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J L Nespoulous

Publications and source records attributed to J L Nespoulous.

At least 19 recordsLinked to original sources
PubMed1999

ERP correlates of phoneme perception in speech and sound contexts.

To address the question of the existence of a phonetic module for speech perception, event-related potentials were recorded using a 32 channel system in subjects performing a detection task where the target was the ambiguous, noise-like phoneme /f/ presented either among syllables (speech context) or among environmental sounds (non-speech context). Significant context effects were observed on the N2/P3 complex elicited by the target. In particular, a well localized N2b (250-280 ms) appeared at the left temporoparietal sites on the difference wave between contexts as the result of an enhanced negativity when the target was presented among non-speech stimuli. These findings suggest the involvement of the left temporoparietal region in autonomous, modular processes of speech perception.

Acoustic Stimulation↗
PubMed1999

Differential fMRI responses in the left posterior superior temporal gyrus and left supramarginal gyrus to habituation and change detection in syllables and tones.

Using a habituation-recovery paradigm adapted to functional magnetic resonance imaging, we investigated the brain responses to syllables and tones in six right-handed male subjects. We opposed a standard condition (STD) in which the subjects were listening to homogeneous sequences of four identical stimuli, to a deviant condition (DEV) in which the fourth stimulus of the sequence differed in pitch or spectral content for tones and in the initial stop consonant for syllables. The corresponding runs alternated four rest periods with two STD and two DEV conditions. In addition to a marked rightward asymmetry in the primary and secondary auditory cortex for tones and a right inferior frontal activation for the tone condition where the deviant had increased spectral content, the experiment revealed differential activations in the left posterior superior temporal gyrus and in the left supramarginal gyrus. Activations within the left posterior superior temporal gyrus were observed for the DEV condition with tones and for the STD and DEV conditions with syllables. Activation within the inferior part of the left supramarginal gyrus was only observed for the DEV condition with syllables. The analysis of the decreases and increases in the BOLD signal across the STD, DEV, and rest conditions suggests that the left posterior superior temporal gyrus is implicated in the preattentive change detection of acoustic changes in speech as well as nonspeech stimuli, whereas the left supramarginal gyrus is more specifically engaged in the detection of changes in phonological units.

Adult↗
PubMed1998

Optic aphasia with pure alexia: a mild form of visual associative agnosia? A case study.

A single-case study is reported of a naming disorder selective to the visual modality. The patient showed intact access to structural knowledge of objects and letters, but impaired access to complete semantic knowledge of objects and alphabetical knowledge of letters from visual input. The impairment was most striking when the patient had to discriminate between semantically similar objects or within a given symbolic repertoire, i.e. letters. The co-occurrence of a partial deficit of visual recognition for objects and for letters indicated features of optic aphasia and pure alexia. This symmetric performance between object and letter processing may also constitute a mild form of visual associative agnosia.

Aged↗
PubMed1997

Dual processing of open- and closed-class words.

A series of articles in the past two decades has suggested differential processing of open- and closed-class lexical items by normal adults. Difficulties in replicating a crucial study (Bradley, 1978), however, have weakened the dual route hypothesis. We matched 16 French open-class items to 16 closed-class items for phonological structure, world length, and relative word frequency. Three agrammatic aphasics revealed strikingly more phonological errors on closed-class than open-class items. Dysfluencies were greater on closed-class items and contributed to greater overall reading time for the closed-class words, consistent with a two-route model for the production of closed- and open-class lexical items in Broca's aphasics and, thus, normals.

Aged↗
PubMed1992

Cerebral blood flow correlates of word monitoring in sentences: influence of semantic incoherence. A spect study in normals.

The aim of this study was to assess the cerebral blood flow (CBF) changes induced by the semantic incoherence of sentences whose words were to be monitored by the subjects. According to Marslen-Wilson and Tyler, word processing would be parallel (global) in semantically coherent sentences, and serial (local) in semantically incoherent ones. We hypothesized that, in comparison with the parallel mode, the serial mode of word processing would result in a preponderant activation of the frontal lobes and/or of the left hemisphere, hence in a flow increase in these regions. In addition, one could assume that the increase in task complexity resulting from the breaking of semantic coherence would reinforce the functional links between hemispheres. Furthermore, as interactions between the processing of semantically coherent vs incoherent of verbal materials and the processing of imageable vs non-imageable stimuli was recently suspected, we designed a study combining coherent vs incoherent sentences and imageable vs non-imageable words. The results we obtained in 12 normal volunteers by measuring regional cerebral blood flow by SPECT and IV injection of Xenon 133 during the four experimental conditions, did not allow us to firmly establish our hypotheses. Indeed, we failed to demonstrate any significant CBF changes across conditions and there was no interaction between coherent vs incoherent and imageable vs non-imageable conditions. However, the analysis of the inter-regional correlations pointed to an increase in the functional links between the hemispheres in the incoherent conditions, whatever the imageability.

Adult↗
PubMed1992

The anatomy of phonological and semantic processing in normal subjects.

We assessed brain activation of nine normal right-handed volunteers in a positron emission tomography study designed to differentiate the functional anatomy of the two major components of auditory comprehension of language, namely phonological versus lexico-semantic processing. The activation paradigm included three tasks. In the reference task, subjects were asked to detect rising pitch within a series of pure tones. In the phonological task, they had to monitor the sequential phonemic organization of non-words. In the lexico-semantic task, they monitored concrete nouns according to semantic criteria. We found highly significant and different patterns of activation. Phonological processing was associated with activation in the left superior temporal gyrus (mainly Wernicke's area) and, to a lesser extent, in Broca's area and in the right superior temporal regions. Lexico-semantic processing was associated with activity in the left middle and inferior temporal gyri, the left inferior parietal region and the left superior prefrontal region, in addition to the superior temporal regions. A comparison of the pattern of activation obtained with the lexico-semantic task to that obtained with the phonological task was made in order to account for the contribution of lower stage components to semantic processing. No difference in activation was found in Broca's area and superior temporal areas which suggests that these areas are activated by the phonological component of both tasks, but activation was noted in the temporal, parietal and frontal multi-modal association areas. These constitute parts of a large network that represent the specific anatomic substrate of the lexico-semantic processing of language.

Adult↗
PubMed1989

Anomia in moderate aphasia: problems in accessing the lexical representation.

This study has two objectives: (1) to determine through the analysis of surface manifestations of anomia whether one or several anomic syndromes exist, (2) to identify the psycholinguistic process at fault in anomia with reference to M. F. Garrett's (1982, in A. Ellis (Ed.), Normality and pathology in cognitive functions, London/New York: Academic Press) language production model. Two naming tasks were administered to 24 moderate aphasics. Test A was a standard naming task, and test B was a similar task which included subtests designed to indicate which level of representation was affected whenever patients did not name the target word. The subtests required, respectively, the identification of (a) a conceptual property, (b) two semantic attributes, (c) the first and (d) last syllable of the target word, and (e) the target word itself. Descriptive statistics yielded three groups of subjects different in terms of surface anomic manifestations, yet unrelated to clinical type of aphasia. Moreover, no significant differences between groups emerged on the subtests. All groups showed a good performance on the conceptual and the semantic subtests, suggesting preservation of high-level cognitive and semantic processes. In contrast, subjects evidenced poorer performances in syllabic identification, indicating a disruption of lower level mechanisms which are assumed to retrieve and process formal lexical representations. Results support the view that aphasic anomia originates from a difficulty in accessing the formal lexical representation and not from a semantic problem.

Adult↗
PubMed1988

Agrammatism in sentence production without comprehension deficits: reduced availability of syntactic structures and/or of grammatical morphemes? A case study.

A French-speaking patient with Broca's aphasia--following a left-hemisphere lesion involving the sylvian region but sparing Broca's area--is presented. Like G. Miceli, A. Mazzuchi, L. Menn, and H. Goodglass's (1983, Brain and Language, 19, 65-97) case 2, this patient produces agrammatic speech in the absence of any comprehension deficit. Unlike Miceli's patient, though, agrammatic speech can be observed in all sentence production tasks (from spontaneous speech to repetition, oral reading, and writing) whereas production of individual words--be they open class or closed class--is almost always intact. On the basis of extensive (psycho)linguistic testing, it is argued that this patient's deficit is not central and not crucially syntactic (at least) at the level of knowledge but seems to disrupt specifically those (automatic?) processes responsible for both retrieval and production of free-standing grammatical morphemes whenever they have to be inserted into phrases and sentences.

Aphasia↗
PubMed1987

Pantomimes and aging.

The goal of this study was to verify the evolution of pantomiming in normal aged subjects in comparison to normal younger adults. Ninety-six subjects participated in this study: 30 between the ages of 20 and 30; 30 between the ages of 40 and 50; and 36 between the ages of 60 and 82. The subjects were required to execute 42 pantomimes on verbal command. The executed gestures were divided into two categories and analyzed separately: (a) the static constituents which refer to the shape the subject gave to the body part(s) involved; and (b) the dynamic constituents which refer to the executed action and to the relations established between several static constituents during the execution. The results showed that the aged subjects' performance was different from the younger subjects' performance principally in the static constituents of self-oriented one-hand gestures where the aged subjects used a part of their body to serve as the absent object.

Adult↗
PubMed1987

[Coprolalic behavior in patients with Gilles de la Tourette syndrome. Form and functional aspects].

Coprolalia as described by Gilles de la Tourette can take two forms: it either turns around a specific theme and serves as a specific and uniform commentary on the discourse of the patient or of others, or on the patient's situation; it may also take the form of seemingly arbitrary "scatalogical punctuations" the semiotic function of which is not evident. It seems clear that coprolalia is involuntary. The limbic lobe may be involved in episodic scatalogical productions; this structure, as observed by Yakovlev, plays a role in "emotive motility" which is essentially centripetal and automatic. The involvement of the limbic lobe would not explain, however, why such verbal behavior is not censored by internal control mechanisms.

Humans↗
PubMed1986

Informative content of narrative discourse in right-brain-damaged right-handers.

Thirty-six right-brain-damaged (RBD) right-handers and 20 controls (C) were submitted to a narrative production task using the pictorial representation of a trivial story. Each subject's narrative was analyzed, using a "propositional analysis," in order to study amount as well as nature of informative content. Results show that RBD subjects' narratives contain a smaller amount of information that did not appear to be related to a smaller amount of verbal output or to the presence of a visual neglect, that the information contained in RBD subjects' narratives appears to be a subset of that contained in C subjects' narratives, and that these results do not pertain to all C or RBD subjects, since both groups are nonhomogeneous. Even though these results are not linked to the presence of some visual neglect or visual agnosia per se, they could be, at least in part, the expression of some degree of perceptive difficulties of the iconography. However, they are also interpreted as expressing a problem with the organization of narrative discourse at levels of cognitive processing which may not be exclusive to language, but which are nonetheless essential for discourse organization.

Brain Damage, Chronic↗
PubMed1982

[Crossed aphasia in right-handed patients. I. Review of the literature].

More than 70 cases of crossed dextral aphasia have been reported in the literature since the end of the XIXth century. If a genetic, environmental or even pathological factor--or lack of information about it--could be suspected to be responsible of a majority of these cases, 10 of them in which all these factors were eliminated still remain. A summary of the neurological, neuropsychological and neurolinguistic features of these 10 cases shows, among other things: 1. that nearly all of them present a (left) motor deficit associated with a quite large and deep right-hemispheric lesion; 2. that most of them also report the presence of one or the other of the neuropsychological signs usually seen in right hemisphere lesions in dextrals; 3. that if reduction and agrammatism are frequent aphasic signs, fluent jargon is also reported, more so in written than in oral expression. Some of the hypotheses put forward to explain crossed aphasia in dextrals are discussed in the light of these facts. It appears that none of these hypotheses can satisfactorily account for the occurrence of a right hemisphere aphasia in some dextrals.

Adult↗
PubMed1982

[Crossed aphasia in right-handed patients. II. Neuropsychological and neurolinguistic study of a case. Evolution over a 2 year period].

We present an unusual case of crossed aphasia in a doctor who is totally right handed, following an infarction which almost completely destroyed his right hemisphere. The observations--linguistic and extra linguistic--during a study over two years are presented. The aphasia evolved in three stages, taking semiological and evolutive aspects not commonly met with. In speech and writing there were: 1. an oral agrammatism and a written dyssyntaxia in the initial stage; 2. the evolution of a non-fluent speech typically agrammatic leading to a jargonaphasia; 3. a dissociation between oral and written language, characterised by phonemic paraphasias in speech and dyssyntaxia in writing. Comprehension was good except for a verbal class called "empty signs" of language, in which the lexic which refers to the notion of space and time has a primary role. On an extra linguistic level some of the usual signs of right hemisphere lesions were present indicating disturbances of a spatial type. The patient could no longer grasp the concept of numerical value and showed severe difficulties in relation to time. On a linguistic level, the discussion is first considered from a typological point of view; this allows to compare our patient's disorders with a Broca's then with a conduction aphasia, Secondly, the discussion is considered from a semiological point of view, taking into consideration the 10 selected cases in the literature and adding our own; a semiological formula of crossed aphasia is given: agrammatism and/or dyssyntaxia + phonemic paraphasia and/or dysorthographia. A suggestion concerning the role of each hemisphere in the language of our patient is proposed: the possible role played by a congenital deafness in the right ear (discovered in the patient at the age of 8) to explain this abnormal hemispherical functional specialisation is discussed. Original comprehension difficulties concerning the time-space lexic are replaced by a perspective of a cognitive type. We conclude that in our patient, there was a "breakdown" of time and space which comes close to the "indifferenciation" of spatial order and time which Piaget has described in children.

Aphasia↗