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Reaction time performance is related to brain blood flow during gravitational stress
Author(s) -
Phillips Aaron A,
Warburton Darren E.R.,
Drury C Taylor,
Bredin Shan S.D.
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.1085.8
Subject(s) - cerebral blood flow , medicine , heart rate , blood pressure , blood flow , cardiology , anesthesia
Speed of information processing is critical to effective air combat; however, little is known about the effect of gravitational stress on measures of processing speed. To examine, eight young healthy males (26 ± 6 years of age) underwent progressive lower body negative pressure (LBNP) while recording beat‐to‐beat blood pressure (BP), heart rate variability, brain blood flow (MCABF), and while testing simple reaction time (SRT). Baseline values were compared to the last tolerated stage of LBNP (LBNPmax) and the median stage (LBNP50). During LBNP, SRT was significantly slower compared to baseline (Baseline: 280±33, LBNP50: 324±39, LBNPmax: 316±37 ms, P < 0.05). Also, MCABF (Baseline: 65±6, LBNP50: 63±63, LBNPmax: 59±60 cm/s, P < 0.05) and pulsatility index (Baseline: 0.83±0.1, LBNP50: 0.72±0.15, LBNPmax: 0.65±0.1 au, P < 0.05) decreased during LBNPmax. From baseline to LBNP50 a significant correlation existed between changes in pulsatility index and SRT (r = −0.7; P < 0.05). Our data shows that SRT increases during LBNP. Further, it appears that at moderate gravitational stress those with greater reductions in brain blood perfusion demonstrate a more profound negative affect on SRT. At severe LBNP however, SRT does not appear to be related to brain blood flow or indirect markers of sympathovagal tone. This research was supported by the Natural Sciences and Engineering Research Council of Canada.