THE REGULATION OF SLEEP AND AROUSAL - DEVELOPMENT AND PSYCHOPATHOLOGY

Throughout early development, a child spends more time asleep than in any waking activity. Yet, the specific role of sleep in brain maturati on is a complete mystery. In this article, the developmental psychobio logy of sleep regulation is conceptualized within the context of close links to the control of arousal, affect, and attention. The interacti ons among these systems are considered from an ontogenetic and evoluti onary biological perspective. A model is proposed for the development of sleep and arousal regulation with the following major tenets: 1. Sl eep and vigilance represent opponent processes in a larger system of a rousal regulation. 2. The regulation of sleep, arousal, affect, and at tention overlap in physiological, neuroanatomical, clinical, and devel opmental domains. 3. Complex interactions among these regulatory syste ms are modulated and integrated in regions of the prefrontal cortex (P FC). 4. Changes at the level of PFC underlie maturational shifts in th e relative balance across these regulatory systems (such as decreases in the depth/length of sleep and increased capacity for vigilance and attention), which occur with normal development. 5. The effects of sle ep deprivation (including alterations in attention, emotions, and goal -directed behaviors) also involve changes at the level of PFC integrat ion across regulatory systems. This model is then discussed in the con text of developmental pathology in the control of affect and attention , with an emphasis on sleep changes in depression.