Action plan interrupted: resolution of proactive interference while coordinating execution of multiple action plans during sleep deprivation

The ability to retain an action plan to execute another is necessary for most complex, goal-directed behavior. Research shows that executing an action plan to an interrupting event can be delayed when it partly overlaps (vs. does not overlap) with the retained action plan. This phenomenon is known as partial repetition costs (PRCs). PRCs reflect proactive interference, which may be resolved by inhibitory, executive control processes. We investigated whether these inhibitory processes are compromised due to one night of sleep deprivation. Participants were randomized to a sleep-deprived group or a well-rested control group. All participants performed an action planning task at baseline after a full night of sleep, and again either after a night of sleep deprivation (sleep-deprived group) or a full night of sleep (control group). In this task, two visual events occurred in a sequence. Participants retained an action plan to the first event in working memory while executing a speeded action to the second (interrupting) event; afterwards, they executed the action to the first event. The two action plans either partly overlapped (required the same hand) or did not (required different hands). Results showed slower responses to the interrupting event during sleep deprivation compared to baseline and the control group. However, the magnitude of the PRCs was no different during sleep deprivation compared to baseline and the control group. Thus, one night of sleep deprivation slowed global responses to the interruption, but inhibitory processes involved in reducing proactive interference while responding to an interrupting event were not compromised. These findings are consistent with other studies that show sleep deprivation degrades global task performance, but does not necessarily degrade performance on isolated, executive control components of cognition. The possibility that our findings involve local as opposed to central inhibition is also discussed.