‘Waking activity’: The neglected state of infancy

Abstract

The significance of the waking activity state was investigated using naturalistic observations of 20 infants at 2, 3, 4 and 5 weeks of age. Sleep and wake states were recorded at 10-s intervals throughout a 7-h day, along with co-occurring behaviors of the mother. The infant's behavioral state was classified as ‘waking activity’ when the eyes were open but unfocused, and there was diffuse motor activity. Thus the infant was not alert, drowsy, dazed, or crying. Infants showed individual consistency in amount of waking activity over weeks, although this state composed only 4.4% of the total observation. The mean amount of waking activity over weeks was related to an index of stability in state organization, as measured by the consistency of state profiles over weeks. Profile consistency was assessed by an ANOVA for each infant's data. Separate stability indexes were derived for that portion of the day when the infants were alone, and for that portion when they were with their mothers. Infants with higher levels of waking activity had lower state stability scores in each context. The results indicate that waking activity is a behavioral state which reflects overall state control and is therefore significant for an understanding of brain-behavior relationships.