Touch is the first of the five senses to develop, yet scientists know far less about the baby’s brain response to touch than to, say, the sight of mom’s face, or the sound of her voice.
Now, through the use of safe, new brain imaging techniques, University of Washington researchers provide one of the first looks inside the infant’s brain to show where the sense of touch is processed — not just when a baby feels a touch to the hand or foot, but when the baby sees an adult’s hand or foot being touched, as well.
The evidence of activity in the somatosensory cortex for both “felt touch” and “observed touch” shows that 7-month-old infants have already made a basic connection between “self” and “other,” which researchers say lays the groundwork for imitating and learning from the behavior of other people, and for empathizing with them.
The findings by the UW Institute for Learning & Brain Sciences (I-LABS) are published this week in Developmental Science.
“Long before babies acquire spoken language, touch is a crucial channel of communication between caregivers and babies,” said the study’s primary author, Andrew Meltzoff, UW psychology professor and co-director of I-LABS. “Now we have the tools to see how the baby’s body is represented in the baby’s brain. This allows us to catch the first glimpse of a primitive sense of self that provides a building block for social learning.”
Past studies investigated how infants’ brains respond to touch, generally. The authors believe this is the first experiment to measure the specific networks of the brain where this processing occurs, and to illuminate how babies’ brains respond to seeing another person being touched, in the absence of being touched themselves.
For the study, researchers used the I-LABS Magnetoencephalography (MEG) machine to capture images of brain activity in 7-month-old infants as they were touched on the hand and foot, and as they watched videos of an adult hand and foot being touched.