Maturation of EEG power spectra in early adolescence: a longitudinal study

Abstract

This study investigated the fine-grained development of the EEG power spectra in early adolescence, and the extent to which it is reflected in changes in peak frequency. It also sought to determine whether sex differences in the EEG power spectra reflect differential patterns of maturation. A group of 56 adolescents were tested at age 10 years and then at two further time-points approximately 18 months apart. The EEG was recorded during both eyes-closed and eyes-open conditions and Fourier transformed to provide estimates of absolute and relative spectral power at 0.5 Hz intervals from 0.5 to 40 Hz. The peak alpha frequency for each individual at each time-point was also determined for relative spectral power. Partial Least Squares (PLS) analysis was used to determine the combination of electrodes and frequencies that showed developmental change, or differed between the sexes. As a function of age, absolute delta and theta frequencies power decreased, and relative alpha2 and beta frequencies increased, replicating the standard findings of a decrease in lower, and increase in higher, frequencies with age. A small but significant increase in peak alpha frequency with age was detected. Moreover PLS analysis performed with individual alpha frequencies aligned to 10 Hz suggested that the age-related increase seen in alpha2 relative power was driven by changes in the peak frequency. Although males demonstrated higher alpha power than females, there were no sex differences in peak frequency, suggesting that there may be more to sex differences in EEG power than simply different rates of maturation between the two sexes.

Lifespan Differences in Cortico-Striatal Resting State Connectivity

“…Interestingly, we observed no age differences in any of the frequency bands. This might due to the fact that our current frequency range (0-0.08 Hz) was significantly lower than what has been reported in the literature [e.g., 0.5-40 Hz in Cragg et al (2011); 2-13 Hz in Zhu et al (2011)]. Thus, differences in the frequency content of resting state neuronal oscillations is unlikely to have impacted our findings of age differences in network connectivity strength.…”

“…Thus, before comparing age groups in connectivity strength, we first evaluated the frequency content of the resting state BOLD signals among three age groups. Previous developmental studies have documented that there is a decreased power in the lower frequency band and an increased power in higher frequencies with age, throughout childhood and early adolescence (Cragg et al, 2011). By contrast, normal aging shows the opposite pattern; as a function of age, lower frequency power increases and higher frequency power decreases (Zhu et al, 2011).…”

Disrupted Functional Brain Networks in Autistic Toddlers

“…1A). We deviated from the standard definition of frequency bands, since in developing young children the power spectrum is dominated by slow frequencies; the alpha peak occurs at slower frequencies (*8 Hz) in young children (Boersma et al, 2011;Marshall et al, 2002), which is in contrast with the faster alpha peak frequencies in adults (*10 Hz) (Cragg et al, 2011;Smit et al, 2011). To prevent splitting up the alpha band at this 8 Hz alpha peak and capturing as much slow oscillations as possible, we chose to combine the alpha and theta frequency bands, ranging from 4 to 10 Hz.…”

EEG (Electroencephalography) Abnormality in First Episode Mania: Is It Trait or State?

“…In the present study, in cases with trait EEG abnormality, the age of menarche was found to start at a younger age. In a more recent study, it was reported that in early puberty, EEG spectral power intensity changed developmentally and maturation occurred at different rates in both sexes (Cragg, Kovacevic, McIntosh, Poulsen, Martinu, Leonard, & Paus, 2011). According to the results of this prospective study, if compared in terms of EEG, female sex has a developmental delay interval.…”