Int. J. Environ. Res. Public Health 2009, 6 2010 drinks and (2) and total lifetime drinks controlling for weight (body weight in kg). Delay ALCs reported an average lifetime total volume of alcohol exposure of 87312 drinks or 17004 g/kg when corrected for body weight. During all drinking phases, ALCs reported a mean of 11 (SD = 7.8) standard drinks per drinking day and a mean maximum of 14 (SD = 8.7) standard drinks per drinking day. To assist in clarifying the severity of drinking across time, we also derived the average number of drinks per day consumed during reported heaviest consecutive 3-year period of drinking. The mean, for this measure, was 13 (SD = 9.2). For a profile of each alcoholic participant’s drinking history, see Table 1. On the Self-Administered Short Michigan Alcoholism Screening Test (SMAST) [21], a self- reported measure of alcoholic behavior, ALCs reported scores ranging from 3 to 13 with a mean score of 8 (SD = 3.2). Selzer and colleagues [21] suggest that a score of 0-1 on the SMAST represents a nonalcoholic profile, a score of 2 indicates a possible alcoholic profile, and a score of 3 or higher represents an alcoholic profile. Twelve delay ALCs met DSM-IV diagnostic criteria for Alcohol Dependence on the Diagnostic Interview Schedule for DSM-IV (DIS-IV) [22], and four met criteria for alcohol abuse. The entire 90–120 minute DIS computerized instrument was administered to participants. There were some discrepancies between the computerized measure of alcoholic behavior and participants’ self-reported and questionnaire-based history (see Table 1). It is possible that some participants had difficulty attending to the entire DIS-IV computer interview and answered unreliably during the substance abuse module, which came during the latter part of the interview. Individuals that demonstrated inconsistency between computerized DIS-IV interview and self-reported history of drinking behavior were asked to return to the laboratory for follow up DIS-IV Substance Abuse Module administration in which they answered only the 28 substance abuse related items. Four individuals were lost to follow up and the Substance Abuse Module could not be re-administered. For these participants available SMAST, LDH, and questionnaire data was used to confirm alcohol history. These four individuals reported a history consistent with alcohol abuse as defined by ≥ 21 drinks/week for a minimum of five years and self-identified as alcoholics. Two participants who did not meet criteria for alcohol abuse/dependence on the DIS-IV were classified as alcoholics on the SMAST (ALC011, ALC019; see Table 5). One of the remaining two participants with a negative diagnosis based on the DIS-IV (ALC015) reported alcohol consumption of > 20 drinks per day for over a twenty-five year period. The final participant who was lost to follow up with a negative diagnosis on the DIS-IV reported a less severe drinking history, but met criteria of ≥ 21 drinks/week for a minimum of five years and self- identified as an alcoholic (ALC004) (see Table 1). Trace Conditioning ALCs. Seventeen abstinent alcoholic individuals were included in the trace discrimination reversal task (6 men, 11 women). The mean age of the trace ALC group was 51 years (standard deviation, SD = 6.6), the mean education in years was 14 (SD = 2.0), the mean verbal intelligence as measured by the Wechsler Adult Intelligence Scale, Third Edition (WAIS-III) was 104 (SD = 19.3). The mean duration of abstinence prior to testing was 7.1 years (SD = 9.6) but ranged from 1 month to 26 years. On the Lifetime Drinking History (LDH) [20], abstinent alcoholics reported a significant history of alcohol abuse that ranged in duration from 12 years to 41 years. The mean length of abuse was 27 years (SD = 7.0). Trace ALCs reported an average lifetime total volume of alcohol exposure of