Effects of sensory modality on cerebral blood flow velocity during vigilance.
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 discrimination difficulty. Signal detection responses (correct detections and false alarms) and CBFV declined significantly over time in a linear manner for both modalities. In addition, the overall level of CBFV and the temporal decline in this measure were greater in the right than the left cerebral hemisphere. The results are consistent with the view that a right hemispheric system is involved in the functional control of vigilance and that this system operates in a similar manner in the auditory and visual channels.
Shaw
Tyler H
TH
George Mason University, Fairfax, VA 22030-4444, United States. tshaw4@gmu.edu
Warm
Joel S
JS
Finomore
Victor
V
Tripp
Lloyd
L
Matthews
Gerald
G
Weiler
Ernest
E
Parasuraman
Raja
R
D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D001288:Attention; D001783:Blood Flow Velocity; D002560:Cerebrovascular Circulation; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008297:Male; D010775:Photic Stimulation; D055815:Young Adult