Exploratory individual differences analysis
Additional exploratory analyses were conducted to examine whether individual differences between participants explains the magnitude of alcohol induced effects within the Oddball and Regularity tasks, and whether any chance differences between samples could explain differences between tasks.
For this analysis, we computed the magnitude of alcohol induced change for each variable. For instance, P1 peak was measured in alcohol and placebo conditions, and the difference between these is the alcohol induced P1 effect.
For each participant, we measured alcohol-induced changes to P1 peak, N1 drop, P300, SPN, behavioural performance, light-headedness, and alertness. For this analysis, the SPN was defined averaged over early and late windows. We also computed gap between sessions, AUDIT score and age. Correlations between these 10 variables were assessed within Oddball and Regularity tasks separately. Light-headedness and alertness scores were averaged over the final pre-experiment rating and post experiment rating.