Within-session reproducibility of motion-onset VEPs: effect of adaptation/habituation or fatigue on N2 peak amplitude and latency.
We explored the effect of repeated visual stimulation on motion-onset visual evoked potentials (M-VEPs) during 25 min recording sessions in 10 subjects. The aim of the experiment was to determine influence of global motion adaptation (without motion-aftereffect) on intra-individual variability of M-VEPs and to suggest an optimal recording design for clinical examination. In addition to well described middle-time sensory adaptation, we also observed a long-time effect on motion specific N2 peak (155 ms). The N2 peak exhibited a strong relationship between its latency and inter-peak amplitude to the duration of recording in occipito-parietal derivations. In addition to the middle-term adaptation, N2 peak latency was prolonged by 10 ms and amplitude was attenuated by 30% with respect to the start of the experiment. An exponential model was employed to describe the dependency. The model can be used to reduce intra-individual variability during examination. Observed resemblance between the measured electrophysiological values and already published metabolic changes (glucose and oxygen utilization) during brain processing of visual information is discussed.
Kremlácek
Jan
J
Department of Pathophysiology, Faculty of Medicine in Hradec Králové, Charles University in Prague, Simkova 870, Hradec Kralove, 500 38, Czech Republic. jan.kremlacek@lfhk.cuni.cz
Kuba
Miroslav
M
Kubová
Zuzana
Z
Langrová
Jana
J
Vít
Frantisek
F
Szanyi
Jana
J
D000222:Adaptation, Physiological; D000328:Adult; D003627:Data Interpretation, Statistical; D005074:Evoked Potentials, Visual; D005221:Fatigue / Q000503:physiopathology*; D005260:Female; D006185:Habituation, Psychophysiologic / Q000502:physiology*; D006801:Humans; D016018:Least-Squares Analysis; D008297:Male; D008875:Middle Aged; D009039:Motion Perception / Q000502:physiology*; D010775:Photic Stimulation; D011930:Reaction Time; D015203:Reproducibility of Results