Figure 1

Activity related to improvisation: Results of the group level, random effects analysis of variance (ANOVA) comparing improvised and conventional conditions are illustrated.

Warm colors represent significant increases in BOLD signal during improvised, cool colors represent significant decreases. Results, revealing dissociated frontal and left lateralized patterns, are displayed (a) on a 3D brain surface rendered using SUMA (SUrface MApping) and (b), as axial slices with planes of section relative to the bi-commissural line indicated. The bar plot (c) illustrates the mean values ± standard errors of signal changes (improvised-conventional) in DLPFC and MPFC ROIs defined in the GLM contrast and homotopic ROIs in the contralateral hemisphere. MPFC activations were strongest on the left, while activations in the right hemisphere were sub-threshold and DLPFC deactivations were strongest on the right, while left hemisphere regions were non-significantly decreased. It should be noted that the activity in the DLPFC was significantly attenuated when the improvised condition was compared directly to an implicit baseline, indicating that this finding was not simply produced by contrast with the conventional condition (in which activity in the DLPFC did not itself differ from baseline).