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Selectivity for speed gradients in human area MT/V5

Martinez-Trujillo, Julio C.1 CA; Tsotsos, John K.2 3; Simine, Evgueni2 3; Pomplun, Marc4; Wildes, Richard2 3; Treue, Stefan5; Heinze, Hans-Jochen6; Hopf, Jens-Max6


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.

1Department of Physiology, McGill University, Montreal, Canada

2Centre for Vision Research, York University, Toronto, Ontario, Canada

3Department of Computer Science York University, Toronto, Ontario, Canada

4Department of Computer Science, University of Massachusetts, Boston, Massachusetts, USA

5Cognitive Neuroscience Laboratory, German Primate Center, Goettingen, Germany

6Department of Neurology II, Otto-von-Guericke University, Magdeburg, Germany

CACorresponding Author:

Received 23 November 2004; accepted 18 January 2005

© 2005 Lippincott Williams & Wilkins, Inc.