Spectral dynamics of electroencephalographic rhythms during verbal learning: analysis of the Rey test stages

This study is devoted to analyzing changes in the spectral power of primary cortical rhythms (delta: 1–4 Hz; theta: 4–8 Hz; alpha: 8–13 Hz; beta: 13–30 Hz; gamma: 30–50 Hz) in healthy adult participants while performing the Rey Auditory Verbal Learning Test (RAVLT). Particular attention is paid to the topographic distribution and dynamics of these rhythms during the stages of memorizing words from a verbal list, introducing an interfering list, and during immediate and delayed recall of the material. The study aims to identify neurophysiological markers of initial encoding, automation of memorization, mechanisms for overcoming interference, and processes of systemic consolidation of long-term memory. The obtained data are intended to clarify the temporal organization of mnemonic processes and spectral indicators of cognitive load, which may contribute to the development of diagnostic and rehabilitation techniques for assessing and correcting verbal memory. The study involved 60 healthy subjects (ages 18–44) who had no neurological or mental disorders. EEG was recorded using 19 channels (10–20 system) with a "Mizar-202" electroencephalograph. Spectral analysis was conducted using the Welch method, and power was logarithmically transformed. Statistical processing included RM-ANOVA with Holm correction (α = 0.05). The study of neurophysiological markers of memory and mechanisms of interference is gaining particular significance in the context of assessing cognitive disorders. The evaluation of electroencephalographic rhythms accompanying the processes of memorization, interference, and recall of information allows for a deeper understanding of the mechanisms of cognitive resource redistribution and an assessment of the role of functional organization of rhythms in implementing mnemonic tasks. The results demonstrate statistically significant differences in the power of EEG rhythms depending on the stage of the RAVLT test. Alpha and beta synchronization are associated with active information processing and voluntary attention, while the reduction of low-frequency rhythms indicates the overcoming of interference. The observed dynamics of rhythms confirm the functional specialization of cortical areas when performing verbal tasks of varying complexity. Experimental data supplement the understanding of the temporal and spatial organization of mnemonic processes and can be utilized for assessing the state of cognitive functions in clinical practice.

Electroencephalography, Spectral analysis, Delta rhythm, Beta rhythm, Alpha rhythm, RAVLT, Verbal learning, Interference, Memory, Cognitive functions