The sample size was pre-estimated using G*Power 3.1. Based on a large effect size estimated by a previous study for EC difference between AUD and HCs (Cohen’s d = 0.80) [32], a sample size of 21 participants was required to detect a reliable effect with an error probability of 0.05 and power of 0.80 in an independent sample t-test. Thirty-two men with HCs and 30 men with AUD in abstinence were recruited from Anhui Mental Health Center at Hefei Fourth People’s Hospital (data set 1). All HCs were recruited through posters and Internet advertisements. Before the experiment, all AUD patients had abstained from alcohol for a minimum of two weeks (mean, 32.9 days; range, 15–120 days) and were prohibited from consuming alcohol in the center. Briefly, AUD patients met the following criteria: (a) DSM-V diagnostic criteria for AUD without acute alcohol withdrawal syndrome (abstinent for at least two weeks), and having a Clinical Institute Withdrawal Assessment of Alcohol Scale (CIWA) score of greater than 7; (b) without dependent on substances other than alcohol or nicotine. Both AUD patients and HCs
