Time course of response suppression for Imc neurons with switch-like versus gradual competitor response profiles (CRPs). A–D, Analysis of response time courses of Imc neurons with gradual competitor response profiles; columns, responses binned by the relative strength of S1 and S2 (S2-S1). A, B, Instantaneous firing rates (IFRs) of neurons to S1 alone (A) or to S1 and S2 presented together (B), computed by smoothing PSTHs (1 ms time bins) with a Gaussian kernel (SD = 12 ms; Materials and Methods). For each neuron, instantaneous firing rates are normalized by the peak firing rate of that neuron to S1 alone. Neurons in A are sorted by the half-peak firing rate; neurons in B are in the same order as in A. C, Pooled average firing rates to S1 alone (gray) or to S1 and S2 (green) of all neurons within each bin. Translucent bands indicate SEM. D, Time course of p values obtained by performing ANOVA between the responses to S1 versus to S1 and S2 at each millisecond. Vertical dashed arrows (and colored text), time to suppression (defined as the first instant at which responses to paired S1 and S2 diverge significantly from responses to S1 alone; Materials and Methods); horizontal dashed lines, p value thresholds used in determining time to suppression (bottom line, p = 0.05; top line, p = 0.01. E–H, Same as A–D, but for Imc neurons with switch-like competitor response profiles. I, Comparison of time to suppression for neurons with switch-like (magenta) versus gradual competitor response profiles (green) J, Plot of average amount of response suppression (±SEM) for switch-like versus gradual neurons for the two relative strength bins on either side of the selection boundary. Text reports the effect size (η²).