Figure 4 |. Population effects – correct trials are associated with higher order coordination in area V4.

(a) Top panels: The difference in coordination rates (for pairs, triplets, and quartets) between correct and incorrect trials measured using a 300-ms window shifted in 10-ms increments (average of sessions; n=22 for V1, and n=12 for V4). The small gap during the delay period is due to the variable interval between target and test. Bottom panels: Statistical significance of the 2-sided Wilcoxon signed rank test (P-value) for the difference in coordination rates between correct and incorrect trials. Triplets and quartets are combined as ‘higher-order’ coordination events. The dashed lines mark the significance threshold of the p-value (0.05). (b) Normalized coordination rates for pairs, triplets, and quartets, measured for the 300 ms window starting 150 ms after test onset (dots represent individual sessions). A hyperbolic scale was used for the y-axis to optimize representations for all sessions (n=22 for V1, and n=12 for V4). The bar shows average across sessions. The star indicates statistical significance (see Methods). (c) The distribution of coordination rates for (left) correct and incorrect trials for a sample quartet, (middle) all six possible pairs within the quartet, and (right) the firing rates of all four neurons within the quartet. Insets: ROC curves for correct vs. incorrect trials. (d) A_ROC for correct vs. incorrect trials averaged across all coordination events of the same order (pairs, triplets, quartets) within each session (dots represent individual sessions).