title: Relation of cerebral blood flow velocity and level of vigilance in humans.
abstract: Blood flow velocities in both middle cerebral arteries (MCA) were measured using transcranial Doppler ultrasound (TCD) in healthy subjects engaged in a continuous static visual vigilance task. Stimuli comprised white vertical gratings on a black background with a size of 5 x 5" (non-targets) or 5 x 3.5" (targets). Button presses were required to the rare (8.5%) targets. Over the 30 min session a decrease in hit rate and an increase in reaction time were seen, indicating a decrease in vigilance. These performance changes were paralleled by a decrease in flow velocity in both MCAs. No hemispheric difference was seen. These data suggest a close coupling of performance and blood flow in vigilance tasks. Modulation of cholinergic activity during the vigilance task might be the common underlying mechanism.
authors.affiliation: Department of Neurology, Medizinische Rochschule Hannover, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Schnittger
authors.forename: S
authors.initials: S
authors.lastname: Johannes
authors.forename: A
authors.initials: A
authors.lastname: Arnavaz
authors.forename: T F
authors.initials: TF
authors.lastname: Münte
mesh_terms: D000328:Adult; D001143:Arousal / Q000502:physiology*; D001783:Blood Flow Velocity / Q000502:physiology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D011930:Reaction Time / Q000502:physiology*; D013647:Task Performance and Analysis; D017585:Ultrasonography, Doppler, Transcranial