Distributed neural activity during object, spatial and integrated processing in humans.
Information about the form and the spatial location of objects is seamlessly integrated during visual perception. We used event-related potentials (ERPs) to explore neural activity related to processing form, location or the combination of both kinds of features. Healthy subjects performed three versions of a 'match-to-sample' task: a two-object task, a two-location task and an integrated object-location task. Responses were quickest and most accurate during the integrated task, slower and less accurate in the two-location task and slowest and least accurate in the two-object task. ERPs locked to the 'sample' stimulus at encoding, and to the 'target' stimulus during feature comparison differentiated between tasks. 'Sample' stimulus ERPs exhibited task-specific posterior cortical involvement in processing distinct visual features. 'Target' stimulus ERPs revealed task-related differences in features associated with frontal lobe mediated attentional processes: an early latency P300 showed increased amplitude during the integrated task. Results from this experiment support the view that distinct neural circuits mediate form vs. location processing and that form-location integration engages both pathways and upregulates frontal-parietal association networks.
Simon-Thomas
Emiliana R
ER
Department of Psychology & Helen Wills Neuroscience Institute, Tolman Hall, University of California, Berkeley, CA 94703, USA. emiliana@socrates.berkley.edu
Brodsky
Kim
K
Willing
Cammy
C
Sinha
Rashmi
R
Knight
Robert T
RT
D000328:Adult; D001921:Brain / Q000502:physiology*; D003071:Cognition / Q000502:physiology; D004569:Electroencephalography; D004585:Electrooculography; D018913:Event-Related Potentials, P300 / Q000502:physiology; D005260:Female; D005556:Form Perception / Q000502:physiology*; D006801:Humans; D008297:Male; D011597:Psychomotor Performance / Q000502:physiology; D013028:Space Perception / Q000502:physiology*