The effects of self-control on cognitive resource allocation during sustained attention: a transcranial Doppler investigation.

Vigilance, or sustained attention, is a required ability in many operational professions. While past research has consistently indicated that vigilance performance declines over time, referred to as the vigilance decrement, the theoretical mechanisms underlying the decrement continue to be explored. In the current study, trait self-control was examined to determine how this individual differences measure may contribute to the theoretical explanation of vigilance decrement. Transcranial Doppler sonography (TCD) was used as a measure of cerebral blood flow velocity (CBFV), as previous research has indicated that CBFV may index attentional resource allocation during vigilance (e.g., Shaw et al. in Hum Factors Ergon Soc 50:1619-1623, 2009). Participants performed a demanding 12-min computer-based vigilance task. Prior to the task, a validated self-report measure was used to determine trait-level self-control, and subjective workload was measured after the task was completed. Participants were divided, based upon survey responses, as either low- or high-trait self-control. Performance results showed a significant decrement across participants, but no significant main effect or interaction relating to the self-control measure was observed. Results relating to the TCD measure showed a significant decline in CBFV in the low self-control group, but no CBFV decrement was observed in the high self-control group. The subjective workload results revealed a nonsignificant trend of the low self-control group becoming more frustrated after the task. These results suggest that there are differences in the resource allocation strategies between low and high self-control participants. How trait self-control can add to an understanding of the theoretical underpinnings of sustained attention performance is discussed.