Presented at TARMAC 2020. Access recording via link: https://www.youtube.com/watch?v=zyuwvlcTvX4&list=PLfjltJSHA9mqEI3gjUYXylY-t6hBm6fE2

1. The effects of post-traumatic alcohol intoxication upon
episodic memory accuracy and completeness
Benjamin Butterworth, Glasgow Caledonian
University
Dr Julie Gawrylowicz, Abertay University
Dr Christopher Hand, Glasgow Caledonian
University
Dr Karen Lorimer, Glasgow Caledonian University
Email: benjamin.butterworth@gcu.ac.uk Twitter: @memoreasy

2. Overview
• Intro (Completeness & Accuracy, Alcohol Myopia
Theory, Heavy Drinking Individuals)
• Method (Participants, Design, Materials,
Procedure)
• Results (Free and cued recall tasks)
• Discussion

3. Completeness and Accuracy
• Episodic memory performance can be measured in terms of ‘completeness’ and
‘accuracy’
• Effect of acute alcohol intoxication on accuracy is mixed, with evidence for
impairments and null effects.
• Completeness can be impaired by acute alcohol intoxication (Karlen et al., 2015;
Gawrylowicz et al., 2017; Altman et al., 2018).
• Impairment of completeness is more consistently evidenced than accuracy.

4. Alcohol Myopia Theory
• Alcohol Myopia Theory- focus on central vs. peripheral details (Cilfasefi et al.,
2006)
• Evidence that accuracy only impaired for peripheral details, with lower
completeness overall (Compo et al., 2012; Flowe et al., 2017)
• Peripheral details not always impaired (Harvey et al., 2013), low salience
(Crossland et al., 2016)
• Useful explanation to evidence negative effects of alcohol intoxication upon
memory (e.g., Dual Representation Theory of PTSD, Brewin, 2014)

5. Heavy Drinking Individuals
• Heavy drinking individuals more susceptible to negative effects of alcohol upon
memory
• Acute alcohol intoxication very common following a traumatic event, particularly
for heavy drinking individuals.
• Theory suggests that effect of alcohol upon memory is dependent upon time of
intoxication (i.e., retrograde facilitation)
• Very few studies test post-encoding alcohol intoxication (Gawrylowicz et al.,
2017; Schreiber Compo et al., 2017, Doss et al., 2018)

6. Participants
• 63 heavy drinking individuals
(>14 units per week)
• Screened for alcohol use
disorder and traumatic stress
symptoms
• Mixture of students and
people recruited from
Greater Glasgow

7. Design and Procedure
• Experimental design (Alcohol group vs. placebo group)
• Low dose of alcohol (~0.2mg:L alcohol:breath)
• Experiment takes place over one week:
1. Watch analogue trauma film (“Cow” PSA, 2009)
2. Complete cognitive processing questionnaire
3. Consume beverages and complete distractor task (45 minutes)
4. Complete free and cued recall tasks
5. Leave session one, keep online diary for one week
6. Return for session two, complete free and cued recall tasks again

8. Materials
• Free recall
• Completeness
• Accuracy
• Cued recall
• “Remember” responses for
recollection / conceptual
memory
• “Know” responses for
familiarity / data driven
memory

9. Free Recall Results
• No significant differences in
completeness or accuracy in
either session (p<.10)
• Completeness (total and
accurate details) significant
increased between the
sessions for the alcohol group
(p<.001), but not in the
control condition (p>.20).

10. Cued Recall Results
• Alcohol group gave fewer “Know”
responses in session one (p<.05) than
placebo.
• Otherwise, no differences (p>.10) in
response frequency or accuracy in
sessions one and two.
• Between sessions, alcohol group
made significantly fewer correct
“remember” responses (p=.04) and
significantly more correct “know”
responses (p=.012). “Know” accuracy
also improved significantly (p=.032).
No changes in placebo responses
(p>.10).

11. Results Overview
• Post-encoding intoxication related to more detailed completeness after one
week, but no changes in accuracy.
• Familiarity-based memory improved following post-encoding intoxication over
one week, whereas some evidence for poorer recollection-based memory.
• Differences mainly observed within groups over time, not between.

12. Interpreting Theory
• Retrograde facilitation- greater cognitive resources to process episodic event may
improve recall of peripheral details.
• Occurs over time, therefore improvement to completeness not evident shortly
after encoding in session one.
• Improvement in familiarity-based memory harder to explain- Doss et al. (2018)
show improved familiarity AND recollection.
• Dual representation theory suggests that impaired contextual representations are
compensated with greater sensory representations- may be that changes in
familiarity do not affect/ represent changes in recollection.

13. Future Work
• Does post-encoding intoxication affect heavy drinking individuals differently?
• Trauma symptom development (PhD work)
• Alcohol blackouts (Wetherill & Fromme, 2016)
• Effects of post-encoding intoxication in different scenarios
• Over greater length of time (Kaysen et al., 2007)
• Different doses (e.g. Bisby et al., 2010)
• Naturalistic settings (e.g. Altman et al., 2018).

14. Discussion Questions
• Why only within group effects and not between groups?
• What about confounding variables?
• Sex
• Cognitive processing style
• Alcohol use through the week
• Can this be considered as a positive effect of alcohol upon memory for heavy
drinking individuals?

15. References
• Altman, C. M., Schreiber Compo, N., McQuiston, D., Hagsand, A. V., & Cervera, J. (2018). Witnesses’ memory for events and faces under elevated levels of intoxication. Memory, 1-14.
• Bisby, J. A., Leitz, J. R., Morgan, C. J., & Curran, H. V. (2010). Decreases in recollective experience following acute alcohol: A dose–response study. Psychopharmacology, 208(1), 67-74.
• Brewin, C. R. (2014). Episodic memory, perceptual memory, and their interaction: foundations for a theory of posttraumatic stress disorder. Psychological Bulletin, 140(1), 69-97.
• Compo, N. S., Evans, J. R., Carol, R. N., Villalba, D., Ham, L. S., Garcia, T., & Rose, S. (2012). Intoxicated eyewitnesses: Better than their reputation?. Law and Human Behavior, 36(2), 77-90.
• Clifasefi, S. L., Takarangi, M. K., & Bergman, J. S. (2006). Blind drunk: The effects of alcohol on inattentional blindness. Applied Cognitive Psychology: The Official Journal of the Society for Applied Research in Memory and Cognition, 20(5), 697-
704.
• Crossland, D., Kneller, W., & Wilcock, R. (2016). Intoxicated witnesses: Testing the validity of the alcohol myopia theory. Applied Cognitive Psychology, 30(2), 270-281.
• Doss, M. K., Weafer, J., Ruiz, N. A., Gallo, D. A., & De Wit, H. (2018). Alcohol and pharmacologically similar sedatives impair encoding and facilitate consolidation of both recollection and familiarity in episodic memory. Cognitive neuroscience,
9(3-4), 89-99.
• Flowe, H. D., Colloff, M. F., Karoğlu, N., Zelek, K., Ryder, H., Humphries, J. E., & Takarangi, M. K. (2017). The Effects of Alcohol Intoxication on Accuracy and the Confidence–Accuracy Relationship in Photographic Simultaneous Line‐ups. Applied
cognitive psychology, 31(4), 379-391.
• Gawrylowicz, J., Ridley, A. M., Albery, I. P., Barnoth, E., & Young, J. (2017). Alcohol-induced retrograde facilitation renders witnesses of crime less suggestible to misinformation. Psychopharmacology, 234(8), 1267-1275.
• Harvey, A. J., Kneller, W., & Campbell, A. C. (2013). The elusive effects of alcohol intoxication on visual attention and eyewitness memory. Applied Cognitive Psychology, 27(5), 617-624.
• Hildebrand Karlén, M., Roos af Hjelmsäter, E., Fahlke, C., Granhag, P. A., & Söderpalm Gordh, A. (2015). Alcohol intoxicated eyewitnesses' memory of intimate partner violence. Psychology, Crime & Law, 21(2), 156-171.
• Kaysen, D., Dillworth, T. M., Simpson, T., Waldrop, A., Larimer, M. E., & Resick, P. A. (2007). Domestic violence and alcohol use: Trauma-related symptoms and motives for drinking. Addictive behaviors, 32(6), 1272-1283.
• Schreiber Compo, N., Carol, R. N., Evans, J. R., Pimentel, P., Holness, H., Nichols-Lopez, K., Rose, F., & Furton, K. G. (2017). Witness memory and alcohol: The effects of state-dependent recall. Law and human behavior, 41(2), 202-215.
• Wetherill, R. R., & Fromme, K. (2016). Alcohol‐induced blackouts: A review of recent clinical research with practical implications and recommendations for future studies. Alcoholism: clinical and experimental research, 40(5), 922-935.