The functional significance of some movement related potential (MRP) components was examined by using an adaptation of the "oddball" paradigm. Subjects had to move a load, that randomly varied from trial to trial according to different schedules, by pressing a telegraph key. Four paradigms of load presentation were used: (1) three loads equally probable; (2) two loads, the lighter one presented in 20% of the trials; (3) the same to the previous paradigm but the heavier load presented in 20% of the trials; (4) three loads equally probable and presented in a fixed sequence. N1 amplitude behaved as a direct function of the magnitude of the Expected Load (the most frequent load) and modulation of P2 amplitude seems to arise from the discrepancy between Expected and Perceived Load. We postulate that N1 could be a by-product of the parameter specification for a "motor-program" and that P2 could reflect the checking and adjustment of such a program when the motor parameters do not agree with the task requirements.
|Journal||Revista CENIC Ciencias Biológicas|
|Publication status||Published - 2002|