Publications

Abstract

This study focuses on the main work of Gilbert Ryle, “The concept of Mind” (1949). Here the author demolishes what he refers to as the cartesian dogma of “the ghost in the machine”, highlighting the absurdity of categorical ordering in dualist systems, where mental activities are explained as separate from physical actions. Surprisingly, the Italian translator of “The concept of Mind”, Ferruccio Rossi-Landi, missed this key aspect of Ryle’s work, writing up what resulted into a significantly misleading translation. This can be clearly noticed from the title already: “Lo spirito come comportamento” [The ghost as behavior]. This erroneous translation affected the interpretation of “The concept of Mind” as a mere study on behavioral reductionism in Italy. Here, I argue in favor of the originality of Ryle’s approach in pointing out the socio-cultural dynamics as the non - physical dimensions of the human mind, and yet, linked to the human brain. In doing so, I trace the crucial influence of Wittgenstein’s philosophy in Ryle’s interpretation of the concept of mind, which helps in grasping a better understanding of his work. Wittgenstein’s influence shows clearly in Ryle’s conceptual operation of grounding the acquisition of dispositions and competences - which ultimately define the rational subjects as rational agents – in the shared background of social and cultural dynamics. In a nutshell, this social dimension is the defining characteristic of the human mind and of all human actions in Ryle’s philosophy. As Ryle argues in “On thinking” (1979), this intrinsic quality of human actions can reveal itself in actions that one performs absent-mindendly in everyday life, as well as in more complex ones: for instance, when the mind reflects upon itself.

Abstract

Attention deficit/hyperactivity disorder (ADHD) is a common heritable disorder with a childhood onset. Molecular genetic studies of ADHD have previously focused on examining the roles of specific candidate genes, primarily those involved in dopaminergic pathways. We have performed the first systematic genomewide linkage scan for loci influencing ADHD in 126 affected sib pairs, using a ∼10-cM grid of microsatellite markers. Allele-sharing linkage methods enabled us to exclude any loci with a λs of ⩾3 from 96% of the genome and those with a λs of ⩾2.5 from 91%, indicating that there is unlikely to be a major gene involved in ADHD susceptibility in our sample. Under a strict diagnostic scheme we could exclude all screened regions of the X chromosome for a locus-specific λs of ⩾2 in brother-brother pairs, demonstrating that the excess of affected males with ADHD is probably not attributable to a major X-linked effect. Qualitative trait maximum LOD score analyses pointed to a number of chromosomal sites that may contain genetic risk factors of moderate effect. None exceeded genomewide significance thresholds, but LOD scores were >1.5 for regions on 5p12, 10q26, 12q23, and 16p13. Quantitative-trait analysis of ADHD symptom counts implicated a region on 12p13 (maximum LOD 2.6) that also yielded a LOD >1 when qualitative methods were used. A survey of regions containing 36 genes that have been proposed as candidates for ADHD indicated that 29 of these genes, including DRD4 and DAT1, could be excluded for a λs of 2. Only three of the candidates—DRD5, 5HTT, and CALCYON—coincided with sites of positive linkage identified by our screen. Two of the regions highlighted in the present study, 2q24 and 16p13, coincided with the top linkage peaks reported by a recent genome-scan study of autistic sib pairs.

Abstract

Developmental dyslexia, a specific impairment of reading ability despite adequate intelligence and educational opportunity, is one of the most frequent childhood disorders. Since the first documented cases at the beginning of the last century, it has become increasingly apparent that the reading problems of people with dyslexia form part of a heritable neurobiological syndrome. As for most cognitive and behavioural traits, phenotypic definition is fraught with difficulties and the genetic basis is complex, making the isolation of genetic risk factors a formidable challenge. Against such a background, it is notable that several recent studies have reported the localization of genes that influence dyslexia and other language-related traits. These investigations exploit novel research approaches that are relevant to many areas of human neurogenetics.

Abstract

Developmental disorders affecting speech and language are highly heritable, but very little is currently understood about the neuromolecular mechanisms that underlie these traits. Integration of data from diverse research areas, including linguistics, neuropsychology, neuroimaging, genetics, molecular neuroscience, developmental biology, and evolutionary anthropology, is becoming essential for unraveling the relevant pathways. Recent studies of the FOXP2 gene provide a case in point. Mutation of FOXP2 causes a rare form of speech and language disorder, and the gene appears to be a crucial regulator of embryonic development for several tissues. Molecular investigations of the central nervous system indicate that the gene may be involved in establishing and maintaining connectivity of corticostriatal and olivocerebellar circuits in mammals. Notably, it has been shown that FOXP2 was subject to positive selection in recent human evolution. Consideration of findings from multiple levels of analysis demonstrates that FOXP2 cannot be characterized as “the gene for speech,” but rather as one critical piece of a complex puzzle. This story gives a flavor of what is to come in this field and indicates that anyone expecting simple explanations of etiology or evolution should be prepared for some intriguing surprises.

Abstract

Developmental dyslexia is defined as a specific and significant impairment in reading ability that cannot be explained by deficits in intelligence, learning opportunity, motivation or sensory acuity. It is one of the most frequently diagnosed disorders in childhood, representing a major educational and social problem. It is well established that dyslexia is a significantly heritable trait with a neurobiological basis. The etiological mechanisms remain elusive, however, despite being the focus of intensive multidisciplinary research. All attempts to map quantitative-trait loci (QTLs) influencing dyslexia susceptibility have targeted specific chromosomal regions, so that inferences regarding genetic etiology have been made on the basis of very limited information. Here we present the first two complete QTL-based genome-wide scans for this trait, in large samples of families from the United Kingdom and United States. Using single-point analysis, linkage to marker D18S53 was independently identified as being one of the most significant results of the genome in each scan (P< or =0.0004 for single word-reading ability in each family sample). Multipoint analysis gave increased evidence of 18p11.2 linkage for single-word reading, yielding top empirical P values of 0.00001 (UK) and 0.0004 (US). Measures related to phonological and orthographic processing also showed linkage at this locus. We replicated linkage to 18p11.2 in a third independent sample of families (from the UK), in which the strongest evidence came from a phoneme-awareness measure (most significant P value=0.00004). A combined analysis of all UK families confirmed that this newly discovered 18p QTL is probably a general risk factor for dyslexia, influencing several reading-related processes. This is the first report of QTL-based genome-wide scanning for a human cognitive trait.

Abstract

This chapter highlights the research in isolating genetic factors underlying specific language impairment (SLI), or developmental dysphasia, which exploits newly developed genotyping technology, novel statistical methodology, and DNA sequence data generated by the Human Genome Project. The author begins with an overview of results from family, twin, and adoption studies supporting genetic involvement and then goes on to outline progress in a number of genetic mapping efforts that have been recently completed or are currently under way. It has been possible for genetic researchers to pinpoint the specific mutation responsible for some speech and language disorders, providing an example of how the availability of human genomic sequence data can greatly accelerate the pace of disease gene discovery. Finally, the author discusses future prospects on how molecular genetics may offer new insight into the etiology underlying speech and language disorders, leading to improvements in diagnosis and treatment.

Abstract

Learning to talk is one of the most important milestones in human development, but we still have only a limited understanding of the way in which the process occurs. It normally takes just a few years to go from babbling newborn to fluent communicator. During this period, the child learns to produce a rich array of speech sounds through intricate control of articulatory muscles, assembles a vocabulary comprising thousands of words, and deduces the complicated structural rules that permit construction of meaningful sentences. All of this (and more) is achieved with little conscious effort.

Abstract

Purpose of review: The human brain supports acquisition mechanisms that can extract structural regularities implicitly from experience without the induction of an explicit model. Reber defined the process by which an individual comes to respond appropriately to the statistical structure of the input ensemble as implicit learning. He argued that the capacity to generalize to new input is based on the acquisition of abstract representations that reflect underlying structural regularities in the acquisition input. We focus this review of the implicit learning literature on studies published during 2004 and 2005. We will not review studies of repetition priming ('implicit memory'). Instead we focus on two commonly used experimental paradigms: the serial reaction time task and artificial grammar learning. Previous comprehensive reviews can be found in Seger's 1994 article and the Handbook of Implicit Learning. Recent findings: Emerging themes include the interaction between implicit and explicit processes, the role of the medial temporal lobe, developmental aspects of implicit learning, age-dependence, the role of sleep and consolidation. Summary: The attempts to characterize the interaction between implicit and explicit learning are promising although not well understood. The same can be said about the role of sleep and consolidation. Despite the fact that lesion studies have relatively consistently suggested that the medial temporal lobe memory system is not necessary for implicit learning, a number of functional magnetic resonance studies have reported medial temporal lobe activation in implicit learning. This issue merits further research. Finally, the clinical relevance of implicit learning remains to be determined.

Abstract

In this paper we investigate the neural correlates of syntactic classification of an acquired grammatical sequence structure in an event-related FMRI study. During acquisition, participants were engaged in an implicit short-term memory task without performance feedback. We manipulated the statistical frequency-based and rule-based characteristics of the classification stimuli independently in order to investigate their role in artificial grammar acquisition. The participants performed reliably above chance on the classification task. We observed a partly overlapping corticostriatal processing network activated by both manipulations including inferior prefrontal, cingulate, inferior parietal regions, and the caudate nucleus. More specifically, the left inferior frontal BA 45 and the caudate nucleus were sensitive to syntactic violations and endorsement, respectively. In contrast, these structures were insensitive to the frequency-based manipulation.

Abstract

Turn on your affective system by tweaking your face muscles - or getting an eyeful of someone else doing the same.

Abstract

Find the fire that's cooking your memory systems.

Abstract

Emotions are powerful on the inside but often displayed in subtle ways on the outside. Are these displays culturally dependent or universal?

Abstract

Genomewide quantitative-trait locus (QTL) linkage analysis was performed using a continuous measure of relative hand skill (PegQ) in a sample of 195 reading-disabled sibling pairs from the United Kingdom. This was the first genomewide screen for any measure related to handedness. The mean PegQ in the sample was equivalent to that of normative data, and PegQ was not correlated with tests of reading ability (correlations between −0.13 and 0.05). Relative hand skill could therefore be considered normal within the sample. A QTL on chromosome 2p11.2-12 yielded strong evidence for linkage to PegQ (empirical P=.00007), and another suggestive QTL on 17p11-q23 was also identified (empirical P=.002). The 2p11.2-12 locus was further analyzed in an independent sample of 143 reading-disabled sibling pairs, and this analysis yielded an empirical P=.13. Relative hand skill therefore is probably a complex multifactorial phenotype with a heterogeneous background, but nevertheless is amenable to QTL-based gene-mapping approaches.

Abstract

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

Abstract

A locus on chromosome 2p12-16 has been implicated in dyslexia susceptibility by two independent linkage studies, including our own study of 119 nuclear twin-based families, each with at least one reading-disabled child. Nonetheless, no variant of any gene has been reported to show association with dyslexia, and no consistent clinical evidence exists to identify candidate genes with any strong a priori logic. We used 21 microsatellite markers spanning 2p12-16 to refine our 1-LOD unit linkage support interval to 12cM between D2S337 and D2S286. Then, in quantitative association analysis, two microsatellites yielded P values<0.05 across a range of reading-related measures (D2S2378 and D2S2114). The exon/intron borders of two positional candidate genes within the region were characterized, and the exons were screened for polymorphisms. The genes were Semaphorin4F (SEMA4F), which encodes a protein involved in axonal growth cone guidance, and OTX1, encoding a homeodomain transcription factor involved in forebrain development. Two non-synonymous single nucleotide polymorphisms were found in SEMA4F, each with a heterozygosity of 0.03. One intronic single nucleotide polymorphism between exons 12 and 13 of SEMA4F was tested for quantitative association, but no significant association was found. Only one single nucleotide polymorphism was found in OTX1, which was exonic but silent. Our data therefore suggest that linkage with reading disability at 2p12-16 is not caused by coding variants of SEMA4F or OTX1. Our study outlines the approach necessary for the identification of genetic variants causing dyslexia susceptibility in an epidemiological population of dyslexics.

Abstract

Dyslexia, a disorder of reading and spelling, is a heterogeneous neurological syndrome with a complex genetic and environmental aetiology. People with dyslexia differ in their individual profiles across a range of cognitive, physiological, and behavioural measures related to reading disability. Some or all of the subtypes of dyslexia might have partly or wholly distinct genetic causes. An understanding of the role of genetics in dyslexia could help to diagnose and treat susceptible children more effectively and rapidly than is currently possible and in ways that account for their individual disabilities. This knowledge will also give new insights into the neurobiology of reading and language cognition. Genetic linkage analysis has identified regions of the genome that might harbour inherited variants that cause reading disability. In particular, loci on chromosomes 6 and 18 have shown strong and replicable effects on reading abilities. These genomic regions contain tens or hundreds of candidate genes, and studies aimed at the identification of the specific causal genetic variants are underway.

Abstract

Theeffects of spatial filtering in functional magnetic resonance imaging were investigated by reevaluating the data of a previous study of episodic memory encoding at 2 × 2 × 4-mm3 resolution with use of a SPM99 analysis involving a Gaussian kernel of 8-mm full width at half maximum. In addition, a multisubject analysis of activated regions was performed by normalizing the functional images to an approximate Talairach brain atlas. In individual subjects, spatial filtering merged activations in anatomically separated brain regions. Moreover, small foci of activated pixels which originated from veins became blurred and hence indistinguishable from parenchymal responses. The multisubject analysis resulted in activation of the hippocampus proper, a finding which could not be confirmed by the activation maps obtained at high resolution. It is concluded that the validity of multisubject fMRI analyses can be considerably improved by first analyzing individual data sets at optimum resolution to assess the effects of spatial filtering and minimize the risk of signal contamination by macroscopically visible vessels.

Abstract

BACKGROUND: There is a growing interest in the study of the genetic origins of comorbidity, a direct consequence of the recent findings of genetic loci that are seemingly linked to more than one disorder. There are several potential causes for these shared regions of linkage, but one possibility is that these loci may harbor genes with manifold effects. The established genetic correlation between reading disability (RD) and attention-deficit/hyperactivity disorder (ADHD) suggests that their comorbidity is due at least in part to genes that have an impact on several phenotypes, a phenomenon known as pleiotropy. METHODS: We employ a bivariate linkage test for selected samples that could help identify these pleiotropic loci. This linkage method was employed to carry out the first bivariate genome-wide analysis for RD and ADHD, in a selected sample of 182 sibling pairs. RESULTS: We found evidence for a novel locus at chromosome 14q32 (multipoint LOD=2.5; singlepoint LOD=3.9) with a pleiotropic effect on RD and ADHD. Another locus at 13q32, which had been implicated in previous univariate scans of RD and ADHD, seems to have a pleiotropic effect on both disorders. 20q11 is also suggested as a pleiotropic locus. Other loci previously implicated in RD or ADHD did not exhibit bivariate linkage. CONCLUSIONS: Some loci are suggested as having pleiotropic effects on RD and ADHD, while others might have unique effects. These results highlight the utility of this bivariate linkage method to study pleiotropy.

Abstract

Irrelevant speech impairs the immediate serial recall of visually presented material. Previously, we have shown that the irrelevant speech effect (ISE) was associated with a relative decrease of regional blood flow in cortical regions subserving the verbal working memory, in particular the superior temporal cortex. In this extension of the previous study, the working memory load was increased and an increased activity as a response to irrelevant speech was noted in the dorsolateral prefrontal cortex. We suggest that the two studies together provide some basic insights as to the nature of the irrelevant speech effect. Firstly, no area in the brain can be ascribed as the single locus of the irrelevant speech effect. Instead, the functional neuroanatomical substrate to the effect can be characterized in terms of changes in networks of functionally interrelated areas. Secondly, the areas that are sensitive to the irrelevant speech effect are also generically activated by the verbal working memory task itself. Finally, the impact of irrelevant speech and related brain activity depends on working memory load as indicated by the differences between the present and the previous study. From a brain perspective, the irrelevant speech effect may represent a complex phenomenon that is a composite of several underlying mechanisms, which depending on the working memory load, include top-down inhibition as well as recruitment of compensatory support and control processes. We suggest that, in the low-load condition, a selection process by an inhibitory top-down modulation is sufficient, whereas in the high-load condition, at or above working memory span, auxiliary adaptive cognitive resources are recruited as compensation

Abstract

Semantic verbal fluency tasks are commonly used in neuropsychological assessment. Investigations of the influence of level of literacy have not yielded consistent results in the literature. This prompted us to investigate the ecological relevance of task specifics, in particular, the choice of semantic criteria used. Two groups of literate and illiterate subjects were compared on two verbal fluency tasks using different semantic criteria. The performance on a food criterion (supermarket fluency task), considered more ecologically relevant for the two literacy groups, and an animal criterion (animal fluency task) were compared. The data were analysed using both quantitative and qualitative measures. The quantitative analysis indicated that the two literacy groups performed equally well on the supermarket fluency task. In contrast, results differed significantly during the animal fluency task. The qualitative analyses indicated differences between groups related to the strategies used, especially with respect to the animal fluency task. The overall results suggest that there is not a substantial difference between literate and illiterate subjects related to the fundamental workings of semantic memory. However, there is indication that the content of semantic memory reflects differences in shared cultural background - in other words, formal education –, as indicated by the significant interaction between level of literacy and semantic criterion.

Abstract

The discussion on root infinitives has mainly centered around their supposed modal usage. This article aims at modelling the form-function relation of the root infinitive phenomenon by taking into account the full range of interpretational facets encountered cross-linguistically and interindividually. Following the idea of a subsequent ‘‘cell partitioning’’ in the emergence of form-function correlations, I claim that it is the major fission between [+-finite] which is central to express temporal reference different from the default here&now in tense-oriented languages. In aspectual-oriented languages, a similar opposition is mastered with the marking of early aspectual forms. It is observed that in tense-oriented languages like Dutch and German, the progression of functions associated with the infinitival form proceeds from nonmodal to modal, whereas the reverse progression holds for the Russian infinitive. Based on this crucial observation, a model of acquisition is proposed which allows for a flexible and systematic relationship between morphological forms and their respective interpretational biases dependent on their developmental context. As for early child language, I argue that children entertain only two temporal parameters: one parameter is fixed to the here&now point in time, and a second parameter relates to the time talked about, the topic time; this latter time overlaps the situation time as long as no empirical evidence exists to support the emergence of a proper distinction between tense and aspect.

Abstract

The central topic of this study is to investigate three- and four-place predicate in Yaqui, which are characterized by having multiple object arguments. As with other Southern Uto-Aztecan languages, it has been said that Yaqui follows the Primary/Secondary Object pattern (Dryer 1986). Actually, Yaqui presents three patterns: verbs like nenka ‘sell’ follow the direct–indirect object pattern, verbs like miika ‘give’ follow the primary object pattern, and verbs like chijakta ‘sprinkle’ follow the locative alternation pattern; the primary object pattern is the exclusive one found with derived verbs. This paper shows that the contrast between direct object and primary object languages is not absolute but rather one of degree, and hence two “object” selection principles are needed to explain this mixed system. The two principles are not limited to Yaqui but are found in other languages as well, including English.

Abstract

Trumai, a genetically isolated language spoken in Brazil (Xingu reserve), is an example of an endangered language. Although the Trumai population consists of more than 100 individuals, only 51 people speak the language. The oral traditions are progressively dying. Given the current scenario, the documentation of this language and its cultural aspects is of great importance. In the framework of the DoBeS program (Documentation of Endangered Languages), the project "Documentation of Trumai" has selected and organized a collection of Trumai texts, with a multi-media representation of the corpus. Several kinds of information and data types are being included in the archive of the language: texts with audio and video recordings; written texts from educational materials; drawings; photos; songs; annotations in different formats; lexicon; field notes; results from scientific studies of the language (sound system, sketch grammar, comparative studies with other Xinguan languages), etc. All materials are integrated into the IMDI-Browser, a specialized tool for presenting and searching for linguistic data. This paper explores the processing phases and the results of the Trumai project taking into consideration the issue of how to combine the needs and wishes of field linguistics (content and research aspects) and the needs of archiving (structure and workflow aspects) in a well-organized corpus.

Abstract

A prototypical lexicon tool was implemented which was intended to allow researchers to collaboratively create lexicons of endangered languages. Increasingly often researchers documenting or analyzing a language work at different locations. Lexicons that evolve through continuous interaction between the collaborators can only be efficiently produced when it can be accessed and manipulated via the Internet. The SHAWEL tool was developed to address these needs; it makes use of a thin Java client and a central database solution.

Abstract

In speaking and comprehending language, word information is retrieved from memory and combined into larger units (unification). Unification operations take place in parallel at the semantic, syntactic and phonological levels of processing. This article proposes a new framework that connects psycholinguistic models to a neurobiological account of language. According to this proposal the left inferior frontal gyrus (LIFG) plays an important role in unification. Research in other domains of cognition indicates that left prefrontal cortex has the necessary neurobiological characteristics for its involvement in the unification for language. I offer here a psycholinguistic perspective on the nature of language unification and the role of LIFG.

Abstract

Although the sentences that we hear or read have meaning, this does not necessarily mean that they are also true. Relatively little is known about the critical brain structures for, and the relative time course of, establishing the meaning and truth of linguistic expressions. We present electroencephalogram data that show the rapid parallel integration of both semantic and world
knowledge during the interpretation of a sentence. Data from functional magnetic resonance imaging revealed that the left inferior prefrontal cortex is involved in the integration of both meaning and world knowledge. Finally, oscillatory brain responses indicate that the brain keeps a record of what makes a sentence hard to interpret.

Abstract

We present a quantitative model of word order and movement constraints that enables a simple and uniform treatment of a seemingly heterogeneous collection of linear order phenomena in English, Dutch and German complement constructions (Wh-extraction, clause union, extraposition, verb clustering, particle movement, etc.). Underlying the scheme are central assumptions of the psycholinguistically motivated Performance Grammar (PG). Here we describe this formalism in declarative terms based on typed feature unification. PG allows a homogenous treatment of both the within- and between-language variations of the ordering phenomena under discussion, which reduce to different settings of a small number of quantitative parameters.

Abstract

Drawings of objects were presented in series of 54 each to 14 German speaking subjects with the tasks to indicate by button presses a) whether the grammatical gender of an object name was masculine ("der") or feminine ("die") and b) whether the depicted object was man-made or nature-made. The magnetoencephalogram (MEG) was recorded with a whole-head neuromagnetometer and task-specific patterns of brain activity were determined in the source space (Minimum Norm Estimates, MNE). A left-temporal focus of activity 150-275 ms after stimulus onset in the gender decision compared to the semantic classification task was discussed as indicating the retrieval of syntactic information, while a more expanded left hemispheric activity in the gender relative to the semantic task 300-625 ms after stimulus onset was discussed as indicating phonological encoding. A predominance of activity in the semantic task was observed over right fronto-central region 150-225 ms after stimulus-onset, suggesting that semantic and syntactic processes are prominent in this stage of lexical selection.

Abstract

Morphology is the study of the internal structure of words. A vigorous ongoing debate surrounds the question of how such internal structure is best accounted for: by means of lexical entries and deterministic symbolic rules, or by means of probabilistic subsymbolic networks implicitly encoding structural similarities in connection weights. In this review, we separate the question of subsymbolic versus symbolic implementation from the question of deterministic versus probabilistic structure. We outline a growing body of evidence, mostly external to the above debate, indicating that morphological structure is indeed intrinsically graded. By allowing probability into the grammar, progress can be made towards solving some long-standing puzzles in morphological theory.

Abstract

When a sentence such as The model embraced the designer and the photographer laughed is read, the noun phrase the photographer is temporarily ambiguous: It can be either one of the objects of embraced (NP-coordination) or the subject of a new, conjoined sentence (S-coordination). It has been shown for a number of languages, including Dutch (the language used in this study), that readers prefer NP-coordination over S-coordination, at least in isolated sentences. In the present paper, it will be suggested that NP-coordination is preferred because it is the simpler of the two options in terms of topic-structure; in NP-coordinations there is only one topic, whereas S-coordinations contain two. Results from off-line (sentence completion) and online studies (a self-paced reading and an eye tracking experiment) support this topic-structure explanation. The processing difficulty associated with S-coordinated sentences disappeared when these sentences followed contexts favoring a two-topic continuation. This finding establishes topic-structure as an important factor in online sentence processing.

Abstract

Form-priming effects from sublexical (syllabic or segmental) primes in masked priming can be accounted for in two ways. One is the sublexical pre-activation view according to which segments are pre-activated by the prime, and at the time the form-related target is to be produced, retrieval/assembly of those pre-activated segments is faster compared to an unrelated situation. However, it has also been argued that form-priming effects from sublexical primes might be due to lexical pre-activation. When the sublexical prime is presented, it activates all form-related words (i.e., cohorts) in the lexicon, necessarily including the form-related target, which—as a consequence—is produced faster than in the unrelated case. Note, however, that this lexical pre-activation account makes previous pre-lexical activation of segments necessary. This study reports a nonword naming experiment to investigate whether or not sublexical pre-activation is involved in masked form priming with sublexical primes. The results demonstrated a priming effect suggesting a nonlexical effect. However, this does not exclude an additional lexical component in form priming.

Abstract

When participants are presented simultaneously with spoken language and a visual display depicting objects to which that language refers, participants spontaneously fixate the visual referents of the words being heard [Cooper, R. M. (1974). The control of eye fixation by the meaning of spoken language: A new methodology for the real-time investigation of speech perception, memory, and language processing. Cognitive Psychology, 6(1), 84–107; Tanenhaus, M. K., Spivey-Knowlton, M. J., Eberhard, K. M., & Sedivy, J. C. (1995). Integration of visual and linguistic information in spoken language comprehension. Science, 268(5217), 1632–1634]. We demonstrate here that such spontaneous fixation can be driven by partial semantic overlap between a word and a visual object. Participants heard the word ‘piano’ when (a) a piano was depicted amongst unrelated distractors; (b) a trumpet was depicted amongst those same distractors; and (c), both the piano and trumpet were depicted. The probability of fixating the piano and the trumpet in the first two conditions rose as the word ‘piano’ unfolded. In the final condition, only fixations to the piano rose, although the trumpet was fixated more than the distractors. We conclude that eye movements are driven by the degree of match, along various dimensions that go beyond simple visual form, between a word and the mental representations of objects in the concurrent visual field.

Abstract

This paper presents a meta-analysis of hemodynamic studies on passive auditory language processing. We assess the overlap of hemodynamic activation areas and activation maxima reported in experiments involving the presentation of sentences, words, pseudowords, or sublexical or non-linguistic auditory stimuli. Areas that have been reliably replicated are identified. The results of the meta-analysis are compared to electrophysiological, magnetencephalic (MEG), and clinical findings. It is concluded that auditory language input is processed in a left posterior frontal and bilateral temporal cortical network. Within this network, no processing leve l is related to a single cortical area. The temporal lobes seem to differ with respect to their involvement in post-lexical processing, in that the left temporal lobe has greater involvement than the right, and also in the degree of anatomical specialization for phonological, lexical, and sentence -level processing, with greater overlap on the right contrasting with a higher degree of differentiation on the left.

Abstract

This paper presents the results of a comprehensive meta-analysis of the relevant imaging literature on word production (82 experiments). In addition to the spatial overlap of activated regions, we also analyzed the available data on the time course of activations. The analysis specified regions and time windows of activation for the core processes of word production: lexical selection, phonological code retrieval, syllabification, and phonetic/articulatory preparation. A comparison of the word production results with studies on auditory word/non-word perception and reading showed that the time course of activations in word production is, on the whole, compatible with the temporal constraints that perception processes impose on the production processes they affect in picture/word interference paradigms.

Abstract

Following up on an earlier positron emission tomography (PET) experiment (Indefrey et al., 2001), we used a scene description paradigm to investigate whether a posterior inferior frontal region subserving syntactic encoding for speaking is also involved in syntactic parsing during listening. In the language production part of the experiment, subjects described visually presented scenes
using either sentences, sequences of noun phrases, or sequences of syntactically unrelated words. In the language comprehension part of the experiment, subjects were auditorily presented with the same kinds of utterances and judged whether they matched the visual scenes. We were able to replicate the previous finding of a region in caudal Broca s area that is sensitive to the complexity of
syntactic encoding in language production. In language comprehension, no hemodynamic activation differences due to syntactic complexity were found. Given that correct performance in the judgment task did not require syntactic processing of the auditory stimuli, the results suggest that the degree to which listeners recruit syntactic processing resources in language comprehension may be a function of the syntactic demands of the task or the stimulus material.

Abstract

In order to separate the cognitive processes associated with phonological encoding and the use of a visual word form lexicon in reading, it is desirable to compare the processing of words presented in a visually familiar form with words in a visually unfamiliar form. Japanese Kana orthography offers this possibility. Two phonologically equivalent but visually dissimilar syllabaries allow the writing of, for example, foreign loanwords in two ways, only one of which is visually familiar. Familiarly written words, unfamiliarly written words, and pseudowords were presented in both Kana syllabaries (yielding six conditions in total) to participants during an fMRI measurement with a silent articulation task (Experiment 1) and a phonological lexical decision task (Experiment 2) using an event-related design. Consistent over two experimental tasks, the three different stimulus types (familiar, unfamiliar, and pseudoword) were found to activate selectively different brain regions previously associated with phonological encoding and word retrieval or meaning. Compatible with the predictions of the dual-route model for reading, pseudowords and visually unfamiliar words, which have to be read using phonological assembly, caused an increase in brain activity in left inferior frontal regions (BA 44/47), as compared to visually familiar words. Visually familiar and unfamiliar words were found to activate a range of areas associated with lexico-semantic processing more strongly than pseudowords, such as the left and right temporo-parietal region (BA 39/40), a region in the left middle/inferior temporal gyrus (BA 20/21), and the posterior cingulate (BA 31).

Abstract

Natural fast speech differs from normal-rate speech with respect to its temporal pattern. Previous results showed that word intelligibility of heavily artificially time-compressed speech could not be improved by making its temporal pattern more similar to that of natural fast speech. This might have been due to the extrapolation of timing rules for natural fast speech to rates that are much faster than can be attained by human speakers. The present study investigates whether, at a speech rate that human speakers can attain, artificially time-compressed speech is easier to process if its timing pattern is similar to that of naturally produced fast speech. Our first experiment suggests, however, that word processing speed was slowed down, relative to linear compression. In a second experiment, word processing of artificially time-compressed speech was compared with processing of naturally produced fast speech. Even when naturally produced fast speech is perfectly intelligible, its less careful articulation, combined with the changed timing pattern, slows down processing, relative to linearly time-compressed speech. Furthermore, listeners preferred artificially time-compressed speech over naturally produced fast speech. These results suggest that linearly time-compressed speech has both a temporal and a segmental advantage over natural fast speech.

Abstract

This study investigated the encoding of syllable boundary information during speech production in Dutch. Based on Levelt's model of phonological encoding, we hypothesized segments and syllable boundaries to be encoded in an incremental way. In a selfmonitoring experiment, decisions about the syllable affiliation (first or second syllable) of a pre-specified consonant, which was the third phoneme in a word, were required (e.g., ka.No canoe vs. kaN.sel pulpit ; capital letters indicate pivotal consonants, dots mark syllable boundaries). First syllable responses were faster than second syllable responses, indicating the incremental nature of segmental encoding and syllabification during speech production planning. The results of the experiment are discussed in the context of Levelt 's model of phonological encoding.

Abstract

Three experiments are reported that examined whether stem complexity plays a role in inflecting polymorphemic words in language production. Experiment 1 showed that preparation effects for words with polymorphemic stems are larger when they are produced among words with constant inflectional structures compared to words with variable inflectional structures and simple stems. This replicates earlier findings for words with monomorphemic stems (Janssen et al., 2002). Experiments 2 and 3 showed that when inflectional structure is held constant, the preparation effects are equally large with simple and compound stems, and with compound and complex adjectival stems. These results indicate that inflectional encoding is blind to the complexity of the stem, which suggests that specific inflectional rather than generic morphological frames guide the generation of inflected forms in speaking words.

Abstract

The authors report six implicit priming experiments that examined the production of inflected forms. Participants produced words out of small sets in response to prompts. The words differed in form or shared word-initial segments, which allowed for preparation. In constant inflectional sets, the words had the same number of inflectional suffixes, whereas in variable sets the number of suffixes differed. In the experiments, preparation effects were obtained, which were larger in the constant than in the variable sets. Control experiments showed that this difference in effect was not due to syntactic class or phonological form per se. The results are interpreted in terms of a slot-and-filler model of word production, in which inflectional frames, on the one hand, and stems and affixes, on the other hand, are independently spelled out on the basis of an abstract morpho-syntactic specification of the word, which is followed by morpheme-to-frame association.

Abstract

As people find their way through their environment, objects at navigationally relevant locations can serve as crucial landmarks. The parahippocampal gyrus has previously been shown to be involved in object and scene recognition. In the present study, we investigated the neural representation of navigationally relevant locations. Healthy human adults viewed a route through a virtual museum with objects placed at intersections (decision points) or at simple turns (non-decision points). Event-related functional magnetic resonance imaging (fMRI) data were acquired during subsequent recognition of the objects in isolation. Neural activity in the parahippocampal gyrus reflected the navigational relevance of an object's location in the museum. Parahippocampal responses were selectively increased for objects that occurred at decision points, independent of attentional demands. This increase occurred for forgotten as well as remembered objects, showing implicit retrieval of navigational information. The automatic storage of relevant object location in the parahippocampal gyrus provides a part of the neural mechanism underlying successful navigation.

Abstract

This study investigates the time-course of information processing in both visual as well as in the auditory speech as used for word identification in face-to-face communication. It extends the limited previous research on this topic and provides a valuable database for future research in audiovisual speech perception. An evaluation of models of speech perception by ear and eye in their ability to account for the audiovisual gating data shows a superior role of the fuzzy logical model of perception (FLMP) [1] over additive models of perception. A new dynamic version of the FLMP seems to be a promising model to account for the complex interplay of perceptual and cognitive information in audiovisual spoken word recognition.

Abstract

In face-to-face communication, information from the face as well as from the voice contributes to the identification of spoken words. This dissertation investigates the time-course of the evaluation and integration of visual and auditory speech in audiovisual word identification. A large-scale audiovisual gating study extends previous research on this topic by (1) using a set of words that includes all possible initial consonants in English in three vowel contexts, (2) tracking the information processing for individual words not only across modalities, but also over time, and (3) testing quantitative models of the time-course of multimodal word recognition. There was an advantage in accuracy for audiovisual speech over auditory-only and visual-only speech. Auditory performance was, however, close to ceiling while performance on visual-only trials was near the floor of the scale, but well above chance. Visual information was used at all gates to identify the presented words. Information theoretic feature analyses of the confusion matrices revealed that the auditory signal is highly informative about voicing, manner, frication, duration, and place of articulation. Visual speech is mostly informative about place of articulation, but also about frication and duration. The auditory signal provides more information about the place of articulation for back consonants, whereas the visual signal provides more information for the labial consonants. The data were sufficient to discriminate between models of audiovisual word recognition. The Fuzzy Logical Model of Perception (FLMP; Massaro, 1998) gave a better account of the confusion matrix data than additive models of perception. A dynamic version of the FLMP was expanded to account for the evaluation and integration of information over time. This dynamic FLMP provided a better description of the data than dynamic additive competitor models. The present study builds a good foundation to investigate the role of the complex interplay between stimulus information and the structure of the lexicon. It provides an important step in building a formal representation of a lexical dynamic FLMP that can account not only for the time-course of speech information and its perceptual processing, but also for lexical influences.

Abstract

Mutations of the epidermal growth factor receptor (EGFR) gene are found at a relatively high frequency in glioma, with the most common being the de2-7 EGFR (or EGFRvIII). This mutation arises from an in-frame deletion of exons 2–7, which removes 267 amino acids from the extracellular domain of the receptor. Despite being unable to bind ligand, the de2-7 EGFR is constitutively active at a low level. Transfection of human glioma cells with the de2-7 EGFR has little effect in vitro, but when grown as tumor xenografts this mutated receptor imparts a dramatic growth advantage. We have now mapped the phosphorylation pattern of de2-7 EGFR, both in vivo and in vitro, using a panel of antibodies unique to the different phosphorylated tyrosine residues. Phosphorylation of de2-7 EGFR was detected constitutively at all tyrosine sites surveyed both in vitro and in vivo, including tyrosine 845, a known target in the wild-type EGFR for src kinase. There was a substantial upregulation of phosphorylation at every tyrosine residue of the de2-7 EGFR when cells were grown in vivo compared to the receptor isolated from cells cultured in vitro. Upregulation of phosphorylation could be mimicked in vitro by the addition of specifi c components of the ECM such as collagen via an integrin-dependent mechanism. Since this increase in in vivo phosphorylation enhances de2-7 EGFR signaling, this observation explains why the growth enhancement mediated by de2-7 EGFR is largely restricted to the in vivo environment. In a second set of experiments we analyzed the interaction between EGFRvIII and ErbB2. Co-expression of these proteins in NR6 cells, a mouse fi broblast line devoid of ErbB family members, dramatically enhanced in vivo tumorigenicity of these cells compared to cells expressing either protein alone. Detailed analysis of these xenografts demonstrated that EGFRvIII could heterodimerize and transphosphorylate the ErbB2. Since both EGFRvIII and ErbB2 are commonly expressed at gliomas, this data suggests that the co-expression of these two proteins may enhance glioma tumorigenicity.

Abstract

Mutations of the epidermal growth factor receptor (EGFR) gene are found at a relatively high frequency in glioma, with the most common being the de2-7 EGFR (or EGFRvIII). This mutation arises from an in-frame deletion of exons 2-7, which removes 267 amino acids from the extracellular domain of the receptor. Despite being unable to bind ligand, the de2-7 EGFR is constitutively active at a low level. Transfection of human glioma cells with the de2-7 EGFR has little effect in vitro, but when grown as tumor xenografts this mutated receptor imparts a dramatic growth advantage. We mapped the phosphorylation pattern of de2-7 EGFR, both in vivo and in vitro, using a panel of antibodies specific for different phosphorylated tyrosine residues. Phosphorylation of de2-7 EGFR was detected constitutively at all tyrosine sites surveyed in vitro and in vivo, including tyrosine 845, a known target in the wild-type EGFR for src kinase. There was a substantial upregulation of phosphorylation at every yrosine residue of the de2-7 EGFR when cells were grown in vivo compared to the receptor isolated from cells cultured in vitro. Upregulation of phosphorylation at tyrosine 845 could be stimulated in vitro by the addition of specific components of the ECM via an integrindependent mechanism. These observations may partially explain why the growth enhancement mediated by de2-7 EGFR is largely restricted to the in vivo environment

Abstract

Retaining detailed representations of unstressed syllables is a logical prerequisite for infants' use of probabilistic phonotactics to segment iambic words from fluent speech. The head-turn preference study was used to investigate the nature of English- learners' representations of iambic word onsets. Fifty-four 10.5-month-olds were familiarized to passages containing the nonsense iambic word forms ginome and tupong. Following familiarization, infants were either tested on familiar (ginome and tupong) or near-familiar (pinome and bupong) versus unfamiliar (kidar and mafoos) words. Infants in the familiar test group (familiar vs. unfamiliar) oriented significantly longer to familiar than unfamiliar test items, whereas infants in the near-familiar test group (near-familiar vs. unfamiliar) oriented equally long to near-familiar and unfamiliar test items. Our results provide evidence that infants retain fairly detailed representations of unstressed syllables and therefore support the hypothesis that infants use phonotactic cues to find words in fluent speech.

Abstract

In this study, we use the association between various measures of the morphological family and decision latencies to reveal the way in which the components of Dutch and English compounds are processed. The results show that for constituents of concatenated compounds in both languages, a position-related token count of the morphological family plays a role, whereas English open compounds show an effect of a type count, similar to the effect of family size for simplex words. When Dutch compounds are written with an artificial space, they reveal no effect of type count, which shows that the differential effect for the English open compounds is not superficial. The final experiment provides converging evidence for the lexical consequences of the space in English compounds. Decision latencies for English simplex words are better predicted from counts of the morphological family that include concatenated and hyphenated but not open family members.

Abstract

Words can occur as constituents of other words. Some words have a high morphological productivity, in that they occur in many complex words, whereas others are morphological islands. Previous studies have found that the size of a word's morphological family can co-determine response latencies in lexical decision tasks. This thesis shows, using lexical decision as well as otherexperimental tasks, that the effect of family size is a semantic effect,reflecting the spreading of activation in the mental lexicon along the lines of morphological and semantic relatedness between words.

Abstract

In early Dutch learner varieties, there is no evidence of finiteness being a functional category. There is no V2nd: no correlation between inflectional morphology and movement. Initially, learners express the illocutive function of finiteness through the use of illocutive markers, with the non-use of an illocutive marker expressing the default illocutive function of assertion. Illocutive markers are functioning as adjuncts with scope over the predicate. Illocutive markers become re-analysed as functional elements.The driving force is the acquisition of the auxiliary verbs that occur with past participles. It leads to a reanalysis of illocutive markers as two separate elements: an auxiliary verb and a scope adverb. The (modal) auxiliary carries illocutive function. Lexical verb-argument structure (including the external argument) occurs within the domain of the auxiliary verb. The predicate as the focus constituent occurs within the domain of a scope adverb. This reanalysis establishes a position for the external argument within the domain of AUX. The acquisition of AUX causes the acquisition of a (hierarchical) structure with a complement as a constituent which represents an underlying verb-argument structure, a predicate as the domain of elements that are in focus, and an external (specifier) position as a landing site for elements with topic function.

Abstract

We describe a reaction time study in which listeners detected word or nonword syllable targets (e.g. zoo, trel) in sequences consisting of the target plus a consonant or syllable residue (trelsh, trelshek). The pattern of responses differed from an earlier word-spotting study with the same material, in which words were always harder to find if only a consonant residue remained. The earlier results should thus not be viewed in terms of syllabic parsing, but in terms of a universal role for syllables in speech perception; words which are accidentally present in spoken input (e.g. sell in self) can be rejected when they leave a residue of the input which could not itself be a word.