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Cognitive and psychomotor responses to high-altitude exposure in sea level and high-altitude residents of Ecuador.

Davis JE, Wagner DR, Garvin N, Moilanen D, Thorington J, Schall C - J Physiol Anthropol (2015)

Bottom Line: Cognitive/psychomotor measurements included a go-no-go test (responding to a non-visual stimulus), a verbal fluency test (verbalizing a series of words specific to a particular category), and a hand movement test (rapidly repeating a series of hand positions).There were no significant differences (p = 0.168) between LOW, MOD, and HIGH for the verbal fluency test.However, the go-no-go test was significantly lower (p < 0.001) in the HIGH group (8.8 ± 1.40 correct responses) than the LOW (9.8 ± 0.61) or MOD (9.8 ± 0.55) groups, and both MOD (97.9 ± 31.2) and HIGH (83.5 ± 26.7) groups completed fewer correct hand movements than the LOW (136.6 ± 37.9) subjects (p < 0.001).

View Article: PubMed Central - PubMed

Affiliation: Department of Integrative Physiology and Health Science, Alma College, 614 Superior Street, Alma, MI, 48801, USA. davisj@alma.edu.

ABSTRACT

Background: High-altitude inhabitants have cardiovascular and respiratory adaptations that are advantageous for high-altitude living, but they may have impaired cognitive function. This study evaluated the influence of altitude of residence on cognitive and psychomotor function upon acute exposure to very high altitude.

Findings: Ecuadorians (31 residing at 0-1,500 m [LOW], 78 from 1,501-3,000 m [MOD], and 23 living >3,000 m [HIGH]) were tested upon their arrival to a hut at 4,860 m on Mount Chimborazo. Cognitive/psychomotor measurements included a go-no-go test (responding to a non-visual stimulus), a verbal fluency test (verbalizing a series of words specific to a particular category), and a hand movement test (rapidly repeating a series of hand positions). Mean differences between the three altitude groups on these cognitive/psychomotor tests were evaluated with one-way ANOVA. There were no significant differences (p = 0.168) between LOW, MOD, and HIGH for the verbal fluency test. However, the go-no-go test was significantly lower (p < 0.001) in the HIGH group (8.8 ± 1.40 correct responses) than the LOW (9.8 ± 0.61) or MOD (9.8 ± 0.55) groups, and both MOD (97.9 ± 31.2) and HIGH (83.5 ± 26.7) groups completed fewer correct hand movements than the LOW (136.6 ± 37.9) subjects (p < 0.001).

Conclusions: Based on this field study, high-altitude residents appear to have some impaired cognitive function suggesting the possibility of maladaptation to long-term exposure to hypobaric hypoxia.

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Related in: MedlinePlus

Number of correct words produced in 60 s for the LOW, MOD, and HIGH groups. There were no significant differences between residence altitudes (p = 0.168).
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Fig1: Number of correct words produced in 60 s for the LOW, MOD, and HIGH groups. There were no significant differences between residence altitudes (p = 0.168).

Mentions: A total of 132 Ecuadorians (31 LOW, 78 MOD, 23 HIGH) completed the study. There was no significant difference in age, body mass, height, arterial oxygen saturation (SaO2), or a self-assessment of acute mountain sickness (LLSS) between groups (Table 1). For the verbal fluency test, HIGH produced the fewest number of words (Figure 1); however, there were no significant differences (F2,130 = 1.807, p = 0.168) between groups. Virués-Ortega and colleagues [15] highlighted numerous examples of impaired verbal fluency as a result of high-altitude exposure in their review of neuropsychological functioning associated with this environment. However, the majority of these studies involved mountaineers going to extreme altitudes. Other researchers have shown that verbal impairment due to high altitude occurs only at 6,000 m or higher [16] and is only temporary, returning to baseline upon return to sea level [17].Table 1


Cognitive and psychomotor responses to high-altitude exposure in sea level and high-altitude residents of Ecuador.

Davis JE, Wagner DR, Garvin N, Moilanen D, Thorington J, Schall C - J Physiol Anthropol (2015)

Number of correct words produced in 60 s for the LOW, MOD, and HIGH groups. There were no significant differences between residence altitudes (p = 0.168).
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4320830&req=5

Fig1: Number of correct words produced in 60 s for the LOW, MOD, and HIGH groups. There were no significant differences between residence altitudes (p = 0.168).
Mentions: A total of 132 Ecuadorians (31 LOW, 78 MOD, 23 HIGH) completed the study. There was no significant difference in age, body mass, height, arterial oxygen saturation (SaO2), or a self-assessment of acute mountain sickness (LLSS) between groups (Table 1). For the verbal fluency test, HIGH produced the fewest number of words (Figure 1); however, there were no significant differences (F2,130 = 1.807, p = 0.168) between groups. Virués-Ortega and colleagues [15] highlighted numerous examples of impaired verbal fluency as a result of high-altitude exposure in their review of neuropsychological functioning associated with this environment. However, the majority of these studies involved mountaineers going to extreme altitudes. Other researchers have shown that verbal impairment due to high altitude occurs only at 6,000 m or higher [16] and is only temporary, returning to baseline upon return to sea level [17].Table 1

Bottom Line: Cognitive/psychomotor measurements included a go-no-go test (responding to a non-visual stimulus), a verbal fluency test (verbalizing a series of words specific to a particular category), and a hand movement test (rapidly repeating a series of hand positions).There were no significant differences (p = 0.168) between LOW, MOD, and HIGH for the verbal fluency test.However, the go-no-go test was significantly lower (p < 0.001) in the HIGH group (8.8 ± 1.40 correct responses) than the LOW (9.8 ± 0.61) or MOD (9.8 ± 0.55) groups, and both MOD (97.9 ± 31.2) and HIGH (83.5 ± 26.7) groups completed fewer correct hand movements than the LOW (136.6 ± 37.9) subjects (p < 0.001).

View Article: PubMed Central - PubMed

Affiliation: Department of Integrative Physiology and Health Science, Alma College, 614 Superior Street, Alma, MI, 48801, USA. davisj@alma.edu.

ABSTRACT

Background: High-altitude inhabitants have cardiovascular and respiratory adaptations that are advantageous for high-altitude living, but they may have impaired cognitive function. This study evaluated the influence of altitude of residence on cognitive and psychomotor function upon acute exposure to very high altitude.

Findings: Ecuadorians (31 residing at 0-1,500 m [LOW], 78 from 1,501-3,000 m [MOD], and 23 living >3,000 m [HIGH]) were tested upon their arrival to a hut at 4,860 m on Mount Chimborazo. Cognitive/psychomotor measurements included a go-no-go test (responding to a non-visual stimulus), a verbal fluency test (verbalizing a series of words specific to a particular category), and a hand movement test (rapidly repeating a series of hand positions). Mean differences between the three altitude groups on these cognitive/psychomotor tests were evaluated with one-way ANOVA. There were no significant differences (p = 0.168) between LOW, MOD, and HIGH for the verbal fluency test. However, the go-no-go test was significantly lower (p < 0.001) in the HIGH group (8.8 ± 1.40 correct responses) than the LOW (9.8 ± 0.61) or MOD (9.8 ± 0.55) groups, and both MOD (97.9 ± 31.2) and HIGH (83.5 ± 26.7) groups completed fewer correct hand movements than the LOW (136.6 ± 37.9) subjects (p < 0.001).

Conclusions: Based on this field study, high-altitude residents appear to have some impaired cognitive function suggesting the possibility of maladaptation to long-term exposure to hypobaric hypoxia.

Show MeSH
Related in: MedlinePlus