(A) RT motion discrimination task. Upon fixation and onset of the choice
targets, a random-dot-motion stimulus appeared in the center of the display. Two
monkeys discriminated the direction of motion and, when ready, indicated their
choice with a saccade to one of two choice targets.
(B) Behavioral data pooled across all sessions and both monkeys (19,749
trials). RT (top) and the proportion of rightward choices (bottom) are plotted
as a function of motion strength. Positive and negative motion strengths
indicate rightward and leftward motion, respectively. Solid curves depict fits
of a bounded evidence-accumulation model.
(C) Simultaneous recordings in SC and LIP. Populations of neurons were
recorded in SC with a multi-channel V-probe and in LIP with a prototype
macaque-Neuropixels probe.
(D) The RF of an example LIP neuron. The color map depicts the mean
firing rate, interpolated across target locations (white circles), during the
delay epoch of a visually guided saccade task. Red circles depict the location
of the choice targets in the RDM task in this session.
(E) The RF of an example neuron in SC, recorded simultaneously as the
example LIP neuron in (D).