Fig. 3.

Speed tuning curves of 9 example neurons from area MT. In all conditions the dot patterns (in both preferred and antipreferred directions) were moving at the speed indicated on the x-axis. A–I: 9 cells that span the range of effects we found. Error bars on the data points indicate SE. The solid curves represent the best fit; the colored areas around the curves represent the family of tuning curves consistent with the data (see materials and methods). Consistent with previous reports (Snowden et al. 1991), many cells responded less to bidirectional motion than to unidirectional motion. This suppression, however, was not constant across speeds, and most cells also showed enhanced responses to bidirectional motion of certain speeds.