title: The prosthetics of vigilant attention: random cuing cuts processing demands.
abstract: OBJECTIVE
  Engagement in tasks requiring vigilant attention is susceptible to modulation by exogenous stimulation, reflected in changes in performance accuracy and speed. The shift from endogenous to exogenous control may be observed not only when the external cue is meaningful to the task, but also when it holds no information about the task or performance. The purpose of this study was to examine how the shift to exogenous engagement is reflected in changes to the well-documented, right-lateralized, frontal-parietal-thalamic vigilant attention network.
  
  
  METHODS
  Using functional magnetic resonance imaging , healthy participants were scanned as they performed the Sustained Attention to Response Task (SART) in 60-s blocks, some of which were presented with brief, random, auditory tones. The SART requires participants to overcome the tendency to respond in an automatic, task-driven manner in response to infrequent no-go stimuli.
  
  
  RESULTS
  Despite no overall effect on performance, and only a transient increase in response times immediately following the tones, the SART with alerting tones was associated with a diminished pattern of activation in key nodes of the network. The pattern of right-lateralized activity observed with the SART was attenuated with the tones, and activity in the right middle frontal gyrus was significantly diminished, as revealed by region-of-interest analyses.
  
  
  CONCLUSIONS
  Alerting tones provided the stimulation to cue the maintenance of the goal-state, reducing reliance on prefrontal control mechanisms and demonstrating the shift from endogenous top-down control to exogenous control. These findings suggest a neural mechanism for the facilitatory effects of exogenous engagement for patients with damaged top-down attentional brain systems.
authors.affiliation: Rotman Research Institute, University of Toronto.
authors.forename: Charlene
authors.initials: C
authors.lastname: O'Connor
authors.affiliation: Department of Psychology, Trinity College.
authors.forename: Ian H
authors.initials: IH
authors.lastname: Robertson
authors.affiliation: Rotman Research Institute, University of Toronto.
authors.forename: Brian
authors.identifier: 0000-0003-4343-811X
authors.initials: B
authors.lastname: Levine
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods; D000328:Adult; D001288:Attention / Q000502:physiology*; D001921:Brain / Q000098:blood supply / Q000502:physiology*; D001931:Brain Mapping; D003463:Cues; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation; D011930:Reaction Time; D014851:Wakefulness / Q000502:physiology*; D055815:Young Adult
chemical_list: D010100:Oxygen