Sleep EEG-pattern alteration as a specific marker of neuroplasticity in intellectually gifted schoolchildren

Abstract

BACKGROUND: At school, children constantly acquire new knowledge, which provokes changes in the brain structures, especially during intensive learning. Neuroplasticity enables a person to realize his potential, to show giftedness. However, data on electroencephalographic (EEG) features during the sleep in gifted schoolchildren are insufficient and contradictory.
 AIM: To study the features of EEG sleep patterns according to neurophysiological research data in intellectually gifted schoolchildren and their correlation with verbal and non-verbal mental abilities.
 MATERIALS AND METHODS: 48 lyceum students aged 14-15 years were examined. All participants were performed the Wechsler-Intelligence test (childrens version) to determine them intelligence quotient (IQ). Two groups of adolescents were identified: the main group (n = 20) with a high IQ (137.012.7 points), the control group (n = 28) with an average IQ (110.910.4 points). Neurophysiological examination during the sleep was performed using an ambulatory wireless system for registration of electroencephalograms and polysomnograms Neuron-Spectrum-AM (Neurosoft, Ivanovo, Russian Federation,). The identification and analysis of EEG sleep patterns: cyclic alternating patterns and sleep spindles were carried out according to standard methods. Differences between groups were considered statistically significant at p 0.05.
 RESULTS: In gifted schoolchildren, significant changes were revealed as an increase in the time and the rate of cyclic alternating patterns with a predominance of A1 subtype (p = 0.0001) and a decrease in the proportion of А2-A3 subtypes, as well as an increase of sleep spindles density (p = 0.01), which significantly correlated with the Wechsler-Intelligence Tests scores. So, percentage of A1 subtype had correlation with the index of thinking flexibility, while percentage of A2 subtype correlated with general and non-verbal intelligence, non-verbal visual-spatial abilities, the index of working memory) and the index of verbal perception, as well as the sleep spindles index and sleep spindles frequency peak correlated with the index of verbal perception, the index of working memory, the index of information processing speed and general intelligence.
 CONCLUSIONS: Thus, we have demonstrated significant changes in the sleep microstructure and different correlations depending on the IQ values in schoolchildren, which was not previously covered in the literature. Cyclic alternating patterns and sleep spindles are recommended to be considered as physiological indicators of intelligence and academic performance, as well as specific markers of neuroplasticity in the intensification of learning.