Delta, Theta, Alpha and Beta Power Spectrum of Sleep Electroencephalogram in Infants Aged Two to Eleven Months

Abstract

Summary: Automatic sleep EEG analysis was performed on infants from 2 to 11 months of age. Partial power spectra of 1>, e, Ct, and 131 bands were studied as function of sleep stages, age, and time of the night. 131' Ct, and 1> power spectra are significantly lower in paradoxical sleep (PS) than in quiet sleep (QS) whatever the age; but theta is lower in PS than in QS only after 5 months of age. 1>, e, and Ct power increase with age in QS. Only 1> and e are greater in the first half of the night than in the second half. 131 power does not differ significantly in stages 2 and 3 of QS, during the course of the night or as a function of age. Thus 1>, e, Ct may be the best spectral parameters for the maturation of quiet sleep EEGs during the first year of life. Key Words: Automatic analysis-Sleep EEG-Infants.We have previously developed and reported a system of automatic computerized analysis of sleep in infants (1,2), which is valid for full-term infants aged 2-11 months. U sing data from these subjects we studied the development of different EEG frequency bands as a function of sleep stage and course of the night during the first year of life. SUBJECTS AND METHODSTwenty infants younger than 5 months of age and 23 infants aged 5 -11 months were recorded during sleep (Table O. The younger group was recorded during the day (morning sleep), the older group during the first half of the night. Eighteen other infants aged 3-11 months had all-night recordings. These 61 full-term infants were either control subjects, with no serious neurological or medical pathology, receiving no medication, or siblings of infants who had died of Sudden Infant Death Syndrome (SIDS). Sterman et aI. (3) have found only a few minor differences in SIDS siblings as compared with normal subjects at 4 and 8 weeks of age. All of the infants in our study were older than 8 weeks of age, and no differences were found by Sterman et al. in these older babies. Data from the 18 children who had full-night recordings were used for a com-

Sleep confers a benefit for retention of statistical language learning in 6.5 month old infants

“…However, in the developmental literature, the lack of consistency in identified frequency band ranges reduces the ability to generalize findings across studies (Orekhova, Stroganova, Posikera, & Elam, 2006). A number of studies have identified developmental changes in topography and peak low-frequency NREM between 3 and 12 Hz across early to mid childhood in both wakefulness ( Orekhova, Stroganova, & Posikera, 1999;Orekhova et al, 2006) and sleep (Kurth et al, 2010;Samson-Dollfus, Nogues, Menard, Bertoldi-Lefever, & Geffroy, 1983;Sankupellay et al, 2011;Scher, Sun, Steppe, Guthrie, & Sclabassi, 1994), Furthermore, in work establishing infant correlates of adult EEG, comparable signals tend to occur at lower frequencies in younger compared to older participants. For instance, Marshall et al (2002) documented an increase in the alpha signal in awake infants across the first year ranging from 6-7 Hz at 5 months to 9 Hz at age 4 years.…”

Development of the nocturnal sleep electroencephalogram in human infants

“…The typical declining trend of SWS or delta activity in the course of the night was reported for infants at the age of 2-5 mo (6,12,52,53,58). If this decline reflects, as in adult sleep, the dissipation of sleep propensity, it would indicate that mechanisms underlying sleep homeostasis emerge early in human life (51).…”

“…Based on these dynamics, SWA was used to delineate the time course of Process S. Prechtl (46) was among the first to apply spectral analysis of the sleep EEG in human infants. Over the past 30 yr, a number of authors have computed power spectra in infants and have contributed to the knowledge about quantitative characteristics of the sleep EEG during development (29,30,42,(52)(53)(54)(55)58). While some reports were based on short daytime recordings (30,55), others focused on the newborn or preterm age period (29,30,42,54).…”

Neonatal EEG/Sleep State Analyses: A Complex Phenotype of Developmental Neural Plasticity

“…Using quantitative assessments of spectral EEG analyses, increases in theta power by 9 months of age [47,48] herald the emergence of the S1 and S2 segments of the NREM sleep segment, codified as adult sleep state criteria [22] . A decline of theta power after 9 months was observed during nocturnal sleep of infants, interpreted as a change in sleep regulatory processes [49] .…”