- Email: [email protected]
Where and when is audiovisual speech integrated: MEG studies
82
Abstracts /International Journal of Psychophysiology 25 0997) 17-84
individual words (cf. the nontrivial meaning difference between Dog bites man and Man bites dog). This distinction between
semantics (sentence meaning) and syntax (sentence form) is a fundamental one in linguistics. However, it is still a matter of debate whether the separation of meaning and form is also upheld at the level of actual, real-time language comprehension. In other words, do separable semantic and syntactic processes exist? We will present event-related brain potential (ERP) data from a series of experiments on semantic and syntactic processing during language comprehension. On the basis of these data we will argue that syntactic and semantic processing operations have distinct electrophysiological signatures. These results imply that the processing of syntactic and semantic information during language understanding is subserved, at least in part, by separate neural structures. WHERE AND WHEN IS AUDIOVISUAL GRATED: MEG STUDIES
SPEECH INTE-
* Mikko Sams and Sari Leviinert. *Department of Psychology, University of Tampere, P.O. Box 607,331Ol Tampere, Finland and Low Temperature Laboratory, Helsinki University of Technology, 02150 Espoo, Finland We recently recorded MEG responses of the human brain during audiovisual speech perception. When we presented infrequent deviant discordant pairings (auditory/pa/together with visual /ka/) among frequent concordant stimuli (auditory and visual /pa/), the deviants elicited a specific response, which we suggested to be generated in the auditory cortex. In a more recent experiment, the subjects were experienced lip readers. Now the concordant and discordant stimuli were also delivered equiprobably. The measured MEG signals were complex and showed a lot of individual variability. However, some subjects showed a specific response to a discordant stimulus both when presented equiprobably with concordant stimuli and when presented as an infrequent deviant. The response was rather late, peaking about 200 ms from the onset of the auditory stimulus. We suggest that the perisylvian cortex, close to the source of the auditory lOO-ms response (MlOO), may be activated by the discordant stimuli. APPLICATIONS OF CLINICAL PSYCHOPHYSIOLOGY IN DEVELOPMENTAL NEUROLOGY AND NEUROPSYCHOLOGY G.A. Chiarenza*, S. Ceruti and M. Cucci Servizio di Neuropsichiatria Infantile, Azienda USSL 33,20017 Rho, Italy The view that perceptual and/or perceptual-motor dysfunction underlies reading failure is widespread. This clinical psychophysiological investigation is dealing with the understanding of the etiological aspects and consequences of reading
disability. The method proposed by the authors to approach learning disabled children consists of a battery of different tests from the field of psychophysics, psychophysiology, neuropsychology and clinical psychology, which diagnoses, corroborates and investigates the causes and consequences of learning disability. The perceptual common denominator was evaluated with the Mangina test. The reading abilities with the Boder test and another letter recognition test. The Mang ina test diagnoses ‘analytical-specific perceptual skills’ and is correlated with reading, comprehension, writing and mathematical abilities. The Boder and. the letter recognition test enable dyslexic children to be classified into one of three main subtypes - dysphonetic, unable to integrate symbols with their sounds; dyseidetic, unable to perceive letters and whole words as gestalts, or a combination of both. The clinical psychophysiology evidence was investigated by recording movement-related potential during the execution of a skilled perceptual-motor task. The psychological characteristics were evaluated with the Rorschach test and clinical interviews. All subjects were diagnosed as reading disabled according to DSM-IV criteria. The psychophysiological evidence indicates that the movement-related potentials of the dyslexic subjects were abnormal; the Mangina test showed varying degrees of perceptual disabilities and the Boder and letter recognition test showed dysphonetic and/or dyseidetic behaviour. The psychological consequences showed weakness of the Ego, difficulty in reality testing, cognitive inhibition in spite of normal I.Q., difficulties to cope with environmental requests, an inner resonance of extratensive type with poor impulse control. DRIVER BEHAVIOR DURING TION AT A CROSSING
A CRITICAL
SITUA-
A. Priez*‘, C. Petit2, C. Brigout2, L.‘ Boulommier’, F. Guilion’, A. DBmont’, C. Tarribre3, E. Vemet-Mamy and A. Dittmar4 ‘AARISTE, 132r. des suisses, F92000 Nanterre, France 21RBA, 132r. des suisses, F92000 Nanterre, France 3Renault, 132r. des suisses, F92000 Nanterre, France 4CNRS, Lab. de thermoregulation, Fat. de medecine, 8 av. Rockefeller, F69373 Lyon cedex, France 67 average drivers were asked to drive along a track in order to study their emotional load. At a certain time, an unexpected dummy car ran out from their right and stopped in the middle of the road, leaving the left line free. As the stopping distance was too short to avoid the accident, a steering manoeuvre was required. Skin resistance, potential, temperature, blood flow and heart rate were recorded continuously during the test as well as parameters on the car. Links were established between physiological measurements and the performance of driving during the critical phase. As tonic resistance is relevant of the attentional level, two populations (good and unadapted manoeuvre) were distinguished. Shapes of the phasic resistance and potential responses also differed
Abstracts /International Journal of Psychophysiology 25 0997) 17-84
individual words (cf. the nontrivial meaning difference between Dog bites man and Man bites dog). This distinction between
semantics (sentence meaning) and syntax (sentence form) is a fundamental one in linguistics. However, it is still a matter of debate whether the separation of meaning and form is also upheld at the level of actual, real-time language comprehension. In other words, do separable semantic and syntactic processes exist? We will present event-related brain potential (ERP) data from a series of experiments on semantic and syntactic processing during language comprehension. On the basis of these data we will argue that syntactic and semantic processing operations have distinct electrophysiological signatures. These results imply that the processing of syntactic and semantic information during language understanding is subserved, at least in part, by separate neural structures. WHERE AND WHEN IS AUDIOVISUAL GRATED: MEG STUDIES
SPEECH INTE-
* Mikko Sams and Sari Leviinert. *Department of Psychology, University of Tampere, P.O. Box 607,331Ol Tampere, Finland and Low Temperature Laboratory, Helsinki University of Technology, 02150 Espoo, Finland We recently recorded MEG responses of the human brain during audiovisual speech perception. When we presented infrequent deviant discordant pairings (auditory/pa/together with visual /ka/) among frequent concordant stimuli (auditory and visual /pa/), the deviants elicited a specific response, which we suggested to be generated in the auditory cortex. In a more recent experiment, the subjects were experienced lip readers. Now the concordant and discordant stimuli were also delivered equiprobably. The measured MEG signals were complex and showed a lot of individual variability. However, some subjects showed a specific response to a discordant stimulus both when presented equiprobably with concordant stimuli and when presented as an infrequent deviant. The response was rather late, peaking about 200 ms from the onset of the auditory stimulus. We suggest that the perisylvian cortex, close to the source of the auditory lOO-ms response (MlOO), may be activated by the discordant stimuli. APPLICATIONS OF CLINICAL PSYCHOPHYSIOLOGY IN DEVELOPMENTAL NEUROLOGY AND NEUROPSYCHOLOGY G.A. Chiarenza*, S. Ceruti and M. Cucci Servizio di Neuropsichiatria Infantile, Azienda USSL 33,20017 Rho, Italy The view that perceptual and/or perceptual-motor dysfunction underlies reading failure is widespread. This clinical psychophysiological investigation is dealing with the understanding of the etiological aspects and consequences of reading
disability. The method proposed by the authors to approach learning disabled children consists of a battery of different tests from the field of psychophysics, psychophysiology, neuropsychology and clinical psychology, which diagnoses, corroborates and investigates the causes and consequences of learning disability. The perceptual common denominator was evaluated with the Mangina test. The reading abilities with the Boder test and another letter recognition test. The Mang ina test diagnoses ‘analytical-specific perceptual skills’ and is correlated with reading, comprehension, writing and mathematical abilities. The Boder and. the letter recognition test enable dyslexic children to be classified into one of three main subtypes - dysphonetic, unable to integrate symbols with their sounds; dyseidetic, unable to perceive letters and whole words as gestalts, or a combination of both. The clinical psychophysiology evidence was investigated by recording movement-related potential during the execution of a skilled perceptual-motor task. The psychological characteristics were evaluated with the Rorschach test and clinical interviews. All subjects were diagnosed as reading disabled according to DSM-IV criteria. The psychophysiological evidence indicates that the movement-related potentials of the dyslexic subjects were abnormal; the Mangina test showed varying degrees of perceptual disabilities and the Boder and letter recognition test showed dysphonetic and/or dyseidetic behaviour. The psychological consequences showed weakness of the Ego, difficulty in reality testing, cognitive inhibition in spite of normal I.Q., difficulties to cope with environmental requests, an inner resonance of extratensive type with poor impulse control. DRIVER BEHAVIOR DURING TION AT A CROSSING
A CRITICAL
SITUA-
A. Priez*‘, C. Petit2, C. Brigout2, L.‘ Boulommier’, F. Guilion’, A. DBmont’, C. Tarribre3, E. Vemet-Mamy and A. Dittmar4 ‘AARISTE, 132r. des suisses, F92000 Nanterre, France 21RBA, 132r. des suisses, F92000 Nanterre, France 3Renault, 132r. des suisses, F92000 Nanterre, France 4CNRS, Lab. de thermoregulation, Fat. de medecine, 8 av. Rockefeller, F69373 Lyon cedex, France 67 average drivers were asked to drive along a track in order to study their emotional load. At a certain time, an unexpected dummy car ran out from their right and stopped in the middle of the road, leaving the left line free. As the stopping distance was too short to avoid the accident, a steering manoeuvre was required. Skin resistance, potential, temperature, blood flow and heart rate were recorded continuously during the test as well as parameters on the car. Links were established between physiological measurements and the performance of driving during the critical phase. As tonic resistance is relevant of the attentional level, two populations (good and unadapted manoeuvre) were distinguished. Shapes of the phasic resistance and potential responses also differed