Aviat Space Envir Md
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Aviat Space Envir Md · Feb 2006
Controlled Clinical TrialCardio-respiratory responses evoked by transient linear acceleration.
Predictive control of the responses to re-orientating stimuli and its interaction with vestibular signals may be an important factor in protecting against spatial disorientation. Here we evaluated the influence of stimulus predictability on the cardio-respiratory responses to transient fore-aft linear accelerations. ⋯ A vestibulo-cardiac response is evoked by transient linear acceleration, independently from the phase of the breathing cycle and from the predictability of the stimulus. A vestibular signal of motion appears to be required to produce a prolonged increase in heart rate.
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Aviat Space Envir Md · Feb 2006
Randomized Controlled TrialCerebral blood flow velocity and psychomotor performance during acute hypoxia.
The physiological effects of hypoxic environments can help determine safe limits for workers where cognitive and motor performance is important. We investigated the effects of a PIO2 of 15 kPa and 10 kPa on medial cerebral artery blood flow velocity (CBFV) and psychomotor performance. ⋯ A PIo2 of 15 kPa did not affect subject performance, and should not cause operational risk. At 10 kPa PIO2, accuracy and vigilance were slightly affected; however, the reduction in oxygenation was not great enough to cause major decrements. CBFV was not a good indicator of mental stress during hypoxia.