Relationships between mood states and performances in reaction time, psychomotor ability, and mental efficiency during a 31-day gradual decompression in a hypobaric chamber from sea level to 8848 m equivalent altitude

High altitude is characterized by hypoxic environmental conditions that may induce a set of pathological disorders, known as acute mountain sickness. In addition to the physiological symptoms, exposure to high altitude may also produce adverse changes in motor skills, mental efficiency, and mood states, including anxiety. In the present study, we investigated the relationships between mood states, including anxiety, and performance changes in reaction time, psychomotor ability and mental efficiency in eight climbers participating in the ‘Everest-Comex 97’, a 31-day gradual decompression in a hypobaric chamber from sea level to 8848 m equivalent altitude. Tests of visual reaction time, manual dexterity, and number ordination were used; anxiety responses and mood states were assessed using the Spielberger State–Trait Anxiety Inventory (STAI) and the ‘Profile of Mood States’ (POMS), respectively. A significant positive correlation was found between the climbers' performance in reaction time and changes in state-type anxiety levels, suggesting that anxiety could lead to an improved reaction time. In addition, significant negative correlations were also found between the climbers' performance in psychomotor ability, mental efficiency, and reaction time, and several POMS factors, including Tension, Hostility, Confusion, and Fatigue. Overall, these data indicate, in agreement with previous studies, that anxiety may favour, or at least not alter, the processes of information of relatively simple tasks, such as reaction time, and further suggest that adverse changes in moods could modulate performance negatively.