Reversal negativity and bistable stimuli: Attention, awareness, or something else?
Ambiguous (or bistable) figures are visual stimuli that have two mutually exclusive perceptual interpretations that spontaneously alternate with each other. Perceptual reversals, as compared with non-reversals, typically elicit a negative difference called reversal negativity (RN), peaking around 250 ms from stimulus onset. The cognitive interpretation of RN remains unclear: it may reflect either bottom-up processes, attentional processes that select between the alternative views of the stimulus, or it may reflect the change in the contents of subjective awareness. In the present study, event-related potentials in response to endogenous unilateral and bilateral reversals of two Necker lattices were compared with exogenously induced reversals of unambiguous lattices. The RN neither resembled the attention-related N2pc response, nor did it correlate with the content of subjective visual awareness. Thus, we conclude that RN is a non-attentional ERP correlate of the changes in the perceptual configuration of the presented object.
Intaite
Monika
M
Department of Biochemistry and Biophysics, Vilnius University, Lithuania. monika.intaite@gf.vu.lt
Koivisto
Mika
M
Ruksenas
Osvaldas
O
Revonsuo
Antti
A
D000328:Adult; D001288:Attention / Q000502:physiology*; D001364:Awareness / Q000502:physiology*; D002540:Cerebral Cortex / Q000502:physiology*; D004569:Electroencephalography; D005074:Evoked Potentials, Visual / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D009903:Optical Illusions / Q000502:physiology*; D010775:Photic Stimulation; D011930:Reaction Time / Q000502:physiology; D014796:Visual Perception / Q000502:physiology*