Figure 4.

Incorrect choice prior and switch–stay signals in the brain. A, Brain regions showing a significant correlation with the prior incorrect signal from the state-based algorithm (time-locked to the time of choice). Significant effects were found in the rDLPFC (39, 36, 33 mm; z = 4.30), the anterior cingulate cortex (6, 21, 45 mm; z = 3.37), and the right anterior insula (48, 15, 9 mm; z = 3.96). The threshold was set at p < 0.001. B, Plot showing relationship between fMRI responses in the dorsolateral PFC at the time of choice and the prior incorrect signal from the Bayesian model, illustrating strong colinearity between this signal and activity in this region. C, Brain regions responding to trials in which subjects decide to switch compared with when they do not switch (stay) their choice of stimulus. Significant effects were found in the anterior cingulate cortex (−3, 24, 30 mm; z = 4.54) and the anterior insula (−39, 18, −12 mm; z = 4.26; 51, 21, 3 mm; z = 4.23) bilaterally. The fact that the anterior cingulate and anterior insula respond on these switch trials, as well as responding to the prior incorrect signals, suggest that the decision to switch may be implemented in these regions. Error bars indicate SEM. L, Left.