Neural fate of ignored stimuli: dissociable effects of perceptual and working memory load.
Observers commonly experience functional blindness to unattended visual events, and this problem has fuelled an intense debate concerning the fate of unattended visual information in neural processing. Here we used functional magnetic resonance imaging (fMRI) to demonstrate that the type of task that a human subject engages in determines the way in which ignored visual background stimuli are processed in parahippocampal cortex. Increasing the perceptual difficulty of a foveal target task attenuated processing of task-irrelevant background scenes, whereas increasing the number of objects held in working memory did not have this effect. These dissociable effects of perceptual and working memory load clarify how task-irrelevant, unattended stimuli are processed in category-selective areas in human ventral visual cortex.
Department of Psychology, Yale University, PO Box 208205, 2 Hillhouse Avenue, New Haven, Connecticut 06520, USA.
Do-Joon
DJ
Yi
Geoffrey F
GF
Woodman
David
D
Widders
René
R
Marois
Marvin M
MM
Chun
D000328:Adult; D001288:Attention / Q000502:physiology*; D001931:Brain Mapping; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D010100:Oxygen / Q000097:blood; D020534:Parahippocampal Gyrus / Q000098:blood supply / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D014793:Visual Cortex / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*
D010100:Oxygen