Fig. 2: History-dependent threshold and lapse rate modulations in a large-scale rat dataset.
From: Trial-history biases in evidence accumulation can give rise to apparent lapses in decision-making
a Schematic of evidence accumulation task in rats: (Top): Phases of the ‘Poisson clicks’ task, including trial initiation in center port (left), evidence accumulation based on two streams of Poisson-distributed auditory clicks (middle) and choice report in one of two side ports followed by water reward for correct choices (right). (Bottom): Time-course of trial events in a typical trial. (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 Individual differences in history-dependence: Psychometric functions of three example rats from a large-scale dataset, displaying different kinds of history modulation. Choices are plotted conditioned on previous left (blue), right (pink) or all wins (black). (Left): Example rat with no history-dependence in choices, resembling the ideal observer. (Middle): Example rat with modulations of the threshold parameter alone, resembling the dominant conceptualization of history bias. (Right): Example rat with history-dependent modulation of both threshold and lapse rate parameter, similar to the majority of the population. Errorbars represent 95% binomial confidence intervals around the mean (n = [16946, 20577, 37523] trials for example 1, [8568, 9549, 18117] trials for example 2, [29358, 30821, 60179] trials for example 3 for psychometric curves conditioned on [right, left or all wins]) c Dataset displays significant modulations of both threshold and lapse rate parameters: Scatters showing parameters of psychometric functions following leftward wins (post left, blue) or rightward wins (post right, pink). Each pair of connected gray points represents an individual animal, solid colored dots represent average parameter values across animals. Trial history does not significantly affect the sensitivity parameter (top left) but significantly affects left, right lapse rate and threshold parameters (top right and bottom panels). (p = 0.8 for sensitivity, 3 × 10−17 for bias, 8 × 10−8 for left lapse, 6 × 10−7 for right lapse, two-sided Mann-Whitney U-test, n = 152) d Scatter comparing threshold and lapse rate modulations in the entire population (n = 152). Each dot is an individual animal, best-fit parameter values ± 95% bootstrap CIs. Black points represent example rats. The majority of the population lies in the top left quadrant, showing comodulations of both threshold and lapse rate parameters by history.
