en
Scientific article
English

Right parietal brain activity precedes perceptual alternation of bistable stimuli

Published inCerebral cortex, vol. 19, no. 1, p. 55-65
Publication date2009
Abstract

Momentary fluctuations of baseline activity have been shown to influence responses to sensory stimulation both behaviorally and neurophysiologically. This suggests that perceptual awareness does not solely arise from physical stimulus properties. Here we studied whether the momentary state of the brain immediately before stimulus presentation indicates how a physically unique but perceptually ambiguous stimulus will be perceived. A complex Necker cube was intermittently presented and subjects indicated whether their perception changed with respect to the preceding presentation. EEG was recorded from 256 channels. The prestimulus brain-state was defined as the spatial configuration of the scalp potential map within the 50 ms before stimulus arrival, representing the sum of all momentary ongoing brain processes. Two maps were found that doubly dissociated perceptual reversals from perceptual stability. For EEG sweeps classified as either map, distributed inverse solutions were computed and statistically compared. This yielded activity confined to a region in right inferior parietal cortex that was significantly more active before a perceptual reversal. In contrast, no significant topographic differences of the evoked potentials elicited by stable vs. reversed Necker cubes were found. This indicates that prestimulus activity in right inferior parietal cortex is associated with the perceptual change.

Keywords
  • Adult
  • Attention/physiology
  • Electroencephalography/methods
  • Evoked Potentials, Visual/physiology
  • Female
  • Functional Laterality/physiology
  • Humans
  • Male
  • Memory/physiology
  • Parietal Lobe/physiology
  • Photic Stimulation/methods
Citation (ISO format)
BRITZ, Juliane, LANDIS, Theodor, MICHEL, Christoph. Right parietal brain activity precedes perceptual alternation of bistable stimuli. In: Cerebral cortex, 2009, vol. 19, n° 1, p. 55–65. doi: 10.1093/cercor/bhn056
Main files (1)
Article (Accepted version)
accessLevelRestricted
Secondary files (1)
Identifiers
ISSN of the journal1047-3211
601views
136downloads

Technical informations

Creation10/21/2009 5:37:00 PM
First validation10/21/2009 5:37:00 PM
Update time03/14/2023 3:16:40 PM
Status update03/14/2023 3:16:40 PM
Last indexation01/15/2024 7:08:30 PM
All rights reserved by Archive ouverte UNIGE and the University of GenevaunigeBlack