Figure 1. Behavioral task and location of ECoG electrodes used in decoding.

A) Monkeys performed right hand reaching, grasping, pulling, and releasing tasks in a 3D workspace. During the task, ECoG and hand positioning were recorded simultaneously. B) The planar-surface platinum electrode arrays were implanted on the gyrus between the central sulcus (CS) and the arcuate sulcus (AS) in the primary motor area in left hemisphere. The locations of all 15 and 32 electrodes in monkey A and monkey B are shown with defined channel numbers. Locations of 3, 6, 9, 12, and 15 or 16 electrode groups used in decoding are denoted with green solid, purple dotted, blue dotted, brown dotted, and blue solid lines, respectively. The column nearest the CS was column #1 in the rostral-caudal direction, and the row in the medial-lateral direction was row *1. Note that electrodes inside the blue line were used in both column and row decoding.