Effects of Drinking Patterns on Prospective Memory Performance in College Students Sarah Raskin1, Marta Zamroziewicz1, Kristina Foster1, Lara Novak1, Ethiopia Kabtimer1, Rivkah Rosen2, Howard Tennen3, Carol Austad4, Carolyn Fallahi4, Rebecca Wood4, Godfrey Pearlson2 1Trinity College, Hartford, CT 2Olin Neuropsychiatry Research Center, Institute of Living, Hartford, CT 3University of Connecticut, Storrs, CT 4Central Connecticut State University, New Britain, CT SOURCES INTRODUCTION DISCUSSION RESULTS   In general, participants performed better on the time-based prospective memory tasks than the event-based prospective memory tasks. Such a finding opposes previous research of time-based and event-based prospective memory measurements, which has shown that time-based tasks are more difficult to remember, and thus yield poorer prospective memory outcomes (Raskin, 2009). This discrepancy may suggest a weakness in the design of time-based and event-based prospective memory tasks in this study. Participants who drank alcohol at least one time in a period of 30 days performed better on both event-based and time-based prospective memory tasks. Previous research has shown that alcohol users show significantly less cognitive decline than nondrinkers for males and females (Kritz-Silverstein & Barrett-Connor, 2003). Furthermore, it has been shown that light, or social, drinkers tend to perform better on cognitive measures than teetotalers and binge drinkers (Rodgers et al., 2005). Participants who drank alcohol on ten or more occasions within a period of 30 days performed significantly worse on the event-based prospective memory task than those who consumed alcohol on less than ten occasions in a period of 30 days. Kokavec and Crowe (1998) also showed that those who binge drank more often (consumed alcohol daily) performed worse on cognitive functions, including verbal and visual memory tasks, than those who binge drank less often (consumed alcohol two days or less per week). The neurotoxic effects of withdrawal from long-term excessive alcohol intake may explain the significantly worse cognitive performance of those who consume alcohol more often (Zeigler et al., 2005). - Binge drinking in a period of 30 days at least once did not influence performance on neither time-based nor event-based prospective memory tasks. However, a trend emerged in which participants who drank five or more drinks on a single occasion in a period of 30 days showed worse performance on event-based prospective memory cues. Interestingly, Heffernan et al. (2010) reported a significant detrimental influence of binge drinking (compared to non-binge drinking) on event-based prospective memory tasks. These mixed findings suggest the need for further investigation of the influence of binge drinking on prospective memory performance, such as the examination of the influence of gender on performance. Given that individuals 12-20 years of age drink 11% of alcohol consumed in the United States, the influence of alcohol consumption in college students is of concern (Center for Disease Control and Prevention, 2010). Moreover, 90 percent of alcohol consumption in this age group is characterized by binge drinking (CDC, 2010). Research has indicated that the brain may be particularly susceptible to the toxic effects of alcohol during adolescence and early adulthood, and may effect cognition (Brown et al., 2000).  Studies addressing changes in cognitive functioning caused by excessive use of alcohol have yielded mixed results. Parsons and Nixon (1993) indicated impaired performance in perceptual-motor skills, visuospatial capabilities, problem-solving facilities, and learning abilities. On the other hand, Wood, Sher, and Bartholow (2002) reported a lack of difference in intellectual functioning or neuropsychological impairment between a group of individuals with alcohol use disorder and a matched control group. Knight and Godfrey (1985) specifically reported deficits in everyday memory among chronic heavy alcohol users. In an examination of prospective memory through subjective ratings, chronic heavy alcohol users reported global impairments in prospective memory for long-term, short-term, and internally cued prospective memory (Hefferman et al., 2002). Similarly, binge drinkers showed significantly worse performance than non-binge drinkers on a measure of event-based prospective memory (Heffernan et al., 2010). Beyond these two studies of subjective ratings and only event-based prospective memory tasks, there has been a lack of comprehensive research to illuminate the possible effects of alcohol on prospective memory in both time-based and event-based tasks. This study aims to fill this gap by examining the influence of alcohol use in a sample of college age students on their performance on time-based and event-based measures of prospective memory. Figure 1. Performance on prospective memory tasks. Brown, S.A., Tapert, S.F., Granholm, E., Delis, D.C. (2000). Neurocognitive Functioning of Adolescents: Protracted Alcohol Use. Alcoholism: Clinical and Experimental Research, 24, 164-171. Centers for Disease Control and Prevention. (2010). Alcohol and Public Health: Fact Sheets. Retrieved March 5, 2011, from http://www.cdc.gov/Alcohol/fact-sheets/underage-drinking.htm. 3. Garcia-Moreno, L.M., Conejo, N.M., Pardo, H.G., Gomez, M., Martin, F.R., Alonso, M.J., Arias, J.L. (2001). Physiology and Behavior, 72, 115-121. Heffernan, T., Clark, R., Bartholomew, J. Long, J., Stephens, S. (2010). Does Binge Drinking in Teenages Affect their Everyday Prospective Memory?. Drug and Alcohol Dependence, 109, 73-78. 5. Heffernan, T.M., Moss, M., Ling, J. (2002). Subjective Ratings of Prospective Memory Deficits in Chronic Heavy Alcohol Users. Alcohol and Alcoholism, 37, 269-271. Hunt, W.A. (1993). Are Binge Drinkers More At Risk of Developing Brain Damage? Alcohol, 10, 559-561. 7. Knight, R.G., Godfrey, H.P. (1985). The Assessment of Memory Impairment: The Relationship Between Different Methods of Evaluating Dysmnesic Deficits. British Journal of Clinical Psychology, 24, 25-31.   Kritz-Silverstein, D., Barrett-Connor, E. (2003). Cognitive Function After 11.5 Years of Alcohol Use: Relation to Alcohol Use. American Journal of Epidemiology, 158, 394-395. 9. Parsons, O.A., Nixon, S.J. (1993). Neurobehavioral Sequelae of Alcoholism. Neurologic Clinics, 11, 205-218. 10. Raskin, S.A. (2009). Memory for Intentions Screening Test: Psychometric Properties and Clinical Evidence. Brain Impairment, 10, 23-33. Rodgers, B., Windsor, T.D., Anstey, K.J., Dear, K.B.G., Jorm, A.F., Christensen. (2005). Non-Linear Relationships Between Cognitive Function and Alcohol Consumption in Young, Middle-Aged, and Older Adults: the PATH Through Life Project. Addiction, 100, 1280-1290. 12. Wechsler, H., Nelson, T.F. (2001). Binge Drinking and the American College Student. Psychology of Additive Behaviors, 15, 287-291. 13. Wood, P.K., Sher, K.J., Bartholow, B.D. (2002). Alcohol Use Disorders and Cognitive Abilities in Young Adulthood: A Prospective Study. Journal of Consulting and Clinical Psychology, 70, 897-907.   *** Figure 2. Influence of consumption of alcohol in a period of 30 days on performance on prospective memory tasks. ** *** MATERIALS AND METHODS Event-based Time-based Figure 3. Influence of number of occasions of alcohol intake in a period of 30 days on prospective memory performance. Participants Participants include 117 first year students at Trinity College who were recruited to participate in the BARCS (Brain and Alcohol Research in College Students) Study. Participants were between the ages of 18 and 22. Measures Alcohol intake was measured by the administration of the Self-Rating Effects of Alcohol (SREA), Modified Timeline Follow-back (TFLB), and Alcohol Effects Questionnaire (AEQ). Prospective memory was assessed using two measures, including a time-based measure and an event-based measure. The time-based measure required students to close the testing room door in exactly two minutes and the ongoing task was the Mini International Neuropsychiatric Interview (MINI) DSM-IV-TR alcohol use items. The event-based measure required students to sign their name when they encountered a colored sheet of paper in the testing package and the ongoing task was to complete the paperwork in the testing package (reading and signing the consent form, filling out a subject referral form, and filling out a demographics form). The time-based measure was scored as 0 if no recognition of the task was given, 1 if the task was partially completed or completed late, and 2 if the task was correct and completed at the correct time. The event-based measure was scored as 0 if the task was not completed in response to the proper cue, and 2 if the task was correct. Defining Alcohol Use Participants were divided into three categories in terms of alcohol consumption, binge drinkers, social drinkers, and teetotalers. Social drinkers were students who consume alcohol but had not binged in the last 30 days. Binge drinkers were students who consume alcohol and had binged (4 or more consecutive drinks for females, 5 or more consecutive drinks for males) in the last 30 days. Teetotalers were students who had never consumed alcohol. Analyses Overall performance on time-based versus event-based prospective memory tasks was examined using a two-tailed t-test. The influence of alcohol intake in a period of 30 days and the number of alcohol intake occasions on time-based and event-based prospective memory performance was examined via an analysis of variance (ANOVA). Also, an ANOVA was used to compare performance on event-based and time-based prospective memory tasks between binge drinkers, social drinkers, and teetotalers (measured by the number of drinks consumed on an occasion in a period of 30 days). Finally, an ANOVA was used to reveal the influence of consuming five or more drinks (male definition of binge drinking) in a single sitting in a period of 30 days. *** CONCLUSION This research revealed the influence of alcohol use on prospective memory performance both in terms of the number of alcoholic beverages consumed and the number of occasions of alcoholic consumption. Occasional drinking (one or more times in a period of 30 days) yielded better prospective memory performance on both event-based and time-based tasks than abstaining from drinking while frequent drinking (at least ten times in a period of 30 days) yielded significantly worse prospective memory performance on event-based tasks. Interestingly, binge drinking in a period of 30 days did not influence prospective memory performance while consumption of five or more beverages within a period of 30 days yielded a trend of worse prospective memory performance on event-based tasks. In terms of future research, the amelioration of the time-based task in this study may enhance the validity of these results. Additionally, the examination of the influence of participant gender may reveal more significant relationships between alcohol use and prospective memory performance. Event-based Time-based Figure 4. Influence of binge drinking in a period of 30 days on prospective memory performance. Event-based Time-based ACKNOWLEDGEMENTS Figure 5. Influence of maximum number of drinks consumed in one sitting in a period of 30 days on prospective memory performance. We would like to thank: Trinity College BARCS participants Other BARCS researchers of the Trinity College Cognitive Neuroscience Lab David Correll Sarah Isaac Nick Caggiano * Significance *** P > 0.01 ** P > 0.05 * P > 0.10 Research funded by grant RO1 AA016599 (BARCS Study) to Dr. Godfrey Pearlson Event-based Time-based