Fig 1.
(A) Timing of a trial of the auditory four-choice RT task. (B) Peri-error RTs, illustrating both pre-error speeding and PES. The latter was quantified using both ‘traditional’ and ‘robust’ methods (see Materials and Methods). (C) Peri-error response accuracy. Pre-error effects in b and c are linear contrasts across consecutive trials. Error bars indicate s.e.m. **p<0.01, *p<0.05, #p<0.1.
Fig 2.
Relationships between pupil dilation and next-trial behavior.
(A) Grand-average evoked pupil dilations conditioned on response accuracy (correct, error) and locked to response execution. (B) Distributions of single-trial pupil dilation amplitudes conditioned on response accuracy. Single-trial values were z-scored within subjects but across accuracy conditions, and pooled across subjects prior to plotting. Pooled distributions were normalized within condition such that each distribution integrates to 1. (C) Mean β coefficients from within-subjects linear regressions of next-trial RT onto current-trial pupil dilation for each accuracy condition (Eq 2, Materials and Methods). Significant effect of condition is derived from the interaction term of multi-factorial regression models that included pupil dilation and current-trial accuracy as predictors (Eq 1, Materials and Methods). (D) Mean β coefficients from within-subjects logistic regressions of next-trial accuracy on current-trial pupil dilation (Eqs 3 and 4, Materials and Methods). (E) Scatterplots illustrating the linear relationships between current-trial pupil dilation and next-trial RT, separately for correct and error trials. Data were z-scored within condition and within subjects, pooled across subjects, sorted by pupil dilation and grouped into 12 quantiles. Previous-trial RT was partialled out of next-trial RT prior to pooling (see Materials and Methods). (F) Scatterplots illustrating the logistic relationships between current-trial pupil dilation and next-trial accuracy, separately for correct and error trials. Shaded regions in a and error bars in c and d indicate s.e.m. **p = 0.01, *p<0.05.