Somatic Responses and Performance Levels during Anticipatory Physical-Threat Stress

Abstract

20 general aviation pilots flew a series of simulated instrument flights under stress and non-stress conditions. During flight, muscle action potentials from the masseter muscle and eye blink were monitored. The relationship of these two measures of somatic activity to each other and to performance scores was determined on an inter- and intra-individual basis. Both linear and curvilinear coefficients were computed. Levels of somatic activity rose significantly from the control to stress flight. Individual reliability of blink rate and intra-individual reliability of masseter activity and blink rate were significant across flights. A significant curvilinear relationship was present between blink rate and masseter tension. In general, performance errors were fewer in those Ss with lower levels of somatic tension and during flight sectors in which masseter activity was low or moderate. High error scores were found in those sectors in which blink rate was low or moderate.