A baby's sensory hunger
Babies experience two kinds of hungers: the hunger for milk, and the hunger for sensory experience. The hunger for milk is potentially life-threatening if it’s not satisfied; the hunger for sensory stimulation is not directly life-threatening, it’s true, but vital anyway because the baby’s neuronal pathways wire up in direct response to sensory input.
This second biological hunger, the hunger for sensation, is still poorly understood in our society, which shows how there can be a huge lag between what is known in the evidence and what is recommended in practice! Parents are still very commonly advised to avoid ‘overstimulating’ their baby in order to promote sleep and settled behaviour, though this belief arises out of a 1950s and 1960s version of behaviourism which ignores important aspects of the new infant neuroscience.
In the same way that babies cry and complain when they are hungry for milk, they cry and complain when they are hungry for sensation. That is, just as the hunger for milk turns up the dial on the sympathetic nervous system, so the hunger for a healthy sensory diet turns up the dial on the sympathetic nervous system.
Parents are still commonly advised to stay at home and focus on a sleep routine if they have an unsettled baby. But very often, this approach only turns up the dial on the sympathetic nervous system, due to the decreased sensory input.
Persistent high levels of sympathetic nervous system arousal in the early months may cause a re-setting of the threshold of the baby’s stress response, at least in the short-term, so that the baby becomes very sensitive, or highly strung – which is tough for parents to live through but which generally does no harm since babies and families are remarkably resilience and everything settles down in time. In some cases, though, the stress response may be re-set with life-long effects, which is more problematic.
So responding to our new baby’s needs for a healthy sensory diet plays an important part in keeping the baby downregulated as best we can. We don’t have to worry about ‘over-’ or ‘under-‘ stimulation: we simply offer cued care, which is a pattern of sensible responsiveness to our baby’s communications over time, experimenting to see what works, and remembering that two basic hungers make babies unsettled, one of which is a hunger for rich sensory experience.
We can’t always respond, and responding doesn’t always downregulate the baby, but cued care is a way of orienting ourselves in communications with our baby. In offering cued care, we let our babies regulate the amount of stimulation they need, which varies from hour to hour and day to day. We experiment and see what they enjoy.
So in our society, babies often cry and fuss because they are not receiving enough satisfying sensory stimulation. Those of us working with parents in early life generally want to protect new mothers in particular from high levels of exhaustion and sleep deprivation, but may do this by invoking those old 1950s and 1960s behavioural strategies (known as first-wave behavioural strategies), which aim to teach independence - by not letting baby fall asleep at the breast or bottle, or by putting baby down in a separate room to learn to self-settle, or by teaching the baby that he or she can’t expect to be picked up or carried about too much, out of concern that we’ll set up bad habits or create ‘a rod for our own back.’ These strategies also decrease sensory input.
Yet the research demonstrates that our baby’s sleep and the way we approach it in the first year of life, including attempts to avoid ‘overstimulation’, actually does not affect sleep habits, brain development, or independence in later childhood.1, 2 Unfortunately, because a common side-effect of these strategies is to turn up the dial on the baby’s sympathetic nervous system, particularly in the first six months, they can make life much more exhausting than it needs to be for new parents.3, 4
One important study shows that babies who have about 10 hours a day of contact (whether awake or asleep) with a carer’s body, in the context of cued care, cry half as much as those who have about 6 hours of physical contact in a 24 hour period, in the context of routinized care.4 Some babies have higher sensory needs than others, but all babies will crave diverse sensory input: touch, sight, pressure on the body and joints, sound, movement, warmth, smell, taste. Parenting is easiest if we try in sensible ways to meet the baby’s sensory needs, and this sensory engagement also becomes an important investment in our family's well-being long-term.
There are many ways to meet our baby’s sensory needs. Certainly getting out beyond the boring four walls of the house to meet our own needs for social contact, or exercise (like walking), or getting tasks done, offers the baby a lovely sensory bath each day, as he or she comes along for the ride and experiences the glorious sensory kaleidoscope of this amazing world.
1. Price AM, Wake M, Ukoumunne OC, Hiscock H. Outcomes at six years of age for children with infant sleep problems: longitudinal community-based study. Sleep Medicine. 2012;13 991-998. 2. Mindell J, Lee C. Sleep, mood, and development in infants. Infant Behaviour and Development. 2015;41:102-107. 3. Sirvinskiene G, Zemaitene N, Zaborskis A, Markuniene E, Jusiene R. Infant difficult behaviors in the context of perinatal biomedical conditions and early child environment. BMC Pediatr. 2012;12:44. 4. St James-Roberts I, Alvarez M, Csipke E, Abramsky T, Goodwin J, Sorgenfrei E. Infant crying and sleeping in London, Copenhagen and when parents adopt a "proximal" form of care. Pediatrics. 2006;117:e1146-e1155.