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P300 to visual and auditory stimuli in normal and learning disabled children
Abstracts 7th IOP Scientific Meeting /International physiological events their chemical deciphering can also be used. Practically all modern physiological research includes computer treatment of the data obtained. Thus the so-called “central psychophysiology” is methodologically a mutually enriching combination of physiological, psychological, chemical as well as computer science possibilities. However psychophysiology is not only a borderline field, enriched by the advantages of the disciplines mentioned above. As a whole it closely borders some clinical disciplines, making it possible to optimise the diagnosis and treatment of nervous diseases, first of all brain diseases as well as social sciences, permitting the understanding and correction on a scientific basis of the changes happening in a society. There is a strong possibility that psychophysiology will enrich computer science as well. Thus compared with basic physiology, psychophysiology can be considered a highly practical and fruitful field of fundamental research. I would like to stress that the future prospects of psychophysiology are connected with development of new methodology of data analysis to meet the high requirements of brain complexity. P300 to visual and auditory stimuli in normal and
learning disabled children J. Bemal, A. Reyes, T. Harmony, M. Rodriguez, G.Yanez, T. Fernandez, L. Galan, E. Marosi, J. Silva, V. Guerrero, H. Rodriguez, National University of Mexico, Iztacala, Mexico P3OOs to visual and auditory stimuli in an oddball paradigm were recorded in 19 monopolar leads (lo/20 International System) in 14 normal and 14 learning-disabled children between 10.5 and 11.5 years old. The auditory stimuli were tones of 500 Hz and 3000 Hz, and the visual stimuli consisted of triangles and squares. The probability of presentation was 80% and 20%. Visual P3OOs had longer latenties (400-500 msec) and major amplitudes than the auditory P300 (300400 msec). The evoked responses had the same morphology in both modalities at Pz, P3, P4 and Cz and visual stimuli produced longer and larger P3OOs at T5, T6,Ol and 02. No significant differences in latency or amplitude between groups were observed using the permutation test either to visual or to auditory stimuli. These results are different from those reported by Holcomb et al. (1985) and by Taylor et al. (1990), who used verbal stimuli. The reason for the absence of differences between groups in our study might be due to the use of very simple and easy task requirements, which does not need extra cognitive resources from the learning-disabled children.
Intracerebral
ERPs
and
Mangina
Test
Journal of Psychophysiology 18 (1994) 87-159
95
performance J.H. Beuzeron-Mangina, CA. Mangina, Montreal Neurological Institute and Montreal Research And Treatment Centre for LAD, Montreal, Quebec, Canada The Mangina Test is a highly valid measure of varying degrees of “analytical-specific perception” as it relates to learning abilities and disabilities (Mangina 1981, 1994). “Analytical specific perception” is a more complicated process than simple sensory perception itself. In the Mangina Test, 16 of the 44 visual stimuli deal with “analytical-specific perceptual tasks” pertaining to size and dimension and are related to mathematical abilities (Mangina 1981, 1994). Another 16 visual stimuli deal with direcrion and spatial orientation and are related to abilities in reading and reading comprehension (Mangina 1981, 1994), A literature review suggests that no data investigating the nature of the relationship between intracerebral ERPs and specific performance tests are available. Thus, the purpose of this investigation was to delineate whether a relationship was present between intracerebral ERPs obtained from different limbic and cortical structures bilaterally and the Mangina Test performance with special emphasis on stimuli dealing on the one hand with size and dimension and on the other with direction and spatial orientation. The results tend to support the conclusion that (a) the “analytical-specific perceptual tasks” of the Mangina Test dealing with size and dimension pertain more to right hemispheric intracerebral functions, and (b) the “analytical-specific perceptual stimuli” dealing with direction and spatial orientation involve more left hemispheric intracerebral processes.
Intracerebral
ERPs during memory workload
J.H. Beuzeron-Mangina, Neurosurger) Department, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada Event-related brain potentials (ERPs) offer the possibility of investigating brain processes while an individual is engaged in processing information. Surface ERPs however. do not provide knowledge about specific brain structures that generate the late components of ERPs. Moreover, the use of several scalp electrodes in ERP studies pertaining to memory workload tasks with words as visual stimuli has never been conducted before. Therefore, the goals of this research were to devise an original Memory Workload Paradigm with visually presented words and to explore the following points: (1) To establish a baseline in normal subjects using this novel Memory Workload Paradigm through surface ERPs with the inclusion of several scalp electrodes. (2) With depth electrodes, stereotaxically implanted in
learning disabled children J. Bemal, A. Reyes, T. Harmony, M. Rodriguez, G.Yanez, T. Fernandez, L. Galan, E. Marosi, J. Silva, V. Guerrero, H. Rodriguez, National University of Mexico, Iztacala, Mexico P3OOs to visual and auditory stimuli in an oddball paradigm were recorded in 19 monopolar leads (lo/20 International System) in 14 normal and 14 learning-disabled children between 10.5 and 11.5 years old. The auditory stimuli were tones of 500 Hz and 3000 Hz, and the visual stimuli consisted of triangles and squares. The probability of presentation was 80% and 20%. Visual P3OOs had longer latenties (400-500 msec) and major amplitudes than the auditory P300 (300400 msec). The evoked responses had the same morphology in both modalities at Pz, P3, P4 and Cz and visual stimuli produced longer and larger P3OOs at T5, T6,Ol and 02. No significant differences in latency or amplitude between groups were observed using the permutation test either to visual or to auditory stimuli. These results are different from those reported by Holcomb et al. (1985) and by Taylor et al. (1990), who used verbal stimuli. The reason for the absence of differences between groups in our study might be due to the use of very simple and easy task requirements, which does not need extra cognitive resources from the learning-disabled children.
Intracerebral
ERPs
and
Mangina
Test
Journal of Psychophysiology 18 (1994) 87-159
95
performance J.H. Beuzeron-Mangina, CA. Mangina, Montreal Neurological Institute and Montreal Research And Treatment Centre for LAD, Montreal, Quebec, Canada The Mangina Test is a highly valid measure of varying degrees of “analytical-specific perception” as it relates to learning abilities and disabilities (Mangina 1981, 1994). “Analytical specific perception” is a more complicated process than simple sensory perception itself. In the Mangina Test, 16 of the 44 visual stimuli deal with “analytical-specific perceptual tasks” pertaining to size and dimension and are related to mathematical abilities (Mangina 1981, 1994). Another 16 visual stimuli deal with direcrion and spatial orientation and are related to abilities in reading and reading comprehension (Mangina 1981, 1994), A literature review suggests that no data investigating the nature of the relationship between intracerebral ERPs and specific performance tests are available. Thus, the purpose of this investigation was to delineate whether a relationship was present between intracerebral ERPs obtained from different limbic and cortical structures bilaterally and the Mangina Test performance with special emphasis on stimuli dealing on the one hand with size and dimension and on the other with direction and spatial orientation. The results tend to support the conclusion that (a) the “analytical-specific perceptual tasks” of the Mangina Test dealing with size and dimension pertain more to right hemispheric intracerebral functions, and (b) the “analytical-specific perceptual stimuli” dealing with direction and spatial orientation involve more left hemispheric intracerebral processes.
Intracerebral
ERPs during memory workload
J.H. Beuzeron-Mangina, Neurosurger) Department, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada Event-related brain potentials (ERPs) offer the possibility of investigating brain processes while an individual is engaged in processing information. Surface ERPs however. do not provide knowledge about specific brain structures that generate the late components of ERPs. Moreover, the use of several scalp electrodes in ERP studies pertaining to memory workload tasks with words as visual stimuli has never been conducted before. Therefore, the goals of this research were to devise an original Memory Workload Paradigm with visually presented words and to explore the following points: (1) To establish a baseline in normal subjects using this novel Memory Workload Paradigm through surface ERPs with the inclusion of several scalp electrodes. (2) With depth electrodes, stereotaxically implanted in