Fig. 2.

Hand movements induced by long-duration photostimulation. (A) Examples of hand (red), elbow (green), and shoulder (cyan) positions of marmosets (Top) E and (Bottom) F at 0 and 500 ms from photostimulation onset. Squares indicate the original positions, and circles indicate the positions at the time points indicated at the bottom of the images. (B) (Left) Trajectories of the hand, elbow, and shoulder positions across −300 ms to +500 ms from stimulation onset in marmoset E (n = 10 trials; colors as in A). (Right) Superimposed hand trajectories induced by 50-ms (gray, n = 17 trials) and 500-ms photostimulation (red, n = 12 trials) aligned to the original positions. (C) The same plots as in B, but from marmoset F (Left, n = 10; Right, n = 20 and 12 for 50- and 500-ms stimulation, respectively). (D) Distribution of the direction of the hand (red) and elbow (green) movements in B. (E) The same plots as in D, but for marmoset F. (F) Displacement of the hand positions induced by the photostimulation with different stimulation strengths at 100- and 10-Hz frequencies. The session was the same across A–F for each marmoset; the sessions for the 50-ms stimulation experiments were the same sessions as in Fig. 1.