Fig. 4: Model predictions about reaction times are borne out in data.
From: Trial-history biases in evidence accumulation can give rise to apparent lapses in decision-making
a Schematic of reaction time task in rats (Figure adapted with permission from Bingni W. Brunton et al., Rats and Humans Can Optimally Accumulate Evidence for Decision Making. Science 340,95-98(2013). DOI:10.1126/science.1233912) b Average choice behavior on all trials (left; n = 223231 trials) and following previous right (n = 86109 trials) or left wins (n = 82678 trials; right) across 6 rats (solid line), overlaid on individual rat behavior (translucent lines). Errorbars represent 95% binomial confidence intervals around the mean. c Average parameters (solid points) of history-conditioned psychometric curves, overlaid on individual parameters (translucent points) showing significant history modulations in threshold and lapse rate parameters (p = 0.69 for sensitivity, 0.004 for threshold, 0.02 for left lapse rate, 0.02 for right lapse rate, two-sided Mann-Whitney U-test; n = 6). d–f Reaction time signatures (d) expected from accumulator models with no history dependence in initial states, (e) expected from accumulator models with history-dependent initial states and (f) observed in data (n = 223,231 trials across all stimulus strengths and rats). (Leftmost column) error reaction times are expected to be shorter if initial states are history-dependent. Red (green) represents RTs on errors (wins). (Middle column) reaction times on trials following right wins (blue) are expected to be lower on rightward stimuli (positive half of x-axis), and similarly following left wins (pink). (Rightmost columns) repetition biases in choices are expected to occur more frequently for short reaction times, when the effect of initial states is strong. Error bars represent SEM. g Joint fits of the accumulator model with history-dependent initial states to choices (left) and reaction times (right) of an example rat (n = 24413 trials). Data represented by points (circles: choices, mean accuracy ± 95% binomial confidence intervals; squares: reaction times, mean RT ± SEM) and model fits represented by lines (choices) or shaded bars (reaction times, thickness represents 95% bootstrap prediction intervals). Reaction times (right) are split by wins (green) or errors (red). h Scatter plot showing correspondence between history modulations in threshold (left) or lapse rate (right) parameters derived from data (x-axis) and model fits (y-axis). Individual points represent individual rats (n = 6), best-fit parameter values ± 95% bootstrap CIs.
