Supplementary Figure 4: Simulations with imperfect memory reinstatement.
From: Reinstated episodic context guides sampling-based decisions for reward
We used the simulation to illustrate how our mechanism can eliminate the effect of reminded trials while sparing an effect of recent rewards and context. We followed the simulation procedure of Figure S3, again generating populations of 1,600 subjects, this time with each population using a different value of αevoked, the probability that a reminder probe would result in reward information being reinstated from the reminded trial and context. All other model parameters were fixed. a. Shown here is the full regression model fit to a simulated population of 32 subjects that sampled 12 episodes before each choice, with αevoked set to 0.3. Error bars are +/- 1 SEM. b. As the probability of reinstating reward information decreases, so does the contribution of both item and context memory to decisions. We ran the experiment for 9 populations of 1,600 simulated subjects each. Each population used a different value of the αevoked parameter. We then measured the regression weights for the reminded trial and the reminded context, plotted here by their ratio to the regression weight for reward experienced one trial ago. As αevoked decreased, so did the ratio of each type of memory-based effect to the effect of recent rewards. While the effect of reminded context is preserved at even very small values for αevoked, the effect of the reminded trial drops to near zero. This pattern matches the reduced effect of both reminded trial and context in Experiment 2. Error bars are +/- 1 SEM.
