Temporal structure of the apparent motion perception: a magnetoencephalographic study.
Humans perceive motion when numerous small dots pattern is followed by one of the same pattern but with all the dots shifted a little in one direction. When the amount of shift exceeds a level humans no more perceive motion even though physical visual information does not change. Using this stimulus, we addressed to elucidate the temporal structure of the neural activity related to this apparent motion perception. The magnetic responses to the random-dot patterns with various amounts of shift were measured while the subjects were performing a direction discrimination task. A significant magnetic response amplitude change occurred with three distinct peaks when the response inducing apparent motion was compared with those inducing no motion without change in the response latencies. The major difference occurred at about 110, 140, 210 ms after the stimulus onset. The response origin was always within the occipitotemporal area. The results indicate that the neural activity for the perception of apparent motion can be measured by MEG that occur at least 110 ms after the stimulus onset possibly in the human MT+. Three distinct peaks in the response difference may represent the sequential multiple neural process proposed theoretically though further study is necessary to prove.
Kubota
Tetsuo
T
Department of Integrative Physiology, National Institute for Physiological Sciences, Myodaiji-cho, Okazaki 444-8585, Japan.
Kaneoke
Yoshiki
Y
Maruyama
Koichi
K
Watanabe
Kazuyoshi
K
Kakigi
Ryusuke
R
D000328:Adult; D001931:Brain Mapping; D004192:Discrimination, Psychological; D004574:Electromagnetic Fields; D005260:Female; D006801:Humans; D015225:Magnetoencephalography / Q000379:methods*; D008297:Male; D008959:Models, Neurological; D009039:Motion Perception / Q000502:physiology*; D010775:Photic Stimulation; D011930:Reaction Time; D013997:Time Factors