A common parieto-frontal network is recruited under both low visibility and high perceptual interference conditions.
A fundamental property of visual attention is to select targets from interfering distractors. However, attention can also facilitate the detectability of near-threshold items presented in isolation. The extent to which these two perceptually challenging conditions are resolved by the same neural mechanisms is not well known. In the present event-related fMRI experiment, subjects performed a letter identification task under two perceptually challenging conditions; when the luminance contrast of a target letter was reduced (perceptual visibility manipulation) and when the target letter was flanked by distractors (perceptual interference manipulation). Perceptual interference recruited the right parietal and mid-lateral frontal cortex, while perceptual visibility activated these regions bilaterally. The overlap of activated areas between the two perceptual manipulations suggests that a single parieto-frontal network is summoned under both perceptual visibility and interference conditions.
Marois
René
R
Department of Psychology, Vanderbilt Vision Research Center, Vanderbilt University, 111 21st Ave., Nashville, TN 37203, USA. rene.marois@vanderbilt.edu
Chun
Marvin M
MM
Gore
John C
JC
D001288:Attention / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods*; D006801:Humans; D008279:Magnetic Resonance Imaging; D009415:Nerve Net / Q000502:physiology; D010296:Parietal Lobe / Q000502:physiology; D010465:Perception; D014795:Visual Pathways / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*