ABSTRACT
A typical aspect of the EEG during Paradoxical Sleep (PS) was noted in 76% of 68 infants, 3 to 11 months old. This consisted in delta waves of high amplitude recorded during PS. These waves were seen from the beginning to the end of the first year of life; they could occupy all or part of each stage of PS and were seen at any time during the night. Few works have been published by other authors on the same subject. However, Tanguay et al. (1974) have observed that high delta waves in PS were present until four and a half year of age and that the relative delta power in PS decreased slowly between the first and fifth year of life. The problem consisted in finding out whether this type of tracing was related to the immaturity of some brain structures.
