Each task varied in how the monkeys were instructed to respond to perturbations applied to the limb: correct for the disturbance in the Posture Task (A), not required to respond in the Movie Task (B), move to a spatial target in the IN/OUT Task (C). (D) Perturbation response, in the cell’s preferred torque direction, in the Posture Task of a neuron in A5 and in M1. Tick marks denote action potentials, each row representing a separate trial. (E) Population responses in each cortical area (Mean2SEM). Arrows depict when population signal surpassed threshold (baseline + 3SD) for >20 ms. Pre-perturbation baseline activity (-100:0 ms pre-perturbation, horizontal insets) in each area is stated below each corresponding population response. Scale bars denote 20 sp/s. Population activity between 60–250 ms (denoted by thick horizontal line) is compressed for visualization purposes. The 'American Pie' picture is reproduced with permission from Universal Studios.
© 1999, Universal Pictures, All Rights Reserved. Figure 1 part B photo (from the film American Pie) is reproduced with permission from Universal Studios.