Figure 7: Characterization of rule-selective neurons.

(a) Results of an ANOVA with the factors ‘rule’, ‘cue modality’ and ‘sample picture’. Fifteen percent of NCL neurons encoded only the abstract behavioural rule, with an additional 5% exhibiting main factors of ‘rule’ and ‘modality’ (but no interaction between factors). (b) Quality of rule coding. Histogram of AUROC values of all rule neurons. By convention, values <0.5 represent neurons preferring the ‘nonmatch’ rule (pink), values >0.5 represent neurons preferring the ‘match’ rule (blue). There were equal numbers of neurons preferring each rule. (c) Time course of rule selectivity for all rule neurons. Neurons are sorted based on their rule preference and the latency of rule selectivity. Middle: AUROC values of each individual rule neuron throughout the Delay2 period. The white bar at 1,500 ms indicates the onset of the rule cue. The white line marks each neuron’s latency of rule discrimination. Top: average AUROC values of all neurons preferring the ‘match’ rule. Bottom: average AUROC values of all neurons preferring the ‘nonmatch’ rule. Dashed lines show s.e.m., n=33 each.