Fig. 6

Prevalence and dynamics of gaze shift-related activity in the cortico-basal ganglia network. a Model of gaze-related modulation in single neurons. Top: parameters fitting the effect of gaze on neural activity as multiplicative scaling (left), additive increase or decrease in firing rate (middle), or both (right). Bottom: parameters fitting the time course of gaze-modulation by setting the temporal offset between neural modulation and gaze shifts (left, neurons first vs. gaze first) and the rate that modulation builds up over time (right, gradual vs. rapid). b Model fits for each neuron evaluated by difference in log likelihood when fitting the real data vs. shuffled data. 31% of neurons were significantly modulated in relation to gaze (dark histogram, p < 0.05, permutation test); remaining neurons were not (light histogram). c Percentage of significantly gaze-related neurons (ACC n = 69/221, icbDS n = 37/127, Pal n = 43/129). Error bars are ± 1 SE. *** indicates p < 0.001 (binomial test). d Fitted gaze-related response gains in each neuron in log₂ units (0 = no gain change; −1 = halved response; + 1 = doubled response). n = 2 outliers fitted with complete cessation of activity during gaze are plotted at −6. More neurons had gain increases than decreases, especially in gaze-related neurons (dark histogram, 127 increases vs. 22 decreases). e Fitted relationship between gaze state and firing rate in gaze-related neurons (black) and nonsignificant neurons (gray) resembles increased response gain rather than an additive offset. Lines are medians, shaded areas are bootstrap 95% confidence intervals. f Mean fitted time course of gaze-modulation around gaze shifts for neurons in each area with significant gaze-modulation (ACC, magenta; icbDS, green; Pal, blue). Asterisks indicate significance. The latency of gaze-modulation, defined at the time of 10% of maximal modulation, is significantly earlier in ACC than icbDS and Pal (gaze-modulated neurons, p = 0.001 and 0.003; all neurons, p = 0.001 and 0.003; permutation tests). Inset: cumulative distribution of gaze-modulation latencies for individual gaze-modulated neurons. Median latency is earlier in ACC than icbDS and Pal (gaze-modulated neurons, p = 0.002 and p = 0.006; all neurons, p < 0.001 and p = 0.035; rank-sum tests)