Fig. 1. Modification of neural firing properties during brain control.

a. For each daily session, subjects were required to serially perform a delayed center-out task in manual control (MC₁), brain control and then manual control (MC₂). In the brain control task shown, visual guides (i.e. lines shown in red) enforced straight trajectories. Trials were started by the animal physically moving to the center target. After a hold period, brain control (i.e. absence of any movements) was initiated. b. Changes in the preferred direction of a direct neuron. Solid lines are the cosine fit (R² is the percent of variance accounted for by the fit). Circles and bars (s.e.m.) show the directional modulation of the firing rate. Panels on the right show the waveform, crosscorrelograms (0.1% of spikes in a window < 1.5 ms) and the mean trajectories during manual control and brain control. Statistics performed with boostrap analysis. c. Changes in the preferred direction of indirect neurons. The directional modulation relationships are arranged similarly to b. Insets show waveforms of the respective indirect neurons.