Fig. 5: Cortico-cerebellar model mimics mouse behaviour during evidence accumulation task.

a Schematic of evidence accumulation task²⁷: a random sequence of non-zero inputs ("air puffs'') is delivered in the leftward (−) or rightward (+) direction. The model must integrate this input and decide at the end of the task which side received more input overall. b Learning curves of models (fixed RNN; α = 0.1) without feedback (grey), with readout feedback (blue) and with cerebellar feedback (orange). c Change in average training error of the cortico-cerebellar model with respect to the no feedback model across different levels of cortical internal memory (α) and degrees of cortical plasticity. d Model beliefs over time without (orange) and with complete cerebellar ablation (purple) in model (upper panels) and data-derived behavioural model (lower panels) reproduced from Deverett et al.²⁷. Thin model lines represent one example seed. Belief P denotes model output probability. e Normalised regression weights at different periods of input presentation (cue) during control (upper) and ablation (lower) conditions for both model (orange line) and behavioural data (black line). f Model and data error under different ablation periods and degrees of cortical plasticity. g Average change in task error for models with versus without cerebellar feedback across different cue durations. h Average change in task error for models with versus without cerebellar feedback during and after training across different degrees of cortical plasticity. All model results are averaged over 5 different initial conditions. Error bars represent standard error of the mean.