Multistable visual perception refers to phenomena, in which one invariant stimulus pattern is perceived in at least two different, mutually exclusive ways. In this EEG study we differentiate between perceptual- and motor-related processes during perceptual reversals. Delta- and alpha-band activity was analyzed while participants answered to a perceptual reversal either immediately or with a delay of approximately 1500 ms, thereby separating reversal-related and motor-related activity. On the single sweep level a reversal-related positive delta response and reversal-related desynchronisation of alpha activity could be detected irrespective of the motor response. Both conditions elicited the strongest reversal-related modulations at posterior locations. Contrary, motor-related responses were found predominantly at central locations. These findings were supported by a control experiment, using a slightly modified stimulus that allowed unambiguous perceptual changes to be triggered exogenously. In conclusion, this study demonstrates that the brain response to perceptual reversals differs from motor-related processes elicited by the button press indicating the perceptual reversal. The results of this study, therefore, indicate that perceptual- and motor-related processes are achieved in multiple selectively distributed and parallel working oscillatory networks of the brain.
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