The neural correlates of cognitive control functioning in individuals with insomnia disorder.

Individuals with insomnia disorder (ID) commonly report associated complaints of cognitive functioning. Conversely, both behavioral and neurological evidence supporting this notion of cognitive impairments in ID remain remarkably scarce and inconclusive. In this ERP study, we aimed to investigate the dynamic interplay of proactive control (i.e., maintenance and updating of task-relevant information) and reactive control (i.e., interference monitoring and resolution) using the AX-Continuous Performance Task in ID compared with good sleeper controls (GSC). The results indicate that GSC show the expected proactive recruitment of cognitive control (i.e., enhanced BX performance at the expense of the AY performance), whereas ID show an impaired performance on both AY and BX trials, suggesting an impaired functioning of both proactive and reactive control. The probe-related ERP indices show a clear N2 deflection on AY trials for the GSC, suggesting a compensatory shift to reactive control in order to resolve response interference. On BX trials a clear N2 deflection is not observed, suggesting that GSC might not experience response conflict and therefore might not engage in reactive control. Interestingly, in contrast to the GSC, individuals with ID do not show significant differences in N2 amplitudes between AY and BX trials. This result, in combination with an impaired performance on both type of trials, suggest that insomniacs might not recruit reactive control in order to resolve response interference. In conclusion, our results suggest a reduced engagement of both proactive and reactive control in ID, which is corroborated behaviorally (i.e., impaired task performance) and neurologically (i.e., abnormal modulation of probe-related ERP components).