Fig. 1. Large scale electrode implants and behavioral tasks.

(A) Monkey C (left) and monkey M (right) were chronically implanted with eight and four 96-channel arrays, respectively. (B) The monkey is seated in front of a screen showing two virtual arms and uses either joystick movements or modulations in neural activity to control the avatar arms. (C) 441 sample waveforms from typical Monkey C recording sessions with the color of the waveform indicating the recording site (shown in A). (D) Left to right: Trial sequence began with both hands holding a center target for a random interval. Next, two peripheral targets appeared which had to be reached to and held with the respective hands to receive a juice reward. (E, F) Raster plot of spike events from 438 neurons (y-axis) over time (x-axis) for a single unimanual (E) and bimanual (F) trial. Target location and position traces of trial are indicated to the right of the raster panel.