August 01, 2011
Touch has been called "the mother of the senses": perhaps because it was the first to develop in evolution. Touch is defined as "the most general of the bodily senses, diffused through all parts of the skin, but in humans, especially developed in the tips of the fingers and the lips." The fingers and lips have a disproportionately large number of neurons that travel to and from the brain. Thus they are the means by which the infant does most of its early learning; hence the need for “baby-proofing.”
Touch is the earliest sensory system to develop. When a human embryo is less than an inch long and less than two months gestation, the skin is already highly developed. For example, when the palm is touched at two months gestation, the fingers grasp the palm. The fingers and thumb will close at three months when the palm is touched. Touch can have strong effects on our physiology. When the skin is touched, that stimulation is quickly transmitted to the brain, which in turn regulates our physiology. Different types of touch lead to different responses. Light pressure touch, for example, can lead to physiological arousal, and moderate pressure touch can be calming. Neonatal perception research by our group suggests that touch discrimination by mouth and by the hands is evident as early as the newborn period. Different texture nipples (nubby versus smooth), for example, can be discriminated by the newborn's mouth and by their hands.
Affectionate touch
Surprisingly, affectionate touch has rarely been studied in both the home and in infant daycare. Affectionate, stimulating and instrumental types of touch have been observed during natural care-giving and mother-child play sessions in the home. Maternal affection and stimulating touch decreased significantly during the second six months of life. This may relate to the infants’ accelerated gross motor development during the second half of the first year, namely crawling and walking, that would naturally move infants away from close physical contact with their mothers. Affectionate forms of touch such as hugging, kissing and stroking also decreased in infant daycare in later infancy and the toddler years. However, reciprocal communication increased in the second half-year of life and was predicted by the frequency of affectionate touch that occurred in the first half-year of life.
Touch deprivation
Infants and children in institutional care often receive minimal touching from caregivers, which is predictive of later cognitive and neurodevelopmental delays. The deprived children are often below average on cognitive skills when compared to same-age children who are raised in families. Unfortunately, in at least one study, this deprivation and the associated developmental delays persisted for many years after adoption.
Touch deprivation has also occurred in infants of depressed mothers. For example, in one study, infants of depressed mothers versus those of nondepressed mothers spent more time touching themselves, which may have compensated for the less frequent positive touch from their mothers. They also showed more aggressive types of touching (i.e., grabbing, patting and pulling) than infants of nondepressed mothers during stressful situations, as if calming themselves.
Massage Therapy
Massage therapy has been noted to compensate for touch deprivation. Positive effects have been documented in many infant massage studies, especially for preterm infants who have gained significantly more weight and more bone density. In addition, following massage therapy, preterm infants have shown fewer stress behaviors, lower energy expenditure and enhanced neurological, psychomotor and sensorimotor development. A developmental follow-up at two years suggested that new preterm infants who received massage from their mothers had higher motor and mental development scores. In studies we have conducted we have shown increased vagal activity, gastric motility and IGF-1 (growth hormone) levels following massage of preterm infants, suggesting that these infants have been significantly calmed by the massage which may be the underlying mechanisms for the weight gain and improved development of the infants.
Mothers of low birth weight infants have also helped reduce their infants’ developmental delays by massaging them. And, high-risk mothers, for example depressed mothers who massaged their infants showed more affectionate touch, and their infants were more responsive. The mothers benefited from massaging their infants and by their depression thus decreasing, and their infants’ growth and development also benefited. The mothers’ sensitivity and responsivity during interactions with their infants and the infants’ responsivity improved both in nondepressed and depressed mothers and their infants. These data demonstrate positive effects for the massager simply from giving the massages. These data were not surprising given that pressure receptors are also stimulated in the hands of the person providing the massage, and it is the stimulation of pressure receptors that mediates the positive effects of massage.
Massage therapy has also been beneficial for normal full-term infants. In several studies infant irritability and sleep disturbances (the infancy problems most often presented to pediatricians) have been reduced. Massaging infants before sleep has been a more effective way to induce sleep than rocking infants. Massaging infants has also improved the interactions of mothers and infants. And, in a study on fathers massaging their infants, the fathers became more expressive and affectionate toward their infants
Potential underlying mechanisms for infant massage effects
Based on our comparisons between light and moderate pressure massage, we have suggested that the stimulation of pressure receptors by moderate pressure massage leads to enhanced vagal activity which in turn “slows down” physiology (e.g. slows heart rate) and stress hormone (cortisol) production. In turn, these massage effects would be expected to reduce pain syndromes, autoimmune conditions like asthma and diabetes and enhance immune function. For example, we have noted an increase in natural killer cells which kill bacterial, viral and cancer cells which would suggest less illness and disease for infants and young children.
Summary
Thus, touch is a critical sense for the development of infant perception and cognition. The parents’ affectionate touch helps the infant thrive and fosters the relationships between parents and infants. Touch deprivation, which is happening even in some of our infant nurseries, can lead to delayed development. Infant massage can compensate for the lack of touch. Infant massage has far-reaching effects. The use of moderate pressure massage (moving the skin) has contributed to weight gain and bone development in preterm infants and to less irritability and improved sleep in normal full-term infants. In China, parents learn to massage their infants from birth in the hospitals’ touch rooms. We might encourage all parents to learn infant massage and all nursery schools to have massage as part of their curriculum. In Sweden’s Peaceful Touch program all preschoolers receive backrubs as nursery rhymes are recited. Infant massage not only facilitates health and development, but also contributes to better parent-infant relationships. And, the massager benefits as much as the massagee.
Links: Liddle Kidz website, Nurturing Touch for the Growing Child: http://liddlekidz.com/tiffany-field.html