Publications

Abstract

Retinoic acid-related orphan receptor alpha gene (RORa) and the microRNA MIR137 have both recently been identified as novel candidate genes for neuropsychiatric disorders. RORa encodes a ligand-dependent orphan nuclear receptor that acts as a transcriptional regulator and miR-137 is a brain enriched small non-coding RNA that interacts with gene transcripts to control protein levels. Given the mounting evidence for RORa in autism spectrum disorders (ASD) and MIR137 in schizophrenia and ASD, we investigated if there was a functional biological relationship between these two genes. Herein, we demonstrate that miR-137 targets the 3'UTR of RORa in a site specific manner. We also provide further support for MIR137 as an autism candidate by showing that a large number of previously implicated autism genes are also putatively targeted by miR-137. This work supports the role of MIR137 as an ASD candidate and demonstrates a direct biological link between these previously unrelated autism candidate genes

Abstract

FOXP2 was the first gene shown to cause a Mendelian form of speech and language disorder. Although developmentally expressed in many organs, loss of a single copy of FOXP2 leads to a phenotype that is largely restricted to orofacial impairment during articulation and linguistic processing deficits. Why perturbed FOXP2 function affects specific aspects of the developing brain remains elusive. We investigated the role of FOXP2 in neuronal differentiation and found that FOXP2 drives molecular changes consistent with neuronal differentiation in a human model system. We identified a network of FOXP2 regulated genes related to retinoic acid signaling and neuronal differentiation. FOXP2 also produced phenotypic changes associated with neuronal differentiation including increased neurite outgrowth and reduced migration. Crucially, cells expressing FOXP2 displayed increased sensitivity to retinoic acid exposure. This suggests a mechanism by which FOXP2 may be able to increase the cellular differentiation response to environmental retinoic acid cues for specific subsets of neurons in the brain. These data demonstrate that FOXP2 promotes neuronal differentiation by interacting with the retinoic acid signaling pathway and regulates key processes required for normal circuit formation such as neuronal migration and neurite outgrowth. In this way, FOXP2, which is found only in specific subpopulations of neurons in the brain, may drive precise neuronal differentiation patterns and/or control localization and connectivity of these FOXP2 positive cells

Abstract

Developmental dyslexia, a severe and persistent reading and spelling impairment, is characterized by difficulties in processing speech sounds (i.e., phonemes). Here, we test the hypothesis that these phonological difficulties are associated with a dysfunction of the auditory sensory thalamus, the medial geniculate body (MGB). By using functional MRI, we found that, in dyslexic adults, the MGB responded abnormally when the task required attending to phonemes compared with other speech features. No other structure in the auditory pathway showed distinct functional neural patterns between the two tasks for dyslexic and control participants. Furthermore, MGB activity correlated with dyslexia diagnostic scores, indicating that the task modulation of the MGB is critical for performance in dyslexics. These results suggest that deficits in dyslexia are associated with a failure of the neural mechanism that dynamically tunes MGB according to predictions from cortical areas to optimize speech processing. This view on task-related MGB dysfunction in dyslexics has the potential to reconcile influential theories of dyslexia within a predictive coding framework of brain function.

Abstract

The extent to which the phonetic system of a second language is mastered varies across individuals. The present study evaluates the pattern of individual differences in late bilinguals across different phonological processes. Fifty-five late Dutch-English bilinguals were tested on their ability to perceive a difficult L2 speech contrast (the English /æ/-/ε/ contrast) in three different tasks: A categorization task, a word identification task and a lexical decision task. As a group, L2 listeners were less accurate than native listeners. However, at the individual level, almost half of the L2 listeners scored within the native range in the categorization task whereas a small percentage scored within the native range in the identification and lexical decision tasks. These results show that L2 listeners' performance crucially depends on the nature of the task, with higher L2 listener accuracy on an acoustic-phonetic analysis task than on tasks involving lexical processes. These findings parallel previous results for early bilinguals, where the pattern of performance was consistent with the processing hierarchy proposed by different models of speech perception. The results indicate that the analysis of patterns of non-native performance can provide important insights concerning the architecture of the speech perception system and the issue of language learnability.

Abstract

Prosody, particularly accent, aids comprehension by drawing attention to important elements such as the information that answers a question. A study using ERP registration investigated how the brain deals with the interpretation of prosodic prominence. Sentences were embedded in short dialogues and contained accented elements that were congruous or incongruous with respect to a preceding question. In contrast to previous studies, no explicit prosodic judgment task was added. Robust effects of accentuation were evident in the form of an “accent positivity” (200–500 msec) for accented elements irrespective of their congruity. Our results show that incongruously accented elements, that is, superfluous accents, activate a specific set of neural systems that is inactive in case of incongruously unaccented elements, that is, missing accents. Superfluous accents triggered an early positivity around 100 msec poststimulus, followed by a right-lateralized negative effect (N400). This response suggests that redundant information is identified immediately and leads to the activation of a neural system that is associated with semantic processing (N400). No such effects were found when contextually expected accents were missing. In a later time window, both missing and superfluous accents triggered a late positivity on midline electrodes, presumably related to making sense of both kinds of mismatching stimuli. These results challenge previous findings of greater processing for missing accents and suggest that the natural processing of prosody involves a set of distinct, temporally organized neural systems.

Abstract

The present dissertation investigates what neurocognitive processes are activated in the brain when listeners comprehend spoken language and in particular the melody and rhythm of speech, also referred to as prosody. The findings of several electrophysiological studies show that prosody influences the early and late stages of spoken language processing. When words are accented, listeners consider them important, and the brain responds to accentuation already 200 milliseconds after stimulus onset. The processing of prosodic prominence occurs whether or not a context is present and whether or not accent is congruent with context, although the responses to accentuation may be modified by either of these factors and by the focus particle only. Listeners are sensitive not only to the presence of prosodic prominence but also to the type of accents speakers use: corrective prosody activates additional interpretation mechanisms related to the construction of corrective meaning. The parallel between accents across clauses impacts the disambiguation of sentences with verb ellipsis. By interpreting prosodically parallel elements as syntactically parallel, listeners arrive at less preferred interpretations of conjoined clauses. The research indentifies early correlates of incongruous prosody in strongly predictive contexts as well as late integration processes for prosody comprehension, which are related to the processing of structural complexity in isolated and ambiguous sentences. The dissertation provides evidence that the brain is sensitive to differences in prosody even in the absence of prosodic judgment. However, by changing the task, one modulates the neural mechanisms of prosody processing.

Abstract

Als je wereldwijd gesprekken beluistert, merk je dat de menselijke dialoog universele regels volgt. Die sturen en verrijken onze sociale interactie.

Abstract

We present a new transcription mode for the annotation tool ELAN. This mode is designed to speed up the process of creating transcriptions of primary linguistic data (video and/or audio recordings of linguistic behaviour). We survey the basic transcription workflow of some commonly used tools (Transcriber, BlitzScribe, and ELAN) and describe how the new transcription interface improves on these existing implementations. We describe the design of the transcription interface and explore some further possibilities for improvement in the areas of segmentation and computational enrichment of annotations.

Abstract

Ideophones are marked words that depict sensory imagery found in many of the world’s languages. They are noted for their special forms, distinct grammatical behaviour, rich sensory meanings, and interactional uses related to experience and evidentiality. This review surveys recent developments in ideophone research. Work on the semiotics of ideophones helps explain why they are marked and how they realise the depictive potential of speech. A true semantic typology of ideophone systems is coming within reach through a combination of language-internal analyses and language-independent elicitation tools. Documentation of ideophones in a wide variety of genres as well as sequential analysis of ideophone use in natural discourse leads to new insights about their interactional uses and about their relation to other linguistic devices like reported speech and grammatical evidentials. As the study of ideophones is coming of age, it sheds new light on what is possible and probable in human language.

Abstract

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

Abstract

Ideophones are found in many of the world’s languages. Though they are a major word class on a par with nouns and verbs, their origins are ill-understood, and the question of ideophone creation has been a source of controversy. This paper studies ideophone creation in naturally occurring speech. New, unconventionalised ideophones are identified using native speaker judgements, and are studied in context to understand the rules and regularities underlying their production and interpretation. People produce and interpret new ideophones with the help of the semiotic infrastructure that underlies the use of existing ideophones: foregrounding frames certain stretches of speech as depictive enactments of sensory imagery, and various types of iconicity link forms and meanings. As with any creative use of linguistic resources, context and common ground also play an important role in supporting rapid ‘good enough’ interpretations of new material. The making of new ideophones is a special case of a more general phenomenon of creative depiction: the art of presenting verbal material in such a way that the interlocutor recognises and interprets it as a depiction.

Abstract

Mensen groeien op in verschillende omgevingen, met verschillende ervaringen en verschillende talen. Betekent dat ook dat ze verschillend denken? En als er invloed is van taal op denken, hoe ver reikt die dan? Wordt ons denken begrensd door woorden, of is de invloed meer gematigd en kunnen we er soms zelfs aan ontkomen?

Abstract

Recent developments in the science of language signal the emergence of a new paradigm for language study: a social approach to the fundamental questions of what language is like, how much languages really have in common, and why only our species has it. The key to these developments is a new appreciation of the need to study everyday spoken language, with all its complications and ‘imperfections’, in a systematic way. The work reviewed in this article —on turn-taking, timing, and other-initiated repair in languages around the world— has important implications for our understanding of human sociality and sheds new light on the social shape of language. For the first time in the history of linguistics, we are no longer tied to what can be written down or thought up. Rather, we look at language as a biologist would: as it occurs in nature.

Abstract

The widespread occurrence of ideophones, large classes of words specialized in evoking sensory imagery, is little known outside linguistics and anthropology. Ideophones are a common feature in many of the world’s languages but are underdeveloped in English and other Indo-European languages. Here we study the meanings of ideophones in Siwu (a Kwa language from Ghana) using a pile-sorting task. The goal was to uncover the underlying structure of the lexical space and to examine the claimed link between ideophones and perception. We found that Siwu ideophones are principally organized around fine-grained aspects of sensory perception, and map onto salient psychophysical dimensions identified in sensory science. The results ratify ideophones as dedicated sensory vocabulary and underline the relevance of ideophones for research on language and perception.

Abstract

People often talk about musical pitch using spatial metaphors. In English, for instance, pitches can be “high” or “low” (i.e., height-pitch association), whereas in other languages, pitches are described as “thin” or “thick” (i.e., thickness-pitch association). According to results from psychophysical studies, metaphors in language can shape people’s nonlinguistic space-pitch representations. But does language establish mappings between space and pitch in the first place, or does it only modify preexisting associations? To find out, we tested 4-month-old Dutch infants’ sensitivity to height-pitch and thickness-pitch mappings using a preferential-looking paradigm. The infants looked significantly longer at cross-modally congruent stimuli for both space-pitch mappings, which indicates that infants are sensitive to these associations before language acquisition. The early presence of space-pitch mappings means that these associations do not originate from language. Instead, language builds on preexisting mappings, changing them gradually via competitive associative learning. Space-pitch mappings that are language-specific in adults develop from mappings that may be universal in infants.

Abstract

Numerous experiments show that space and musical pitch are
closely linked in people's minds. However, the exact nature of
space-pitch associations and their neuronal underpinnings are
not well understood. In an fMRI experiment we investigated
different types of spatial representations that may underlie
musical pitch. Participants judged stimuli that varied in
spatial height in both the visual and tactile modalities, as well
as auditory stimuli that varied in pitch height. In order to
distinguish between unimodal and multimodal spatial bases of
musical pitch, we examined whether pitch activations were
present in modality-specific (visual or tactile) versus
multimodal (visual and tactile) regions active during spatial
height processing. Judgments of musical pitch were found to
activate unimodal visual areas, suggesting that space-pitch
associations may involve modality-specific spatial
representations, supporting a key assumption of embodied
theories of metaphorical mental representation.

Abstract

People often talk about musical pitch in terms of spatial metaphors. In English, for instance, pitches can be high or low, whereas in other languages pitches are described as thick or thin. According to psychophysical studies, metaphors in language can also shape people’s nonlinguistic space-pitch representations. But does language establish mappings between space and pitch in the first place or does it modify preexisting associations? Here we tested 4-month-old Dutch infants’ sensitivity to height-pitch and thickness-pitch mappings in two preferential looking tasks. Dutch infants looked significantly longer at cross-modally congruent stimuli in both experiments, indicating that infants are sensitive to space-pitch associations prior to language. This early presence of space-pitch mappings suggests that these associations do not originate from language. Rather, language may build upon pre-existing mappings and change them gradually via some form of competitive associative learning.

Abstract

This paper presents a study of the spontaneous pre-sentential negations
of ten English-speaking children between the ages of 1; 6 and 3; 4 which
supports the hypothesis that child English nonanaphoric pre-sentential
negation is a form of metalinguistic exclamatory sentence negation. A
detailed discourse analysis reveals that children's pre-sentential negatives
like No Nathaniel a king (i) are characteristically echoic, and (it)
typically express objection and rectification, two characteristic functions
of exclamatory negation in adult discourse, e.g. Don't say 'Nathaniel's a
king'! A comparison of children's pre-sentential negations with their
internal predicate negations using not and don't reveals that the two
negative constructions are formally and functionally distinct. I argue
that children's nonanaphoric pre-sentential negatives constitute an
independent, well-formed class of discourse negation. They are not
'primitive' constructions derived from the miscategorization of emphatic
no in adult speech or children's 'inventions'. Nor are they an
early derivational variant of internal sentence negation. Rather, these
negatives reflect young children's competence in using grammatical
negative constructions appropriately in discourse.

Abstract

Previous studies have demonstrated that native listeners
modify their interpretation of a speech sound when a talker
produces an ambiguous sound in order to quickly tune into a
speaker, but there is hardly any evidence that non-native
listeners employ a similar mechanism when encountering
ambiguous pronunciations. So far, one study demonstrated
this lexically-guided perceptual learning effect for nonnatives,
using phoneme categories similar in the native
language of the listeners and the non-native language of the
stimulus materials. The present study investigates the question
whether phoneme category retuning is possible in a nonnative
language for a contrast, /l/-/r/, which is phonetically
differently embedded in the native (Dutch) and nonnative
(English) languages involved. Listening experiments indeed
showed a lexically-guided perceptual learning effect.
Assuming that Dutch listeners have different phoneme
categories for the native Dutch and non-native English /r/, as
marked differences between the languages exist for /r/, these
results, for the first time, seem to suggest that listeners are not
only able to retune their native phoneme categories but also
their non-native phoneme categories to include ambiguous
pronunciations.

Abstract

Overview Since the early nineties, the on-going dramatic loss of the world’s linguistic diversity has gained attention, first by the linguists and increasingly also by the general public. As a response, the new field of language documentation emerged from around 2000 on, starting with the funding initiative ‘Dokumentation Bedrohter Sprachen’ (DoBeS, funded by the Volkswagen foundation, Germany), soon to be followed by others such as the ‘Endangered Languages Documentation Programme’ (ELDP, at SOAS, London), or, in the USA, ‘Electronic Meta-structure for Endangered Languages Documentation’ (EMELD, led by the LinguistList) and ‘Documenting Endangered Languages’ (DEL, by the NSF). From its very beginning, the new field focused on digital technologies not only for recording in audio and video, but also for annotation, lexical databases, corpus building and archiving, among others. This development not just coincides but is intrinsically interconnected with the increasing focus on digital data, technology and methods in all sciences, in particular in the humanities.

Abstract

This contribution explores the potentials of combining corpora of language use data with language description in e-grammars (or digital grammars). We present three directions of ongoing research and discuss the advantages of combining these and similar approaches, arguing that the technological possibilities have barely begun to be explored.

Abstract

Since the late 1990s, the technical group at the Max-Planck-Institute for Psycholinguistics has worked on solutions for important challenges in building sustainable data archives, in particular, how to guarantee long-time-availability of digital research data for future research. The support for the well-known DOBES (Documentation of Endangered Languages) programme has greatly inspired and advanced this work, and lead to the ongoing development of a whole suite of tools for annotating, cataloguing and archiving multi-media data. At the core of the LAT (Language Archiving Technology) tools is the IMDI metadata schema, now being integrated into a larger network of digital resources in the European CLARIN project. The multi-media annotator ELAN (with its web-based cousin ANNEX) is now well known not only among documentary linguists. We aim at presenting an overview of the solutions, both achieved and in development, for creating and exploiting sustainable digital data, in particular in the area of documenting languages and cultures, and their interfaces with related other developments

Abstract

This contribution presents “The Language Archive” (TLA), a new unit at the MPI for Psycholinguistics, discussing the current developments in management of scientific data, considering the need for new data research infrastructures. Although several initiatives worldwide in the realm of language resources aim at the integration, preservation and mobilization of research data, the state of such scientific data is still often problematic. Data are often not well organized and archived and not described by metadata ― even unique data such as field-work observational data on endangered languages is still mostly on perishable carriers. New data centres are needed that provide trusted, quality-reviewed, persistent services and suitable tools and that take legal and ethical issues seriously. The CLARIN initiative has established criteria for suitable centres. TLA is in a good position to be one of such centres. It is based on three essential pillars: (1) A data archive; (2) management, access and annotation tools; (3) archiving and software expertise for collaborative projects. The archive hosts mostly observational data on small languages worldwide and language acquisition data, but also data resulting from experiments

Abstract

Although laughter forms an important part of human non-verbal communication, it has received rather less attention than it deserves in both the experimental and the observational literatures. Relaxed social (Duchenne) laughter is associated with feelings of wellbeing and heightened affect, a proximate expla- nation for which might be the release of endorphins. We tested this hypothesis in a series of six experimental studies in both the laboratory (watching videos) and naturalistic contexts (watching stage performances), using change in pain threshold as an assay for endorphin release. The results show that pain thresholds are significantly higher after laughter than in the control condition. This pain-tolerance effect is due to laughter itself and not simply due to a change in positive affect. We suggest that laughter, through an endorphin-mediated opiate effect, may play a crucial role in social bonding.

Abstract

In the absence of comparative method reconstruction, high rate of lexical cognate candidates is often used as evidence for relationships between languages. This paper uses the Oswalt Monte Carlo Shift test (a variant of Oswalt 1970) to explore the statistical basis of the claim that the four Papuan languages of the Solomon Islands have greater than chance levels of lexical similarity. The results of this test initially appear to show that the lexical similarities between the Central Solomons Papuan languages are statistically significant, but the effect disappears when known Oceanic loanwords are removed. The Oswalt Monte Carlo test is a useful technique to test a claim of greater than chance similarity between any two word lists — with the proviso that undetected loanwords strongly increase the chance of spurious identification.

Abstract

A review of "Anthropological papers of the University of Alaska: The Dene-Yeniseian connection." Ed. by JAMES KARI and BEN A. POTTER Fairbanks, AK: University of Alaska, Fairbanks. 2010. Pp. vi, 363.

Abstract

Genome wide complex trait analysis (GCTA) is extended to include environmental effects of the maternal genotype on offspring phenotype (“maternal effects”, M-GCTA). The model includes parameters for the direct effects of the offspring genotype, maternal effects and the covariance between direct and maternal effects. Analysis of simulated data, conducted in OpenMx, confirmed that model parameters could be recovered by full information maximum likelihood (FIML) and evaluated the biases that arise in conventional GCTA when indirect genetic effects are ignored. Estimates derived from FIML in OpenMx showed very close agreement to those obtained by restricted maximum likelihood using the published algorithm for GCTA. The method was also applied to illustrative perinatal phenotypes from ~4,000 mother-offspring pairs from the Avon Longitudinal Study of Parents and Children. The relative merits of extended GCTA in contrast to quantitative genetic approaches based on analyzing the phenotypic covariance structure of kinships are considered.

Abstract

Approach and avoidance are two behavioral responses that make people tend to approach positive and avoid negative situations. This study examines whether postural behavior is influenced by the affective state of pictures. While standing on the Wii™ Balance Board, participants viewed pleasant, neutral, and unpleasant pictures (passively viewing phase). Then they had to move their body to the left or the right (lateral movement phase) to make the next picture appear. We recorded movements in the anterior-posterior direction to examine approach and avoidant behavior. During passively viewing, people approached pleasant pictures. They avoided unpleasant ones while they made a lateral movement. These findings provide support for the idea that we tend to approach positive and avoid negative situations.

Abstract

1. Introduction Speech conveys not only linguistic meaning but also paralinguistic information, such as features of the speaker’s social background, physiology, and emotional state. Linguistic and paralinguistic information is encoded in speech by using largely the same vocal apparatus and both are transmitted simultaneously in the acoustic signal, drawing on a limited set of acoustic cues. How this simultaneous encoding is achieved, how the different types of information are disentangled by the listener, and how much they interfere with one another is presently not well understood. Previous research has highlighted the importance of acoustic source and filter cues for emotion and linguistic encoding respectively, which may suggest that the two types of information are encoded independently of each other. However, those lines of investigation have been almost completely disconnected (Murray & Arnott, 1993).

Abstract

Definition Perceptual learning in speech describes a change in the mapping from acoustic cues in the speech signal to abstract linguistic representations. Learning leads to a lasting benefit to the listener by improving speech comprehension. The change can occur as a response to a specific feature (such as a talker- or accent idiosyncrasy) or to a global degradation of the signal (such as in synthesized or compressed speech). In perceptual learning, a top-down process is involved in causing the change, whereas purely bottom-up, signal-driven phenomena are considered to be adaptation.

Abstract

Language resource centers allow researchers to reliably deposit their structured data together with associated meta data and run services operating on this deposited data. We are looking into possibilities to create long-term persistency of both the deposited data and the services operating on this data. Challenges, both technical and non-technical, that need to be solved are the need to replicate more than just the data, proper identification of the digital objects in a distributed environment by making use of persistent identifiers and the set-up of a proper authentication and authorization domain including the management of the authorization information on the digital objects. We acknowledge the investment that most language resource centers have made in their current infrastructure. Therefore one of the most important requirements is the loose coupling with existing infrastructures without the need to make many changes. This shift from a single language resource center into a federated environment of many language resource centers is discussed in the context of a real world center: The Language Archive supported by the Max Planck Institute for Psycholinguistics.

Abstract

In the present article, we introduce the continuous unified electronic (CUE) diary method, a longitudinal, event-based, electronic parent report method that allows real-time recording of infant and child behavior in natural contexts. Thirty-nine expectant mothers were trained to identify and record target behaviors into programmed handheld computers. From birth to 18 months, maternal reporters recorded the initial, second, and third occurrences of seven target motor behaviors: palmar grasp, rolls from side to back, reaching when sitting, pincer grip, crawling, walking, and climbing stairs. Compliance was assessed as two valid entries per behavior: 97 % of maternal reporters met compliance criteria. Reliability was assessed by comparing diary entries with researcher assessments for three of the motor behaviors: palmar grasp, pincer grip and walking. A total of 81 % of maternal reporters met reliability criteria. For those three target behaviors, age of emergence was compared across data from the CUE diary method and researcher assessments. The CUE diary method was found to detect behaviors earlier and with greater sensitivity to individual differences. The CUE diary method is shown to be a reliable methodological tool for studying processes of change in human development.

Abstract

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

Abstract

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

Abstract

Book review of James R. Hurford THE ORIGINS OF GRAMMAR 791pp. Oxford University Press. ISBN 978 0 19 920787 9

Abstract

Noise-vocoded speech is a spectrally highly degraded signal, but it preserves the temporal envelope of speech. Listeners vary considerably in their ability to adapt to this degraded speech signal. Here, we hypothesized that individual differences in adaptation to vocoded speech should be predictable by non-speech auditory, cognitive, and neuroanatomical factors. We tested eighteen normal-hearing participants in a short-term vocoded speech-learning paradigm (listening to 100 4-band-vocoded sentences). Non-speech auditory skills were assessed using amplitude modulation (AM) rate discrimination, where modulation rates were centered on the speech-relevant rate of 4 Hz. Working memory capacities were evaluated (digit span and nonword repetition), and structural MRI scans were examined for anatomical predictors of vocoded speech learning using voxel-based morphometry. Listeners who learned faster to understand degraded speech also showed smaller thresholds in the AM discrimination task. This ability to adjust to degraded speech is furthermore reflected anatomically in increased volume in an area of the left thalamus (pulvinar) that is strongly connected to the auditory and prefrontal cortices. Thus, individual non-speech auditory skills and left thalamus grey matter volume can predict how quickly a listener adapts to degraded speech.

Abstract

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

Abstract

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

Abstract

We investigated whether regional differences in the native language (L1) influence the perception of second language (L2) sounds. Many cross-language and L2 perception studies have assumed that the degree of acoustic similarity between L1 and L2 sounds predicts cross-linguistic and L2 performance. The present study tests this assumption by examining the perception of the English contrast between /e{open}/ and /æ/ in native speakers of Dutch spoken in North Holland (the Netherlands) and in East- and West-Flanders (Belgium). A Linear Discriminant Analysis on acoustic data from both dialects showed that their differences in vowel production, as reported in and Adank, van Hout, and Van de Velde (2007), should influence the perception of the L2 vowels if listeners focus on the vowels' acoustic/auditory properties. Indeed, the results of categorization tasks with Dutch or English vowels as response options showed that the two listener groups differed as predicted by the discriminant analysis. Moreover, the results of the English categorization task revealed that both groups of Dutch listeners displayed the asymmetric pattern found in previous word recognition studies, i.e. English /æ/ was more frequently confused with English /e{open}/ than the reverse. This suggests a strong link between previous L2 word learning results and the present L2 perceptual assimilation patterns.

Abstract

Nuclear orphan receptor TLX (NR2E1) functions primarily as a transcriptional repressor and its pivotal role in brain development, glioblastoma, mental retardation and retinopathologies make it an attractive drug target. TLX is expressed in the neural stem cells (NSCs) of the subventricular zone and the hippocampus subgranular zone, regions with persistent neurogenesis in the adult brain, and functions as an essential regulator of NSCs maintenance and self-renewal. Little is known about the TLX social network of interactors and only few TLX coregulators are described. To identify and characterize novel TLX-binders and possible coregulators, we performed yeast-two-hybrid (Y2H) screens of a human adult brain cDNA library using different TLX constructs as baits. Our screens identified multiple clones of Atrophin-1 (ATN1), a previously described TLX interactor. In addition, we identified an interaction with the oncoprotein and zinc finger transcription factor BCL11A (CTIP1/Evi9), a key player in the hematopoietic system and in major blood-related malignancies. This interaction was validated by expression and coimmunoprecipitation in human cells. BCL11A potentiated the transrepressive function of TLX in an in vitro reporter gene assay. Our work suggests that BCL11A is a novel TLX coregulator that might be involved in TLX-dependent gene regulation in the brain.

Abstract

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

Abstract

In the current eye-tracking study, we explored whether 12-month-old infants can predict others' social preferences. We showed infants scenes in which two characters alternately helped or hindered an agent in his goal of climbing a hill. In a control condition, the two characters moved up and down the hill in identical ways to the helper and hinderer but did not make contact with the agent; thus, they did not cause him to reach or not reach her or his goal. Following six alternating familiarization trials of helping and hindering interactions (help-hinder condition) or up and down interactions (up-down condition), infants were shown one test trial in which they could visually anticipate the agent approaching one of the two characters. As predicted, infants in the help-hinder condition made significantly more visual anticipations toward the helping than hindering character, suggesting that they predicted the agent to approach the helping character. In contrast, infants revealed no difference in visual anticipations between the up and down characters. The up-down condition served to control for low-level perceptual explanations of the results for the help-hinder condition. Thus, together the results reveal that 12-month-old infants make predictions about others' behaviour and social preferences from a third-party perspective.

Abstract

Across two experiments, we examined the relationship between 18-month-old infants’ mimicry and social behavior – particularly invitations to play with an adult play partner. In Experiment 1, we manipulated whether an adult mimicked the infant's play or not during an initial play phase. We found that infants who had been mimicked were subsequently more likely to invite the adult to join their play with a new toy. In addition, they reenacted marginally more steps from a social learning demonstration she gave. In Experiment 2, infants had the chance to spontaneously mimic the adult during the play phase. Complementing Experiment 1, those infants who spent more time mimicking the adult were more likely to invite her to play with a new toy. This effect was specific to play and not apparent in other communicative acts, such as directing the adult's attention to an event or requesting toys. Together, the results suggest that infants use mimicry as a tool to establish social connections with others and that mimicry has specific influences on social behaviors related to initiating subsequent joint interactions.

Abstract

Infants imitate others’ individual actions, but do they also replicate others’ joint activities? To examine whether observing joint action influences infants’ initiation of joint action, forty-eight 18-month-old infants observed object demonstrations by 2 models acting together (joint action), 2 models acting individually (individual action), or 1 model acting alone (solitary action). Infants’ behavior was examined after they were given each object. Infants in the joint action condition attempted to initiate joint action more often than infants in the other conditions, yet they were equally likely to communicate for other reasons and to imitate the demonstrated object-directed actions. The findings suggest that infants learn to replicate others’ joint activity through observation, an important skill for cultural transmission of shared practices.

Abstract

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

Abstract

We examine representations of time among the Mianmin of Papua New Guinea. We begin by describing the patterns of spatial and temporal reference in Mian. Mian uses a system of spatial terms that derive from the orientation and direction of the Hak and Sek rivers and the surrounding landscape. We then report results from a temporal arrangement task administered to a group of Mian speakers. The results reveal evidence for a variety of temporal representations. Some participants arranged time with respect to their bodies (left to right or toward the body). Others arranged time as laid out on the landscape, roughly along the east/west axis (either east to west or west to east). This absolute pattern is consistent both with the axis of the motion of the sun and the orientation of the two rivers, which provides the basis for spatial reference in the Mian language. The results also suggest an increase in left-to-right temporal representations with increasing years of formal education (and the reverse pattern for absolute spatial representations for time). These results extend previous work on spatial representations for time to a new geographical region, physical environment, and linguistic and cultural system.

Abstract

The constituents of attractiveness differ across the sexes. Many relevant traits are dimorphic, suggesting that they are the product of intersexual selection. However, direction of causality is generally difficult to determine, as aesthetic criteria can as readily result from, as cause, dimorphism. Women have proportionately smaller feet than men. Prior work on the role of foot size in attractiveness suggests an asymmetry across the sexes, as small feet enhance female appearance, yet average, rather than large, feet are preferred on men. Previous investigations employed crude stimuli and limited samples. Here, we report on multiple cross-cultural studies designed to overcome these limitations. With the exception of one rural society, we find that small foot size is preferred when judging women, yet no equivalent preference applies to men. Similarly, consonant with the thesis that a preference for youth underlies intersexual selection acting on women, we document an inverse relationship between foot size and perceived age. Examination of preferences regarding, and inferences from, feet viewed in isolation suggests different roles for proportionality and absolute size in judgments of female and male bodies. Although the majority of these results bolster the conclusion that pedal dimorphism is the product of intersexual selection, the picture is complicated by the reversal of the usual preference for small female feet found in one rural society. While possibly explicable in terms of greater emphasis on female economic productivity relative to beauty, the latter finding underscores the importance of employing diverse samples when exploring postulated evolved aesthetic preferences.

Abstract

The evolutionary origins of music are much debated. One theory holds that the ability to produce complex musical sounds might reflect qualities that are relevant in mate choice contexts and hence, that music is functionally analogous to the sexually-selected acoustic displays of some animals. If so, women may be expected to show heightened preferences for more complex music when they are most fertile. Here, we used computer-generated musical pieces and ovulation predictor kits to test this hypothesis. Our results indicate that women prefer more complex music in general; however, we found no evidence that their preference for more complex music increased around ovulation. Consequently, our findings are not consistent with the hypothesis that a heightened preference/bias in women for more complex music around ovulation could have played a role in the evolution of music. We go on to suggest future studies that could further investigate whether sexual selection played a role in the evolution of this universal aspect of human culture.

Abstract

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

Abstract

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

Abstract

What is the key cognitive ability that makes humans unique among all the other animals? Our work aims at contributing to this research question adopting a comparative and philosophical approach to the origins of verbal language. In particular, we adopt three strands of analysis that are relevant in the context of comparative investigation on the the origins of verbal language: a) research on the evolutionary ‘homologies’, which provides information on the phylogenetic traits that humans and other primates share with their common ancestor; b) investigations on “analogous” traits, aimed at finding the evolutionary pressures that guided the emergence of the same biological traits that evolved independently in phylogenetically distant species; the ontogenetic development of the ability to produce and understand verbal language in human infants. Within this comparative approach, we focus on three key apsects that we addressed bridging recent empiric evidence on language processing with philosophical investigations on verbal language: (i) pattern processing as a biologocal precursor of syntax and algebraic rule acquisition, (ii) sound modulation as a guide to pattern comprehension in speech, animal vocalization and music, (iii) social strategies for mutual understanding, survival and group cohesion. We conclude emphasizing the interplay between these three sets of cognitive processes as a fundamental dimension grounding the emergence of the human ability for propositional language.

Abstract

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

Abstract

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

Abstract

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

Abstract

Research on pattern perception and rule learning, grounded in formal language theory (FLT) and using artificial grammar learning paradigms, has exploded in the last decade. This approach marries empirical research conducted by neuroscientists, psychologists and ethologists with the theory of computation and FLT, developed by mathematicians, linguists and computer scientists over the last century. Of particular current interest are comparative extensions of this work to non-human animals, and neuroscientific investigations using brain imaging techniques. We provide a short introduction to the history of these fields, and to some of the dominant hypotheses, to help contextualize these ongoing research programmes, and finally briefly introduce the papers in the current issue.

Abstract

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

Abstract

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

Abstract

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

Abstract

No abstract is available for this article

Abstract

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

Abstract

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

Abstract

Understanding the progression of neurological diseases is vital for accurate and early diagnosis and treatment planning. We introduce a new characterization of disease progression, which describes the disease as a series of events, each comprising a significant change in patient state. We provide novel algorithms to learn the event ordering from heterogeneous measurements over a whole patient cohort and demonstrate using combined imaging and clinical data from familial-Alzheimer's and Huntington's disease cohorts. Results provide new detail in the progression pattern of these diseases, while confirming known features, and give unique insight into the variability of progression over the cohort. The key advantage of the new model and algorithms over previous progression models is that they do not require a priori division of the patients into clinical stages. The model and its formulation extend naturally to a wide range of other diseases and developmental processes and accommodate cross-sectional and longitudinal input data.

Abstract

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

Abstract

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

Abstract

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

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

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

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

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