Thompson rivers university – open learning
Infant States: The Development and Shifts in Sleep Patterns
Psych 344: Assignment 2
Julia Daria – Student # 100114222
When Peter Wolff (1966) observed baby’s eye movements and muscle activity in his classic study, he distinguished seven states of arousal: non-rapid-eye-movement sleep (NREM), rapid-eye-movement sleep (REM), periodic sleep, drowsiness, alert inactivity, active alert, distress. These were further confirmed by EEG recordings that showed a different wave pattern associated with each state. Newborns are observed to have two kinds of sleep that are the precursors of adult sleep, REM and NREM, occurring in that order for the first 2 to 3 months. This pattern shifts after 2 to 3 months to resemble more the adult sleep pattern that starts with NREM and then falls into REM. This change is considered a sign of normal development and maturation of the brain. Adults, especially in North America and other industrialized countries, usually try to modify baby’s sleep schedule right from birth. Sleeping through the night is not a goal to some of the cultures where even adults are more flexible in their sleep patterns. (Cole & Lightfoot, pp. 140, 141)
Parents of new babies also attempt to change the pattern of feeding as it progresses from the reflex of sucking to nursing. In the ‘60s pediatricians recommended a four hour gap between feedings but that caused babies to cry more. The result of a subsequent study showed that babies left to feed on demand prefer, on average, a three hour interval between feedings. Today, feeding on demand is more common. When babies feed they can go through different states of arousal. Initially they are in distress from the moment they show the first sign of hunger to the time when they start feeding. The most evident sign of distress is crying. Crying is a complex behavior that involves the coordination of breathing and movements of the vocal tract. It is initially coordinated by the brain stem in the first few months and later by the cerebral cortex when crying becomes voluntary. (Cole & Lightfoot, pp. 144)
In trying to identify the connection between the states of arousal and the development of coordinated behavior and more precisely how the seven states of arousal as described by Wolff are affected by the development of coordinated behavior the actions of a two and half months baby and his mother were observed and recorded for 120 minutes.
Subjects: The project involved a two month and three week baby, Max (not his real name), who is generally calm and healthy, was born six weeks early and is still breastfed. According to his mother Max is a ‘book baby’, sleeping about 15 hours a day, feeding 2 to 2.5 hours apart. Max goes to sleep at around 9pm and wakes up at around 11pm for his last nap of the day. He then stays up for about an hour and goes to sleep for the night at 12 midnight. He sleeps until 7am with only 2 interruptions when he whines...