Figure 2.

Three example neurons with different tuning onsets. For each neuron, precision grip trials are shown on the left panel and power grips on the right panel. Different colors indicate various handle orientations, for which spike rasters (on top) and averaged firing rates (at bottom) are shown individually. The dotted line within the movement epoch indicates the release of the hand rest button (movement start). All trials are aligned to both the end of the cue epoch and the start of the movement (arrow heads below); gaps in the curves (at ∼0.6 s) indicate the realignment. A, Neuron that exhibits tuning for the handle orientation and the instructed grip type starting in the cue period and extending until movement execution. B, Neuron with tuning for the handle orientation starting in cue, but with significant grip type modulation only during movement execution. C, Neuron showing no response during cue presentation and movement planning, but with a strong selectivity for precision grips during movement execution without significant orientation tuning. D, Population firing rate across all 571 neurons for each combination of the cells' preferred and nonpreferred grip type and orientation.