Figure 2. Experimental task and simulation and behavioural results (N=21).

(a) Example stimuli and timing of presentation. This example depicts an incongruent trial, followed by a congruent trial. (b) Individual mean model LRs, plotted as a function of run type. Each line represents a subject. (c) The time course of group mean LR and s.e.m. in the first and last 10 trials of volatile (in blue) and stable (in red) blocks. Note that in this graph, which averages over all blocks, the difference in LR at the beginning of the blocks was driven by volatile blocks 2–4 in the volatile runs, as in these blocks the LR had already been raised by preceding volatile blocks. (d) Time courses of the underlying proportion congruency (in black) and the corresponding predicted conflict level (in red) of an example run. (e) Individual RS, plotted as a function of congruency. Each line represents one subject. Note that higher RT equals lower RS. (Con=congruent trials; Inc=incongruent trials). (f) Group mean RS and s.e.m., centred across trials for each subject, plotted as a function of unsigned prediction error of congruency (control prediction error).