Development of EEG Response to Unpleasant, Pleasant, and Neutral Tactile Stimuli.

Background: The study of tactile perception during a childhood is extremely important for understanding the social and communicative aspects of the child's development. Tactile perception of stimuli with different valence can have different normative stages of development. Methods: In the present study, we examined changes in linear and nonlinear electroencephalogram (EEG) parameters during the presentation of pleasant (C-tactile optimal stroking), unpleasant (ice stroking), and neutral tactile stimuli in three groups of healthy volunteers: preschoolers 4 and 5 years, school-age children from 8 to 10 years, and adults from 20 to 40 years. Results: According to our findings, child maturation plays a significant role in the perception of pleasant and neutral tactile stimuli. Patterns of EEG dynamics related to tactile perception showed greater similarity between adult volunteers and school-aged children than preschoolers. Conclusions: Non-linear EEG parameters such as fractal dimension (FD), envelope mean frequency (EMF), and power spectral density (PSD) dynamics of the theta-rhythm were particularly sensitive to developmental changes in tactile perception. Hjorth complexity and peak alpha frequency (PAF) scores may serve as indicators of mature perception of C-tactile (CT)-stimuli. [ABSTRACT FROM AUTHOR]