© 1970 by Thieme Medical Publishers, Inc.
18 November 2008 (online)
The first two cycles of spontaneous night sleep were polygraphically recorded in 21 healthy infants, aged 2 months to 2Œ years. The duration of spindles and the length of intervals between spindles in the right and left fronto-central leads of the EEG were measured.
The spindles are of low amplitude at the age of two months. They are longest and most frequent during the third and fourth month. During the following months the intervals between the spindles increase and become more variable whilst the duration of the single spindles decreases. During the first two years of life spindle activity occurs during almost the whole NREM sleep, whereas it is restricted to stage 2 at the onset of NREM sleep later in life.
During one epoch of NREM sleep the duration of spindles and the length of intervals between spindles change irregularly. No correlation is found between length of one interval and duration of the foregoing or following spindle, between the duration of spindles following each other and between the length of two successive intervals. Examples for distributions of spindle duration and length of intervals are shown and data given for individual subjects.
Electroencephalography - sleep - sleep spindles