Selectivity for speed gradients in human area MT/V5.
Cortical area MT/V5 in the human occipito-temporal cortex is activated by visual motion. In this study, we use functional imaging to demonstrate that a subregion of MT/V5 is more strongly activated by unidirectional motion with speed gradients than by other motion patterns. Our results suggest that like the monkey homolog middle temporal area (MT), human MT/V5 contains neurons selective for the processing of speed gradients. Such neurons may constitute an intermediate stage of processing between neurons selective for the average speed of unidirectional motion and neurons selective for different combinations of speed gradient and different motion directions such as expanding optical flow patterns.
Martinez-Trujillo
Julio C
JC
Department of Physiology, McGill University, Montreal, Canada. julio.martinez@mcgill.ca
Tsotsos
John K
JK
Simine
Evgueni
E
Pomplun
Marc
M
Wildes
Richard
R
Treue
Stefan
S
Heinze
Hans-Jochen
HJ
Hopf
Jens-Max
JM
D000328:Adult; D001931:Brain Mapping; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D009039:Motion Perception / Q000502:physiology*; D009068:Movement / Q000502:physiology; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation / Q000379:methods; D014793:Visual Cortex / Q000098:blood supply / Q000502:physiology*; D014795:Visual Pathways / Q000098:blood supply / Q000502:physiology*
D010100:Oxygen