Adaptation dynamics in pattern-reversal visual evoked potentials.
Recording a VEP usually involves prolonged repetitions of the stimulus, but the influence of adaptation is rarely discussed in this context. Two experiments were performed. In Experiment 1 the time course of the response amplitude during steady-state stimulation was assessed. During the first seconds of stimulation we found an increase in amplitude, followed by a continuous exponential decline. This confirmed earlier results. There is considerable inter-subject variability concerning all aspects of the time course in our 19 subjects. Experiment 2 used two types of transient pattern reversal stimuli: one regular stimulus as used in standard clinical applications and one with a pause in between each reversal. N1 and P1 amplitudes did not show significant differential effects. N2 amplitude was reduced by 73% in the standard condition whereas P1 peak time increased slightly but significantly (3.2 ms).
Heinrich
S P
SP
Elektrophysiologisches Labor, Univ.-Augenklinik Freiburg, Germany.
Bach
M
M
D000221:Adaptation, Ocular / Q000502:physiology*; D000328:Adult; D002540:Cerebral Cortex / Q000502:physiology; D005074:Evoked Potentials, Visual / Q000502:physiology*; D006801:Humans; D014795:Visual Pathways / Q000502:physiology