Figure 6.
Effects of the timing of the incongruent stimulus in the 27.5% uncertainty condition (7 congruent; 1 incongruent). A, Significantly greater activation was observed within the intraparietal sulcus (IPS) bilaterally when the single incongruent stimulus was presented in the second half of the 8-stimulus sequence, compared with when it was presented in the first half of the sequence (p range, uncorrected, 0.001-0.00001). B, Examination of the time course of activation revealed that the late incongruent stimuli evoked activation during the decision phase of the task. Note that the context stimuli were presented over the first 6 s (4 time points) of each trial, and the observed change in fMRI activation attributable to the late incongruent event peaked ∼12 s after trial onset. L, Left; R, right.