Event-related cerebral hemodynamics in 2-D and 3-D Visual Vigilance Tasks

Abstract

Recently, Greenlee et al. (2015) demonstrated that a stereoscopic 3-D display attenuated the vigilance decrement, stabilizing optimal detection performance. Yet, the 3-D display did not halt the decline in global cerebral blood flow velocity (CBFV), an index of cortical resource utilization, which typically accompanies the vigilance decrement. One possible explanation for this enigmatic finding is that global CBFV may not have been sensitive enough to detect the neurological correlates of superior sustained performance in the 3-D condition. Perhaps a more fine-grained measure of CBFV would reveal the underlying neural markers. To explore that possibility, event-related analyses were employed to uncover moment-to-moment changes in CBFV. These analyses revealed that CBFV increased selectively in response to signal detections in the 3-D condition but not in the 2-D. Like performance in the 3-D condition, the detection-related CBFV response in that condition remained stable over time on task. These findings indicate that event-related measurement of detection-specific neural activity can uncover hemodynamic effects that may otherwise be buried by the tides of global CBFV. Implications for future CBFV research are discussed.