Figure 5. Directional selectivity around choice execution.

a) Normalized PETHs for contraversive (leftward) and ipsiversive (rightward) movements for four cell classes. To be included, a cell had to have a peak firing rate of at least 5 Hz within 1 s of movement onset (toward either direction). For each cell class, the top plot shows normalized PETHs for individual neurons (rank ordered by the time of peak firing) and the bottom plots show population PETH. Grey lines indicate the 5th and 95th centile of confidence intervals; portions of the mean line that extend outside of this interval for at least two consecutive bins are indicated by increased thickness. Shaded area = S.E.M. b) Time epochs of significant directional selectivity. For each cell class, the top plots indicate epochs for which each neuron fired at a significantly higher rate on trials with contraversive (gold) or ipsiversive (green) movements (p<0.01, based on t-stat of regression b_d; see Methods); bottom plots indicate the instantaneous percentage of cells showing significantly higher firing rates for each movement direction (time bin = 5ms with 3-point smoothing). c) Selectivity index values for different cell classes. Vertical line indicates mean. d) Scatter plot of directional selectivity vs spatial (i.e. which of the three central holes) selectivity. Filled circles indicate that either the peak directional or spatial selectivity was significant (p<0.01).