TABLE 2.

Minimum cluster thresholds by mask for Monte Carlo corrections for multiple comparisons (MCMC) simulations.

Early extinction, CS+I > CS+U	MCMC minimum cluster threshold (regional activation; p ≤ 0.005)	MCMC minimum cluster threshold (vmPFC interaction; p ≤ 0.05)
Anterior cingulate cortex and ventral prefrontal cortex	55.6	20.5
Amgydala	15.2	34.9
Dorsal prefrontal cortex	173	87.3
Hippocampus	33.4	42.5
Insula	38.7	44.2
Parahippocampus	28.9	35.4

Minimum cluster thresholds represent the minimum required number of voxels showing significant activation greater than that due to noise at the a priori established p-value of 0.005 for the ROI-based analysis and 0.05 for PPI with the left vmPFC as the seed. All masks, including those for which there were no significant findings, are presented. Masks are bilateral; contrast is CS+I > CS+U for the early phase (first six trials) of extinction.