Specific changes in auditory cognitive evoked potentials in those who participated in the liquidation of the chernobyl accident: I. Analysis of the early N1 component

• Published in: Human physiology 2010-03, Vol.36 (2), p.147-157
• Main Authors: Zhavoronkova, L. A, Belostocky, A. P, Koulikov, M. A, Oknina, L. B, Kholodova, N. B, Kuptsova, S. V
• Format: Article
• Language: English
• Subjects: auditory cognitive evoked potential; Biomedical and Life Sciences; Biomedicine; Chernobyl accident; Human Physiology; Life Sciences; N1 component
• ISSN: 0362-1197; 1608-3164
• DOI: 10.1134/S0362119710020040

The amplitude and temporal parameters of the N1 component of the auditory cognitive evoked potential (EP) were analyzed in ten people who participated in the elimination of the consequences of the Chernobyl accident (the liquidators) and ten healthy subjects aged 47 ± 6.0 and 50.5 ± 4.0 years, respectively. In the liquidators of the Chernobyl accident, the amplitudes of the N1 component of the auditory EP were decreased in all cortical areas. This decrease was the greatest in the central and frontal areas. The changes in response to stimuli of different significances in the liquidators were inverted as compared to the healthy subjects of the same age. The differences between the control group and the liquidators were the most pronounced in the temporal characteristics of the N1 component. The latent periods (LPs) for all stimuli presented under all experimental conditions were significantly shorter in the group of liquidators, and this effect was even stronger for the significant stimulus in the case of stimulus counting. In the liquidators, the maximum changes in the LPs of the N1 component were observed in the frontal area of the left hemisphere, and they were associated with an inversion of the LP asymmetry. Changes in this parameter were smaller in the central areas and were similar in the parietal areas in both groups studied. Changes in the amplitude and temporal characteristics of the N1 component of the auditory cognitive EP observed in the liquidators of the Chernobyl accident indicate the impairments of their involuntary attention and its capacity due to weakening of inhibition processes as compared to healthy subjects. This effect is similar to that found in elderly subjects. Our data support the hypothesis on the accelerated aging of the brain in the liquidators of the Chernobyl accident due to the effect of low doses of irradiation. The data also suggest that irradiation results in pathological aging.