Behavioral measurement. (A) Behavioral measurement of fear learning in sham, BLA, BST, or combined BLA+BST lesion animals. Acquisition of conditional fear as indexed by percent-time observed freezing during an immediate postshock period. Mean (±SEM) percentage of observations spent freezing during a 76-footshock contextual-fear conditioning session. (B) Context-fear memory in sham, BLA, BST, or combined BLA+BST lesioned animals. Total mean (±SEM) percentage of observations spent freezing during an 8-min test session for conditional fear.