title: Selectivity for speed gradients in human area MT/V5.
abstract: 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.
authors.affiliation: Department of Physiology, McGill University, Montreal, Canada. julio.martinez@mcgill.ca
authors.forename: Julio C
authors.initials: JC
authors.lastname: Martinez-Trujillo
authors.forename: John K
authors.initials: JK
authors.lastname: Tsotsos
authors.forename: Evgueni
authors.initials: E
authors.lastname: Simine
authors.forename: Marc
authors.initials: M
authors.lastname: Pomplun
authors.forename: Richard
authors.initials: R
authors.lastname: Wildes
authors.forename: Stefan
authors.initials: S
authors.lastname: Treue
authors.forename: Hans-Jochen
authors.initials: HJ
authors.lastname: Heinze
authors.forename: Jens-Max
authors.initials: JM
authors.lastname: Hopf
mesh_terms: 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*
chemical_list: D010100:Oxygen