Publications

Abstract

Human implicit learning can be investigated with implicit artificial grammar learning, a simple model for aspects of natural language acquisition. In this paper we investigate the remaining effect of modality transfer in syntactic classification of an acquired grammatical sequence structure after implicit grammar acquisition. Participants practiced either on acoustically presented syllable sequences or visually presented consonant letter sequences. During classification we independently manipulated the statistical frequency-based and rule-based characteristics of the classification stimuli. Participants performed reliably above chance on the within modality classification task although more so for those working on syllable sequence acquisition. These subjects were also the only group that kept a significant performance level in transfer classification. We speculate that this finding is of particular relevance in consideration of an ecological validity in the input signal in the use of artificial grammar learning and in language learning paradigms at large.

Abstract

The molecular, developmental, and evolutionary bases of human brain asymmetry are almost completely unknown. Genetic linkage and association mapping have pin-pointed a gene called LRRTM1 (leucine-rich repeat transmembrane neuronal 1) that may contribute to variability in human handedness. Here I describe how LRRTM1's involvement in handedness was discovered, and also the latest knowledge of its functions in brain development and disease. The association of LRRTM1 with handedness was derived entirely from the paternally inherited gene, and follow-up analysis of gene expression confirmed that LRRTM1 is one of a small number of genes that are imprinted in the human genome, for which the maternally inherited copy is suppressed. The same variation at LRRTM1 that was associated paternally with mixed-/left-handedness was also over-transmitted paternally to schizophrenic patients in a large family study.
LRRTM1 is expressed in specific regions of the developing and adult forebrain by post-mitotic neurons, and the protein may be involved in axonal trafficking. Thus LRRTM1 has a probable role in neurodevelopment, and its association with handedness suggests that one of its functions may be in establishing or consolidating human brain asymmetry.
LRRTM1 is the first gene for which allelic variation has been associated with human handedness. The genetic data also suggest indirectly that the epigenetic regulation of this gene may yet prove more important than DNA sequence variation for influencing brain development and disease.
Intriguingly, the parent-of-origin activity of LRRTM1 suggests that men and women have had conflicting interests in relation to the outcome of lateralized brain development in their offspring.

Abstract

Left-right asymmetrical brain function underlies much of human cognition, behavior and emotion. Abnormalities of cerebral asymmetry are associated with schizophrenia and other neuropsychiatric disorders. The molecular, developmental and evolutionary origins of human brain asymmetry are unknown. We found significant association of a haplotype upstream of the gene LRRTM1 (Leucine-rich repeat transmembrane neuronal 1) with a quantitative measure of human handedness in a set of dyslexic siblings, when the haplotype was inherited paternally (P=0.00002). While we were unable to find this effect in an epidemiological set of twin-based sibships, we did find that the same haplotype is overtransmitted paternally to individuals with schizophrenia/schizoaffective disorder in a study of 1002 affected families (P=0.0014). We then found direct confirmatory evidence that LRRTM1 is an imprinted gene in humans that shows a variable pattern of maternal downregulation. We also showed that LRRTM1 is expressed during the development of specific forebrain structures, and thus could influence neuronal differentiation and connectivity. This is the first potential genetic influence on human handedness to be identified, and the first putative genetic effect on variability in human brain asymmetry. LRRTM1 is a candidate gene for involvement in several common neurodevelopmental disorders, and may have played a role in human cognitive and behavioral evolution.

Abstract

Francks et al. (2007) performed a recent study in which the first putative genetic effect on human handedness was identified (the imprinted locus LRRTM1 on human chromosome 2). In this issue of Laterality, Tim Crow and colleagues present a critique of that study. The present paper presents a personal response to that critique which argues that Francks et al. (2007) published a substantial body of evidence implicating LRRTM1 in handedness and schizophrenia. Progress will now be achieved by others trying to validate, refute, or extend those findings, rather than by further armchair discussion.

Abstract

We present a computational model that provides a unified account of inference, coherence, and disambiguation. It simulates how the build-up of coherence in text leads to the knowledge-based resolution of referential ambiguity. Possible interpretations of an ambiguity are represented by centers of gravity in a high-dimensional space. The unresolved ambiguity forms a vector in the same space. This vector is attracted by the centers of gravity, while also being affected by context information and world knowledge. When the vector reaches one of the centers of gravity, the ambiguity is resolved to the corresponding interpretation. The model accounts for reading time and error rate data from experiments on ambiguous pronoun resolution and explains the effects of context informativeness, anaphor type, and processing depth. It shows how implicit causality can have an early effect during reading. A novel prediction is that ambiguities can remain unresolved if there is insufficient disambiguating information.

Abstract

Disruptions of the human FOXP2 gene cause problems with articulation of complex speech sounds, accompanied by impairment in many aspects of language ability. The FOXP2/Foxp2 transcription factor is highly similar in humans and mice, and shows a complex conserved expression pattern, with high levels in neuronal subpopulations of the cortex, striatum, thalamus, and cerebellum. In the present study we generated mice in which loxP sites flank exons 12-14 of Foxp2; these exons encode the DNA-binding motif, a key functional domain. We demonstrate that early global Cre-mediated recombination yields a null allele, as shown by loss of the loxP-flanked exons at the RNA level and an absence of Foxp2 protein. Homozygous null mice display severe motor impairment, cerebellar abnormalities and early postnatal lethality, consistent with other Foxp2 mutants. When crossed to transgenic lines expressing Cre protein in a spatially and/or temporally controlled manner, these conditional mice will provide new insights into the contributions of Foxp2 to distinct neural circuits, and allow dissection of roles during development and in the mature brain.

Abstract

Discourse markers (DMs) are linguistic elements that index different relations and coherence between units of talk (Schiffrin, Deborah, 1987. Discourse Markers. Cambridge University Press, Cambridge). Most research on the development of these forms has focused on conversations rather than narratives and furthermore has not directly compared children's use of DMs to adult usage. This study examines the development of three DMs (şey ‘uuhh’, yani ‘I mean’, işte ‘y’know’) that mark interactional levels of discourse in oral Turkish narratives in 60 Turkish children (3-, 5- and 9-year-olds) and 20 Turkish-speaking adults. The results show that the frequency and functions of DMs change with age. Children learn şey, which mainly marks exchange level structures, earliest. However, yani and işte have multi-functions such as marking both information states and participation frameworks and are consequently learned later. Children also use DMs with different functions than adults. Overall, the results show that learning to use interactional DMs in narratives is complex and goes beyond age 9, especially for multi-functional DMs that index an interplay of discourse coherence at different levels.

Abstract

This study addresses how verbal self-monitoring and the Error-Related Negativity (ERN) are affected by time pressure
when a task is performed in a second language as opposed to performance in the native language. German–Dutch
bilinguals were required to perform a phoneme-monitoring task in Dutch with and without a time pressure manipulation.
We obtained an ERN following verbal errors that showed an atypical increase in amplitude under time
pressure. This finding is taken to suggest that under time pressure participants had more interference from their native
language, which in turn led to a greater response conflict and thus enhancement of the amplitude of the ERN. This
result demonstrates once more that the ERN is sensitive to psycholinguistic manipulations and suggests that the
functioning of the verbal self-monitoring systemduring speaking is comparable to other performance monitoring, such
as action monitoring.

Abstract

This paper presents a new architecture for optical burst switched networks where the control plane of the network functions in a cooperative manner. Each node interprets the data conveyed by the control packet and forwards it to the next nodes, making the control plane of the network distribute the relevant information to all the nodes in the network. A cooperation transmission tree is used, thus allowing all the nodes to store the information related to the traffic management in the network, and enabling better network resource planning at each node. A model of this network architecture is proposed, and its performance is evaluated.

Abstract

Phonagnosia, the inability to recognize familiar voices, has been studied in brain-damaged patients but no cases due to developmental problems have been reported. Here we describe the case of KH, a 60-year-old active professional woman who reports that she has always experienced severe voice recognition difficulties. Her hearing abilities are normal, and an MRI scan showed no evidence of brain damage in regions associated with voice or auditory perception. To better understand her condition and to assess models of voice and high-level auditory processing, we tested KH on behavioural tasks measuring voice recognition, recognition of vocal emotions, face recognition, speech perception, and processing of environmental sounds and music. KH was impaired on tasks requiring the recognition of famous voices and the learning and recognition of new voices. In contrast, she performed well on nearly all other tasks. Her case is the first report of developmental phonagnosia, and the results suggest that the recognition of a speaker’s vocal identity depends on separable mechanisms from those used to recognize other information from the voice or non-vocal auditory stimuli.

Abstract

In the context of large and ever growing archives, generating annotation suggestions automatically from textual resources related to the documents to be archived is an interesting option in theory. It could save a lot of work in the time consuming and expensive task of manual annotation and it could help cataloguers attain a higher inter-annotator agreement. However, some questions arise in practice: what is the quality of the automatically produced annotations? How do they compare with manual annotations and with the requirements for annotation that were defined in the archive? If different from the manual annotations, are the automatic annotations wrong? In the CHOICE project, partially hosted at the Netherlands Institute for Sound and Vision, the Dutch public archive for audiovisual broadcasts, we automatically generate annotation suggestions for cataloguers. In this paper, we define three types of evaluation of these annotation suggestions: (1) a classic and strict evaluation measure expressing the overlap between automatically generated keywords and the manual annotations, (2) a loosened evaluation measure for which semantically very similar annotations are also considered as relevant matches, and (3) an in-use evaluation of the usefulness of manual versus automatic annotations in the context of serendipitous browsing. During serendipitous browsing, the annotations (manual or automatic) are used to retrieve and visualize semantically related documents.

Abstract

Irrelevant speech effect (ISE) is defined as a decrement in visually presented digit-list short-term memory performance due to exposure to irrelevant auditory material. Perhaps the most successful theoretical explanation of the effect is the changing state hypothesis. This hypothesis explains the effect in terms of confusion between amodal serial order cues, and represents a view based on the interference caused by the processing of similar order information of the visual and auditory materials. An alternative view suggests that the interference occurs as a consequence of the similarity between the visual and auditory contents of the stimuli. An important argument for the former view is the observation that ISE is almost exclusively observed in tasks that require memory for serial order. However, most short-term memory tasks require that both item and order information be retained in memory. An ideal task to investigate the sensitivity of maintenance of serial order to irrelevant speech would be one that calls upon order information but not item information. One task that is particularly suited to address this issue is serial recognition. In a typical serial recognition task, a list of items is presented and then probed by the same list in which the order of two adjacent items has been transposed. Due to the re-presentation of the encoding string, serial recognition requires primarily the serial order to be maintained while the content of the presented items is deemphasized. In demonstrating a highly significant ISE of changing versus steady-state auditory items in a serial recognition task, the present finding lends support for and extends previous empirical findings suggesting that irrelevant speech has the potential to interfere with the coding of the order of the items to be memorized.

Abstract

OBJECTIVES: Combining the analysis of family-based samples with unrelated individuals can enhance the power of genetic association studies. Various combined analysis techniques have been recently developed; as yet, there have been no comparisons of their power, or robustness to confounding factors. We investigated empirically the power of up to six combined methods using simulated samples of trios and unrelated cases/controls (TDTCC), trios and unrelated controls (TDTC), and affected sibpairs with parents and unrelated cases/controls (ASPFCC). METHODS: We simulated multiplicative, dominant and recessive models with varying risk parameters in single samples. Additionally, we studied false-positive rates and investigated, if possible, the coverage of the true genetic effect (TDTCC). RESULTS/CONCLUSIONS: Under the TDTCC design, we identified four approaches with equivalent power and false-positive rates. Combined statistics were more powerful than single-sample statistics or a pooled chi(2)-statistic when risk parameters were similar in single samples. Adding parental information to the CC part of the joint likelihood increased the power of generalised logistic regression under the TDTC but not the TDTCC scenario. Formal testing of differences between risk parameters in subsamples was the most sensitive approach to avoid confounding in combined analysis. Non-parametric analysis based on Monte-Carlo testing showed the highest power for ASPFCC samples.

Abstract

Using parametric and nonparametric techniques, our study investigated the presence of single locus and pairwise effects between 20 markers of the Genetic Analysis Workshop 15 (GAW15) North American Rheumatoid Arthritis Consortium (NARAC) candidate gene data set (Problem 2), analyzing 463 independent patients and 855 controls. Specifically, our work examined the correspondence between logistic regression (LR) analysis of single-locus and pairwise interaction effects, and random forest (RF) single and joint importance measures. For this comparison, we selected small but stable RFs (500 trees), which showed strong correlations (r~0.98) between their importance measures and those by RFs grown on 5000 trees. Both RF importance measures captured most of the LR single-locus and pairwise interaction effects, while joint importance measures also corresponded to full LR models containing main and interaction effects. We furthermore showed that RF measures were particularly sensitive to data imputation. The most consistent pairwise effect on rheumatoid arthritis was found between two markers within MAP3K7IP2/SUMO4 on 6q25.1, although LR and RFs assigned different significance levels. Within a hypothetical two-stage design, pairwise LR analysis of all markers with significant RF single importance would have reduced the number of possible combinations in our small data set by 61%, whereas joint importance measures would have been less efficient for marker pair reduction. This suggests that RF single importance measures, which are able to detect a wide range of interaction effects and are computationally very efficient, might be exploited as pre-screening tool for larger association studies. Follow-up analysis, such as by LR, is required since RFs do not indicate highrisk genotype combinations.

Abstract

The verb has traditionally been characterized as the central element in a sentence. Nevertheless, the exact role of the verb during the actual ongoing comprehension of a sentence as it unfolds in time remains largely unknown. This paper reports the results of two Cross-Modal Lexical Priming (CMLP) experiments detailing the pattern of verb priming during on-line processing of Dutch sentences. Results are contrasted with data from a third CMLP experiment on priming of nouns in similar sentences. It is demonstrated that the meaning of a matrix verb remains active throughout the entire matrix clause, while this is not the case for the meaning of a subject head noun. Activation of the meaning of the verb only dissipates upon encountering a clear signal as to the start of a new clause.

Abstract

This doctoral dissertation investigated the learning of auditory categories by applying insights from child language learning, visual category learning and phonetic categorization by adults. The experiments in chapter 2 concern supervised learning of multidimensional non-speech categories varying in two dimensions: duration and a non speech analogue of formant frequency. In experiment 1, one dimension of variation determined category membership, variation in the other dimension was irrelevant. Listeners quickly learned to categorize according to this distinction. In experiment 2, both dimensions needed to be combined to categorize correctly. Performance was much lower, but most listeners succeeded in this task. However, in a maintenance phase without feedback or distributional information, listeners reverted to a unidimensional solution. In a maintenance phase with distributional information, listeners did use both dimensions correctly, arguing for the importance of distributional information in (auditory) category acquisition. In chapter 3, the listeners had to classify the same categories, but without feedback. In experiment 1, listeners succeeded to discover the relevant dimension of variation (and ignore the irrelevant one) without feedback. Much of this learning was lost in the maintenance phase, especially for the dimension formant frequency. With two relevant dimensions (Experiment 2), listeners were not able to learn to use both dimensions and reverted to a unidimensional solution. Chapter 4 applied the paradigms of chapter 2 and 3 to the learning of speech categories. Spanish native listeners learned Dutch vowel contrast with one relevant dimension of variation. With feedback, learning was swift, although was not well maintained without feedback or distributional information. Without feedback, Spanish listeners reverted to the dimensions best known in their native phonology, formant frequency, even when distributional information pointed to duration. The results are discussed in chapter 5. The implications for models of speech acquisition are discussed.

Abstract

Distributional learning is almost certainly involved in the human acquisition of phonetic categories. Because speech is inherently a multidimensional signal, learning phonetic categories entails multidimensional learning. Yet previous studies of auditory category learning have shown poor maintenance of learned multidimensional categories. Two experiments explored ways to improve maintenance: by increasing the costs associated with applying a unidimensional strategy; by providing additional information about the category structures; and by giving explicit instructions on how to categorize. Only with explicit instructions were categorization strategies maintained in a maintenance phase without supervision or distributional information.

Abstract

Learning to recognize the contrasts of a language-specific phonemic repertoire can be viewed as forming categories in a multidimensional psychophysical space. Research on the learning of distributionally defined visual categories has shown that categories defined over I dimension are easy to learn and that learning multidimensional categories is more difficult but tractable under specific task conditions. In 2 experiments, adult participants learned either a unidimensional ora multidimensional category distinction with or without supervision (feedback) during learning. The unidimensional distinctions were readily learned and supervision proved beneficial, especially in maintaining category learning beyond the learning phase. Learning the multidimensional category distinction proved to be much more difficult and supervision was not nearly as beneficial as with unidimensionally defined categories. Maintaining a learned multidimensional category distinction was only possible when the distributional information (hat identified the categories remained present throughout the testing phase. We conclude that listeners are sensitive to both trial-by-trial feedback and the distributional information in the stimuli. Even given limited exposure, listeners learned to use 2 relevant dimensions. albeit with considerable difficulty.

Abstract

Prolectin, a previously undescribed glycan-binding receptor, has been identified by re-screening of the human genome for genes encoding proteins containing potential C-type carbohydrate-recognition domains. Glycan array analysis revealed that the carbohydrate-recognition domain in the extracellular domain of the receptor binds glycans with terminal α-linked mannose or fucose residues. Prolectin expressed in fibroblasts is found at the cell surface, but unlike many glycan-binding receptors it does not mediate endocytosis of a neoglycoprotein ligand. However, compared with other known glycan-binding receptors, the receptor contains an unusually large intracellular domain that consists of multiple sequence motifs, including phosphorylated tyrosine residues, that allow it to interact with signaling molecules such as Grb2. Immunohistochemistry has been used to demonstrate that prolectin is expressed on a specialized population of proliferating B cells in germinal centers. Thus, this novel receptor has the potential to function in carbohydrate-mediated communication between cells in the germinal center.

Abstract

In this paper we introduce Functional Data Analysis (FDA) as a tool for analyzing dynamic transitions in speech signals. FDA makes it possible to perform statistical analyses of sets of mathematical functions in the same way as classical multivariate analysis treats scalar measurement data. We illustrate the use of FDA with a reduction phenomenon affecting the French word c'était /setε/ 'it was', which can be reduced to [stε] in conversational speech. FDA reveals that the dynamics of the transition from [s] to [t] in fully reduced cases may still be different from the dynamics of [s] - [t] transitions in underlying /st/ clusters such as in the word stage.

Abstract

The goal of this task is to investigate cross-cultural emotion categories in language and thought. This entry is designed to provide researchers with some guidelines to describe the emotional repertoire of a community from an emic perspective. The first objective is to offer ethnographic tools and a questionnaire in order to understand the semantics of emotional terms and the local conception of emotions. The second objective is to identify the local display rules of emotions in communicative interactions.

Abstract

There is growing evidence that addressees in interaction integrate the semantic information conveyed by speakers’ gestures. Little is known, however, about whether and how addressees’ attention to gestures and the integration of gestural information can be modulated. This study examines the influence of a social factor (speakers’ gaze to their own gestures), and two physical factors (the gesture’s location in gesture space and gestural holds) on addressees’ overt visual attention to gestures (direct fixations of gestures) and their uptake of gestural information. It also examines the relationship between gaze and uptake. The results indicate that addressees’ overt visual attention to gestures is affected both by speakers’ gaze and holds but for different reasons, whereas location in space plays no role. Addressees’ uptake of gesture information is only influenced by speakers’ gaze. There is little evidence of a direct relationship between addressees’ direct fixations of gestures and their uptake.

Abstract

This paper argues that speech-associated gestures can usefully inform studies exploring development of meaning in first and second language acquisition. The example domain is caused motion or placement meaning (putting a cup on a table) where acquisition problems have been observed and where adult native gesture use reflects crosslinguistically different placement verb semantics. Against this background, the paper summarises three studies examining the development of semantic representations in Dutch children acquiring Dutch, and adult learners’ acquiring Dutch and French placement verbs. Overall, gestures change systematically with semantic development both in children and adults and (1) reveal what semantic elements are included in current semantic representations, whether target-like or not, and (2) highlight developmental shifts in those representations. There is little evidence that gestures chiefly act as a support channel. Instead, the data support the theoretical notion that speech and gesture form an integrated system, opening new possibilities for studying the processes of acquisition.

Abstract

This study examines to what extent English speakers of L2 Dutch reconstruct the meanings of placement verbs when moving from a general L1 verb of caused motion (put) to two specific caused posture verbs (zetten/leggen ‘set/lay’) in the L2 and whether the existence of low-frequency cognate forms in the L1 (set/lay) alleviates the reconstruction problem. Evidence from speech and gesture indicates that English speakers have difficulties with the specific verbs in L2 Dutch, initially looking for means to express general caused motion in L1-like fashion through over-generalisation. The gesture data further show that targetlike forms are often used to convey L1-like meaning. However, the differentiated use of zetten for vertical placement and dummy verbs (gaan ‘go’ and doen ‘do’) and intransitive posture verbs (zitten/staan/liggen ‘sit, stand, lie’) for horizontal placement, and a positive correlation between appropriate verb use and target-like gesturing suggest a beginning sensitivity to the semantic parameters of the L2 verbs and possible reconstruction.

Abstract

The aim of this chapter is to provide researchers with a tool kit of semi-experimental and experimental techniques for studying code-switching. It presents an overview of the current off-line and on-line research techniques, ranging from analyses of published bilingual texts of spontaneous conversations, to tightly controlled experiments. A multi-task approach used for studying code-switched sentence production in Papiamento-Dutch bilinguals is also exemplified.

Abstract

Gestures, the symbolic movements speakers perform while they speak, are systematically related to speech and language in non-trivial ways. This chapter presents an overview of what gestures can and cannot tell us about the monolingual and the bilingual mental lexicon. Gesture analysis opens for a broader view of the mental lexicon, targeting the interface between conceptual, semantic and syntactic aspects of event construal, and offers new possibilities for examining how languages co-exist and interact in bilinguals beyond the level of surface forms. The first section of this chapter gives a brief introduction to gesture studies and outlines the current views on the relationship between gesture, speech, and language. The second section targets the key questions for the study of the monolingual and bilingual lexicon, and illustrates the methods employed for addressing these questions. It further exemplifies systematic cross-linguistic patterns in gestural behaviour in monolingual and bilingual contexts. The final section discusses some implications of an expanded view of the multilingual lexicon that includes gesture, and outlines directions for future inquiry.

Abstract

A central and influential idea among researchers of language is that our language faculty is organized according to Fregean compositionality, which states that the meaning of an utterance is a function of the meaning of its parts and of the syntactic rules by which these parts are combined. Since the domain of syntactic rules is the sentence, the implication of this idea is that language interpretation takes place in a two-step fashion. First, the meaning of a sentence is computed. In a second step, the sentence meaning is integrated with information from prior discourse, world knowledge, information about the speaker and semantic information from extra-linguistic domains such as co-speech gestures or the visual world. Here, we present results from recordings of event-related brain potentials that are inconsistent with this classical two-step model of language interpretation. Our data support a one-step model in which knowledge about the context and the world, concomitant information from other modalities, and the speaker are brought to bear immediately, by the same fast-acting brain system that combines the meanings of individual words into a message-level representation. Underlying the one-step model is the immediacy assumption, according to which all available information will immediately be used to co-determine the interpretation of the speaker's message. Functional magnetic resonance imaging data that we collected indicate that Broca's area plays an important role in semantic unification. Language comprehension involves the rapid incorporation of information in a 'single unification space', coming from a broader range of cognitive domains than presupposed in the standard two-step model of interpretation.

Abstract

This contribution focuses on the neural infrastructure for parsing and syntactic encoding. From an anatomical point of view, it is argued that Broca's area is an ill-conceived notion. Functionally, Broca's area and adjacent cortex (together Broca's complex) are relevant for language, but not exclusively for this domain of cognition. Its role can be characterized as providing the necessary infrastructure for unification (syntactic and semantic). A general proposal, but with required level of computational detail, is discussed to account for the distribution of labor between different components of the language network in the brain.Arguments are provided for the immediacy principle, which denies a privileged status for syntax in sentence processing. The temporal profile of event-related brain potential (ERP) is suggested to require predictive processing. Finally, since, next to speed, diversity is a hallmark of human languages, the language readiness of the brain might not depend on a universal, dedicated neural machinery for syntax, but rather on a shaping of the neural infrastructure of more general cognitive systems (e.g., memory, unification) in a direction that made it optimally suited for the purpose of communication through language.

Abstract

Language and communication are about the exchange of meaning. A key feature of understanding and producing language is the construction of complex meaning from more elementary semantic building blocks. The functional characteristics of this semantic unification process are revealed by studies using event related brain potentials. These studies have found that word meaning is assembled into compound meaning in not more than 500 ms. World knowledge, information about the speaker, co-occurring visual input and discourse all have an immediate impact on semantic unification, and trigger similar electrophysiological responses as sentence-internal semantic information. Neuroimaging studies show that a network of brain areas, including the left inferior frontal gyrus, the left superior/middle temporal cortex, the left inferior parietal cortex and, to a lesser extent their right hemisphere homologues are recruited to perform semantic unification.

Abstract

How does intention to speak become the action of speaking? It involves the generation of a preverbal message that is tailored to the requirements of a particular language, and through a series of steps, the message is transformed into a linear sequence of speech sounds (1, 2). These steps include retrieving different kinds of information from memory (semantic, syntactic, and phonological), and combining them into larger structures, a process called unification. Despite general agreement about the steps that connect intention to articulation, there is no consensus about their temporal profile or the role of feedback from later steps (3, 4). In addition, since the discovery by the French physician Pierre Paul Broca (in 1865) of the role of the left inferior frontal cortex in speaking, relatively little progress has been made in understanding the neural infrastructure that supports speech production (5). One reason is that the characteristics of natural language are uniquely human, and thus the neurobiology of language lacks an adequate animal model. But on page 445 of this issue, Sahin et al. (6) demonstrate, by recording neuronal activity in the human brain, that different kinds of linguistic information are indeed sequentially processed within Broca's area.

Abstract

In an ERP experiment we investigated how the recruitment and integration of world knowledge information relate to the integration of information within a current discourse context. Participants were presented with short discourse contexts which were followed by a sentence that contained a critical word that was correct or incorrect based on general world knowledge and the supporting discourse context, or was more or less acceptable based on the combination of general world knowledge and the specific local discourse context. Relative to the critical word in the correct world knowledge sentences following a neutral discourse, all other critical words elicited an N400 effect that began at about 300 ms after word onset. However, the magnitude of the N400 effect varied in a way that suggests an interaction between world knowledge and discourse context. The results indicate that both world knowledge and discourse context have an effect on sentence interpretation, but neither overrides the other.

Abstract

Written language comprehension at the word and the sentence level was analysed by the combination of spatial and temporal analysis of functional magnetic resonance imaging (fMRI). Spatial analysis was performed via general linear modelling (GLM). Concerning the temporal analysis, local differences in neurovascular coupling may confound a direct comparison of blood oxygenation level-dependent (BOLD) response estimates between regions. To avoid this problem, we parametrically varied linguistic task demands and compared only task-induced within-region BOLD response differences across areas. We reasoned that, in a hierarchical processing system, increasing task demands at lower processing levels induce delayed onset of higher-level processes in corresponding areas. The flow of activation is thus reflected in the size of task-induced delay increases. We estimated BOLD response delay and duration for each voxel and each participant by fitting a model function to the event-related average BOLD response. The GLM showed increasing activations with increasing linguistic demands dominantly in the left inferior frontal gyrus (IFG) and the left superior temporal gyrus (STG). The combination of spatial and temporal analysis allowed a functional differentiation of IFG subregions involved in written language comprehension. Ventral IFG region (BA 47) and STG subserve earlier processing stages than two dorsal IFG regions (BA 44 and 45). This is in accordance with the assumed early lexical semantic and late syntactic processing of these regions and illustrates the complementary information provided by spatial and temporal fMRI data analysis of the same data set.

Abstract

Whitesands is an under-described language of southern Vanuatu, and this thesis presents Whitesands-specific data based on primary in-situ field research. The thesis addresses the distinction of noun and verb word classes in the language. It claims that current linguistic syntax theory cannot account for the argument structure of canonical object-denoting roots. It is shown that there are distinct lexical noun and verb classes in Whitesands but this is only a weak dichotomy. Stronger is the NP and VP distinction, and this is achieved by employing a new theoretical approach that proposes functional categories and their selection of complements as crucial tests of distinction. This approach contrasts with previous analyses of parts of speech in Oceanic languages and cross-linguistically. It ultimately explains many of the syntactic phenomena seen in the language family, including the above argument assignment dilemma, the alienable possession of nouns with classifiers and also the nominalisation processes.

Abstract

Rheumatoid arthritis is the most common systematic autoimmune disease and its etiology is believed to have both strong genetic and environmental components. We demonstrate the utility of including genetic and clinical phenotypes as covariates within a linkage analysis framework to search for rheumatoid arthritis susceptibility loci. The raw genotypes of 1302 affected relative pairs were combined from four large family-based samples (North American Rheumatoid Arthritis Consortium, United Kingdom, European Consortium on Rheumatoid Arthritis Families, and Canada). The familiality of the clinical phenotypes was assessed. The affected relative pairs were subjected to autosomal multipoint affected relative-pair linkage analysis. Covariates were included in the linkage analysis to take account of heterogeneity within the sample. Evidence of familiality was observed with age at onset (p <} 0.001) and rheumatoid factor (RF) IgM (p {< 0.001), but not definite erosions (p = 0.21). Genome-wide significant evidence for linkage was observed on chromosome 6. Genome-wide suggestive evidence for linkage was observed on chromosomes 13 and 20 when conditioning on age at onset, chromosome 15 conditional on gender, and chromosome 19 conditional on RF IgM after allowing for multiple testing of covariates.

Abstract

All humans are equipped with perceptual and articulatory mechanisms which (in healthy humans) allow them to learn to perceive and produce speech. One basic question in psycholinguistics is whether humans share similar underlying processing mechanisms for all languages, or whether these are fundamentally different due to the diversity of languages and speakers. This book provides a cross-linguistic examination of speech comprehension by investigating word recognition in users of different languages. The focus is on how listeners segment the quasi-continuous stream of sounds that they hear into a sequence of discrete words, and how a universal segmentation principle, the Possible Word Constraint, applies in the recognition of Slovak and German.

Abstract

Two experiments were carried out to examine the syllable affiliation of intervocalic consonant clusters and their effects on speech segmentation in two different languages. In a syllable reversal task, Slovak and German speakers divided bisyllabic non-words that were presented aurally into two parts, starting with the second syllable. Following the maximal onset principle, intervocalic consonants should be maximally assigned to the onset of the following syllable in conformity with language-specific restrictions, e.g., /du.gru/, /zu.kro:/ (dot indicates a syllable boundary). According to German phonology, syllables require branching rhymes (hence, /zuk.ro:/). In Slovak, both /du.gru/ and /dug.ru/ are possible syllabifications. Experiment 1 showed that German speakers more often closed the first syllable (/zuk.ro:/), following the requirement for a branching rhyme. In Experiment 2, Slovak speakers showed no clear preference; the first syllable was either closed (/dug.ru/) or open (/du.gru/). Correlation analyses on previously conducted word-spotting studies (Hanulíková, in press, 2008) suggest that speech segmentation is unaffected by these syllabification preferences.

Abstract

Syntactic parsers and generators need highquality grammars of coordination and coordinate ellipsis—structures that occur very frequently but are much less well understood theoretically than many other domains of grammar. Modern grammars of coordinate ellipsis are based nearly exclusively on linguistic judgments (intuitions). The extent to which grammar rules based on this type of empirical evidence generate all and only the structures in text corpora, is unknown. As part of a project on the development of a grammar and a generator for coordinate ellipsis in German, we undertook an extensive exploration of the TIGER treebank—a syntactically annotated corpus of about 50,000 newspaper sentences. We report (1) frequency data for the various patterns of coordinate ellipsis, and (2) several rarely (but regularly) occurring ‘fringe deviations’ from the intuition-based rules for several ellipsis types. This information can help improve parser and generator performance.

Abstract

The potential of sentence generators as engines in Intelligent Computer-Assisted Language Learning and teaching (ICALL) software has hardly been explored. We sketch the prototype of COMPASS, a system that supports integrated writing and grammar curricula for 10 to 14 year old elementary or secondary schoolers. The system enables first- or second-language teachers to design controlled writing exercises, in particular of the “sentence combining” variety. The system includes facilities for error diagnosis and on-line feedback. Syntactic structures built by students or system can be displayed as easily understood phrase-structure or dependency trees, adapted to the student’s level of grammatical knowledge. The heart of the system is a specially designed generator capable of lexically guided sentence generation, of generating syntactic paraphrases, and displaying syntactic structures visually.

Abstract

Present-day sentence generators are often in-capable of producing a wide variety of well-formed elliptical versions of coordinated clauses, in particular, of combined elliptical phenomena (Gapping, Forward and Back-ward Conjunction Reduction, etc.). The ap-plicability of the various types of clausal co-ordinate ellipsis (CCE) presupposes detailed comparisons of the syntactic properties of the coordinated clauses. These nonlocal comparisons argue against approaches based on local rules that treat CCE structures as special cases of clausal coordination. We advocate an alternative approach where CCE rules take the form of postediting rules ap-plicable to nonelliptical structures. The ad-vantage is not only a higher level of modu-larity but also applicability to languages be-longing to different language families. We describe a language-neutral module (called Elleipo; implemented in JAVA) that gener-ates as output all major CCE versions of co-ordinated clauses. Elleipo takes as input linearly ordered nonelliptical coordinated clauses annotated with lexical identity and coreferentiality relationships between words and word groups in the conjuncts. We dem-onstrate the feasibility of a single set of postediting rules that attains multilingual coverage.

Abstract

This thesis elaborates on a methodological approach to reliably infer cognitive preferences in an extinct evolutionary ancestor of modern humans. In attempts to understand cognitive evolution, humans have been compared to capuchin monkeys, tamarins, and chimpanzees to name but a few. But comparisons between humans and one other, maybe even distantly related primate, as interesting as they might be, will not tell us anything about an evolutionary ancestor to humans. To put it bluntly: None of the living primates, not even chimpanzees, are a human ancestor. With that in mind, we can still use a comparative approach to gain information about our evolutionary ancestors, as long as we are careful about whom we compare with whom. If a certain trait exists in all genera of a phylogenetic clade, it was most likely present in their common ancestor. The great apes are such a clade (Pongo, Gorilla, Pan and Homo). It follows that, if members of all great ape genera shared a particular cognitive preference or ability, it is most likely part of the evolutionary inheritance of the clade at least ever since their last common ancestor, and therefore also an evolutionarily old, inherited cognitive default in humans. This thesis contains studies comparing all 4 extant Hominid genera, including humans of 4 different age-groups and 2 different cultures. Results show that all great apes do indeed share some cognitive preferences, which they most likely inherited from an evolutionary ancestor. Additionally, human cognitive preferences can change away from such an inherited predisposition given ontogenetic factors, and are at least in part variably adaptable to cultural circumstance.

Abstract

Recognizing relational similarity relies on the ability to understand that defining object properties might not lie in the objects individually, but in the relations of the properties of various object to each other. This aptitude is highly relevant for many important human skills such as language, reasoning, categorization and understanding analogy and metaphor. In the current study, we investigated the ability to recognize relational similarities by testing five species of great apes, including human children in a spatial task. We found that all species performed better if related elements are connected by logico-causal as opposed to non-causal relations. Further, we find that only children above 4 years of age, bonobos and chimpanzees, unlike younger children, gorillas and orangutans display some mastery of reasoning by non-causal relational similarity. We conclude that recognizing relational similarity is not in its entirety unique to the human species. The lack of a capability for language does not prohibit recognition of simple relational similarities. The data are discussed in the light of the phylogenetic tree of relatedness of the great apes.

Abstract

There has been considerable controversy over the existence of cognitive differences across human cultures: some claim that human cognition is essentially universal [1,2], others that it reflects cultural specificities [3,4]. One domain of interest has been spatial cognition [5,6]. Despite the global universality of physical space, cultures vary as to how space is coded in their language. Some, for example, do not use egocentric ‘left, right, front, back’ constructions to code spatial relations, instead using allocentric notions like ‘north, south, east, west’ [4,6]: “The spoon is north of the bowl!” Whether or not spatial cognition also varies across cultures remains a contested question [7,8]. Here we investigate whether memory for movements of one's own body differs between cultures with contrastive strategies for coding spatial relations. Our results show that the ways in which we memorize movements of our own body differ in line with culture-specific preferences for how to conceive of spatial relations.

Abstract

The results of two self-paced reading experiments are reported, which investigated the on-line processing of subject-object ambiguities in Dutch relative clause constructions like Dat is de vrouw die de meisjes heeft/hebben gezien by German advanced second language (L2) learners of Dutch. Native speakers of both Dutch and German have been shown to have a preference for a subject versus an object reading of such temporarily ambiguous sentences, and so we provided an ideal opportunity for the transfer of first language (L1) processing preferences to take place. We also investigated whether the participants' working memory span would affect their processing of the experimental items. The results suggest that processing decisions may be affected by working memory when task demands are high and in this case, the high working memory span learners patterned like the native speakers of lower working memory. However, when reading for comprehension alone, and when only structural information was available to guide parsing decisions, working memory span had no effect on the L2 learners' on-line processing, and this differed from the native speakers' even though the L1 and the L2 are highly comparable.

Abstract

This paper reports on findings from an elicited production task with German 5-year-old children, investigating their use of intonation to mark information status of discourse referents. In line with findings for adults, new referents were preferably marked by H* and L+H*; textually given referents were mainly deaccented. Accessible referents (whose first mentions were less recent) were mostly accented, and predominantly also realised with H* and L+H*, showing children’s sensitivity to recency of mention. No evidence for the consistent use of a special ‘accessibility accent’ H+L* (as has been proposed for adult German) was found.

Abstract

Objective: To evaluate cognitive outcome in adult survivors of bacterial meningitis. Methods: Data from three prospective multicentre studies were pooled and reanalysed, involving 155 adults surviving bacterial meningitis (79 after pneumococcal and 76 after meningococcal meningitis) and 72 healthy controls. Results: Cognitive impairment was found in 32% of patients and this proportion was similar for survivors of pneumococcal and meningococcal meningitis. Survivors of pneumococcal meningitis performed worse on memory tasks (p<0.001) and tended to be cognitively slower than survivors of meningococcal meningitis (p = 0.08). We found a diffuse pattern of cognitive impairment in which cognitive speed played the most important role. Cognitive performance was not related to time since meningitis; however, there was a positive association between time since meningitis and self-reported physical impairment (p<0.01). The frequency of cognitive impairment and the numbers of abnormal test results for patients with and without adjunctive dexamethasone were similar. Conclusions: Adult survivors of bacterial meningitis are at risk of cognitive impairment, which consists mainly of cognitive slowness. The loss of cognitive speed is stable over time after bacterial meningitis; however, there is a significant improvement in subjective physical impairment in the years after bacterial meningitis. The use of dexamethasone was not associated with cognitive impairment.

Abstract

Experiments 1 and 2 examined the time-course of retrieval of phonological, visual-shape and semantic knowledge as Dutch participants listened to sentences and looked at displays of four pictures. Given a sentence with beker, `beaker', for example, the display contained phonological (a beaver, bever), shape (a bobbin, klos), and semantic (a fork, vork) competitors. When the display appeared at sentence onset, fixations to phonological competitors preceded fixations to shape and semantic competitors. When display onset was 200 ms before (e.g.) beker, fixations were directed to shape and then semantic competitors, but not phonological competitors. In Experiments 3 and 4, displays contained the printed names of the previously-pictured entities; only phonological competitors were fixated preferentially. These findings suggest that retrieval of phonological, shape and semantic knowledge in the spoken-word and picture-recognition systems is cascaded, and that visual attention shifts are co-determined by the time-course of retrieval of all three knowledge types and by the nature of the information in the visual environment.

Abstract

Visual attention can be directed immediately, as a spoken word unfolds, towards conceptually related but nonassociated objects, even if they mismatch on other dimensions that would normally determine which objects in the scene were appropriate referents for the unfolding word (Huettig & Altmann, 2005). Here we demonstrate that the mapping between language and concurrent visual objects can also be mediated by visual-shape relations. On hearing "snake", participants directed overt attention immediately, within a visual display depicting four objects, to a picture of an electric cable, although participants had viewed the visual display with four objects for approximately 5 s before hearing the target word - sufficient time to recognize the objects for what they were. The time spent fixating the cable correlated significantly with ratings of the visual similarity between snakes in general and this particular cable. Importantly, with sentences contextually biased towards the concept snake, participants looked at the snake well before the onset of "snake", but they did not look at the visually similar cable until hearing "snake". Finally, we demonstrate that such activation can, under certain circumstances (e.g., during the processing of dominant meanings of homonyms), constrain the direction of visual attention even when it is clearly contextually inappropriate. We conclude that language-mediated attention can be guided by a visual match between spoken words and visual objects, but that such a match is based on lexical input and may not be modulated by contextual appropriateness.

Abstract

Ten healthy adults encountered pictures of unfamiliar archaic tools and successfully learned either their name, verbal definition of their usage, or both. Neural representation of the newly acquired information was probed with magnetoencephalography in an overt picture-naming task before and after learning, and in two categorization tasks after learning. Within 400 ms, activation proceeded from occipital through parietal to left temporal cortex, inferior frontal cortex (naming) and right temporal cortex (categorization). Comparison of naming of newly learned versus familiar pictures indicated that acquisition and maintenance of word forms are supported by the same neural network. Explicit access to newly learned phonology when such information was known strongly enhanced left temporal activation. By contrast, access to newly learned semantics had no comparable, direct neural effects. Both the behavioral learning pattern and neurophysiological results point to fundamentally different implementation of and access to phonological versus semantic features in processing pictured objects.

Abstract

This chapter investigates the fit of genetic, phenotypic, and linguistic data to two well-known models of population history. The first of these models, termed the population fissions model, emphasizes population splitting, isolation, and independent evolution. It predicts that genetic and linguistic data will be perfectly tree-like. The second model, termed isolation by distance, emphasizes genetic exchange among geographically proximate populations. It predicts a monotonic decline in genetic similarity with increasing geographic distance. While these models are overly simplistic, deviations from them were expected to provide important insights into the population history of northern Island Melanesia. The chapter finds scant support for either model because the prehistory of the region has been so complex. Nonetheless, the genetic and linguistic data are consistent with an early radiation of proto-Papuan speakers into the region followed by a much later migration of Austronesian speaking peoples. While these groups subsequently experienced substantial genetic and cultural exchange, this exchange has been insufficient to erase this history of separate migrations.

Abstract

This paper reports on ongoing research on the role of various kinds of potential substrate languages in the development of the semantic structures of Ndyuka (Eastern Suriname Creole). A set of 100 senses of noun, verb, and other lexemes in Ndyuka were compared with senses of corresponding lexemes in three kinds of languages of the former Slave Coast and Gold Coast areas, and immediately adjoining hinterland: (a) Gbe languages; (b) other Kwa languages, specifically Akan and Ga; (c) non-Kwa Niger-Congo languages. The results of this process provide some evidence for the importance of the Gbe languages in the formation of the Suriname creoles, but also for the importance of other languages, and for the areal nature of some of the collocations studied, rendering specific identification of a single substrate source impossible and inappropriate. These results not only provide information about the role of Gbe and other languages in the formation of Ndyuka, but also give evidence for effects of substrate languages spoken by late arrivals some time after the "founders" of a given creole-speaking society. The conclusions are extrapolated beyond Suriname to creole genesis generally.

Abstract

Neurocognitive studies of language production have provided sufficient evidence on both the spatial and the temporal patterns of brain activation to allow tentative and in some cases not so tentative conclusions about function-structure relationships. This chapter reports meta-analysis results that identify reliable activation areas for a range of word, sentence, and narrative production tasks both in the native language and a second language. Based on a theoretically motivated analysis of language production tasks it is possible to specify relationships between brain areas and functional processing components of language production that could not have been derived from the data provided by any single task.

Abstract

This article reviews neurocognitive evidence on second language (L2) processing at speech sound, word, and sentence levels. Hemodynamic (functional magnetic resonance imaging and positron emission tomography) data suggest that L2s are implemented in the same brain structures as the native language but with quantitative differences in the strength of activation that are modulated by age of L2 acquisition and L2 proficiency. Electrophysiological data show a more complex pattern of first and L2 similarities and differences, providing some, although not conclusive, evidence for qualitative differences between L1 and L2 syntactic processing.

Abstract

Thesaurus alignment is important for efficient access to heterogeneous Cultural Heritage data. Current ontology alignment techniques provide solutions, but with limited value in practice, because the requirements from usage scenarios are rarely taken in account. In this paper, we start from particular requirements for book re-indexing and investigate possible ways of developing, deploying and evaluating thesaurus alignment techniques in this context. We then compare different aspects of this scenario with others from a more general perspective.

Abstract

Thesaurus alignments play an important role in realising efficient access to heterogeneous Cultural Heritage data. Current technology, however, provides only limited value for such access as it fails to bridge the gap between theoretical study and user needs that stem from practical application requirements. In this paper, we explore common real-world problems of a library, and identify solutions that would greatly benefit from a more application embedded study, development, and evaluation of matching technology.

Abstract

The mechanisms underlying language production are often assumed to be universal, and hence not contingent on a speaker’s language. This assumption is problematic for at least two reasons. Given the typological diversity of the world’s languages, only a small subset of languages has actually been studied psycholinguistically. And, in some cases, these investigations have returned results that at least superficially raise doubt about the assumption of universal production mechanisms. The goal of this paper is to illustrate the need for more psycholinguistic work on a typologically more diverse set of languages. We summarize cross-linguistic work on sentence production (specifically: grammatical encoding), focusing on examples where such work has improved our theoretical understanding beyond what studies on English alone could have achieved. But cross-linguistic research has much to offer beyond the testing of existing hypotheses: it can guide the development of theories by revealing the full extent of the human ability to produce language structures. We discuss the potential for interdisciplinary collaborations, and close with a remark on the impact of language endangerment on psycholinguistic research on understudied languages.

Abstract

This study investigates how listeners cope with gradient forms of deletion of word-final /t/ when recognising words in a phonological context that makes /t/-deletion viable. A corpus study confirmed a high incidence of /t/-deletion in an /st#b/ context in Dutch. A discrimination study showed that differences between released /t/, unreleased /t/ and fully deleted /t/ in this specific /st#b/ context were salient. Two on-line experiments were carried out to investigate whether lexical activation might be affected by this form variation. Even though unreleased and released variants were processed equally fast by listeners, a detailed analysis of the unreleased condition provided evidence for gradient activation. Activating a target ending in /t/ is slowest for the most reduced variant because phonological context has to be taken into account. Importantly, activation for a target with /t/ in the absence of cues for /t/ is reduced if there is a surface-matching lexical competitor.

Abstract

In this study we investigated to what extent a meaningful sentence context facilitates spoken word processing in young and older listeners if listening is made taxing by time-compressing the speech. Even though elderly listeners have been shown to benefit more from sentence context in difficult listening conditions than young listeners, time compression of speech may interfere with semantic comprehension, particularly in older listeners because of cognitive slowing. The results of a target detection experiment showed that, unlike young listeners who showed facilitation by context at both rates, elderly listeners showed context facilitation at the intermediate, but not at the fastest rate. This suggests that semantic interpretation lags behind target identification.

Abstract

This study investigates neighbourhood density effects on lexical decision performance (both accuracy and response times) of aphasic patients. Given earlier results on lexical activation and deactivation in Broca's and Wernicke's aphasia, the prediction was that smaller neighbourhood density effects would be found for Broca's aphasic patients, compared to age-matched non-brain-damaged control participants, whereas enlarged density effects were expected for Wernicke's aphasic patients. The results showed density effects for all three groups of listeners, and overall differences in performance between groups, but no significant interaction between neighbourhood density and listener group. Several factors are discussed to account for the present results.

Abstract

This study investigates the relative contributions of auditory and cognitive factors to the common finding that an increase in speech rate affects elderly listeners more than young listeners. Since a direct relation between non-auditory factors, such as age-related cognitive slowing, and fast speech performance has been difficult to demonstrate, the present study took an on-line, rather than off-line, approach and focused on processing time. Elderly and young listeners were presented with speech at two rates of time compression and were asked to detect pre-assigned target words as quickly as possible. A number of auditory and cognitive measures were entered in a statistical model as predictors of elderly participants’ fast speech performance: hearing acuity, an information processing rate measure, and two measures of reading speed. The results showed that hearing loss played a primary role in explaining elderly listeners’ increased difficulty with fast speech. However, non-auditory factors such as reading speed and the extent to which participants were affected by
increased rate of presentation in a visual analog of the listening experiment also predicted fast
speech performance differences among the elderly participants. These on-line results confirm that slowed information processing is indeed part of elderly listeners’ problem keeping up with fast language

Abstract

Successful navigation is facilitated by the presence of landmarks. Previous functional magnetic resonance imaging (fMRI) evidence indicated that the human parahippocampal gyrus automatically distinguishes between landmarks placed at navigationally relevant (decision points) and irrelevant locations (nondecision points). This storage of navigational relevance can provide a neural mechanism underlying successful navigation. However, an efficient wayfinding mechanism requires that important spatial information is learned quickly and maintained over time. The present study investigates whether the representation of navigational relevance is modulated by time and practice. Participants learned 2 film sequences through virtual mazes containing objects at decision and at nondecision points. One maze was shown one time, and the other maze was shown 3 times. Twenty-four hours after study, event-related fMRI data were acquired during recognition of the objects. The results showed that activity in the parahippocampal gyrus was increased for objects previously placed at decision points as compared with objects placed at nondecision points. The decision point effect was not modulated by the number of exposures to the mazes and independent of explicit memory functions. These findings suggest a persistent representation of navigationally relevant information, which is stable after only one exposure to an environment. These rapidly induced and long-lasting changes in object representation provide a basis for successful wayfinding.

Abstract

The human brain distinguishes between landmarks placed at navigationally relevant and irrelevant locations. However, to provide a successful wayfinding mechanism not only landmarks but also the routes between them need to be stored. We examined the neural representation of a memory for route direction and a memory for relevant landmarks. Healthy human adults viewed objects along a route through a virtual maze. Event-related functional magnetic resonance imaging (fMRI) data were acquired during a subsequent subliminal priming recognition task. Prime-objects either preceded or succeeded a target-object on a preciously learned route. Our results provide evidence that the parahippocampal gyri distinguish between relevant and irrelevant landmarks whereas the inferior parietal gyrus, the anterior cingulate gyrus as well as the right caudate nucleus are involved in the coding of route direction. These data show that separated memory systems store different spatial information. A memory for navigationally relevant object information and a memory for route direction exist.

Abstract

The authors compared sublexical and supralexical approaches to morphological processing with unambiguous and ambiguous inflected words and words with ambiguous stems in 3 masked and unmasked priming experiments in Finnish. Experiment 1 showed equal facilitation for all prime types with a short 60-ms stimulus onset asynchrony (SOA) but significant facilitation for unambiguous words only with a long 300-ms SOA. Experiment 2 showed that all potential readings of ambiguous inflections were activated under a short SOA. Whereas the prime-target form overlap did not affect the results under a short SOA, it significantly modulated the results with a long SOA. Experiment 3 confirmed that the results from masked priming were modulated by the morphological structure of the words but not by the prime-target form overlap alone. The results support approaches in which early prelexical morphological processing is driven by morph-based segmentation and form is used to cue selection between 2 candidates only during later processing.

Abstract

Listeners use lexical knowledge to adjust their prelexical representations of speech sounds in response to the idiosyncratic pronunciations of particular speakers. We used an exposure-test paradigm to investigate whether this type of perceptual learning transfers across syllabic positions. No significant learning effect was found in Experiment 1, where exposure sounds were onsets and test sounds were codas. Experiments 2-4 showed that there was no learning even when both exposure and test sounds were onsets. But a trend was found when exposure sounds were codas and test sounds were onsets (Experiment 5). This trend was smaller than the robust effect previously found for the coda-to-coda case. These findings suggest that knowledge about idiosyncratic pronunciations may be position specific: Knowledge about how a speaker produces sounds in one position, if it can be acquired at all, influences perception of sounds in that position more strongly than of sounds in another position.

Abstract

Words repeated in the same voice are better recognized than when they are repeated in a different voice. Such findings have been taken as evidence for the storage of talker-specific lexical episodes. But results on perceptual learning suggest that talker-specific adjustments concern sublexical representations. This study thus investigates whether voice-specific repetition effects in auditory lexical decision are lexical or sublexical. The same critical set of items in Block 2 were, depending on materials in Block 1, either same-voice or different-voice word repetitions, new words comprising re-orderings of phonemes used in the same voice in Block 1, or new words with previously unused phonemes. Results show a benefit for words repeated by the same talker, and a smaller benefit for words consisting of phonemes repeated by the same talker. Talker-specific information thus appears to influence word recognition at multiple representational levels.

Abstract

Listeners use suprasegmental auditory lexical stress information to resolve the competition words engage in during spoken-word recognition. The present study investigated whether (a) visual speech provides lexical stress information, and, more importantly, (b) whether this visual lexical stress information is used to resolve lexical competition. Dutch word pairs that differ in the lexical stress realization of their first two syllables, but not segmentally (e.g., 'OCtopus' and 'okTOber'; capitals marking primary stress) served as auditory-only, visual-only, and audiovisual speech primes. These primes either matched (e.g., 'OCto-'), mismatched (e.g., 'okTO-'), or were unrelated to (e.g., 'maCHI-') a subsequent printed target (octopus), which participants had to make a lexical decision to. To the degree that visual speech contains lexical stress information, lexical decisions to printed targets should be modulated through the addition of visual speech. Results show, however, no evidence for a role of visual lexical stress information in audiovisual spoken-word recognition.

Abstract

Listening to a speaker while hearing another speaker talks is a challenging task for elderly listeners. We show that elderly listeners over the age of 65 with various degrees of age-related hearing loss benefit in this situation from also seeing the speaker they intend to listen to. In a phoneme monitoring task, listeners monitored the speech of a target speaker for either the phoneme /p/ or /k/ while simultaneously hearing a competing speaker. Critically, on some trials, the target speaker was also visible. Elderly listeners benefited in their response times and accuracy levels from seeing the target speaker when monitoring for the less visible /k/, but more so when monitoring for the highly visible /p/. Visual speech therefore aids elderly listeners not only by providing segmental information about the target phoneme, but also by providing more global information that allows for better performance in this adverse listening situation.

Abstract

We investigate differences of cerebral activation in 12 right-handed and left-handed participants, respectively, using a sentence-processing task. Functional MRI shows activation of left-frontal and inferior-parietal speech areas (BA 44, BA9, BA 40) in both groups, but a stronger bilateral activation in left-handers. Direct group comparison reveals a stronger activation in right-frontal cortex (BA 47, BA 6) and left cerebellum in left-handers. Laterality indices for the inferior-frontal cortex are less asymmetric in left-handers and are not related to the degree of handedness. Thus, our results show that sentence-processing induced enhanced activation involving a bilateral network in left-handed participants.

Abstract

Purpose: Factors affecting the efficacy of therapeutic monoclonal antibodies (mAb) directed to the epidermal growth factor receptor (EGFR) remain relatively unknown, especially in glioma. Experimental Design: We examined the efficacy of two EGFR-specific mAbs (mAbs 806 and 528) against U87MG-derived glioma xenografts expressing EGFR variants. Using this approach allowed us to change the form of the EGFR while keeping the genetic background constant. These variants included the de2-7 EGFR (or EGFRvIII), a constitutively active mutation of the EGFR expressed in glioma. Results: The efficacy of the mAbs correlated with EGFR number; however, the most important factor was receptor activation. Whereas U87MG xenografts expressing the de2-7 EGFR responded to therapy, those exhibiting a dead kinase de2-7 EGFR were refractory. A modified de2-7 EGFR that was kinase active but autophosphorylation deficient also responded, suggesting that these mAbs function in de2-7 EGFR–expressing xenografts by blocking transphosphorylation. Because de2-7 EGFR–expressing U87MG xenografts coexpress the wild-type EGFR, efficacy of the mAbs was also tested against NR6 xenografts that expressed the de2-7 EGFR in isolation. Whereas mAb 806 displayed antitumor activity against NR6 xenografts, mAb 528 therapy was ineffective, suggesting that mAb 528 mediates its antitumor activity by disrupting interactions between the de2-7 and wild-type EGFR. Finally, genetic disruption of Src in U87MG xenografts expressing the de2-7 EGFR dramatically enhanced mAb 806 efficacy. Conclusions: The effective use of EGFR-specific antibodies in glioma will depend on identifying tumors with activated EGFR. The combination of EGFR and Src inhibitors may be an effective strategy for the treatment of glioma.

Abstract

English-learning 7.5-month-olds are heavily biased to perceive stressed syllables as word onsets. By 11 months, however, infants begin segmenting non-initially stressed words from speech.Using the same artificial language methodology as Johnson and Jusczyk (2001), we explored the possibility that the emergence of this ability is linked to a decreased reliance on prosodic cues to word boundaries accompanied by an increased reliance on syllable distribution cues. In a baseline study, where only statistical cues to word boundaries were present, infants exhibited a familiarity preference for statistical words. When conflicting stress cues were added to the speech stream, infants exhibited a familiarity preference for stress as opposed to statistical words. This was interpreted as evidence that 11-month-olds weight stress cues to word boundaries more heavily than statistical cues. Experiment 2 further investigated these results with a language containing convergent cues to word boundaries. The results of Experiment 2 were not conclusive. A third experiment using new stimuli and a different experimental design supported the conclusion that 11-month-olds rely more heavily on prosodic than statistical cues to word boundaries. We conclude that the emergence of the ability to segment non-initially stressed words from speech is not likely to be tied to an increased reliance on syllable distribution cues relative to stress cues, but instead may emerge due to an increased reliance on and integration of a broad array of segmentation cues.

Abstract

The nature of social life in human prehistory is elusive, yet knowing how kinship systems evolve is critical for understanding population history and cultural diversity. Post-marital residence rules specify sex-specific dispersal and kin association, influencing the pattern of genetic markers across populations. Cultural phylogenetics allows us to practise 'virtual archaeology' on these aspects of social life that leave no trace in the archaeological record. Here we show that early Austronesian societies practised matrilocal post-marital residence. Using a Markov-chain Monte Carlo comparative method implemented in a Bayesian phylogenetic framework, we estimated the type of residence at each ancestral node in a sample of Austronesian language trees spanning 135 Pacific societies. Matrilocal residence has been hypothesized for proto-Oceanic society (ca 3500 BP), but we find strong evidence that matrilocality was predominant in earlier Austronesian societies ca 5000-4500 BP, at the root of the language family and its early branches. Our results illuminate the divergent patterns of mtDNA and Y-chromosome markers seen in the Pacific. The analysis of present-day cross-cultural data in this way allows us to directly address cultural evolutionary and life-history processes in prehistory.