Fig. 1: Experimental design and protocol.

Recruited smokers came to the lab, completed the craving evaluation, and performed a cue-reactivity task in the fMRI scanner. Twenty-four hours later, they took a placebo or propranolol (40āmg) pill 1āh before they underwent two resting-state fMRI scans. Before the second scan, the participants reactivated the nicotine-associated memories by being exposed to smoking-related pictures. Again 24āh later, all of the participants completed the craving evaluation and the same cue-reactivity task in the scanner.