Sensory Development

Several touch receptors make up the somatosensory system. The infant experiences the sense of touch by any direct contact to the skin. The sensory receptors for touch send messages to the brain, through neurons, concerning temperature, pain, and the texture and pressure of objects applied to the skin.

The somatosensory system begins to develop during gestation. The nervous system, which is the message carrier to the brain for the senses, begins to develop at the third week of gestation. At the ninth week of gestation the sensory nerves have developed and are touching the skin. By the twenty-second week of gestation, the fetus is sensitive to touch and temperature. At birth, the sense of touch can be observed through the infant's reflexes when it comes in contact with different stimuli. One example is the rooting response. This is when an infant will reflexively turn its head in the direction of a touch to its cheek.

It is important for adults to understand what types of touch stimulation a specific infant needs. For example, infants who fall asleep only when rocked and like to be cuddled may prefer firm pressure against the body. One way to apply this pressure is by swaddling infants. This firm pressure relaxes excited neurons that are sending messages back and forth from the surface of the skin to the brain. Some infants are content to lie or sit and play in one spot; this does not mean that they are not as curious as other infants, but that they can absorb only so much stimulation at one time. By contrast, other infants who are constantly exploring by reaching out to touch various objects and textures are more likely seeking stimulation.