Transfer of learning to compensate for impairment by alcohol and visual degradation

Rationale: Past research on social drinkers shows that prior experience performing a task in a visually degraded environment results in the reduction of alcohol-induced impairment. It is possible that task experience under alcohol might similarly carry over to reduce impairment from visual degradation. Objectives: The purpose of this study was to test the symmetry of the transfer of learning between two distinct sources of impairment, visual degradation and alcohol. Materials and methods: Psychomotor impairment was measured by a pursuit rotor tracking task. Forty two participants were randomly assigned to one of six treatment groups. Two groups were tested under alcohol after having prior task experience performing with or without visual degradation. Two groups were tested under visual degradation after having prior task experience performing under active (0.65 g/kg) or inactive (placebo) doses of alcohol. The remaining two groups served as controls that tested the learning effects of repeating each active treatment. Results: Clear evidence for asymmetrical transfer of learning was observed. Prior task experience with visual degradation reduced the impairing effects of alcohol. By contrast, prior task experience under alcohol had no effect on impairment produced by visual degradation. Conclusions: Evidence for differential transfer of learning to compensate for alcohol- and visual-degradation-induced impairment is of practical interest, given that the two disturbances commonly co-occur outside the laboratory. Reasons for the asymmetry are unclear, and likely involve differences in mechanisms by which each treatment impairs psychomotor function.