Der Beitrag von Beta- und Gamma-Oszillationen zur Wahrnehmungsorganisation unter Berücksichtigung der Bottom-up - Top-down-Dichotomie : Studien zu multistabiler visueller Wahrnehmung und auditiver Daueraufmerksamkeit bei Gesunden und schizophren Erkrankten

In the last decade many research reports have provided evidences, that high-frequency oscillatory (HFO) brain activity is inevitably involved in the organization of human perception. Especially the contribution of beta- and gamma-oscillations, has been discussed extensively. Thereto researchers often use the bottom-up and top-down-processing dichotomy to characterize electrophysiological activities. Hence this work investigates HFO electrophysiological correlates of multistable perception in an ambiguous visual motion pattern, the stroboscopic alternative motion, in healthy subjects. In a second study correlates of an auditory sustained attention paradigm were investigated in schizophrenics and healthy controls. The results bear several new aspects of the contribution of HFO, especially in the beta-activity range, to the investigated phenomena and underpin the need for new causal experimental approaches to confirm the functional role of these oscillations. The bottom-up top-down-dichotomy did not prove to be helpful as a nomenclature to characterize the underlying oscillatory processes.