Figure 1.

Experiment sessions and paradigm. A, The sessions of the experiment: (1) first R-fMRI session before perceptual learning; (2) functional localizer task fMRI session (same day); (3) perceptual learning training on the shape orientation discrimination task (no imaging) until performance was >80% of correctly recognized target shapes on three consecutive blocks of trials (2–9 d on average); (4) T-fMRI session during shape orientation discrimination task; and (5) second R-fMRI session (same day). B, Experimental paradigm. Subjects fixated throughout the experiment. A cue indicating the target orientation was presented for 2 s. During perceptual learning, the target orientation was always an inverted T. During T-fMRI, the target orientation was the same as during perceptual learning during trained blocks of trial, and either a left- or right-tilted T during untrained blocks of trials. The stimulus array was briefly presented (150 ms) to minimize eye movements The target shape was always in the left lower quadrant, both for trained and untrained blocks of trials. N, No; Y, yes.