Анализ парадоксальных нейрофизиологических реакций на разных этапах восприятия отрицательных эмоциональных стимулов у больных шизофренией

Abstract

The article is aimed at the study of brain activation to neutral and emotionally significant (threatening) stimuli with evoke potential (EP) method in patients with paranoid schizophrenia and healthy controls. It was shown that threatening stimuli, as more significant, cause greater activation (shortening of latency and increase of amplitude) in the occipital and posterior temporal regions to such stimuli in comparison with neutral ones both in patients and in norm in an intragroup assessment. After 200 ms this increase was observed in the right, after 300 ms – in the left, and after 400 ms – again in the right hemisphere. However, in patients, at the P200 wave, to significant stimuli, there began a physiologically paradoxical effect. In the left lower frontal area there was an increase in both amplitude and latency of the P200 wave and a decrease in both these parameters in the right frontal and central midline areas. 300 ms after the stimulus paradoxical effects (PE) in the form of increase of both parameters were observed in left prefrontal and right lower frontal areas, and a decrease – in the left lower frontal and central midline areas. After 400 ms, PE was observed in left prefrontal and right lower frontal areas as an increase in both parameters and in the right prefrontal – as their decrease. An intergroup comparison showed that patients had either a simultaneous increase or decrease of both parameters of all components of evoked potentials (ERP) starting with the P200 in comparison with norm, thus indicating the pathological state (PS) of the anterior brain regions in response to emotionally significant stimuli, which may be caused by several alternative factors. This can be explained by a disturbance of neural connections due to the pathological process of aberrant pruning in patients with schizophrenia.