Journal of Applied Physiology, Vol 74, Issue 4 1735-1741, Copyright © 1993 by American Physiological Society
Cognitive performance and event-related brain potentials under simulated high altitudes
M. Kida and A. Imai
Department of Autonomic and Behavioral Neurosciences, Nagoya University, Japan.
The effects of hypobaric hypoxia on cognitive processing in humans were
studied by recording event-related potentials (ERPs) from the scalp in a
go/no-go reaction time (RT) paradigm under various simulated high
altitudes. Most subjects indicated abrupt impairment of RT at high
altitudes. RTs lengthened in association with changes in latency and
amplitude of the N2-P3 components, reflecting sensory discrimination and
evaluation processes. Some subjects did not suffer any changes in RT up to
an extremely high altitude of 6,000 m. In the latter case, although the
N2-P3 components did not undergo any changes, the P3 component was followed
by a sequence of negative on-going (frontal maximum) and positive on-going
(parietal maximum) slow waves. The amplitudes of these slow waves increased
as altitude increased. Although these same waves appeared in the ERPs of
subjects who demonstrated the increase in RTs at high altitudes, when the
subjects failed in the RT task, both of the slow waves either disappeared
or diminished. Such slow waves may be associated with attempts to maintain
RTs against the deteriorative effects of hypobaric hypoxia.
