Contents

02 April 1993
Vol 260, Issue 5104

About The Cover

Neural network model of the primate motor cortex, with cells coding different directions of movement (purple balls with directional blue cones). Interactions between cells vary, ranging from strong excitatory (red, similar directions) to strong inhibitory (green, opposite directions), depending on the similarity of the preferred directions in a cell pair. See page 47. [Computer graphics, Masato Taira and Apostolos Georgopoulos. Production: Eugene Eubank, Medical Media Service, Minneapolis Veterans Affairs Medical Center]