The impact of thermal stress on psychological performance has been the subject of considerable research attention. However, the effects of heat on performance are poorly understood. The literature yields inconsistent results, reflecting methodological shortcomings in previous research, particularly with regard to the definition of the independent variable. Investigators have focused on heat stress per se to the neglect of the participants' thermal physiological response. In addition, investigators have typically tested small samples, and have relied on a limited range of performance measures of unknown sensitivity. Few theoretical accounts of performance during thermal stress have been proposed, and these are poorly elaborated. The principal aim of this research programme was to elucidate the effects of heat on psychological performance. Emphasis was placed on defining the independent variable in terms of physiological strain. Performance was measured using a comprehensive range of sensitive tasks. In the first and second experiments, an innovative water immersion technique was used to control thermal strain precisely. The principal effect of heat strain observed in these experiments was an increase in the speed of performance, without variation in accuracy. This effect was attributed to an increase in nerve conduction velocity associated with raised body temperature. The duration of immersion in the second experiment was fifty percent longer than that in the first, but little variation in performance with the duration of heat strain was evident. In light of the limited external validity of the immersion experiments, subsequent investigation focused on the effects of more realistic sources of thermal strain. A survey of military personnel indicated that occupational exposure to thermal stress is perceived to impair some cognitive and psychomotor functions. The final experiment measured performance during prolonged exposure to heat stress in a climatic chamber. The results indicate that the performance changes observed in the immersion experiments generalize to conditions involving exposure to more realistic sources of heat strain
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:299368 |
| Date | January 1999 |
| Creators | O'Connor, Elinor Margaret |
| Publisher | University of Bristol |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1983/b4f02107-da11-401c-b97f-cd7dfdeb200a |
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