How Babies’ Brains Respond to Touch Gives Insights into Empathy

Safe, new brain imaging techniques 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 also when they see an adult’s hand or foot being touched.

Evidence of activity in the somatosensory cortex for both “felt touch” and “observed touch” shows that infants as young as seven months old have already made a basic connection between “self” and “other,” laying the groundwork for empathy.

“Long before babies acquire spoken language, touch is a crucial channel of communication between caregivers and babies,” says the study’s primary author, Andrew Meltzoff, psychology professor at the University of Washington and co-director of the Institute for Learning & Brain Sciences (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.”

For the study, researchers used the I-LABS Magnetoencephalography (MEG) machine to capture images of brain activity in seven-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.

In the first experiment, each infant sat in the MEG to measure brain activity as they received light touches. A small, inflatable balloon-like device was placed on the top of the baby’s hand, and when it expanded and contracted according to a computer-controlled timetable, it produced light taps on the baby’s skin. The same procedure took place for the top of the baby’s foot.

The data showed that, when the hand was touched, the hand area of the somatosensory cortex was activated in all 14 infants tested; when the foot was touched, activation occurred in the foot area of the brains of all the infants but one.

A different group of infants provided data for the “observed touch” experiment, in which they also were seated in the MEG but watched separate videos of an adult hand and an adult foot being touched by a small rod. Researchers discovered that the infants’ own somatosensory cortex also became activated when they observed someone else being touched.

“Before they have words for the body parts, babies recognize that their hand is like your hand, and their foot is like your foot. The neural body map helps connect babies to other people: The recognition that another person is ‘like me’ may be one of the baby’s first social insights,” Meltzoff explains.

With development, this “like-me” recognition eventually flowers into feeling empathy for someone else.

“The idea of using brain science to study how and when humans first feel a sense of connectedness with others is important and fascinating,” Meltzoff says. “We can now look under the hood and see what’s happening when a baby watches and connects to others. It’s a touching sight.”

The research was published in the journal Developmental Science.