Material-independent and material-specific activation in functional MRI after perceptual learning.

Schedule of exposure to similar stimuli contributes to the degree of perceptual learning over and above the amount of exposure in a variety of species and stimuli. In an event-related functional MRI study, investigating schedule and stimulus effects in perceptual learning, we found that intermixed presentation (A, B, A, B ...) resulted in better subsequent discrimination than blocked presentation (C, C ... D, D ...) for face and checkerboard stimuli, despite being matched for the number of exposures. Exposure schedule resulted in differential activation in the same early visual regions in both types of stimuli. There was evidence of material-specific activation in the fusiform face area for faces but not for checkerboards, suggesting that material-specific mechanisms are recruited alongside more material-independent mechanisms in perceptual learning.