Fig. 7.

Directional tuning profile across multiple sessions, 2 neurons from each monkey. The mean firing rate for each target is displayed in the direction of that target. There are 26 targets in 3D space; here we see x–y and z–y slices. Firing rate profiles from each single neuron are rendered simultaneously for all sessions where that cell was recorded. Arrows indicate preferred directions (PDs) from model fit. Scale bars indicate number of spikes per reach. The neurons shown are the first 2 neurons from each monkey that were recorded for at least 14 days with a mean preferred direction measurement error of <5°. Low measurement error does not necessarily limit the amount of variation in PD across sessions.