were unfamiliar to or disliked by the two actors. Experiment 2 extended these findings, showing that children do not generalize a shared preference across unrelated categories of items. Taken together, the results suggest that young children readily recognize when another person holds a preference similar to their own and use that knowledge appropriately to achieve desired outcomes.

Abstract

Two studies examined the influence of similarity on 3-year-old children’s initial liking of their peers. Children were presented with pairs of childlike puppets who were either similar or dissimilar to them on a specified dimension and then were asked to choose one of the puppets to play with as a measure of liking. Children selected the puppet whose food preferences or physical appearance matched their own. Unpacking the physical appearance finding revealed that the stable similarity of hair color may influence liking more strongly than the transient similarity of shirt color. A second study showed that children also prefer to play with a peer who shares their toy preferences, yet importantly, show no bias toward a peer who is similar on an arbitrary dimension. The findings provide insight into the earliest development of peer relations in young children.

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

Objectives: Our goal was to assess MR image uniformity by investigating aspects influencing said uniformity via a method laid out by the National Electrical Manufacturers Association (NEMA).
Methods: Six metallic materials embedded in a glass phantom were scanned (i.e. Au, Ag, Al, Au-Ag-Pd alloy, Ti and Co-Cr alloy) as well as a reference image. Sequences included spin echo (SE) and gradient echo (GRE) scanned in three planes (i.e. axial, coronal, and sagittal). Moreover, three surface coil types (i.e. head and neck, Brain, and temporomandibular joint coils) and two image correction methods (i.e. surface coil intensity correction or SCIC, phased array uniformity enhancement or PURE) were employed to evaluate their effectiveness on image uniformity. Image uniformity was assessed using the National Electrical Manufacturers Association peak-deviation non-uniformity method.
Results: Results showed that temporomandibular joint coils elicited the least uniform image and brain coils outperformed head and neck coils when metallic materials were present. Additionally, when metallic materials were present, spin echo outperformed gradient echo especially for Co-Cr (particularly in the axial plane). Furthermore, both SCIC and PURE improved image uniformity compared to uncorrected images, and SCIC slightly surpassed PURE when metallic metals were present. Lastly, Co-Cr elicited the least uniform image while other metallic materials generally showed similar patterns (i.e. no significant deviation from images without metallic metals).
Conclusions: Overall, a quantitative understanding of the factors influencing MR image uniformity (e.g. coil type, imaging method, metal susceptibility, and post-hoc correction method) is advantageous to optimize image quality, assists clinical interpretation, and may result in improved medical and dental care.

Abstract

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

Abstract

This article presents the ventriloquist paradigm, an innovative method for studying speech processing in dialogue whereby participants interact face-to-face with a confederate who, unbeknownst to them, communicates by playing pre-recorded speech. Results show that the paradigm convinces more participants that the speech is live than a setup without the face-to-face element, and it elicits more interactive conversation than a setup in which participants believe their partner is a computer. By reconciling the ecological validity of a conversational context with full experimental control over phonetic exposure, the paradigm offers a wealth of new possibilities for studying speech processing in interaction.

Abstract

This study investigates the way adult second language (L2) learners of English resolve relative clause attachment ambiguities in sentences such as The dean liked the secretary of the professor who was reading a letter. Two groups of advanced L2 learners of English with Greek or German as their first language participated in a set of off-line and on-line tasks. The results indicate that the L2 learners do not process ambiguous sentences of this type in the same way as adult native speakers of English do. Although the learners’ disambiguation preferences were influenced by lexical–semantic properties of the preposition linking the two potential antecedent noun phrases (of vs. with), there was no evidence that they applied any phrase structure–based ambiguity resolution strategies of the kind that have been claimed to influence sentence processing in monolingual adults. The L2 learners’ performance also differs markedly from the results obtained from 6- to 7-year-old monolingual English children in a parallel auditory study, in that the children’s attachment preferences were not affected by the type of preposition at all. We argue that children, monolingual adults, and adult L2 learners differ in the extent to which they are guided by phrase structure and lexical–semantic information during sentence processing.

Abstract

In this study we describe a distinctive pigment ring that appears in spider eyes after ecdysis and successively decreases in size in the days thereafter. Although pigment stops in spider eyes are well known, size variability is, to our knowledge, reported here for the first time. Representative species from three families (Ctenidae, Sparassidae and Lycosidae) are investigated and, for one of these species (Cupiennius salei, Ctenidae), the progressive increase in pupil diameter is monitored. In this species the pupil occupies only a fourth of the total projected lens surface after ecdysis and reaches its final size after approximately ten days. MicroCT images suggest that the decrease of the pigment ring is linked to the growth of the corneal lens after ecdysis. The pigment rings might improve vision in the immature eye by shielding light rays that would otherwise enter the eye via peripheral regions of the cornea, beside the growing crystalline lens.

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

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

Abstract

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

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

A significant number of individuals have unexplained difficulties with acquiring normal speech and language, despite adequate intelligence and environmental stimulation. Although developmental disorders of speech and language are heritable, the genetic basis is likely to involve several, possibly many, different risk factors. Investigations of a unique three-generation family showing monogenic inheritance of speech and language deficits led to the isolation of the first such gene on chromosome 7, which encodes a transcription factor known as FOXP2. Disruption of this gene causes a rare severe speech and language disorder but does not appear to be involved in more common forms of language impairment. Recent genome-wide scans have identified at least four chromosomal regions that may harbor genes influencing the latter, on chromosomes 2, 13, 16, and 19. The molecular genetic approach has potential for dissecting neurological pathways underlying speech and language disorders, but such investigations are only just beginning.

Abstract

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

Abstract

Between 2 and 5% of children who are otherwise unimpaired have significant difficulties in acquiring expressive and/or receptive language, despite adequate intelligence and opportunity. While twin studies indicate a significant role for genetic factors in developmental disorders of speech and language, the majority of families segregating such disorders show complex patterns of inheritance, and are thus not amenable for conventional linkage analysis. A rare exception is the KE family, a large three-generation pedigree in which approximately half of the members are affected with a severe speech and language disorder which appears to be transmitted as an autosomal dominant monogenic trait. This family has been widely publicised as suffering primarily from a defect in the use of grammatical suffixation rules, thus supposedly supporting the existence of genes specific to grammar. The phenotype, however, is broader in nature, with virtually every aspect of grammar and of language affected. In addition, affected members have a severe orofacial dyspraxia, and their speech is largely incomprehensible to the naive listener. We initiated a genome-wide search for linkage in the KE family and have identified a region on chromosome 7 which co-segregates with the speech and language disorder (maximum lod score = 6.62 at theta = 0.0), confirming autosomal dominant inheritance with full penetrance. Further analysis of microsatellites from within the region enabled us to fine map the locus responsible (designated SPCH1) to a 5.6-cM interval in 7q31, thus providing an important step towards its identification. Isolation of SPCH1 may offer the first insight into the molecular genetics of the developmental process that culminates in speech and language.

Abstract

Dent's disease, an X-linked renal tubular disorder, is a form of Fanconi syndrome which is characterized by proteinuria, hypercalciuria, nephrocalcinosis, kidney stones and renal failure. Previous studies localised the gene responsible to Xp11.22, within a microdeletion involving the hypervariable locus DXS255. Further analysis using new probes which flank this locus indicate that the deletion is less than 515 kb. A 185 kb YAC containing DXS255 was used to screen a cDNA library from adult kidney in order to isolate coding sequences falling within the deleted region which may be implicated in the disease aetiology. We identified two clones which are evolutionarily conserved, and detect a 9.5 kb transcript which is expressed predominantly in the kidney. Sequence analysis of 780 bp of ORF from the clones suggests that the identified gene, termed hCIC-K2, encodes a new member of the CIC family of voltage-gated chloride channels. Genomic fragments detected by the cDNA clones are completely absent in patients who have an associated microdeletion. On the basis of the expression pattern, proposed function and deletion mapping, hCIC-K2 is a strong candidate for Dent's disease.

Abstract

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

Abstract

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

Electrophysiological studies consistently find N400 effects of semantic incongruity in nonnative (L2) language comprehension. These N400 effects are often delayed compared with native (L1) comprehension, suggesting that semantic integration in one's second language occurs later than in one's first language. In this study, we investigated whether such a delay could be attributed to (1) intralingual lexical competition and/or (2) interlingual lexical competition. We recorded EEG from Dutch–English bilinguals who listened to English (L2) sentences in which the sentence-final word was (a) semantically fitting and (b) semantically incongruent or semantically incongruent but initially congruent due to sharing initial phonemes with (c) the most probable sentence completion within the L2 or (d) the L1 translation equivalent of the most probable sentence completion. We found an N400 effect in each of the semantically incongruent conditions. This N400 effect was significantly delayed to L2 words but not to L1 translation equivalents that were initially congruent with the sentence context. Taken together, these findings firstly demonstrate that semantic integration in nonnative listening can start based on word initial phonemes (i.e., before a single lexical candidate could have been selected based on the input) and secondly suggest that spuriously elicited L1 lexical candidates are not available for semantic integration in L2 speech comprehension.

Abstract

This dissertation is an ethnographic study of race and other forms of social categorization as approached through the discourse of the indigenous Chachi people of northwestern lowland Ecuador and their Afro-descendant neighbors. It combines the ethnographic methods of social anthropology with the methods of descriptive linguistics, letting social questions about racial formation guide linguistic inquiry. It provides new information about the largely unstudied indigenous South American language Cha’palaa, and connects that information about linguistic form to problems of the study of race and ethnicity in Latin America. Individual descriptive chapters address how the Cha’palaa number system is based on collectivity rather than plurality according to an animacy hierarchy that codes only human and human-like social collectivities, how a nominal set of ethnonyms linked to Chachi oral history become the recipients of collective marking as human collectivities, how those collectivities are co-referentially linked to speech participants through the deployment of the pronominal system, and how the multi-modal resource of gesture adds to these rich resources supplied by the spoken language for the expression of social realities like race. The final chapters address Chachi and Afrodescendant discourses in dialogue with each other and examine naturally occurring speech data to show how the linguistic forms described in previous chapters are used in social interaction. The central argument advances a position that takes the socially constructed status of race seriously and considers that for such constructions to exist as more abstract macro-categories they must be constituted by instances of social interaction, where elements of the social order are observable at the micro-level. In this way localized articulations of social categories become vehicles for the broader circulation of discourses structured by a history of racialized social inequality, revealing the extreme depth of racialization in human social conditioning. This dissertation represents a contribution to the field of linguistic anthropology as well as to descriptive linguistics of South American languages and to critical approaches to race and ethnicity in Latin America.

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

It has long been claimed that there is no lexical field of smell, and that smell is of too little validity to be expressed in grammar. We demonstrate both claims are false. The Cha'palaa language (Ecuador) has at least 15 abstract smell terms, each of which is formed using a type of classifier previously thought not to exist. Moreover, using conversational corpora we show that Cha'palaa speakers also talk about smell more than Imbabura Quechua and English speakers. Together, this shows how language and social interaction may jointly reflect distinct cultural orientations towards sensory experience in general and olfaction in particular.

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

Gratitude is argued to have evolved to motivate and maintain social reciprocity among people, and to be linked to a wide range of positive effects — social, psychological, and even physical. But is socially reciprocal behaviour dependent on the expression of gratitude, for example by saying "thank you" as in English? Current research has not included cross-cultural elements, and has tended to conflate gratitude as an emotion with gratitude as a linguistic practice, as might appear to be the case in English. Here we ask to what extent people actually express gratitude in different societies by focussing on episodes of everyday life where someone obtains a good, service, or support from another, and comparing these episodes across eight languages from five continents. What we find is that expressions of gratitude in these episodes are remarkably rare, suggesting that social reciprocity in everyday life relies on tacit understandings of people’s rights and duties surrounding mutual assistance and collaboration. At the same time, we also find minor cross-cultural variation, with slightly higher rates in Western European languages English and Italian, showing that universal tendencies of social reciprocity should not be conflated with more culturally variable practices of expressing gratitude. Our study complements previous experimental and culture-specific research on social reciprocity with a systematic comparison of audiovisual corpora of naturally occurring social interaction from different cultures from around the world.

Abstract

This article briefly reviews some recent work on artificial language learning in children and adults. The final part of the article is devoted to a theoretical formulation of the language learning problem from a mechanistic neurobiological viewpoint and we show that it is logically possible to combine the notion of innate language constraints with, for example, the notion of domain general learning mechanisms. A growing body of empirical evidence suggests that the mechanisms involved in artificial language learning and in structured sequence processing are shared with those of natural language acquisition and natural language processing. Finally, by theoretically analyzing a formal learning model, we highlight Fodor’s insight that it is logically possible to combine innate, domain-specific constraints with domain-general learning mechanisms.

Abstract

Patients with stroke offer a unique window into understanding human brain function. Mapping stroke lesions poses several challenges due to the complexity of the lesion anatomy and the mechanisms causing local and remote disruption on brain networks. In this prospective longitudinal study, we compare standard and advanced approaches to white matter lesion mapping applied to acute stroke patients with aphasia. Eighteen patients with acute left hemisphere stroke were recruited and scanned within two weeks from symptom onset. Aphasia assessment was performed at baseline and six-month follow-up. Structural and diffusion MRI contrasts indicated an area of maximum overlap in the anterior external/extreme capsule with diffusion images showing a larger overlap extending into posterior perisylvian regions. Anatomical predictors of recovery included damage to ipsilesional tracts (as shown by both structural and diffusion images) and contralesional tracts (as shown by diffusion images only). These findings indicate converging results from structural and diffusion lesion mapping methods but also clear differences between the two approaches in their ability to identify predictors of recovery outside the lesioned regions.

Abstract

Accurate reconstruction of prehistoric social organization is important if we are to put together satisfactory multidisciplinary scenarios about, for example, the dispersal of human groups. Such considerations apply in the case of Indo-European and Austronesian, two large-scale language families that are thought to represent Neolithic expansions. Ancestral kinship patterns have mostly been inferred through reconstruction of kin terminologies in ancestral proto-languages using the linguistic comparative method, and through geographical or distributional arguments based on the comparative patterns of kin terms and ethnographic kinship ‘facts’. While these approaches are detailed and valuable, the processes through which conclusions have been drawn from the data fail to provide explicit criteria for systematic testing of alternative hypotheses. Here, we use language trees derived using phylogenetic tree-building techniques on Indo-European and Austronesian vocabulary data. With these trees, ethnographic data and Bayesian phylogenetic comparative methods, we statistically reconstruct past marital residence and infer rates of cultural change between different residence forms, showing Proto-Indo-European to be virilocal and Proto-Malayo-Polynesian uxorilocal. The instability of uxorilocality and the rare loss of virilocality once gained emerge as common features of both families

Abstract

An MEG experiment was carried out in order to compare the processing of lexical-tonal and intonational contrasts, based on the tonal dialect of Roermond (the Netherlands). A set of words with identical phoneme sequences but distinct pitch contours, which represented different lexical meanings or discourse meanings (statement vs. question), were presented to native speakers as well as to a control group of speakers of Standard Dutch, a non-tone language. The stimuli were arranged in a mismatch paradigm, under three experimental conditions: in the first condition (lexical), the pitch contour differences between standard and deviant stimuli reflected differences between lexical meanings; in the second condition (intonational), the stimuli differed in their discourse meaning; in the third condition (combined), they differed both in their lexical and discourse meaning. In all three conditions, native as well as non-native responses showed a clear MMNm (magnetic mismatch negativity) in a time window from 150 to 250 ms after the divergence point of standard and deviant pitch contours. In the lexical condition, a stronger response was found over the left temporal cortex of native as well as non-native speakers. In the intonational condition, the same activation pattern was observed in the control group, but not in the group of native speakers, who showed a right-hemisphere dominance instead. Finally, in the combined (lexical and intonational) condition, brain reactions appeared to represent the summation of the patterns found in the other two conditions. In sum, the lateralization of pitch processing is condition-dependent in the native group only, which suggests that language experience determines how processes should be distributed over both temporal cortices, according to the functions available in the grammar.

Abstract

The information we obtain from how speakers sound—for example their accent—affects how we interpret the messages they convey. A clear example is foreign accented speech, where reduced intelligibility and speaker's social categorization (out-group member) affect memory and the credibility of the message (e.g., less trustworthiness). In the present study, we go one step further and ask whether evaluations of messages are also affected by regional accents—accents from a different region than the listener. In the current study, we report results from three experiments on immediate memory recognition and immediate credibility assessments as well as the illusory truth effect. These revealed no differences between messages conveyed in local—from the same region as the participant—and regional accents—from native speakers of a different country than the participants. Our results suggest that when the accent of a speaker has high intelligibility, social categorization by accent does not seem to negatively affect how we treat the speakers' messages.

Abstract

The information we obtain from how speakers sound—for example their accent—affects how we interpret the
messages they convey. A clear example is foreign accented speech, where reduced intelligibility and speaker's
social categorization (out-group member) affect memory and the credibility of the message (e.g., less trust-
worthiness). In the present study, we go one step further and ask whether evaluations of messages are also
affected by regional accents—accents from a different region than the listener. In the current study, we report
results from three experiments on immediate memory recognition and immediate credibility assessments as well
as the illusory truth effect. These revealed no differences between messages conveyed in local—from the same
region as the participant—and regional accents—from native speakers of a different country than the partici-
pants. Our results suggest that when the accent of a speaker has high intelligibility, social categorization by
accent does not seem to negatively affect how we treat the speakers' messages.

Abstract

The aim of the present fMRI study was to investigate whether typical and dyslexic adult readers differed in the neural correlates of audiovisual speech processing. We tested for Blood Oxygen-Level Dependent (BOLD) activity differences between these two groups in a 1-back task, as they processed written (word, illegal consonant strings) and spoken (auditory, visual and audiovisual) stimuli. When processing written stimuli, dyslexic readers showed reduced activity in the supramarginal gyrus, a region suggested to play an important role in phonological processing, but only when they processed strings of consonants, not when they read words. During the speech perception tasks, dyslexic readers were only slower than typical readers in their behavioral responses in the visual speech condition. Additionally, dyslexic readers presented reduced neural activation in the auditory, the visual, and the audiovisual speech conditions. The groups also differed in terms of superadditivity, with dyslexic readers showing decreased neural activation in the regions of interest. An additional analysis focusing on vision-related processing during the audiovisual condition showed diminished activation for the dyslexic readers in a fusiform gyrus cluster. Our results thus suggest that there are differences in audiovisual speech processing between dyslexic and normal readers. These differences might be explained by difficulties in processing the unisensory components of audiovisual speech, more specifically, dyslexic readers may benefit less from visual information during audiovisual speech processing than typical readers. Given that visual speech processing supports the development of phonological skills fundamental in reading, differences in processing of visual speech could contribute to differences in reading ability between typical and dyslexic readers.

Abstract

Several quantitative trait loci (QTLs) that influence developmental dyslexia (reading disability [RD]) have been mapped to chromosome regions by linkage analysis. The most consistently replicated area of linkage is on chromosome 6p23-21.3. We used association analysis in 223 siblings from the United Kingdom to identify an underlying QTL on 6p22.2. Our association study implicates a 77-kb region spanning the gene TTRAP and the first four exons of the neighboring uncharacterized gene KIAA0319. The region of association is also directly upstream of a third gene, THEM2. We found evidence of these associations in a second sample of siblings from the United Kingdom, as well as in an independent sample of twin-based sibships from Colorado. One main RD risk haplotype that has a frequency of ∼12% was found in both the U.K. and U.S. samples. The haplotype is not distinguished by any protein-coding polymorphisms, and, therefore, the functional variation may relate to gene expression. The QTL influences a broad range of reading-related cognitive abilities but has no significant impact on general cognitive performance in these samples. In addition, the QTL effect may be largely limited to the severe range of reading disability.

Abstract

OBJECTIVE: Recent research has provided evidence for a genetically mediated association between language or reading-related cognitive deficits and impaired motor coordination. Other studies have identified relationships between lateralization of hand skill and cognitive abilities. With a large sample, the authors aimed to investigate genetic relationships between measures of reading-related cognition, hand motor skill, and hand skill lateralization.

METHOD: The authors applied univariate and bivariate correlation and familiality analyses to a range of measures. They also performed genomewide linkage analysis of hand motor skill in a subgroup of 195 sibling pairs.

RESULTS: Hand motor skill was significantly familial (maximum heritability=41%), as were reading-related measures. Hand motor skill was weakly but significantly correlated with reading-related measures, such as nonword reading and irregular word reading. However, these correlations were not significantly familial in nature, and the authors did not observe linkage of hand motor skill to any chromosomal regions implicated in susceptibility to dyslexia. Lateralization of hand skill was not correlated with reading or cognitive ability.

CONCLUSIONS: The authors confirmed a relationship between lower motor ability and poor reading performance. However, the genetic effects on motor skill and reading ability appeared to be largely or wholly distinct, suggesting that the correlation between these traits may have arisen from environmental influences. Finally, the authors found no evidence that reading disability and/or low general cognitive ability were associated with ambidexterity.

Abstract

Schizophrenia and non-right-handedness are moderately associated, and both traits are often accompanied by abnormalities of asymmetrical brain morphology or function. We have found linkage previously of chromosome 2p12-q11 to a quantitative measure of handedness, and we have also found linkage of schizophrenia/schizoaffective disorder to this same chromosomal region in a separate study. Now, we have found that in one of our samples (191 reading-disabled sibling pairs), the relative hand skill of siblings was correlated more strongly with paternal than maternal relative hand skill. This led us to re-analyse 2p12-q11 under parent-of-origin linkage models. We found linkage of relative hand skill in the RD siblings to 2p12-q11 with P=0.0000037 for paternal identity-by-descent sharing, whereas the maternally inherited locus was not linked to the trait (P>0.2). Similarly, in affected-sib-pair analysis of our schizophrenia dataset (241 sibling pairs), we found linkage to schizophrenia for paternal sharing with LOD=4.72, P=0.0000016, within 3 cM of the peak linkage to relative hand skill. Maternal linkage across the region was weak or non-significant. These similar paternal-specific linkages suggest that the causative genetic effects on 2p12-q11 are related. The linkages may be due to a single maternally imprinted influence on lateralized brain development that contains common functional polymorphisms.

Abstract

Population-based linkage analysis is a new method for analysing genomewide single nucleotide polymorphism (SNP) genotype data in case-control samples, which does not assume a common disease, common variant model. The genome is scanned for extended segments that show increased identity-by-descent sharing within case-case pairs, relative to case-control or control-control pairs. The method is robust to allelic heterogeneity and is suited to mapping genes which contain multiple, rare susceptibility variants of relatively high penetrance. We analysed genomewide SNP datasets for two schizophrenia case-control cohorts, collected in Aberdeen (461 cases, 459 controls) and Munich (429 cases, 428 controls). Population-based linkage testing must be performed within homogeneous samples and it was therefore necessary to analyse the cohorts separately. Each cohort was first subjected to several procedures to improve genetic homogeneity, including identity-by-state outlier detection and multidimensional scaling analysis. When testing only cases who reported a positive family history of major psychiatric disease, consistent with a model of strongly penetrant susceptibility alleles, we saw a distinct peak on chromosome 19q in both cohorts that appeared in meta-analysis (P=0.000016) to surpass the traditional level for genomewide significance for complex trait linkage. The linkage signal was also present in a third case-control sample for familial bipolar disorder, such that meta-analysing all three datasets together yielded a linkage P=0.0000026. A model of rare but highly penetrant disease alleles may be more applicable to some instances of major psychiatric diseases than the common disease common variant model, and we therefore suggest that other genome scan datasets are analysed with this new, complementary method.

Abstract

A computational model of inference during story comprehension is presented, in which story situations are represented distributively as points in a high-dimensional “situation-state space.” This state space organizes itself on the basis of a constructed microworld description. From the same description, causal/temporal world knowledge is extracted. The distributed representation of story situations is more flexible than Golden and Rumelhart’s [Discourse Proc 16 (1993) 203] localist representation. A story taking place in the microworld corresponds to a trajectory through situation-state space. During the inference process, world knowledge is applied to the story trajectory. This results in an adjusted trajectory, reflecting the inference of propositions that are likely to be the case. Although inferences do not result from a search for coherence, they do cause story coherence to increase. The results of simulations correspond to empirical data concerning inference, reading time, and depth of processing. An extension of the model for simulating story retention shows how coherence is preserved during retention without controlling the retention process. Simulation results correspond to empirical data concerning story recall and intrusion.

Abstract

Results from a recent neuroimaging study on spoken sentence comprehension have been interpreted as evidence for cortical entrainment to hierarchical syntactic structure. We present a simple computational model that predicts the power spectra from this study, even
though the model's linguistic knowledge is restricted to the lexical level, and word-level representations are not combined into higher-level units (phrases or sentences). Hence, the
cortical entrainment results can also be explained from the lexical properties of the stimuli, without recourse to hierarchical syntax.

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

Attention deficit/hyperactivity disorder (ADHD) is one of the most common neuropsychiatric disorders with a worldwide prevalence around 4–5% in children and 1–4% in adults. Although ADHD is highly heritable and familial risk may contribute most strongly to the persistent form of the disorder, there are few studies on the genetics of ADHD in adults. In this paper, we present the first results of the International Multicentre Persistent ADHD Genetics CollaboraTion (IMpACT) that has been set up with the goal of performing research into the genetics of persistent ADHD. In this study, we carried out a combined analysis as well as a meta-analysis of the association of the SLC6A3/DAT1 gene with persistent ADHD in 1440 patients and 1769 controls from IMpACT and an earlier report. DAT1, encoding the dopamine transporter, is one of the most frequently studied genes in ADHD, though results have been inconsistent. A variable number tandem repeat polymorphism (VNTR) in the 3′-untranslated region (UTR) of the gene and, more recently, a haplotype of this VNTR with another VNTR in intron 8 have been the target of most studies. Although the 10/10 genotype of the 3′-UTR VNTR and the 10-6 haplotype of the two VNTRs are thought to be risk factors for ADHD in children, we found the 9/9 genotype and the 9-6 haplotype associated with persistent ADHD. In conclusion, a differential association of DAT1 with ADHD in children and in adults might help explain the inconsistencies observed in earlier association studies. However, the data might also imply that DAT1 has a modulatory rather than causative role in ADHD.

Abstract

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

Abstract

Speaking and listening are complex tasks that we perform on a daily basis, almost without conscious effort. Interestingly, speaking almost never occurs without listening: whenever we speak, we at least hear our own speech. The research in this thesis is concerned with how the perception of our own speech influences our speaking behavior. We show that unconsciously, we actively monitor this auditory feedback of our own speech. This way, we can efficiently take action and adapt articulation when an error occurs and auditory feedback does not correspond to our expectation. Processing the auditory feedback of our speech does not, however, automatically affect speech production. It is subject to a number of constraints. For example, we do not just track auditory feedback, but also its consistency. If auditory feedback is more consistent over time, it has a stronger influence on speech production. In addition, we investigated how auditory feedback during speech is processed in the brain, using magnetoencephalography (MEG). The results suggest the involvement of a broad cortical network including both auditory and motor-related regions. This is consistent with the view that the auditory center of the brain is involved in comparing auditory feedback to our expectation of auditory feedback. If this comparison yields a mismatch, motor-related regions of the brain can be recruited to alter the ongoing articulations.

Abstract

When talking, speakers continuously monitor and use the auditory feedback of their own voice to control and inform speech production processes. When speakers are provided with auditory feedback that is perturbed in real time, most of them compensate for this by opposing the feedback perturbation. But some speakers follow the perturbation. In the current study, we investigated whether the state of the speech production system at perturbation onset may determine what type of response (opposing or following) is given. The results suggest that whether a perturbation-related response is opposing or following depends on ongoing fluctuations of the production system: It initially responds by doing the opposite of what it was doing. This effect and the non-trivial proportion of following responses suggest that current production models are inadequate: They need to account for why responses to unexpected sensory feedback depend on the production-system’s state at the time of perturbation.

Abstract

Speaking is a complex motor skill which requires near instantaneous integration of sensory and motor-related information. Current theory hypothesizes a complex interplay between motor and auditory processes during speech production, involving the online comparison of the speech output with an internally generated forward model. To examine the neural correlates of this intricate interplay between sensory and motor processes, the current study uses altered auditory feedback (AAF) in combination with magnetoencephalography (MEG). Participants vocalized the vowel/e/and heard auditory feedback that was temporarily pitch-shifted by only 25 cents, while neural activity was recorded with MEG. As a control condition, participants also heard the recordings of the same auditory feedback that they heard in the first half of the experiment, now without vocalizing. The participants were not aware of any perturbation of the auditory feedback. We found auditory cortical areas responded more strongly to the pitch shifts during vocalization. In addition, auditory feedback perturbation resulted in spectral power increases in the θ and lower β bands, predominantly in sensorimotor areas. These results are in line with current models of speech production, suggesting auditory cortical areas are involved in an active comparison between a forward model's prediction and the actual sensory input. Subsequently, these areas interact with motor areas to generate a motor response. Furthermore, the results suggest that θ and β power increases support auditory-motor interaction, motor error detection and/or sensory prediction processing.

Abstract

To identify genetic variants associated with birth weight, we meta-analyzed six genome-wide association (GWA) studies (n = 10,623 Europeans from pregnancy/birth cohorts) and followed up two lead signals in 13 replication studies (n = 27,591). rs900400 near LEKR1 and CCNL1 (P = 2 x 10(-35)) and rs9883204 in ADCY5 (P = 7 x 10(-15)) were robustly associated with birth weight. Correlated SNPs in ADCY5 were recently implicated in regulation of glucose levels and susceptibility to type 2 diabetes, providing evidence that the well-described association between lower birth weight and subsequent type 2 diabetes has a genetic component, distinct from the proposed role of programming by maternal nutrition. Using data from both SNPs, we found that the 9% of Europeans carrying four birth weight-lowering alleles were, on average, 113 g (95% CI 89-137 g) lighter at birth than the 24% with zero or one alleles (P(trend) = 7 x 10(-30)). The impact on birth weight is similar to that of a mother smoking 4-5 cigarettes per day in the third trimester of pregnancy.

Abstract

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

Abstract

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

Abstract

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

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

Abstract

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

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

Abstract

As the popularity of sending messages electronically increases, so does the necessity of conveying messages more efficiently. One way of increasing efficiency is to abbreviate words and expressions by combining letters with numbers such as gr8 for “great,” using acronyms, such as lol for “laughing out loud,” or clippings such as msg for “message.” The present study compares the processing of shortcuts to the processing of closely matched pseudo-shortcuts. ERPs were recorded while participants were performing a lexical decision task. Response times showed that shortcuts were categorized more slowly as nonwords than pseudo-shortcuts. The ERP results showed no differences between shortcuts and pseudo-shortcuts at time windows 50–150 ms and 150–270 ms, but there were significant differences between 270 and 500 ms. These results suggest that at early stages of word recognition, the orthographic and phonological processing is similar for shortcuts and pseudo-shortcuts. However, at the time of lexical access, shortcuts diverge from pseudo-shortcuts, suggesting that shortcuts activate stored lexical representations.

Abstract

The current event-related brain potential study examined the processing of observed speech errors.
Participants were asked to detect errors in the speech of others while listening to the description of a visual
network. Networks consisted of colored drawings of objects connected by straight or curved lines. We
investigated the processing of two types of errors in the network descriptions, i.e., incorrect color and errors
in determiners usage (gender agreement violations). In the 100- to 300-ms and 300- to 550-ms time
windows, we found larger PMN and N400 amplitudes for both color and determiner error trials compared to
correct trials. Furthermore, color but not determiner errors led to larger P600 amplitudes compared to
correct color trials. Color errors also showed enhanced P600 amplitudes compared to determiner errors.
Taken together, processing erroneous network descriptions elicits different brain potentials than listening to
the corresponding correct utterances. Hence, speech is monitored for errors not only during speech
production but also during listening to the naturally occurring speech of others.

Abstract

For efficiency reasons, words in electronic messages are sometimes formed by combining letters with numbers, as in gr8 for “great.” The aim of this study was to investigate whether a digit incorporated into a letter—digit shortcut would retain its numerosity. A priming paradigm was used with letter—digit shortcuts (e.g., gr8) and matched pseudoshortcuts (e.g., qr8) as primes. The primes were presented simultaneously with sets of dots (targets) for which even/odd decisions were required, or they appeared 250 msec before target onset. When pseudoshortcuts were presented, decision latencies were shorter when the target and the digit in the prime were matched in parity than when they were mismatched. This main effect of match was not significant for shortcuts. The results suggest that the number concepts of digits combined with letters become activated but are quickly suppressed or deactivated when the digit is part of an existing shortcut.

Abstract

Learning to read a second language (L2) can pose a great challenge for children who have already been struggling to read in their first language (L1). Moreover, it is not clear whether, to what extent, and under what circumstances L1 reading difficulty increases the risk of L2 reading difficulty. This study investigated Chinese (L1) and English (L2) reading skills in a large representative sample of 1,824 Chinese–English bilingual children in Grades 4 and 5 from both urban and rural schools in Beijing. We examined the prevalence of reading difficulty in Chinese only (poor Chinese readers, PC), English only (poor English readers, PE), and both Chinese and English (poor bilingual readers, PB) and calculated the co-occurrence, that is, the chances of becoming a poor reader in English given that the child was already a poor reader in Chinese. We then conducted a multinomial logistic regression analysis and compared the prevalence of PC, PE, and PB between children in Grade 4 versus Grade 5, in urban versus rural areas, and in boys versus girls. Results showed that compared to girls, boys demonstrated significantly higher risk of PC, PE, and PB. Meanwhile, compared to the 5th graders, the 4th graders demonstrated significantly higher risk of PC and PB. In addition, children enrolled in the urban schools were more likely to become better second language readers, thus leading to a concerning rural–urban gap in the prevalence of L2 reading difficulty. Finally, among these Chinese–English bilingual children, regardless of sex and school location, poor reading skill in Chinese significantly increased the risk of also being a poor English reader, with a considerable and stable co-occurrence of approximately 36%. In sum, this study suggests that despite striking differences between alphabetic and logographic writing systems, L1 reading difficulty still significantly increases the risk of L2 reading difficulty. This indicates the shared meta-linguistic skills in reading different writing systems and the importance of understanding the universality and the interdependent relationship of reading between different writing systems. Furthermore, the male disadvantage (in both L1 and L2) and the urban–rural gap (in L2) found in the prevalence of reading difficulty calls for special attention to disadvantaged populations in educational practice.

Abstract

Previous research shows conflicting findings for the effect of font readability on comprehension and memory for language. It has been found that—perhaps counterintuitively–a hard to read font can be beneficial for language comprehension, especially for difficult language. Here we test how font readability influences the subjective experience of poetry reading. In three experiments we tested the influence of poem difficulty and font readability on the subjective experience of poems. We specifically predicted that font readability would have opposite effects on the subjective experience of easy versus difficult poems. Participants read poems which could be more or less difficult in terms of conceptual or structural aspects, and which were presented in a font that was either easy or more difficult to read. Participants read existing poems and subsequently rated their subjective experience (measured through four dependent variables: overall liking, perceived flow of the poem, perceived topic clarity, and perceived structure). In line with previous literature we observed a Poem Difficulty x Font Readability interaction effect for subjective measures of poetry reading. We found that participants rated easy poems as nicer when presented in an easy to read font, as compared to when presented in a hard to read font. Despite the presence of the interaction effect, we did not observe the predicted opposite effect for more difficult poems. We conclude that font readability can influence reading of easy and more difficult poems differentially, with strongest effects for easy poems.

Abstract

Resource-constrained models of language processing predict that perceptual simulation during language understanding would be compromised by sensory limitations (such as reading text in unfamiliar/difficult font), whereas strong versions of embodied theories of language would predict that simulating perceptual symbols in language would not be impaired even under sensory-constrained situations. In 2 experiments, sensory decoding difficulty was manipulated by using easy and hard fonts to study perceptual simulation during sentence reading (Zwaan, Stanfield, & Yaxley, 2002). Results indicated that simulating perceptual symbols in language was not compromised by surface-form decoding challenges such as difficult font, suggesting relative resilience of embodied language processing in the face of certain sensory constraints. Further implications for learning from text and individual differences in language processing will be discussed

Abstract

This article investigates the word order preferences of Tagalog-speaking adults and five- and seven-year-old children. The participants were asked to complete sentences to describe pictures depicting actions between two animate entities. Adults preferred agent-initial constructions in the patient voice but not in the agent voice, while the children produced mainly agent-initial constructions regardless of voice. This agent-initial preference, despite the lack of a close link between the agent and the subject in Tagalog, shows that this word order preference is not merely syntactically-driven (subject-initial preference). Additionally, the children’s agent-initial preference in the agent voice, contrary to the adults’ lack of preference, shows that children do not respect the subject-last principle of ordering Tagalog full noun phrases. These results suggest that language-specific optional features like a subject-last principle take longer to be acquired.

Abstract

It is a common finding across languages that young children have problems in understanding patient-initial sentences. We used Tagalog, a verb-initial language with a reliable voice-marking system and highly frequent patient voice constructions, to test the predictions of several accounts that have been proposed to explain this difficulty: the frequency account, the Competition Model, and the incremental processing account. Study 1 presents an analysis of Tagalog child-directed speech, which showed that the dominant argument order is agent-before-patient and that morphosyntactic markers are highly valid cues to thematic role assignment. In Study 2, we used a combined self-paced listening and picture verification task to test how Tagalog-speaking adults and 5- and 7-year-old children process reversible transitive sentences. Results showed that adults performed well in all conditions, while children’s accuracy and listening times for the first noun phrase indicated more difficulty in interpreting patient-initial sentences in the agent voice compared to the patient voice. The patient voice advantage is partly explained by both the frequency account and incremental processing account.

Abstract

Heterozygous mutations of the human FOXP2 gene are implicated in a severe speech and language disorder. Aetiological mutations of murine Foxp2 yield abnormal synaptic plasticity and impaired motor-skill learning in mutant mice, while knockdown of the avian orthologue in songbirds interferes with auditory-guided vocal learning. Here, we investigate influences of two distinct Foxp2 point mutations on vocalizations of 4-day-old mouse pups (Mus musculus). The R552H missense mutation is identical to that causing speech and language deficits in a large well-studied human family, while the S321X nonsense mutation represents a null allele that does not produce Foxp2 protein. We ask whether vocalizations, based solely on innate mechanisms of production, are affected by these alternative Foxp2 mutations. Sound recordings were taken in two different situations: isolation and distress, eliciting a range of call types, including broadband vocalizations of varying noise content, ultrasonic whistles and clicks. Sound production rates and several acoustic parameters showed that, despite absence of functional Foxp2, homozygous mutants could vocalize all types of sounds in a normal temporal pattern, but only at comparably low intensities. We suggest that altered vocal output of these homozygotes may be secondary to developmental delays and somatic weakness. Heterozygous mutants did not differ from wild-types in any of the measures that we studied (R552H ) or in only a few (S321X ), which were in the range of differences routinely observed for different mouse strains. Thus, Foxp2 is not essential for the innate production of emotional vocalizations with largely normal acoustic properties by mouse pups.

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

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.