Color discrimination under chronic hypoxic conditions (simulated climb "Everest-Comex 97")

Hypoxia is known to alter visual functions. In the present study, the effects of chronic hypobaric hypoxia upon visual color discrimination were studied in 8 subjects participating in a simulated climb from sea level (PO2 = 210 hPa) to 8,848 m (PO2 = 70 hPa) over a 31-day period of confinement in a decompression chamber ('Everst-Comex 97'). During these investigations, the subjects were required to discriminate between colors of different hue in the red, blue, and green ranges. Alterations in color discrimination increased slightly but significantly as altitude increased. Impairments occurred mainly in the red and blue ranges. In addition, our results further indicate that color discrimination would be affected only when a minimum threshold of difference between color stimuli is not present. Methodological and physiological implications are discussed.     

The impact of television,print, and audio on children's recall of the news.

Recent research has shown that children remember more from television news than from print news, a finding that has been explained by the extra mnemonic support offered by redundant television pictures (the dual‐coding hypothesis). The present study was designed to examine three alternative explanations, which attribute children's superior recall of television news to (a) underutilization of the print medium, (b) a recall advantage of listening compared with reading, and imperfect reading ability. A sample of 192 fourth and sixth graders was presented with children's news stories, either in (a) their original television form, (b) a bare print version, a print version supplemented with photo material or in (d) an audio version. Results indicated that the television presentation was remembered better than any of the other three versions. The results of the study were consistent with the dual‐coding hypothesis, whereas no support was found for the alternative explanations tested in the study.     

A study of mood changes and personality during a 31-day period of chronic hypoxia in a hypobaric chamber (Everest-Comex 97)

High altitudes of more than 3,000 meters produce physiological disorders and adverse changes in mood states. In the present study, we report analyses of mood states and personality traits in eight experienced climbers participating in a 31-day period of confinement in hypobaric chamber and gradual decompression from sea level to 8,848 m (Experiment 'Everest-Comex 97'). The subjects were tested at 5,500 m and 6,500 m on Day 13, 5,000 m and 6,500 m on Day 24, and 8,000 m and 8,848 m altitude on Days 27 and 31. Adverse changes in mood states, such as Vigor and Fatigue, occurred at 8,000 m and 8,848 m, which were significantly correlated with cerebral altitude symptomatology. In addition, a significant negative correlation was found between Fatigue and Factor C, which is a personality measure of emotional stability. We suggest that individuals with low emotional stability could be more sensitive to environmental stressors than more emotionally stable subjects who face reality.