Neural systems underlying learning and representation of global motion
- *Brain and Vision Research Laboratory, Department of Biomedical Engineering and Neurology, Boston University, 44 Cummington Street, Boston, MA 02215; †Massachusetts General Hospital NMR Center, Building 149, 13th Street, Charlestown, MA 02129; and §Sensor Systems Inc., Sterling, VA 20166
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Communicated by Charles G. Gross, Princeton University, Princeton, NJ (received for review June 24, 1998)
Abstract
We demonstrate performance-related changes in cortical and cerebellar activity. The largest learning-dependent changes were observed in the anterior lateral cerebellum, where the extent and intensity of activation correlated inversely with psychophysical performance. After learning had occurred (a few minutes), the cerebellar activation almost disappeared; however, it was restored when the subjects were presented with a novel, untrained direction of motion for which psychophysical performance also reverted to chance level. Similar reductions in the extent and intensity of brain activations in relation to learning occurred in the superior colliculus, anterior cingulate, and parts of the extrastriate cortex. The motion direction-sensitive middle temporal visual complex was a notable exception, where there was an expansion of the cortical territory activated by the trained stimulus. Together, these results indicate that the learning and representation of visual motion discrimination are mediated by different, but probably interacting, neuronal subsystems.
ABBREVIATIONS
- fMRI,
- functional magnetic resonance imaging;
- MT,
- middle temporal visual area;
- MST,
- medial superior temporal visual area;
- SC,
- superior colliculus
- Received June 24, 1998.
- Accepted August 14, 1998.
- Copyright © 1998, The National Academy of Sciences
