Event-related desynchronization and synchronization during a memory task in children

Objective: To examine the event-related desynchronization (ERD) and synchronization (ERS) responses of several narrow electroencephalographic (EEG) frequency bands in children during an auditory memory task. Methods: ERD/ERS responses of the 4–6, 6–8, 8–10 and 10–12 Hz EEG frequency bands were studied in 12 children (mean age 12 years) while they performed an auditory memory task. Twelve adult subjects served as a control group. Results: The childrenʹs ERD/ERS responses differed from those of the adultʹs in the 4–6, 6–8 and 8–10 Hz EEG frequency bands, especially during retrieval from memory. The childrenʹs 4–6 Hz initial ERS responses were of lesser amplitude and of delayed latency as compared to those of the adults. In the 6–8 and 8–10 Hz frequency bands, especially during retrieval from memory, the childrenʹs ERD responses were of lesser magnitude than those of the adults. In the 10–12 Hz frequency band, no differences were observed between the ERD/ERS responses between the children and adults. Conclusions: Our results suggest that theta and alpha response systems might participate in auditory information processing already at this age, although not being fully developed. Memory systems involving retrieval may be the last to mature.