Evaluation of the functional state of operators with allowance for individual psychological characteristics

This article deals with the features of the evaluation of changes in the functional state during the professional activity of operators. We estimated the dynamics of the functional state and efficiency of operators under the effect of aircraft noise and individual psychophysiological characteristics. We also investigated changes in the functional state of operators depending on their psychological characteristics. It was found that changes in the functional state of the organism in operators with high levels of anxiety, low degrees of extraversion, and high emotional lability were more pronounced in the modeling of operator activity with exposure to aircraft noise, as evidenced by significant changes in psychophysiological parameters. After 60 minutes of noise stress, the latent period of a simple and a complex sensorimotor reaction in introverts increased by 9.1% (p < 0.05) and 8.1% (p < 0.05), respectively. In the group of subjects with high levels of anxiety, there was a decrease in the general state, activity, and mood by 18.9% (p < 0.01), 20.9%, and 14.9% (p < 0.05), respectively, and a decrease in the accuracy of reaction to a moving object by three times (p < 0.05). The latent period of simple sensorimotor reaction in emotionally labile subjects after the exercise was increased by 15% (p < 0.05), and the reaction time on a moving object was increased by 8.9% (p < 0.05) as compared with the group of emotionally stable subjects. Thus, the data suggest that changes in the functional state of operators depends on the level of extraversion, personal anxiety, and emotional lability, and does not depend on the level of behavioral regulation, which must be taken into consideration during the assessment of functional state.     

Fractal characteristics of the functional state of the brain in patients with anxiuos phobic disorders

The task of estimating the functional state of the CNS with the pain syndrome in patients with anxious phobic disorders is examined. For solving the task, the methods of spectral and multifractal analyses of EEG segments are applied during the perception of psychogenic pain and its removal by the psychorelaxation technique. It has been demonstrated that contrary to power spectra, singularity spectra allow distinguishing EEGs quantitatively in the examined functional states of the brain. Pain suppression in patients with anxious phobic disorders during psychorelaxation is accompanied by changing the width of the singularity spectrum and approximation of the multifractal parameter to the value corresponding to healthy subjects.     

Fractal characteristics of the functional state of the brain in patients with anxious phobic disorders

The task of estimation of the functional state of the human brain during psychotherapeutic treatment of psychogenic pain in patients with anxious phobic disorders is examined. For solving the task the methods of spectral and multifractal analyses of EEG fragments are applied during the perception of psychogenic pain and its removal by the psychorelaxation technique. Contrary to power spectra singularity spectra allow to distinguish EEGs quanitatively in the examined functional states of the human brain. The pain suppression in patients with anxious phobic disorders during psychorelaxation is accompanied by changing the width of the singularity spectrum and approximation of this multifractal partameter to the value corresponding to a healthy subject.     

A model of the smooth pursuit eye movement system

Human, horizontal, smooth-pursuit eye movements were recorded by the search coil method in response to Rashbass step-ramp stimuli of 5 to 30 deg/s. Eye velocity records were analyzed by measuring features such as the time, velocity and acceleration of the point of peak acceleration, the time and velocity of the peaks and troughs of ringing and steady-state velocity. These values were averaged and mean responses reconstructed. Three normal subjects were studied and their responses averaged. All showed a peak acceleration-velocity saturation. All had ringing frequencies near 3.8 Hz and the mean steady-state gain was 0.95.It is argued that a single, linear forward path with any transfer function G(s) and a 100 ms delay (latency) cannot simultaneously simulate the initial rise of acceleration and ring at 3.8 Hz based on a Bode analysis. Also such a simple negative feedback model cannot have a steady-state gain greater than 1.0; a situation that occurs frequently experimentally. L.R. Young's model, which employs internal positive feedback to eliminate the built-in unity negative feedback, was felt necessary to resolve this problem and a modification of that model is proposed which simulates the data base. Acceleration saturation is achieved by borrowing the idea of the local feedback model for saccades so that one nonlinearity can account for the acceleration-velocity saturation: the main sequence for pursuit. Motor plasticity or motor learning, recently demonstrated for pursuit, is also incorporated and simulated.It was noticed that the offset of pursuit did not show the ringing seen in the onset so this was quantified in one subject. Offset velocity could be characterized by a single exponential with a time constant of about 90 ms. This observation suggests that fixation is not pursuit at zero velocity and that the pursuit system is turned on when needed and off during fixation.     

New methods for removing saccades in analysis of smooth pursuit eye movement

New computation methods for removing saccades in analysis of smooth pursuit eye movement characteristics were developed. They have removed saccades more completely than previous methods, and were very effective especially for noisy data recorded by the EOG method. The fully developed method was applicable to eye movement data in tracking of pseudo-random target movement as well as deterministic target movement. Furthermore, the methods were also useful for extracting the number and magnitudes of saccades more precisely.     

Assessment of the functional state from the cardiogram during a bicycle exercise test

The instantaneous heart rate (HR) characterizing the escape of the cardiac muscle from autonomic control is determined by analyzing a mathematical model of the variation of R-R intervals obtained during an exercise test. The relationship between the escaping HR and cyclic exercise intensity determines the possibility of using this criterion for dynamic monitoring of the functional state.     

Monitoring the functional state of human operators by the parameters of the fundamental tone and spectrum of speech

The possibility of distant monitoring of the functional state of a human operator by speech signal parameters is considered. Examples of this monitoring in pilots during simulated and real flights are presented.     

Assessment of the value of prednisone test in differential diagnosis of neutropenic state.

The prednisone test revealed normal bone marrow reserve of neutrophils (BMR) in subjects with innocent neutropenias e.g. neutropenias not associated with any other disturbances in haemopoiesis or with increased incidence of infections, assumed to be an individual anomaly of the subject. On the other hand, diminution or absence of MBR in chronic hypoplastic neutropenias, transient post-chemotherapeutic neutropenias and neutropenias with increased destruction of neutrophils were observed. The magnitude of that diminution was not dependent of the cause of neutropenia. It is suggested, that the prednisone test (and probably tests with other BMR mobilizing agents) may serve as screening tests for exclusion (or confirmation) of relative granulopoietic insufficiency as the cause of neutropenia. Only after confirmation of reduced BMR another explanations of neutropenia should be sought using other method as muramidase level, adrenaline test or granulocyte kinetics with DF32P, 3HDFP, or 51Cr.     

Comparison of characteristic of smooth pursuit in left-handed and right-handed subjects

In a study on healthy young adults with the use of a stroboscopic stimulation, estimation of the efficiency of smooth pursuit has been performed. The influence of manual function asymmetry on smooth pursuit has been studied. It has been shown that markedly right-handed (“strong right-handed”) persons display a high efficiency of smooth pursuit of stimuli moving horizontally in the rightward and leftward directions with velocities of 20°/s and 25°/s. Left-handed persons track similar stimuli, on average, worse than the “strong right-handed” ones. The influence of manual function asymmetry on the dependence of the smooth pursuit efficiency on the moving stimuli direction (left to right or right to left) has not been observed.     

Method for determining the functional state of the human respiratory and circulatory systems in underwater conditions]

An original device has been worked out which permits registering parameters of respiration, gas exchange and circulation in man during diving and performance of some tests under water (graduated exercise, respiration with changed gas mixture, etc.). The correction coefficients have been experimentally determined to calculate the gas exchange and cardiohemodynamics indices in underwater conditions. The indices of human work capacity under water are determined using the above device.