Perceptual Decision-Making in the Human Brain

Findings from single-cell recording studies suggest that a comparison of the outputs of different pools of selectively tuned lower-level sensory neurons may be a general mechanism by which higher-level cortical regions compute perceptual decisions. For example, when monkeys must decide whether a noisy field of dots is moving upward or downward, a decision can be formed by computing the difference in responses between lower-level neurons sensitive to upward motion and those sensitive to downward motion. I will present fMRI evidence that even for high-level object categories, the comparison of the outputs of different pools of selectively tuned neurons could be a general mechanism by which the human brain computes perceptual decisions. Furthermore I will argue that the posterior dorsolateral prefrontal cortex has general decision-making functions, independent of stimulus and response modalities.