Biomedical subjects

P Therme

Publications and source records attributed to P Therme.

8 recordsLinked to original sources

PubMed2000

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.

Adaptation, Psychological↗

PubMed2000

Effects of different stay durations on attentional performance during two mountain expeditions.

BACKGROUND: Hypoxia-induced deficits in intellectual performance are linked to the altitude level reached, the speed of the ascent and the time spent at high altitude. This study analyzes attentional changes during adaptation to two different types of stay at high altitude on two different expeditions: one involving a 16-d trip between 2,000 m and 5,600 m, followed by a 2-d ascent to 6,440 m and back again; the other, a 21-d stay at 6,542 m. We tested the hypothesis that, at similar high altitudes, decrements in attentional performance would only occur during a long duration stay. METHODS: Indexes for attentional performance were calculated for two experimental groups under normoxia before the climb, under acute and chronic hypoxia during the climb, and under normoxia after the climb. They were compared for two control groups tested only under normoxia. RESULTS: The altitude stay was found to have an effect on the 6,542 m group when compared with the controls. Group performance differed at 2 d and 21 d after their arrival at 6,542 m and after their return to normoxia. When all the test administrations were pooled together for this expedition we noted an interaction between the level of difficulty of the task and the experimental and control groups: namely the difference between the groups was greater for the difficult task than it was for the easy task. No effect was found for the other expedition (at 5,600 m) when the group tested was compared with the controls. CONCLUSION: For a 21-d stay at an altitude of 6,542 m with the same ascent protocol as a group climbing to a lower altitude (16 d between 2,000 m and 5,600 m followed by a 2 d ascent to 6,440 m and back again), subjects appeared to suffer from attentional performance deficits which persisted for several days after the subjects returned to normoxic conditions.

Acclimatization↗

PubMed1999

An anxiety, personality and altitude symptomatology study during a 31-day period of hypoxia in a hypobaric chamber (experiment 'Everest-Comex 1997').

Extreme environmental situations are useful tools for the investigation of the general processes of adaptation. Among such situations, high altitude of more than 3000 m produces a set of pathological disorders that includes both cerebral (cAS) and respiratory (RAS) altitude symptoms. High altitude exposure further induces anxiety responses and behavioural disturbances. The authors report an investigation on anxiety responses, personality traits, and altitude symptoms (AS) in climbers participating in a 31-day period of confinement and gradual decompression in a hypobaric chamber equivalent to a climb from sea-level to Mount Everest (8848 m altitude). Personality traits, state-trait anxiety, and AS were assessed, using the Cattell 16 Personality Factor questionnaire (16PF), the Spielberger's State-Trait Anxiety Inventory (STAI), and the Lake Louise concensus questionnaire. Results show significant group effect for state-anxiety and AS; state-anxiety and AS increased as altitude increased. They also show that state-type anxiety shows a similar time-course to cAS, but not RAS. Alternatively, our results demonstrate a significant negative correlation between Factor M of the 16PF questionnaire, which is a personality trait that ranges from praxernia to autia. In contrast, no significant correlation was found between personality traits and AS. This suggests that AS could not be predicted using personality traits and further support that personality traits, such as praxernia (happening sensitivity), could play a major role in the occurrence of state-type anxiety responses in extreme environments. In addition, the general processes of coping and adaptation in individuals participating in extreme environmental experiments are discussed.

Adaptation, Physiological↗

PubMed1999

Criteria for psychological adaptation to high-altitude hypoxia.

The purpose of this study was to test an ascent program for ideal psychological adaptation to high altitudes. A psychological approach was used to test a model describing a gradual step-by-step ascent. Seven subjects spent nine days between 3,500 m and 4,400 m altitude, followed by eight days climbing 500 m each day from 3,500 m to 5,400 m. They performed a cognitive-motor task three times, once under normoxia, once under acute hypoxia, and once under chronic hypoxic conditions. Durations for these subjects were compared with those obtained by a control group tested under normoxia. Subjects' emotional state was assessed by analyzing their remarks during an interview conducted at 5,400 m and by calculating from the answers given to the three questions, a mood index for each subject. Analysis showed that the performances of both groups improved on the second and third administrations of the test. There was, however, no interaction between the group and the time of administration. Mood indexes indicated that the majority of the subjects had no trouble in adapting to the situation and few cognitive or emotional disturbances were observed. These findings may be attributed to the ascent being well designed and planned thereby preventing various possible forms of mountain sickness and other pathologies from developing in the subjects.

Acclimatization↗

PubMed1998

Personality patterns of anxiety during occupational deep dives with long-term confinement in hyperbaric chamber.

Extreme environments are generally thought to be stressful situations. Occupational deep diving inflicts periods of long-term confinement in hyperbaric chambers and high-pressure exposure on divers. Such extreme environmental conditions have been demonstrated to produce acute responses of anxiety in individual divers. Although these studies have mentioned personality as a factor explaining why some divers reported an increase in ratings of anxiety, the role of personality traits still remains unclear. The present study examines the possible role of personality traits in the development of diving anxiety. Results confirm that diving anxiety remains at the individual level and relatively transient and suggest that personality factors, such as low self-control and emotional instability, that reflect an incapacity to control and express tension in an appropriate manner would play a crucial role in the occurrence of diving anxiety.

Adult↗

PubMed1995

Psychological changes during altitude hypoxia.

We examined the effects of altitude hypoxia on the subject's cognitive functions and psychological state. Two assessment approaches were used, a cognitive-motor task and a structured interview. An experimental group of six subjects was tested three times: once under conditions of normoxia, once 8-20 h after a rapid climb to an altitude of 4383 m, and once 48-60 h after ascent to that altitude. A comparison of the experimental group's performance on the cognitive-motor task with that of a control group showed a difference on the second administration: the experimental group's performance did not improve, whereas the control group's performance did. This difference recovered on the third administration. A comparison of the subjects' verbalizations during the three interviews showed that they experienced a strong crisis during the first period at altitude, which improved partially during the second period. Evidence for use of certain defense mechanisms, e.g. self-concern, was found 8-20 h after ascent; both dependent measures were adversely affected. These measures recovered after 48-60 h.

Adult↗

PubMed1992

Development of complex motor skills in psychotic children.

This article describes the study of the concurrent complex mechanisms which take place during behavioral changes in psychotic children and adolescents when they are asked to learn a motor task, in this case, to practise the sport of judo. Complex motor skills can be acquired by the psychotic subject insofar as the proposed physical activity is isomorphous with the psychosis. The different stages of development are marked by different levels structuring interpersonal space. The examination treats the linking processes between psychic mechanisms and motor behavior from a developmental perspective.

Adolescent↗

PubMed1992

[Training in motor skills and psychopathology. Climbing with psychotic children].

The author investigates learning skills in psychotic and borderline children through the physical activity of climbing. Motor skills are considered as an interaction between the subject and his/her environment. Motor learning skills have been studied throughout 6 training sessions in rock-climbing. Etho-clinical methods of investigation allow to assess behaviors and the meaning given by the subject to different forms of action. The author emphasizes here the pleasure/anxiety dimensions of this activity. Results show remarkable learning skills in these children. Significant increase in motor activity and in the height reached point to an obvious integrity of the mechanisms necessary to motor acquisitions. These results are closely linked with the characteristics of rock climbing, a sport involving clinging behaviors and leading to a mastering of the primary anxiety of loosing support.

Child↗