Figure 2.
Generative model for the Eriksen task. (A) When si = H, each xi(t) is drawn from a normal distribution centered at −1; for si = S, the samples are drawn from a similar distribution centered at 1. Thus, a single sample confers partial and noisy information about the underlying stimulus. (B) Within a trial, a fixed setting of si gives rise to iid samples of xi(t) over time. (C) In the compatibility bias model, the prior probability over compatible is greater than chance: β > .5. Each xi depends only responds to one stimulus si and not to the others. (D) Spatial uncertainty model: p(xi(t)|s) depends not only on si but also the neighboring stimuli.