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Transcranial Doppler sonography was used to measure cerebral blood flow velocity (hemovelocity, CBFV) from the left and right middle cerebral arteries during the performance of 40-min auditory and visual vigilance tasks. Reductions in stimulus duration were the critical signals for detection in both tasks, which were equated for stimulus salience and(More)
Functional near infrared spectroscopy (fNIRS) measures of cerebral oxygenation levels were collected from participants performing difficult and easy versions of a 12 min vigilance task and for controls who merely watched the displays without a work imperative. For the active participants, the fNIRS measurements in both vigilance tasks showed higher levels(More)
Transcranial Doppler sonography (TCD) and transcranial cerebral oximetry (TCCO) measures of cerebral blood flow velocity and oxygenation levels were collected during an abbreviated 12-min vigilance task. Both the TCD and TCCO measures showed higher levels of cerebral vascular activity in the right than in the left cerebral hemisphere; the cerebral(More)
Loss of vigilance may lead to impaired performance in various applied settings including military operations, transportation, and industrial inspection. Individuals differ considerably in sustained attention, but individual differences in vigilance have proven to be hard to predict. The dependence of vigilance on workload factors is consistent with a(More)
A better understanding of how behavioral performance emerges from interacting brain systems may come from analysis of functional networks using functional magnetic resonance imaging. Recent studies comparing such networks with human behavior have begun to identify these relationships, but few have used a time scale small enough to relate their findings to(More)
OBJECTIVE The aim of this study was to track the course of cerebral tissue oxygen saturation (rSO2) and pilot performance during an episode of gravity-induced loss of consciousness (GLOC). BACKGROUND GLOC, a major problem facing pilots of high-performance aircraft, is brought about by a sudden reduction in rSO2 as a result of increased +Gz force. It(More)
INTRODUCTION Electroencephalographic (EEG) correlates of Gz-induced loss of consciousness (G-LOC) were examined to better understand the mechanisms of G-LOC. METHODS There were 10 subjects (4 women) who provided 35 G-LOC episodes during which 13 channels of EEG and eye activity were recorded. Subjects simultaneously performed tracking and mathematical(More)
OBJECTIVES We examine the time course of performance recovery from gravity-induced loss of consciousness (GLOC) and evaluate the utility of exposing participants to repeated bouts of GLOC in promoting recovery time. BACKGROUND A substantial number of accidents among fighter pilots have resulted from episodes of GLOC. U.S. Air Force doctrine holds that(More)
INTRODUCTION Air-to-air refueling, formation flying, and projectile countermeasures all rely on a pilot's ability to be aware of his position and motion relative to another object. METHODS Eight subjects participated in the study, all members of the sustained acceleration stress panel at Wright-Patterson AFB, OH. The task consisted of the subject(More)
Objective: The aim of this study was to track the course of cerebral tissue oxygen saturation (rSO 2) and pilot performance during an episode of gravity-induced loss of consciousness (GLOC). Background: GLOC, a major problem facing pilots of high-performance aircraft, is brought about by a sudden reduction in rSO 2 as a result of increased +Gz force. It(More)