KEY POINTS

  • Researchers looked at MRI scans of teens aged 13 to 16.5
  • Their brains showed increased activity in response to unfamiliar voices than mom's voice
  • "This is a signal that helps teens engage with the world": Study's senior author

There comes a time in adolescents' lives when they just don't connect with their moms like they used to. In a new study, researchers found that teens' brains actually shift to responding more to unfamiliar voices than their moms' voices.

Children tend to be much more receptive to their moms when they're younger. But parents of teenagers would know that this changes during adolescence when they just don't interact with their parents in the same way.

"The social world of young children primarily revolves around parents and caregivers, who play a key role in guiding children's social and cognitive development," the researchers wrote in their study, published Thursday in the Journal of Neuroscience. "However, a hallmark of adolescence is a shift in orientation towards nonfamilial social targets, an adaptive process that prepares adolescents for their independence."

But what exactly is happening in teens' brains during this time?

In 2016, the researchers had found that hearing their mothers' voices triggers responses in the brains of children 12 years old and younger, Stanford School of Medicine (SoM) noted in a release. In fact, they found that moms' voices can trigger various brain systems such as the reward, emotion and face-processing centers -- areas that unfamiliar voices don't trigger.

For their new work, the researchers added data from teenagers aged 13 to 16.5 years old. The teens repeatedly listened to the recordings of their mothers' voices saying nonsense words so that they would focus on the voice and not the meaning of the words. They also listened to recordings of unfamiliar women saying the same words and had to identify their mothers' voices. Indeed, they were able to correctly identify their mothers 97% of the time, noted SoM.

Next, they were placed in the MRI scanner and again listened to recordings, including random sounds this time to see how their brains respond to voices and non-social sounds. The results showed all the voices prompted greater activation in teens' brains compared to the younger kids. However, the teens' brains had greater activity in response to the unfamiliar voice compared to their mothers' voices.

"While younger children showed increased activity in these brain systems for mother's voice compared to nonfamilial voices, older adolescents showed the opposite effect with increased activity for nonfamilial compared to mother's voice," the researchers wrote.

This change was observed at the age of 13 to 14 years, and there was no difference between the boys' and girls' results.

This doesn't mean, however, that they have stopped responding to their mothers, study lead author, Daniel Abrams, Ph.D., of SoM, noted as per Science News. Instead, the unfamiliar voices simply become more rewarding.

According to the researchers, the results present a neurological explanation for the shift that we see in teens. Instead of having their world revolve around their parents, there is a shift that gravitates them towards other people. This change, the researchers noted, is a part of "healthy maturation." As Abrams noted, "this is the way the brain is wired."

"This is a signal that helps teens engage with the world and form connections which allow them to be socially adept outside their families," study senior author, Vinod Menon, Ph.D., of SoM, said in the news release.

"Our findings demonstrate that this process is rooted in neurobiological changes," Menon added. "When teens appear to be rebelling by not listening to their parents, it is because they are wired to pay more attention to voices outside their home."

Mother And Daughter Representation. Photo: Pixabay-Edsavi30