Movement-Related Cortical Potentials: Their Relationship to the Laterality, Complexity and Learning of a Movement

Abstract

Movement-related cortical potentials (MRCPs) to self-paced unilateral movements of different laterality, complexity and practice level were recorded from 14 healthy subjects using the EMG onset as the trigger. The amplitudes at certain time points and slopes of linear regression lines fitted to 3 main shifts have been evaluated. In the early phase of MRCP the potential and slope values were symmetrically distributed around the midline maximum, which indicates that this part of MRCP can not originate from the primary motor area, which is in a contralateral relation with the movement, but from secondary motor areas (SMA and premotor areas). The changes in the voltage levels and slopes of this phase due to the changes in laterality, complexity and practice level of the movement show the relation of this activity with the abstract characteristics of the movement. The decrease of voltages and slope values in the later phases of MRCP in the complex task, which is replaced by higher voltages and slopes after a certain learning period was evaluated as a result of inhibition of associative movements via reafferent feedback signals occurring often in the first stages of learning period.

Aberrant brain activation following motor skill learning in schizophrenic patients as shown by functional magnetic resonance imaging

“…The abnormality may have resulted from neuroleptic treatment ; dopamine antagonists such as neuroleptics reportedly depress MRP amplitude in healthy subjects (Dick et al 1987). Demiralp et al (1990) suggested that in the early phase, MRP originate from secondary motor areas (PMA and SMA). While medication effects need be considered, these observations suggest that schizophrenic patients may manifest impairment of functional neural networks including the SMA and PMA when they perform voluntary motor movements.…”

Ambiguity in Mind and Nature

“…It has been shown that motor potentials, especially Bereitschaftspotentials (readiness potential), not only depend on physical factors of movement, but also on psychological aspects of movement such as attention, motivation, and intentional movement (Deecke et al, 1969, Freude & Ullsperger, 1987 and are due to the complexity of the movement pattern (Demiralp et al, 1990). It has been shown that motor potentials, especially Bereitschaftspotentials (readiness potential), not only depend on physical factors of movement, but also on psychological aspects of movement such as attention, motivation, and intentional movement (Deecke et al, 1969, Freude & Ullsperger, 1987 and are due to the complexity of the movement pattern (Demiralp et al, 1990).…”