The visual stress model--a psycho-physiological method for the evaluation of operational reliability of pilots and cosmonauts.

An experimental psycho-physiological method is presented for the evaluation of visual-cognitive performance preconditions and operational reliability of pilots and cosmonauts. As visual-cognitive stress are used tachistoscopically presented instrument symbols under conditions of individual speed of work and time pressure. The results of the compared extreme groups consisting of pilots with good and insufficient flight performance showed that the pilots with impairments to the quality of flight activity differ already before the test in their individual habitual characteristics and actual motivation, during the stress in their operational parameters, in the dimensions of their cardiorespiratory activation as well as in their efficiency and after the stress in their subjective experience of the stress. Conclusions are drawn for the evaluation of the aptitude of pilots and cosmonauts.

[Variability of normal grapho-elements and the assessment of abnormal grapho-elements in the EEG of clinically healthy test persons]. / Zur Variabilität normaler Wertung abnormer Graphoelemente im EEG klinisch gesunder Probanden.

The percentage pattern and topical distribution of alpha, beta, theta and delta waves, the occipital voltage level asymmetry of the alpha waves and the frequency of temporal functional disorders were studied in 100 17-year-olds, 273 male test persons of various age and 6,000 healthy persons. The results indicated that 1/4--1/8 of the test section is precentrally taken up by theta waves in the E.E.G. of healthy 17-year-olds. Random sampling on a larger scale shows that left occipital alpha wave domination is just as frequent as on the right; voltage level symmetry occurs only in 13--23 per cent of all cases. Three per cent of the clinically healthy persons showed local temporal E.E.G. anomalies which were on the left in 96 per cent of the cases. Attention is drawn to possible consequences with regard to nomenclature, evaluation and diagnostic assessment.

[Changes in acoustically evoked brain potentials during oxygen breathing at normal and increased pressures]. / Izmeneniia akusticheskikh vyzvannykh potentsialov mozga pri dykhanii kislorodom pod normal'nym i izbytochnym davleniem

Acoustically evoked potentials of the human brain were studied when breathing pure oxygen at a normal and positive pressure. An exposure to pure oxygen at a normal pressure reduced the amplitude of evoked potentials. This effect was more pronounced at a positive oxygen pressure. The after-effect was prolonged due to the influence of an increased oxygen concentration. During an exposure to the air at a positive pressure the reduction of the amplitude was smaller and reached the pretest level as soon as the pressure returned to normal. Evoked potentials are a sensitive indicator of the effect of an altered atmosphere on the central nervous system and the sensory system.