Fig. 6 |. Evolution of the condition-invariant signal.
a, Top: Projections of population activity from all single-reach conditions onto one condition-invariant dimension (the second, which best captured the rapid rise). The colored region of each trace highlights peri-reach activity (from 150 ms before reach onset until 150 ms before reach end). Circles indicate the time of target onset (t), reach onset (r), and reach end (e). Bottom: State-space projections of the same activity onto two condition-invariant dimensions. Because the projection is similar for all conditions, the average is shown to simplify presentation. As above, trace color highlights peri-reach activity. Arrows indicate the temporal evolution of activity. b, Same as a but for delayed double-reaches. The two colored regions indicate peri-reach activity for the two reaches. c, Same as b but for compound reaches. d-f, Same as a-c but for monkey H.