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Ambiguous figures and binding: EEG frequency modulations during multistable perception
Author(s) -
Ehm Werner,
Bach Michael,
Kornmeier Jürgen
Publication year - 2011
Publication title -
psychophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.661
H-Index - 156
eISSN - 1469-8986
pISSN - 0048-5772
DOI - 10.1111/j.1469-8986.2010.01087.x
Subject(s) - stimulus (psychology) , psychology , perception , electroencephalography , neuroscience , modulation (music) , cognitive psychology , audiology , communication , physics , acoustics , medicine
Ambiguous figures induce sudden transitions between rivaling percepts. We investigated electroencephalogram frequency modulations of accompanying change‐related de‐ and rebinding processes. Presenting the stimuli discontinously, we synchronized perceptual reversals with stimulus onset, which served as a time reference for averaging. The resultant gain in temporal resolution revealed a sequence of time–frequency correlates of the reversal process. Most conspicuous was a transient right‐hemispheric gamma modulation preceding endogenous reversals by at least 200 ms. No such modulation occurred with exogenously induced reversals of unambiguous stimulus variants. Post‐onset components were delayed for ambiguous compared to unambiguous stimuli. The time course of oscillatory activity differed in several respects from predictions based on binding‐related hypotheses. The gamma modulation preceding endogenous reversals may indicate an unstable brain state, ready to switch.