Cognitive Changes at High Altitude

Abstract

The effects of hypoxia on cognitive functions were investigated in two experiments. Two types of problem-solving and two immediate-memory tasks were used. The first experiment, carried out with five Ss for three days at 12,470 ft. after 15 days of practice at sea level, showed no changes in performance. In the second experiment, practice effects were counterbalanced with seven Ss for two days at sea level and two days at 14,250 ft. The results showed a significant impairment of performance in one kind of problem-solving, significant improvement in the other, and no significant change in immediate memory. In both experiments, Ss showed significant responses to hypoxia on the physiological measures taken. In Exp. II, the improved problem-solving was significantly correlated with changes in temperature and pulse rate, but the impaired problem performance did not achieve a significant correlation with these measures. The results suggest that performance under hypoxic conditions may depend upon an interaction among several factors including degree of practice, complexity of the psychological functions, and Ss' ability to respond to awareness of physiological deficits by increased effort.

Smoking attenuates regular aerobic exercise benefits to episodic free recall immediately following strenuous physical activity

“…These findings are consistent with several studies showing deficits in perceptual, memory and motor processes at altitudes of between 4200 and 8800 m where levels of atmospheric O 2 are attenuated (e.g. Cahoon, 1972;Hornbein, Townes, Schoene, Sutton, & Houston, 1989;Phillips, Griswold, & Pace, 1963). Mountaineers relative to matched controls have also exhibited performance deficits in learning and retention in perceptual and memory tasks (Kramer, Coyne, & Strayer, 1993).…”

Current status of research and theory in human problem solving.

“…Scores on math problems, which were solved concurrently with the vigilance tasks, declined noticeably less over the session than either the psychomotor or vigilance performance. Investigating the effects of hypoxia on problem solving, Phillips, Griswold, and Pace (1963) found that the extra effort exerted under high-altitude (14,250 ft.) conditions improved performance on arithmetic problems but impaired solving wordrhymes problems due to increased competition from strong alternative responses.…”

Actual and perceived cognitive performance during acute altitude exposure

“…However, the altitude at which these visual decrements, along with direct effects of hypoxia on neural tissue, influence performance on more complex tasks is equivocal. In a review of hypoxia literature between 1950and 1963, Tune (1964 tentatively concluded that significant impairments in perceptual-motor performance occur at 10,000 ft. He also issued a plea for more rigorous experimentation and suggested further investigations elucidating the effects of exposure to a specific altitude.…”

“…It has been shown that altitude adversely effects subjects' estimation of their exertion, even when quantitative measures of workload do not increase (Muza, 2000). Phillips et al (1963) noted that performance under hypoxic conditions might depend on an interaction of several factors which includes the subject's ability to respond to awareness of physiological deficits by increased effort. Heath and Williams (1979) reported that although decision-making tends to be impaired at high altitude, it appears such impairment can be overcome by motivation and training.…”