Neural substrates for visual perceptual grouping in humans.
Two experiments investigated the neural mechanisms of Gestalt grouping by recording high-density event-related brain potentials (ERPs) during discrimination tasks. In Experiment 1, stimulus arrays contained luminance-defined local elements that were either evenly spaced or grouped into columns or rows based on either proximity or similarity of shape. Proximity grouping was indexed by a short-latency positivity (110-120 ms) over the medial occipital cortex and a subsequent right occipitoparietal negativity. Grouping by similarity was reflected only in a long-latency occipitotemporal negativity. In Experiment 2, proximity grouping was examined when local elements were defined by motion cues, and was again associated with a medial occipital positivity. However, the subsequent long-latency negativity was now enhanced over the left posterior areas. The implications of these results to the neural substrates subserving different grouping processes are discussed.
Han
S
S
Department of Psychology, Peking University, Beijing, People's Republic of China. shan@pku.edu.cn
Song
Y
Y
Ding
Y
Y
Yund
E W
EW
Woods
D L
DL
D000328:Adult; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D009949:Orientation / Q000502:physiology; D010775:Photic Stimulation; D011930:Reaction Time / Q000502:physiology; D014796:Visual Perception / Q000502:physiology*