A higher order motion region in human inferior parietal lobule: evidence from fMRI.
The proposal that motion is processed by multiple mechanisms in the human brain has received little anatomical support so far. Here, we compared higher- and lower-level motion processing in the human brain using functional magnetic resonance imaging. We observed activation of an inferior parietal lobule (IPL) motion region by isoluminant red-green gratings when saliency of one color was increased and by long-range apparent motion at 7 Hz but not 2 Hz. This higher order motion region represents the entire visual field, while traditional motion regions predominantly process contralateral motion. Our results suggest that there are two motion-processing systems in the human brain: a contralateral lower-level luminance-based system, extending from hMT/V5+ into dorsal IPS and STS, and a bilateral higher-level saliency-based system in IPL.
Claeys
Kristl G
KG
Laboratorium voor Neuro- en Psychofysiologie, Katholieke Universiteit Leuven, Campus Gasthuisberg, Herestraat 49, B-3000 Leuven, Belgium.
Lindsey
Delwin T
DT
De Schutter
Erik
E
Orban
Guy A
GA
D000328:Adult; D000704:Analysis of Variance; D001288:Attention / Q000502:physiology*; D001931:Brain Mapping; D003116:Color; D003118:Color Perception / Q000502:physiology; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008165:Luminol / Q000031:analogs & derivatives*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009039:Motion Perception / Q000502:physiology*; D010296:Parietal Lobe / Q000033:anatomy & histology / Q000502:physiology*; D010775:Photic Stimulation; D011897:Random Allocation; D012684:Sensory Thresholds; D013028:Space Perception; D013997:Time Factors
C032487:isoluminol; D008165:Luminol