The interaction of high altitude and psychotropic drug action

Evans, Wayne Ο.; Witt, Norman F.

doi:10.1007/bf00455979

Cited by 22 publications

(19 citation statements)

References 9 publications

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“…Although performance decrements in either reaction time, psychomotor skills or mental efficiency have been detected at altitudes as low as 2,100-3,000 m [8,14,25,28], there is no clear evidence that such relatively low altitudes have any effect on the performance of well-learned tasks [11,30]; the most clear-cut effect induced by altitudes of up to 3,000 m being an increased learning time [9]. At higher altitudes (4,300-6,100 m), decrements in reaction time [27], psychomotor ability [5,21,22,32,34] and mental efficiency [5,10,16,21,22,32] are clear. However, timedependent adaptive processes may occur as the duration of exposure to high altitude increases, so that repeated testing under hypobaric hypoxic conditions may induce learning effects and thus improve performance [5,25,32].…”

Section: Introductionmentioning

confidence: 99%

Cognitive performance during a simulated climb of Mount Everest: implications for brain function and central adaptive processes under chronic hypoxic stress

Abraini¹,

Bouquet²,

Joulia³

et al. 1998

Pfl�gers Archiv European Journal of Physiology

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High altitude is characterized by hypoxic environmental conditions and is well known to induce both physiological and psychological disturbances. In the present study, called ”Everest-Comex 97”, the authors investigated the effects of high altitude on the psychosensorimotor and reasoning processes of eight climbers participating in a simulated climb from sea level to 8,848 m over a 31-day period of confinement in a decompression chamber. Tests of visual reaction time, psychomotor ability, and number ordination were used. The climbers’ data were compared with data from a similar laboratory study at sea level in control subjects. Continued testing of the control subjects at sea level clearly led to learning effects and improvement of performance in psychomotor ability and number ordination. In the climbers, similar learning effects occurred up to an altitude of 5,500–6,500 m. With further increases in altitude, the climbers’ psychomotor performance and mental efficiency deteriorated progressively, leading to significant differences in psychomotor ability and mental efficiency between control subjects and climbers (9 and 13% respectively at 8,000 m and 17.5 and 16.5% respectively at 8,848 m). Three days (72 h) after the climbers had returned to sea level, their mental and psychomotor performances were still significantly lower than those of control subjects (by approximately 10%). In contrast, visual reaction time showed no significant changes in either climbers or control subjects. It is suggested that chronic hypoxic stress could alter selectively mental learning processes, i.e. explicit, rather than implicit (stimulus-response learning processes) memory and cortico-limbic rather than basal ganglia-sensorimotor system function.

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Section: Introductionmentioning

confidence: 99%

Cognitive performance during a simulated climb of Mount Everest: implications for brain function and central adaptive processes under chronic hypoxic stress

Abraini¹,

Bouquet²,

Joulia³

et al. 1998

Pfl�gers Archiv European Journal of Physiology

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“…Codeine is metabolised to morphine in the body, and pain studies suggest that the analgesic effect from codeine is caused by morphine. Experimental studies have shown impairment in traffic related tests, but concentrations of morphine and codeine in blood have not been measured in these studies [6][7][8][9][10]. Codeine was therefore not included on the list on the assumption that morphine levels will identify cases where codeine, morphine, or heroin have been used.…”

Section: Impairment Limitsmentioning

confidence: 99%

Impairment based legislative limits for driving under the influence of non-alcohol drugs in Norway

Vindenes¹,

Jordbru²,

Knapskog³

et al. 2012

Forensic Science International

115

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“…Color vision has also been found to be affected by higher altitudes; Richalet et al ( 16 ) observed a reduced sensitivity to green in relation to red at altitudes of around 13,123 ft (4000 m). The effects of altitude on attention capacity have also been described; Evans and Witt ( 5 ) found impairments in performance on the digit symbol test at an altitude of 13,780 ft (4200 m), while Stivalet et al ( 29 ) found that hypoxia induces impairments in visual search tasks, and Horng et al ( 10 ) observed that the effective visual fi eld is reduced at higher altitudes.…”

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confidence: 96%