We assessed the canonical views for objects by allowing participants to actively rotate realistically shaded three-dimensional models in realtime. We investigated preferred or canonical views for familiar and novel three-dimensional objects using computer-graphics psychophysics.
In addition, the effect of speed on cortical and muscle activity was also found to be significantly different. Muscle activity was also found to be directionally tuned however, the distributions of preferred directions were found to be significantly different from cortical activity. Electromyographic activity from a number of upper arm muscles was recorded during this task. This equation, which has both independent (speed only) and interactive (speed and direction) com-ponents, described a large portion of the time-varying motor cortical activity during the task. A single equation relating motor cortical discharge rate to these two parameters was developed. In addition to the well-studied average directional selectivity (“preferred direction”) of single-cell activity, we also found the time-varying speed of movement to be represented in the cortical activity.
Single-cell activity patterns were recorded in the proximal arm area of motor cortex during the task. The motor cortical substrate associated with reach-ing was studied as monkeys moved their hands from a central position to one of eight targets spaced around a circle. Sentation of speed and direction during reaching.