title: Discontinuous presentation of ambiguous figures: how interstimulus-interval durations affect reversal dynamics and ERPs.
abstract: If we observe an ambiguous figure, our percept is unstable and alternates between the possible interpretations. Periodically interrupting the presentation sizably modulates the spontaneous reversal rate. We here studied event-related potential (ERP) correlates of the neural processes underlying these strong modulations. An ambiguous Necker stimulus was presented discontinuously with four randomly varying interstimulus intervals (ISI; 14, 43, 130, 390 ms) while participants indicated perceptual reversals. EEG was selectively averaged with respect to the participants' percept and ISI. ERP traces varied markedly between ISIs. A simple model explained a major part of this variation and showed that the ISI-dependent ERP modulation occurs after disambiguation has already taken place. We suggest that perceptual stability (or reversal) depends on a system state, slowly changing from one reversal to the next. ISI can shift this state on a scale between stability and instability.
authors: Sektion Funktionelle Sehforschung, Universität-Augenklinik Freiburg, Freiburg, Germany. juergen.kornmeier@uni-freiburg.de
authors: Jürgen
authors: J
authors: Kornmeier
authors: Werner
authors: W
authors: Ehm
authors: Heiko
authors: H
authors: Bigalke
authors: Michael
authors: M
authors: Bach
mesh_terms: D000328:Adult; D000465:Algorithms; D003627:Data Interpretation, Statistical; D004569:Electroencephalography; D004594:Electrophysiology; D005074:Evoked Potentials, Visual / Q000502:physiology*; D006801:Humans; D010775:Photic Stimulation; D011930:Reaction Time / Q000502:physiology; D014796:Visual Perception / Q000502:physiology*