Orientierung Von Visueller Raumlicher Aufmerksamkeit Nach Visuellen Und Akustischen Hinweisreizen: Eine Studie Mit Ereigniskorrelierten Hirnpotentialen

A number of recent investigations emphasized the sensitivity of event-related potentials (ERP) in visuospatial selective attention tasks. If a spatial location is cued by a central (symbolic) stimulus such as a left or right-pointing arrow an amplitude enhancement for the P1, N1 and N2 components of the ERP to target stimuli appearing on the cued side relative to target stimuli appearing on the uncued side has been described. In the current study peripheral cues were used with a long (1000 ms) cue target interval. Three questions were addressed: 1. How do the effects using peripheral cues compare to those described for central cues? 2. Can similar cue-validity effects be observed for auditory and visual cues? 3. Can electrophysiological correlates of attentional orienting be revealed by examining the ERPs in the cue-target interval? In the condition with visual cues in addition to a marked reaction time effect an enhancement of the posterior N1 and N2 was observed for the validly cued targets. No effect for the P1 component was found. This pattern suggests similarities of attentional orienting after central and peripheral cues. In contrast, the auditory cues did not produce any behavioral effects, while a frontal ERP-effect (N2-modulation) was found as a function of cue-validity. The psychological significance of this effect remains unclear. In the cue-target interval no differential effects of cue-location were seen in the auditory condition. In the visual condition a pronounced negativity with an onset of about 500 ms was seen contralaterally to the cue at the parietal locations. This effect is discussed in light of the proposed role of the parietal lobes for attentional orienting.