Effect of emotional stress on recognition of visual patterns.

The object of the study was to observe the changes in efficiency of perceptive activity of man (recognition of visual patterns against a background of noises) throughout an increase in emotional stress caused by a forthcoming parachuete jump. A moderate degree of emotional stress can improve performance efficiency and decrease the number of the subject's errors. Later an impairment of differentation of similar signals was seen and an increase in the number of "false alarm" errors along with a decrease in the number of omissions to reactions signals. The neurophysiological basis of such changes in perceptive activity consists in a transition from conditional behaviour to reaction through mechanisms of Ukhtomsky's dominant focus.