Publications

Abstract

Regions of the prefrontal cortex (PFC) are typically activated in many different cognitive functions. In most studies, the focus has been on the role of specific PFC regions in specific cognitive domains, but more recently similarities in PFC activations across cognitive domains have been stressed. Such similarities may suggest that a region mediates a common function across a variety of cognitive tasks. In this study, we compared the activation patterns associated with tests of working memory, semantic memory and episodic memory. The results converged on a general involvement of four regions across memory tests. These were located in left frontopolar cortex, left mid-ventrolateral PFC, left mid-dorsolateral PFC and dorsal anterior cingulate cortex. These findings provide evidence that some PFC regions are engaged during many different memory tests. The findings are discussed in relation to theories about the functional contribition of the PFC regions and the architecture of memory.

Abstract

Cognitive studies show that both younger and older adults can increase their memory performance after training in using a visuospatial mnemonic, although age-related memory deficits tend to be magnified rather than reduced after training. Little is known about the changes in functional brain activity that accompany training-induced memory enhancement, and whether age-related activity changes are associated with the size of training-related gains. Here, we demonstrate that younger adults show increased activity during memory encoding in occipito-parietal and frontal brain regions after learning the mnemonic. Older adults did not show increased frontal activity, and only those elderly persons who benefited from the mnemonic showed increased occipitoparietal activity. These findings suggest that age-related differences in cognitive reserve capacity may reflect both a frontal processing deficiency and a posterior production deficiency.

Abstract

Memorializes Martin D. S. Braine, whose research on child language acquisition and on both child and adult thinking and reasoning had a major influence on modern cognitive psychology. Addressing meaning as well as position, Braine argued that children start acquiring language by learning narrow-scope positional formulas that map components of meaning to positions in the utterance. These proposals were critical in starting discussions of the possible universality of the pivot-grammar stage and of the role of syntax, semantics,and pragmatics in children's early grammar and were pivotal to the rise of approaches in which cognitive development in language acquisition is stressed.

Abstract

Attention-deficit/hyperactivity disorder (ADHD [MIM 143465]) is a common, highly heritable neurobehavioral disorder of childhood onset, characterized by hyperactivity, impulsivity, and/or inattention. As part of an ongoing study of the genetic etiology of ADHD, we have performed a genomewide linkage scan in 204 nuclear families comprising 853 individuals and 270 affected sibling pairs (ASPs). Previously, we reported genomewide linkage analysis of a “first wave” of these families composed of 126 ASPs. A follow-up investigation of one region on 16p yielded significant linkage in an extended sample. The current study extends the original sample of 126 ASPs to 270 ASPs and provides linkage analyses of the entire sample, using polymorphic microsatellite markers that define an ∼10-cM map across the genome. Maximum LOD score (MLS) analysis identified suggestive linkage for 17p11 (MLS=2.98) and four nominal regions with MLS values >1.0, including 5p13, 6q14, 11q25, and 20q13. These data, taken together with the fine mapping on 16p13, suggest two regions as highly likely to harbor risk genes for ADHD: 16p13 and 17p11. Interestingly, both regions, as well as 5p13, have been highlighted in genomewide scans for autism.

Abstract

Two recent studies (Coulson et al., 1998;Osterhout et al., 1996)examined the
relationship between the event-related brain potential (ERP) responses to linguistic syntactic anomalies (P600/SPS) and domain-general unexpected events (P300). Coulson et al. concluded that these responses are highly similar, whereas Osterhout et al. concluded that they are distinct. In this comment, we evaluate the relativemerits of these claims. We conclude that the available evidence indicates that the ERP response to syntactic anomalies is at least partially distinct from the ERP response to unexpected anomalies that do not involve a grammatical violation

Abstract

Japanese, British English and American English listeners were presented with spoken words in their native language, and asked to mark on a written transcript of each word the first natural division point in the word. The results showed clear and strong patterns of consensus, indicating that listeners have available to them conscious representations of within-word structure. Orthography did not play a strongly deciding role in the results. The patterns of response were at variance with results from on-line studies of speech segmentation, suggesting that the present task taps not those representations used in on-line listening, but levels of representation which may involve much richer knowledge of word-internal structure.

Abstract

Two experiments examined the processing of Tokyo Japanese pitchaccent distinctions by native speakers of Japanese from two accentlessvariety areas. In both experiments, listeners were presented with Tokyo Japanese speech materials used in an earlier study with Tokyo Japanese listeners, who clearly exploited the pitch-accent information in spokenword recognition. In the "rst experiment, listeners judged from which of two words, di!ering in accentual structure, isolated syllables had been extracted. Both new groups were, overall, as successful at this task as Tokyo Japanese speakers had been, but their response patterns differed from those of the Tokyo Japanese, for instance in that a bias towards H judgments in the Tokyo Japanese responses was weakened in the present groups' responses. In a second experiment, listeners heard word fragments and guessed what the words were; in this task, the speakers from accentless areas again performed significantly above chance, but their responses showed less sensitivity to the information in the input, and greater bias towards vocabulary distribution frequencies, than had been observed with the Tokyo Japanese listeners. The results suggest that experience with a local accentless dialect affects the processing of accent for word recognition in Tokyo Japanese, even for listeners with extensive exposure to Tokyo Japanese.

Abstract

Nasal consonants in syllabic coda position in Japanese assimilate to the place of articulation of a following consonant. The resulting forms may be perceived as different realizations of a single underlying unit, and indeed the kana orthographies represent them with a single character. In the present study, Japanese listeners' response time to detect nasal consonants was measured. Nasals in coda position, i.e., moraic nasals, were detected faster and more accurately than nonmoraic nasals, as reported in previous studies. The place of articulation with which moraic nasals were realized affected neither response time nor accuracy. Non-native subjects who knew no Japanese, given the same materials with the same instructions, simply failed to respond to moraic nasals which were realized bilabially. When the nasals were cross-spliced across place of articulation contexts the Japanese listeners still showed no significant place of articulation effects, although responses were faster and more accurate to unspliced than to cross-spliced nasals. When asked to detect the phoneme following the (cross-spliced) moraic nasal, Japanese listeners showed effects of mismatch between nasal and context, but non-native listeners did not. Together, these results suggest that Japanese listeners are capable of very rapid abstraction from phonetic realization to a unitary representation of moraic nasals; but they can also use the phonetic realization of a moraic nasal effectively to obtain anticipatory information about following phonemes.

Abstract

In this paper we describe a general scheme for internationalization of our talking head, Baldi, to speak other languages. We describe the modular structure of the auditory/visual synthesis software. As an example, we have created a synthetic Arabic talker, which is evaluated using a noisy word recognition task comparing this talker with a natural one.

Abstract

This study investigates how children of different ages talk about a conversation that they have witnessed. 48 Turkish children, five, nine and thirteen years in age, saw a televised dialogue between two Sesame Street characters (Bert and Ernie). Afterward, they narrated what they had seen and heard. Their reports were analysed for the development of linguistic devices used to orient their listeners to the relevant properties of a conversational exchange. Each utterance in the child's narrative was analysed as to its conversational role: (1) whether the child used direct or indirect quotation frames; (2) whether the child marked the boundaries of conversational turns using speakers' names and (3) whether the child used a marker for pairing of utterances made by different speakers (agreement-disagreement, request-refusal, questioning-answering). Within pairings, children's use of (a) the temporal and evaluative connectivity markers and (b) the kind of verb of saying were identified. The data indicate that there is a developmental change in children's ability to use appropriate linguistic means to orient their listeners to the different properties of a conversation. The development and use of these linguistic means enable the child to establish different social roles in a narrative interaction. The findings are interpreted in terms of the child's social-communicative development from being a ' character' to becoming a ' narrator' and ' author' of the reported conversation in the narrative situation.

Abstract

We report three studies investigating children's and adults' comprehension of sentences containing the focus particle only. In Experiments 1 and 2, four groups of participants (6–7 years, 8–10 years, 11–12 years and adult) compared sentences with only in different syntactic positions against pictures that matched or mismatched events described by the sentence. Contrary to previous findings (Crain, S., Ni, W., & Conway, L. (1994). Learning, parsing and modularity. In C. Clifton, L. Frazier, & K. Rayner (Eds.), Perspectives on sentence processing. Hillsdale, NJ: Lawrence Erlbaum; Philip, W., & Lynch, E. (1999). Felicity, relevance, and acquisition of the grammar of every and only. In S. C. Howell, S. A. Fish, & T. Keith-Lucas (Eds.), Proceedings of the 24th annual Boston University conference on language development. Somerville, MA: Cascadilla Press) we found that young children predominantly made errors by failing to process contrast information rather than errors in which they failed to use syntactic information to restrict the scope of the particle. Experiment 3 replicated these findings with pre-schoolers.

Abstract

Demonstrative terms (e.g., this and that) are key items in understanding how a language constructs and interprets spatial relationships. This in-depth questionnaire explores how demonstratives (and similar spatial deixis forms) function in the research language, covering such topics as their morphology and syntax, semantic dimensions, and co-occurring gesture practices. Questionnaire responses should ideally be based on natural, situated discourse as well as elicitation with consultants.

Abstract

"Event realisation" refers to the normal final state of the affected entity of an activity described by a verb. For example, the sentence John killed the mosquito entails that the mosquito is afterwards dead – this is the full realisation of a killing event. By contrast, a sentence such as John hit the mosquito does not entail the mosquito’s death (even though we might assume this to be a likely result). In using a certain verb, which features of event realisation are entailed and which are just likely? This questionnaire supports cross-linguistic exploration of event realisation for a range of event types.

Abstract

What are the preferred ways to describe spatial relationships in different linguistic and cultural groups, and how does this interact with non-linguistic spatial awareness? This game was devised as an interactive supplement to several items that collect information on the encoding and understanding of spatial relationships, especially as relevant to “route descriptions”. This is a director-matcher task, where one consultant has access to stimulus materials that shows a “target” situation, and directs another consultant (who cannot see the target) to recreate this arrangement.

Abstract

In the present PET study we explore some functional aspects of the interaction between attentional/control processes and learning/memory processes. The network of brain regions supporting recall of abstract designs were studied in a less practiced and in a well practiced state. The results indicate that automaticity, i.e., a decreased dependence on attentional and working memory resources, develops as a consequence of practice. This corresponds to the practice related decreases of activity in the prefrontal, anterior cingulate, and posterior parietal regions. In addition, the activity of the medial temporal regions decreased as a function of practice. This indicates an inverse relation between the strength of encoding and the activation of the MTL during retrieval. Furthermore, the pattern of practice related increases in the auditory, posterior insular-opercular extending into perisylvian supra marginal region, and the right mid occipito-temporal region, may reflect a lower degree of inhibitory attentional modulation of task irrelevant processing and more fully developed representations of the abstract designs, respectively. We also suggest that free recall is dependent on bilateral prefrontal processing, in particular non-automatic free recall. The present results cofirm previous functional neuroimaging studies of memory retrieval indicating that recall is subserved by a network of interacting brain regions. Furthermore, the results indicate that some components of the neural network subserving free recall may have a dynamic role and that there is a functional restructuring of the information processing networks during the learning process.

Abstract

Recent event-related FMRI studies indicate that the prefrontal (PFC) and the medial temporal lobe (MTL) regions are more active during effective encoding than during ineffective encoding. The within-subject design and the use of well-educated young college students in these studies makes it important to replicate these results in other study populations. In this PET study, we used an auditory word-pair association cued-recall paradigm and investigated a group of healthy upper middle-aged/older illiterate women. We observed a positive correlation between cued-recall success and the regional cerebral blood flow of the left inferior PFC (BA 47) and the MTLs. Specifically, we used the cuedrecall success as a covariate in a general linear model and the results confirmed that the left inferior PFC and the MTLare more active during effective encoding than during ineffective encoding. These effects were observed during encoding of both semantically and phonologically related word pairs, indicating that these effects are robust in the studied population, that is, reproducible within group. These results generalize the results of Brewer et al. (1998, Science 281, 1185– 1187) and Wagner et al. (1998, Science 281, 1188–1191) to an upper middle aged/older illiterate population. In addition, the present study indicates that effective relational encoding correlates positively with the activity of the anterior medial temporal lobe regions.

Abstract

In a within-subject design we investigated the levels-of-processing (LOP) effect using visual material in a behavioral and a corresponding PET study. In the behavioral study we characterize a generalized LOP effect, using pleasantness and graphical quality judgments in the encoding situation, with two types of visual material, figurative and nonfigurative line drawings. In the PET study we investigate the related pattern of brain activations along these two dimensions. The behavioral results indicate that instruction and material contribute independently to the level of recognition performance. Therefore the LOP effect appears to stem both from the relative relevance of the stimuli (encoding opportunity) and an altered processing of stimuli brought about by the explicit instruction (encoding mode). In the PET study, encoding of visual material under the pleasantness (deep) instruction yielded left lateralized frontoparietal and anterior temporal activations while surface-based perceptually oriented processing (shallow instruction) yielded right lateralized frontoparietal, posterior temporal, and occipitotemporal activations. The result that deep encoding was related to the left prefrontal cortex while shallow encoding was related to the right prefrontal cortex, holding the material constant, is not consistent with the HERA model. In addition, we suggest that the anterior medial superior frontal region is related to aspects of self-referential semantic processing and that the inferior parts of the anterior cingulate as well as the medial orbitofrontal cortex is related to affective processing, in this case pleasantness evaluation of the stimuli regardless of explicit semantic content. Finally, the left medial temporal lobe appears more actively engaged by elaborate meaning-based processing and the complex response pattern observed in different subregions of the MTL lends support to the suggestion that this region is functionally segregated.

Abstract

A fundamental problem in the study of learning is that learning-related changes may be confounded by nonspecific time effects. There are several strategies for handling this problem. This problem may be of greater significance in functional magnetic resonance imaging (fMRI) compared to positron emission tomography (PET). Using the general linear model, we describe, compare, and discuss two approaches for separating learning-related from nonspecific time effects. The first approach makes assumptions on the general behavior of nonspecific effects and explicitly models these effects, i.e., nonspecific time effects are incorporated as a linear or nonlinear confounding covariate in the statistical model. The second strategy makes no a priori assumption concerning the form of nonspecific time effects, but implicitly controls for nonspecific effects using an interaction approach, i.e., learning effects are assessed with an interaction contrast. The two approaches depend on specific assumptions and have specific limitations. With certain experimental designs, both approaches may be used and the results compared, lending particular support to effects that are independent of the method used. A third and perhaps better approach that sometimes may be practically unfeasible is to use a completely temporally balanced experimental design. The choice of approach may be of particular importance when learning related effects are studied with fMRI.

Abstract

The objective of this study was to investigate the central processing of dynamic mechanical allodynia in patients with mononeuropathy. Regional cerebral bloodflow, as an indicator of neuronal activity, was measured with positron emission tomography. Paired comparisons were made between three different states; rest, allodynia during brushing the painful skin area, and brushing of the homologous contralateral area. Bilateral activations were observed in the primary somatosensory cortex (S1) and the secondary somatosensory cortex (S2) during allodynia compared to rest. The S1 activation contralateral to the site of the stimulus was more expressed during allodynia than during innocuous touch. Significant activations of the contralateral posterior parietal cortex, the periaqueductal gray (PAG), the thalamus bilaterally and motor areas were also observed in the allodynic state compared to both non-allodynic states. In the anterior cingulate cortex (ACC) there was only a suggested activation when the allodynic state was compared with the non-allodynic states. In order to account for the individual variability in the intensity of allodynia and ongoing spontaneous pain, rCBF was regressed on the individually reported pain intensity, and significant covariations were observed in the ACC and the right anterior insula. Significantly decreased regional blood flow was observed bilaterally in the medial and lateral temporal lobe as well as in the occipital and posterior cingulate cortices when the allodynic state was compared to the non-painful conditions. This finding is consistent with previous studies suggesting attentional modulation and a central coping strategy for known and expected painful stimuli. Involvement of the medial pain system has previously been reported in patients with mononeuropathy during ongoing spontaneous pain. This study reveals a bilateral activation of the lateral pain system as well as involvement of the medial pain system during dynamic mechanical allodynia in patients with mononeuropathy.

Abstract

In this study data from the first six months of 12 children s multiword speech were used to test the validity of Valian's (1991) syntactic perfor-mance-limitation account and Tomasello s (1992) verb-island account of early multiword speech with particular reference to the development of the English verb category. The results provide evidence for appropriate use of verb morphology, auxiliary verb structures, pronoun case marking, and SVO word order from quite early in development. However, they also demonstrate a great deal of lexical specificity in the children's use of these systems, evidenced by a lack of overlap in the verbs to which different morphological markers were applied, a lack of overlap in the verbs with which different auxiliary verbs were used, a disproportionate use of the first person singular nominative pronoun I, and a lack of overlap in the lexical items that served as the subjects and direct objects of transitive verbs. These findings raise problems for both a syntactic performance-limitation account and a strong verb-island account of the data and suggest the need to develop a more general lexiealist account of early multiword speech that explains why some words come to function as "islands" of organization in the child's grammar and others do not.

Abstract

Observational and checklist measures of vocabulary composition have both recently been used to look at the absolute proportion of nouns in children's early vocabularies. However, they have tended to generate rather different results. The present study is an attempt to investigate the relationship between such measures in a sample of 26 children between 1;1 and 2;1 at approximately 50 and 100 words. The results show that although observational and checklist measures are significantly correlated, there are also systematic quantitative differences between them which seem to reflect a combination of checklist, maternal-report and observational sampling biases. This suggests that, although both kinds of measure may represent good indices of differences in vocabulary size and composition across children and hence be useful as dependent variables in correlational research, neither may be ideal for estimating the absolute proportion of nouns in children's vocabularies. The implication is that questions which rely on information about the absolute proportion of particular kinds of words in children's vocabularies can only be properly addressed by detailed longitudinal studies in which an attempt is made to collect more comprehensive vocabulary records for individual children.

Abstract

This study investigated characteristics of motor cortex activation and response generation in Parkinson's disease with measures of electrocortical activity (lateralized readiness potential [LRP]), electromyographic activity (EMG), and isometric force in a noise-compatibility task. When presented with stimuli consisting of incompatible target and distracter elements asking for responses of opposite hands, patients were less able than control subjects to suppress activation of the motor cortex controlling the wrong response hand. This was manifested in the pattern of reaction times and in an incorrect lateralization of the LRP. Onset latency and rise time of the LRP did not differ between patients and control subjects, but EMG and response force developed more slowly in patients. Moreover, in patients but not in control subjects, the rate of development of EMG and response force decreased as reaction time increased. We hypothesize that this dissociation between electrocortical activity and peripheral measures in Parkinson's disease is the result of changes in motor cortex function that alter the relation between signal-related and movement-related neural activity in the motor cortex. In the LRP, this altered balance may obscure an abnormal development of movement-related neural activity.

Abstract

Investigations of the effects of advance information on movement preparation in Parkinson's disease using reaction time (RT) measures have yielded contradictory results. In order to obtain direct information regarding the time course of movement preparation, we combined RT measurements in a movement precueing task with multi-channel recordings of movement-related potentials in the present study. Movements of the index and middle fingers of the left and right hand were either precued or not by advance information regarding the side (left or right hand) of the required response. Reaction times were slower for patients than for control subjects. Both groups benefited equally from informative precues, indicating that patients utilized the advance information as effectively as control subjects. Lateralization of the movement-preceding cerebral activity [i.e. the lateralized readiness potential (LRP)] confirmed that patients used the available partial information to prepare their responses and started this process no later than controls. In conjunction with EMG onset times, the LRP onset measures allowed for a fractionation of the RTs, which provided clues to the stages where the slowness of Parkinson's disease patients might arise. No definite abnormalities of temporal parameters were found, but differences in the distribution of the lateralized movement-preceding activity between patients and controls suggested differences in the cortical organization of movement preparation. Differences in amplitude of the contingent negative variation (CNV) and differences in the way in which the CNV was modulated by the information given by the precue pointed in the same direction. A difference in amplitude of the P300 between patients and controls suggested that preprogramming a response required more effort from. patients than from control subjects.

Abstract

In languages in which nouns have a grammatical gender, word recognition can be estimated by gender decision response times. Although gender decision has yet to be used extensively, it has proved sensitive to several factors that have been shown to affect lexical access. The task is not restricted to spoken language but can be used with linguistic information from other sensory modalities.

Abstract

The objectives of this article are to characterize the performance and to discuss the performance differences between literate and illiterate participants in a well-defined study population.We describe the participant-selection procedure used to investigate this population. Three groups with similar sociocultural backgrounds living in a relatively homogeneous fishing community in southern Portugal were characterized in terms of socioeconomic and sociocultural background variables and compared on a simple neuropsychological test battery; specifically, a literate group with more than 4 years of education (n = 9), a literate group with 4 years of education (n = 26), and an illiterate group (n = 31) were included in this study.We compare and discuss our results with other similar studies on the effects of literacy and illiteracy. The results indicate that naming and identification of real objects, verbal fluency using ecologically relevant semantic criteria, verbal memory, and orientation are not affected by literacy or level of formal education. In contrast, verbal working memory assessed with digit span, verbal abstraction, long-term semantic memory, and calculation (i.e., multiplication) are significantly affected by the level of literacy. We indicate that it is possible, with proper participant-selection procedures, to exclude general cognitive impairment and to control important sociocultural factors that potentially could introduce bias when studying the specific effects of literacy and level of formal education on cognitive brain function.

Abstract

Is there a relation between socioeconomic factors and aphasia severity and recovery? Connor, Obler, Tocco, Fitzpatrick, and Albert (2001) describe correlations between the educational level and socioeconomic status of aphasic subjects with aphasia severity and subsequent recovery. As stated in the introduction by Connor et al. (2001), studies of the influence of educational level and literacy (or illiteracy) on aphasia severity have yielded conflicting results, while no significant link between socioeconomic status and aphasia severity and recovery has been established. In this brief note, we will comment on their findings and conclusions, beginning first with a brief review of literacy and aphasia research, and complexities encountered in these fields of investigation. This serves as a general background to our specific comments on Connor et al. (2001), which will be focusing on methodological issues and the importance of taking normative values in consideration when subjects with different socio-cultural or socio-economic backgrounds are assessed.

Abstract

Four form-preparation experiments investigated whether aspects of phonological encoding processes and representations are shared between languages in bilingual speakers. The participants were Dutch--English bilinguals. Experiment 1 showed that the basic rightward incrementality revealed in studies for the first language is also observed for second-language words. In Experiments 2 and 3, speakers were given words to produce that did or did not share onset segments, and that came or did not come from different languages. It was found that when onsets were shared among the response words, those onsets were prepared, even when the words came from different languages. Experiment 4 showed that preparation requires prior knowledge of the segments and that knowledge about their phonological features yields no effect. These results suggest that both first- and second-language words are phonologically planned through the same serial order mechanism and that the representations of segments common to the languages are shared.

Abstract

In a recent series of papers, Caramazza and Miozzo [Caramazza, A., 1997. How many levels of processing are there in lexical access? Cognitive Neuropsychology 14, 177-208; Caramazza, A., Miozzo, M., 1997. The relation between syntactic and phonological knowledge in lexical access: evidence from the 'tip-of-the-tongue' phenomenon. Cognition 64, 309-343; Miozzo, M., Caramazza, A., 1997. On knowing the auxiliary of a verb that cannot be named: evidence for the independence of grammatical and phonological aspects of lexical knowledge. Journal of Cognitive Neuropsychology 9, 160-166] argued against the lemma/lexeme distinction made in many models of lexical access in speaking, including our network model [Roelofs, A., 1992. A spreading-activation theory of lemma retrieval in speaking. Cognition 42, 107-142; Levelt, W.J.M., Roelofs, A., Meyer, A.S., 1998. A theory of lexical access in speech production. Behavioral and Brain Sciences, (in press)]. Their case was based on the observations that grammatical class deficits of brain-damaged patients and semantic errors may be restricted to either spoken or written forms and that the grammatical gender of a word and information about its form can be independently available in tip-of-the-tongue stales (TOTs). In this paper, we argue that though our model is about speaking, not taking position on writing, extensions to writing are possible that are compatible with the evidence from aphasia and speech errors. Furthermore, our model does not predict a dependency between gender and form retrieval in TOTs. Finally, we argue that Caramazza and Miozzo have not accounted for important parts of the evidence motivating the lemma/lexeme distinction, such as word frequency effects in homophone production, the strict ordering of gender and pho neme access in LRP data, and the chronometric and speech error evidence for the production of complex morphology.

Abstract

This article presents a new account of the color-word Stroop phenomenon ( J. R. Stroop, 1935) based on an implemented model of word production, WEAVER++ ( W. J. M. Levelt, A. Roelofs, & A. S. Meyer, 1999b; A. Roelofs, 1992, 1997c). Stroop effects are claimed to arise from processing interactions within the language-production architecture and explicit goal-referenced control. WEAVER++ successfully simulates 16 classic data sets, mostly taken from the review by C. M. MacLeod (1991), including incongruency, congruency, reverse-Stroop, response-set, semantic-gradient, time-course, stimulus, spatial, multiple-task, manual, bilingual, training, age, and pathological effects. Three new experiments tested the account against alternative explanations. It is shown that WEAVER++ offers a more satisfactory account of the data than other models.

Abstract

According to most models of speech production, the planning of spoken words involves the independent retrieval of segments and metrical frames followed by segment-to-frame association. In some models, the metrical frame includes a specification of the number and ordering of consonants and vowels, but in the word-form encoding by activation and verification (WEAVER) model (A. Roelofs, 1997), the frame specifies only the stress pattern across syllables. In 6 implicit priming experiments, on each trial, participants produced 1 word out of a small set as quickly as possible. In homogeneous sets, the response words shared word-initial segments, whereas in heterogeneous sets, they did not. Priming effects from shared segments depended on all response words having the same number of syllables and stress pattern, but not on their having the same number of consonants and vowels. No priming occurred when the response words had only the same metrical frame but shared no segments. Computer simulations demonstrated that WEAVER accounts for the findings.

Abstract

P. A. Starreveld and W. La Heij (1995) tested the seriality view of lexical access in speech production, according to which lexical selection and the encoding of a word's form proceed in serial order without feedback. In 2 experiments, they looked at the combined effect of semantic and orthographic relatedness of written distracter words in tasks that required conceptually driven naming. They found an interaction between semantic relatedness and orthographic relatedness and argued that the observed interaction refutes the seriality view of lexical access. In this comment, the authors argue that Starreveld and La Heij's rejection of serial access was based on an oversimplified conception of the seriality view and that interaction, rather than additivity, is predicted by existing conceptions of serial access.

Abstract

This article reports 7 experiments investigating whether utterances are planned in a parallel or rightward incremental fashion during language production. The experiments examined the role of linear order, length, frequency, and repetition in producing Dutch verb–particle combinations. On each trial, participants produced 1 utterance out of a set of 3 as quickly as possible. The responses shared part of their form or not. For particle-initial infinitives, facilitation was obtained when the responses shared the particle but not when they shared the verb. For verb-initial imperatives, however, facilitation was obtained for the verbs but not for the particles. The facilitation increased with length, decreased with frequency, and was independent of repetition. A simple rightward incremental model accounts quantitatively for the results.

Abstract

Accounts that specify semantic and/or syntactic complexity as the primary determinant of the order in which children acquire particular words or grammatical constructions have been highly influential in the literature on question acquisition. One explanation of wh-question acquisition in particular suggests that the order in which English speaking children acquire wh-questions is determined by two interlocking linguistic factors; the syntactic function of the wh-word that heads the question and the semantic generality (or ‘lightness’) of the main verb (Bloom, Merkin & Wootten, 1982; Bloom, 1991). Another more recent view, however, is that acquisition is influenced by the relative frequency with which children hear particular wh-words and verbs in their input (e.g. Rowland & Pine, 2000). In the present study over 300 hours of naturalistic data from twelve two- to three-year-old children and their mothers were analysed in order to assess the relative contribution of complexity and input frequency to wh-question acquisition. The analyses revealed, first, that the acquisition order of wh-questions could be predicted successfully from the frequency with which particular wh-words and verbs occurred in the children's input and, second, that syntactic and semantic complexity did not reliably predict acquisition once input frequency was taken into account. These results suggest that the relationship between acquisition and complexity may be a by-product of the high correlation between complexity and the frequency with which mothers use particular wh-words and verbs. We interpret the results in terms of a constructivist view of language acquisition.

Abstract

Van Valin (Journal of Child Language29, 2002, 161–75) presents a critique of Rowland & Pine (Journal of Child Language27, 2000, 157–81) and argues that the wh-question data from Adam (in Brown, A first language, Cambridge, MA, 1973) cannot be explained in terms of input frequencies as we suggest. Instead, he suggests that the data can be more successfully accounted for in terms of Role and Reference Grammar. In this note we re-examine the pattern of inversion and uninversion in Adam's wh-questions and argue that the RRG explanation cannot account for some of the developmental facts it was designed to explain.

Abstract

In this article, we present the spatial logistics task (SLOT) platform for investigating multimodal communication between 2 human participants. Presented are the SLOT communication task and the software and hardware that has been developed to run SLOT experiments and record the participants’ multimodal behavior. SLOT offers a high level of flexibility in varying the context of the communication and is particularly useful in studies of the relationship between pen gestures and speech. We illustrate the use of the SLOT platform by discussing the results of some early experiments. The first is an experiment on negotiation with a one-way mirror between the participants, and the second is an exploratory study of automatic recognition of spontaneous pen gestures. The results of these studies demonstrate the usefulness of the SLOT platform for conducting multimodal communication research in both human– human and human–computer interactions.

Abstract

Participants' eye movements were monitored as they heard sentences and saw four pictured objects on a computer screen. Participants were instructed to click on the object mentioned in the sentence. There were more transitory fixations to pictures representing monosyllabic words (e.g. ham) when the first syllable of the target word (e.g. hamster) had been replaced by a recording of the monosyllabic word than when it came from a different recording of the target word. This demonstrates that a phonemically identical sequence can contain cues that modulate its lexical interpretation. This effect was governed by the duration of the sequence, rather than by its origin (i.e. which type of word it came from). The longer the sequence, the more monosyllabic-word interpretations it generated. We argue that cues to lexical-embedding disambiguation, such as segmental lengthening, result from the realization of a prosodic boundary that often but not always follows monosyllabic words, and that lexical candidates whose word boundaries are aligned with prosodic boundaries are favored in the word-recognition process.

Abstract

This letter evaluates potential benefits of combining human speech recognition ~HSR! and automatic speech recognition by building a joint model of an automatic phone recognizer ~APR! and a computational model of HSR, viz., Shortlist @Norris, Cognition 52, 189–234 ~1994!#. Experiments based on ‘‘real-life’’ speech highlight critical limitations posed by some of the simplifying assumptions made in models of human speech recognition. These limitations could be overcome by avoiding hard phone decisions at the output side of the APR, and by using a match between the input and the internal lexicon that flexibly copes with deviations from canonical phonemic representations.

Abstract

In this paper, we present an automatic speech recognition (ASR) system based on the combination of an automatic phone recogniser and a computational model of human speech recognition – SpeM – that is capable of computing ‘word activations’ during the recognition process, in addition to doing normal speech recognition, a task in which conventional ASR architectures only provide output after the end of an utterance. We explain the notion of word activation and show that it can be used for ‘early recognition’, i.e. recognising a word before the end of the word is available. Our ASR system was tested on 992 continuous speech utterances, each containing at least one target word: a city name of at least two syllables. The results show that early recognition was obtained for 72.8% of the target words that were recognised correctly. Also, it is shown that word activation can be used as an effective confidence measure.

Abstract

We have recently developed a new model of human speech recognition, based on automatic speech recognition techniques [1]. The present paper has two goals. First, we show that the new model performs well in the recognition of lexically ambiguous input. These demonstrations suggest that the model is able to operate in the same optimal way as human listeners. Second, we discuss how to relate the behaviour of a recogniser, designed to discover the optimum path through a word lattice, to data from human listening experiments. We argue that this requires a metric that combines both path-based and word-based measures of recognition performance. The combined metric varies continuously as the input speech signal unfolds over time.

Abstract

In this paper, we present a novel computational model of human speech recognition – called SpeM – based on the theory underlying Shortlist. We will show that SpeM, in combination with an automatic phone recogniser (APR), is able to simulate the human speech recognition process from the acoustic signal to the ultimate recognition of words. This joint model takes an acoustic speech file as input and calculates the activation flows of candidate words on the basis of the degree of fit of the candidate words with the input. Experiments showed that SpeM outperforms Shortlist on the recognition of ‘real-life’ input. Furthermore, SpeM performs only slightly worse than an off-the-shelf full-blown automatic speech recogniser in which all words are equally probable, while it provides a transparent computationally elegant paradigm for modelling word activations in human word recognition.

Abstract

During language production and comprehension, information about a word's syntactic properties is sometimes needed. While the decision about the grammatical gender of a word requires access to syntactic knowledge, it has also been hypothesized that semantic (i.e., biological gender) or phonological information (i.e., sound regularities) may influence this decision. Event-related potentials (ERPs) were measured while native speakers of German processed written words that were or were not semantically and/or phonologically marked for gender. Behavioral and ERP results showed that participants were faster in making a gender decision when words were semantically and/or phonologically gender marked than when this was not the case, although the phonological effects were less clear. In conclusion, our data provide evidence that even though participants performed a grammatical gender decision, this task can be influenced by semantic and phonological factors.

Abstract

This study investigated the time course of phonological encoding during speech production planning. Previous research has shown that conceptual/semantic information precedes syntactic information in the planning of speech production and that syntactic information is available earlier than phonological information. Here, we studied the relative time courses of the two different processes within phonological encoding, i.e. metrical encoding and syllabification. According to one prominent theory of language production, metrical encoding involves the retrieval of the stress pattern of a word, while syllabification is carried out to construct the syllabic structure of a word. However, the relative timing of these two processes is underspecified in the theory. We employed an implicit picture naming task and recorded event-related brain potentials to obtain fine-grained temporal information about metrical encoding and syllabification. Results revealed that both tasks generated effects that fall within the time window of phonological encoding. However, there was no timing difference between the two effects, suggesting that they occur approximately at the same time.

Abstract

The CELEX lexical database includes a list of Dutch syllables and their frequencies, based on syllabification of isolated word forms. In connected speech, however, sentence-level phonological rules can modify the syllables and their token frequencies. In order to estimate the changes syllables may undergo in connected speech, an empirical investigation was carried out. A large Dutch text corpus (TROUW) was transcribed, processed by word level rules, and syllabified. The resulting lexeme syllables were evaluated by comparing them to the CELEX lexical database for Dutch. Then additional phonological sentence-level rules were applied to the TROUW corpus, and the frequencies of the resulting connected speech syllables were compared with those of the lexeme syllables from TROUW. The overall correlation between lexeme and speech syllables was very high. However, speech syllables generally had more complex CV structures than lexeme syllables. Implications of the results for research involving syllables are discussed. With respect to the notion of a mental syllabary (a store for precompiled articulatory programs for syllables, see Levelt & Wheeldon, 1994) this study revealed an interesting statistical result. The calculation of the cumulative syllable frequencies showed that 85% of the syllable tokens in Dutch can be covered by the 500 most frequent syllable types, which makes the idea of a syllabary very attractive.

Abstract

In this study, we investigated grammatical feature selection during noun phrase production in German and Dutch. More specifically, we studied the conditions under which different grammatical genders select either the same or different determiners or suffixes. Pictures of one or two objects paired with a gender-congruent or a gender-incongruent distractor word were presented. Participants named the pictures using a singular or plural noun phrase with the appropriate determiner and/or adjective in German or Dutch. Significant effects of gender congruency were only obtained in the singular condition where the selection of determiners is governed by the target’s gender, but not in the plural condition where the determiner is identical for all genders. When different suffixes were to be selected in the gender-incongruent condition, no gender congruency effect was obtained. The results suggest that the so-called gender congruency effect is really a determiner congruency effect. The overall pattern of results is interpreted as indicating that grammatical feature selection is an automatic consequence of lexical node selection and therefore not subject to interference from other grammatical features. This implies that lexical node and grammatical feature selection operate with distinct principles.

Abstract

This study investigated the encoding of metrical information during speech production in Dutch. In Experiment 1, participants were asked to judge whether bisyllabic picture names had initial or final stress. Results showed significantly faster decision times for initially stressed targets (e.g., LEpel 'spoon') than for targets with final stress (e.g., liBEL 'dragon fly'; capital letters indicate stressed syllables) and revealed that the monitoring latencies are not a function of the picture naming or object recognition latencies to the same pictures. Experiments 2 and 3 replicated the outcome of the first experiment with bi- and trisyllabic picture names. These results demonstrate that metrical information of words is encoded rightward incrementally during phonological encoding in speech production. The results of these experiments are in line with Levelt's model of phonological encoding.

Abstract

To investigate the role of the syllable in Dutch speech production, five experiments were carried out to examine the effect of visually masked syllable primes on the naming latencies for written words and pictures. Targets had clear syllable boundaries and began with a CV syllable (e.g., ka.no) or a CVC syllable (e.g., kak.tus), or had ambiguous syllable boundaries and began with a CV[C] syllable (e.g., ka[pp]er). In the syllable match condition, bisyllabic Dutch nouns or verbs were preceded by primes that were identical to the target’s first syllable. In the syllable mismatch condition, the prime was either shorter or longer than the target’s first syllable. A neutral condition was also included. None of the experiments showed a syllable priming effect. Instead, all related primes facilitated the naming of the targets. It is concluded that the syllable does not play a role in the process of phonological encoding in Dutch. Because the amount of facilitation increased with increasing overlap between prime and target, the priming effect is accounted for by a segmental overlap hypothesis.

Abstract

Speakers can use pronouns when their conceptual referents are accessible from the preceding discourse, as in 'The flower is red. It turns blue'. Theories of language production agree that in order to produce a noun semantic, syntactic, and phonological information must be accessed. However, little is known about lexical access to pronouns. In this paper, we propose a model of pronoun access in German. Since the forms of German pronouns depend on the grammatical gender of the nouns they replace, the model claims that speakers must access the syntactic representation of the replaced noun (its lemma) to select a pronoun. In two experiments using the lexical decision during naming paradigm [Levelt, W.J.M., Schriefers, H., Vorberg, D., Meyer, A.S., Pechmann, T., Havinga, J., 1991a. The time course of lexical access in speech production: a study of picture naming. Psychological Review 98, 122-142], we investigated whether lemma access automatically entails the activation of the corresponding word form or whether a word form is only activated when the noun itself is produced, but not when it is replaced by a pronoun. Experiment 1 showed that during pronoun production the phonological form of the replaced noun is activated. Experiment 2 demonstrated that this phonological activation was not a residual of the use of the noun in the preceding sentence. Thus, when a pronoun is produced, the lemma and the phonological form of the replaced noun become reactivated.

Abstract

The basic idea behind this task is to find out how languages encode basic shape distinctions such as dimensionality, axial geometry, relative size, etc. More specifically, we want to find out (i) which formal means are used cross linguistically to encode basic shape distinctions, and (ii) which are the semantic distinctions that are made in this domain. In languages with many shape-classifiers, these distinctions are encoded (at least partially) in classifiers. In other languages, positional verbs, descriptive modifiers, such as “flat”, “round”, or nouns such as “cube”, “ball”, etc. might be the preferred means. In this context, we also want to investigate what other “grammatical work” shapeencoding expressions possibly do in a given language, e.g. unitization of mass nouns, or anaphoric uses of shape-encoding classifiers, etc. This task further seeks to determine the role of shape-related parameters which underlie the design of objects in the semantics of the system under investigation.

Abstract

This article discusses how the Trobriand Islanders speak about body and mind. It addresses the following questions: do the linguistic datafit into theories about lexical universals of body-part terminology? Can we make inferences about the Trobrianders' conceptualization of psychological and physical states on the basis of these data? If a Trobriand Islander sees these idioms as external manifestations of inner states, then can we interpret them as a kind of ethnopsychological theory about the body and its role for emotions, knowledge, thought, memory, and so on? Can these idioms be understood as representation of Trobriand ethnopsychological theory?

Abstract

Visiting the Trobriand Islands is advertised as being the highlight of a trip for tourists to Papua New Guinea who want, and can afford, to experience this 'ultimate adventure' with 'expeditionary cruises aboard the luxurious Melanesian Discoverer. The advertisements also promise that the tourists can 'meet the friendly people' and 'observe their unique culture, dances, and art'. During my research in Kaibola and Nuwebila, two neighbouring villages on the northern tip of Kiriwina Island, I studied and analysed the encounters of tourists with Trobriand Islanders, who sing and dance for the Europeans. The analyses of the islanders' tourist performances are based on Erving Goffman's now classic study The Presentation of Self in Everyday Life, which was first published in 1959. In this study Goffmann analyses the structures of social encounters from the perspective of the dramatic performance. The situational context within which the encounter between tourists and Trobriand Islanders takes place frames the tourists as the audience and the Trobriand Islanders as a team of performers. The inherent structure of the parts of the overall performance presented in the two villages can be summarized - within the framework of Goffman's approach - in analogy with the structure of drama. We find parts that constitute the 'exposition', the 'complication', and the 'resolution' of a drama; we even observe an equivalent to the importance of the 'Second Act Curtain' in modern drama theory. Deeper analyses of this encounter show that the motives of the performers and their 'art of impression management' are to control the impression their audience receives in this encounter situation. This analysis reveals that the Trobriand Islanders sell their customers the expected images of what Malinowski (1929) once termed the '...Life of Savages in North-Western Melanesia' in a staged 'illusion'. With the conscious realization of the part they as performers play in this encounter, the Trobriand Islanders are in a position that is superior to that of their audience. Their merchandise or commodity is 'not real', as it is sold 'out of its true cultural context'. It is staged - and thus cannot be taken by any customer whatsoever because it (re)presents just an 'illusion'. The Trobriand Islanders know that neither they nor the core aspects of their culture will suffer any damage within a tourist encounter that is defined by the structure and the kind of their performance. Their pride and self-confidence enable them to bring their superior position into play in their dealings with tourists. With their indigenous humour, they even use this encounter for ridiculing their visitors. It turns out that the encounter is another manifestation of the Trobriand Islanders' self-consciousness, self-confidence, and pride with which they manage to protect core aspects of their cultural identity, while at the same time using and 'selling' parts of their culture as a kind of commodity to tourists.