title: [Changes in spontaneous slow potentials and visually (flash) evoked potentials in response to stimuli with no performance implication].
abstract: The influence of spontaneous slow potential shifts (SPSs) on visual (flash-)evoked potentials (VEPs) was studied. Eighteen subjects received 100 flashes. The sequence of interstimulus-intervals (ISIs) was pseudo-randomized. ISI-durations were 3, 5, 7, 9 or 11 seconds. EEG was recorded from Fz, Cz, Pz and Oz with linked-mastoids as reference. EEG was EOG-corrected and VEPs were calculated for preceding positive SPSs. Averaging was done for local SPSs; VEP pairings as well as VEPs were calculated over occipital SPS-polarities. Results showed an influence of SPSs on VEP-amplitudes. Differences in amplitudes were interpreted with the 'activation-correction'-hypothesis and with the 'ceiling'-hypothesis. Negative SPSs were followed by smaller negative peaks, and positive SPSs were followed by smaller positive peak-amplitudes. Differences in latencies of N145-P300 peak-to-peak amplitudes after SPSs of different polarity were explained with the threshold-regulation hypothesis. Spectral-analysis were done for SPS-data. There were only poor effects, showing increased parietal alpha 2-power after negative SPSs.
authors.affiliation: Psychologisches Institut I, Universität Hamburg.
authors.forename: G
authors.initials: G
authors.lastname: Sammer
mesh_terms: D000328:Adult; D001143:Arousal / Q000502:physiology*; D001288:Attention / Q000502:physiology*; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology*; D004569:Electroencephalography; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D010775:Photic Stimulation; D011930:Reaction Time / Q000502:physiology
vernacular_title: Spontane langsame Potentialänderungen (SPSs) und visuell (Blitz-)evozierte Potentiale auf Stimuli ohne Aufgabenbedeutung.