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Movement related macropotentials in normal and learning disabled children
D. Papakostopouios,
ed. / Psychophysiology
Society Abstracts,
299
1982
when subjects had to wait for the outcome of this prediction without preparing for a motor response, reflexes were not increased. Background EMG of both triceps surae muscles showed no departure from baseline either. In condition II, a choice reaction time task was introduced. Another twenty subjects participated in this condition. The response was a plantar flexion of either the left or the right foot. In this condition reflexes evoked in both legs were increased, but to an equal extent. Background EMG was flat during the foreperiod and showed somewhat larger values in the left leg. it was concluded that anticipation of a significant stimulus is not sufficient for a reflex increase to occur. In addition, our data showed that the reflex increase observed during preparation for a voluntary movement cannot simply be accounted for by changes in background EMG of the agonist muscle.
Reference Brunia, C.H.M., Scheirs, J.G.M. and Haagh, S.A.V.M. (1982). Changes of Achilles tendon amplitudes during a fixed foreperiod of four seconds. Psychophysiology, 19, 63-70.
MOVEMENT RELATED MACROPOTENTIALS LEARNING DISABLED CHILDREN G.A. CHIARENZA, ALDE Istituto di Neuropsichiatria,
A. GUARESCHI-CAZZULLO Infantile
reflex
IN NORMAL AND
and
G. GIAMMARI
Universita di Milano, Italy
D. PAPAKOSTOPOULOS Burden Neurological Institute,
Bristal, U.K.
G. GIORDANA Istituto di Meccanica Polite&co
di Milano, Italy
Relationship between learning disabilities and motor organization have been suggested in terms of theoretical and empirical grounds. The motor impairments in children with learning disabilities have been related with a disturbance in time organization in the performance of motor skills. Recently a model of the processes involved in the organization of the serial order of self-paced movements in man has been proposed by Papakostopoulos
300
D. Papakostopoulos,
ed. / Psychophysrology
Society Abstracts,
I982
(1978, 1980), on the the basis of brain electrical activities associated with these movements. In the present study the Movement Related Brain Macropotentials of 15 children with learning disabilities were compared with those of 15 normal children of the same age and sex. The recordings were obtained from Fp,, C,, right and left precentral. The rectified electromyograms of both arms and performance were also recorded. An HP 2000A computer was used for the analysis of the data. The P200 were not different in two groups. The amplitude of the BP and MCP was significantly smaller in the group of children with learning disabilities. The latency of the SPP was significantly longer in the children with learning disabilities The results indicate that the MRBM studies can discriminate between normal and LD children; they point out an impairment of the preparatory processes, the movements related reafferent activity and the cognitive processes involved in knowledge of results. It could be hypothesized that a combination of inappropriate timing, reduced inhibition of irrelevant activities and diminished utilization of knowledge of results are some of the underlying factors in learning disabilities. References Papakostopoulos, Papakostopoulos,
D. (1978). Journal of Physiology, 70-71. D. (1980). EEG Clinical Neurophysiology,
48, 622-638
A CHRONOMETRIC ANALYSIS OF THE LATE POSITIVE COMPONENT (P3b) Joseph
SERGEANT,
Laboratory for Netherlandr
Experimental
Fridtjof Clinical
MEERLO Psychology,
and Libbe KOOISTRA State
University
Cronmgen,
Groningen,
The
Recent models of divided attention suggest that capacity limitations are due to latency restrictions of controlled processes; search and decision. Recent ERP studies have shown that the late positive component (P3b) becomes delayed in latency as cognitive load increases. According to the additive factor method, the relatively automatic process encoding should remain independent of search and decision. In determining the functional significance of the P3b it would be of interest to know whether the latency of this component is
ed. / Psychophysiology
Society Abstracts,
299
1982
when subjects had to wait for the outcome of this prediction without preparing for a motor response, reflexes were not increased. Background EMG of both triceps surae muscles showed no departure from baseline either. In condition II, a choice reaction time task was introduced. Another twenty subjects participated in this condition. The response was a plantar flexion of either the left or the right foot. In this condition reflexes evoked in both legs were increased, but to an equal extent. Background EMG was flat during the foreperiod and showed somewhat larger values in the left leg. it was concluded that anticipation of a significant stimulus is not sufficient for a reflex increase to occur. In addition, our data showed that the reflex increase observed during preparation for a voluntary movement cannot simply be accounted for by changes in background EMG of the agonist muscle.
Reference Brunia, C.H.M., Scheirs, J.G.M. and Haagh, S.A.V.M. (1982). Changes of Achilles tendon amplitudes during a fixed foreperiod of four seconds. Psychophysiology, 19, 63-70.
MOVEMENT RELATED MACROPOTENTIALS LEARNING DISABLED CHILDREN G.A. CHIARENZA, ALDE Istituto di Neuropsichiatria,
A. GUARESCHI-CAZZULLO Infantile
reflex
IN NORMAL AND
and
G. GIAMMARI
Universita di Milano, Italy
D. PAPAKOSTOPOULOS Burden Neurological Institute,
Bristal, U.K.
G. GIORDANA Istituto di Meccanica Polite&co
di Milano, Italy
Relationship between learning disabilities and motor organization have been suggested in terms of theoretical and empirical grounds. The motor impairments in children with learning disabilities have been related with a disturbance in time organization in the performance of motor skills. Recently a model of the processes involved in the organization of the serial order of self-paced movements in man has been proposed by Papakostopoulos
300
D. Papakostopoulos,
ed. / Psychophysrology
Society Abstracts,
I982
(1978, 1980), on the the basis of brain electrical activities associated with these movements. In the present study the Movement Related Brain Macropotentials of 15 children with learning disabilities were compared with those of 15 normal children of the same age and sex. The recordings were obtained from Fp,, C,, right and left precentral. The rectified electromyograms of both arms and performance were also recorded. An HP 2000A computer was used for the analysis of the data. The P200 were not different in two groups. The amplitude of the BP and MCP was significantly smaller in the group of children with learning disabilities. The latency of the SPP was significantly longer in the children with learning disabilities The results indicate that the MRBM studies can discriminate between normal and LD children; they point out an impairment of the preparatory processes, the movements related reafferent activity and the cognitive processes involved in knowledge of results. It could be hypothesized that a combination of inappropriate timing, reduced inhibition of irrelevant activities and diminished utilization of knowledge of results are some of the underlying factors in learning disabilities. References Papakostopoulos, Papakostopoulos,
D. (1978). Journal of Physiology, 70-71. D. (1980). EEG Clinical Neurophysiology,
48, 622-638
A CHRONOMETRIC ANALYSIS OF THE LATE POSITIVE COMPONENT (P3b) Joseph
SERGEANT,
Laboratory for Netherlandr
Experimental
Fridtjof Clinical
MEERLO Psychology,
and Libbe KOOISTRA State
University
Cronmgen,
Groningen,
The
Recent models of divided attention suggest that capacity limitations are due to latency restrictions of controlled processes; search and decision. Recent ERP studies have shown that the late positive component (P3b) becomes delayed in latency as cognitive load increases. According to the additive factor method, the relatively automatic process encoding should remain independent of search and decision. In determining the functional significance of the P3b it would be of interest to know whether the latency of this component is