Small babies who can smell their mother’s scent are better able to recognize faces

Small babies who can smell their mother’s scent are better able to recognize faces

Written by Simon Makin

Babies experience a large amount of sensory information from the moment they are born. Knowing nothing about the world, they must learn how to categorize this deluge into categories of things, especially faces. “Faces are one of the most relevant visual signals that babies begin to learn in the first month of life,” says Arnaud Leroux, a cognitive neuroscientist at the University of Burgundy in France.

Researchers are studying how infants use different senses for this recognition. For example, newborns classify faces better when visual images are accompanied by sounds. And evidence suggests that babies may also use smell. “We knew babies could combine the senses,” says Tessa Decker, a researcher in visual development at University College London. “But it wasn’t clear whether this was the case for smells, which act very slowly and are not very tied to specific events.”

In recent research, child developmentLeleu et al. confirmed that infants’ perception of faces is aided by their mother’s body odor, and further found that the influence of odor diminishes as infants grow older. The discovery deepens scientists’ understanding of the role multisensory perception plays in early learning.

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The researchers used electroencephalography to record the brain activity of 50 infants between 4 and 12 months of age, as they watched a stream of six images per second. Each sixth image was a human face, and the other images were animals or objects. The researchers found that when babies pay special attention to faces, electrodes placed over brain areas involved in visual processing produce one spike of activity per second, corresponding to the baby’s appearance. We expected that a so-called face selection reaction would occur. The babies were also given a clean T-shirt and a T-shirt soaked with their mother’s body odor.

Overall, face-selective responses increased in strength and complexity with age. But the researchers also found that maternal scent increased responses to faces in the youngest infants, and observed that the effect gradually diminished in older infants. “This may mean that young babies are more dependent on their mother’s scent, since their ability to identify faces using only vision is still developing,” Decker he says. Visual abilities are known to be poor at birth, but the sense of smell develops relatively early.

The findings highlight the importance of multisensory stimulation early in life. “To help young children learn, we need to use all of their senses,” Leroux says. “The way we begin to perceive things with our senses is the basis for developing concepts, language, and memory.” He investigated the extent to which smells influence perception, including in other age groups. Continuing. He says he’s found that if you make the cognitive task difficult enough, even adults will turn up and ask for help. “This works for faces and other objects,” Leleu adds. “I found that using pictures of cars and the smell of gasoline worked.”