Young children’s brains are especially attached to their mother’s voice. Teenage brains, in their typical rebellious glory, certainly aren’t.
That conclusion, described in April 28 Journal of Neuroscience, may sound downright obvious to parents of teens, including neuroscientist Daniel Abrams of Stanford University School of Medicine. “I have two teenage boys, and it’s kind of a funny result,” he says.
But the finding may reflect something much deeper than the punch line. As children grow and expand their social ties beyond their family, their brains need to engage with that growing world. “As soon as an infant is weaned into a mother, teens have this whole class of voices and voices,” says Abrams.
He and his colleagues scanned the brains of 7 to 16-year-olds as they listened to the voices of their mothers or unfamiliar women. To simplify the experiment to the sound of only one voice, the terms were ambiguous: tbudysault, keybudishault and peebudishault. As children and teens listened, parts of their brains became active.
Previous experiments by Abrams and her colleagues have shown that certain areas of the brains of children aged 7 to 12 – particularly the parts that are involved in detecting and paying attention to rewards – speak to an unknown female voice. react more strongly to mother’s voice than “In adolescence, we show the exact opposite,” Abrams says.
In these same brain regions in adolescence, unfamiliar voices elicited more responses than their beloved mothers’ voices. The transition from mother to another occurs between the ages of 13 and 14.
It’s not like these teen brain regions stop responding to mom, Abrams says. Rather, unfamiliar voices become more rewarding and noticeable.
And that’s exactly how it should be, Abrams says. Exploring new people and situations is a hallmark of adolescence. “What we are seeing here is entirely a reflection of this phenomenon.”
Voice can carry powerful signals. When stressed girls listened to their mothers’ voices on the phone, the girls’ stress hormones dropped, said biological anthropologist Leslie Seltzer of the University of Wisconsin-Madison and colleagues found in 2011 (SN: 8/12/11) The same was not true for the texts of their mothers.
The current results support the idea that the brain changes to reflect the new needs that come with time and experience, Seltzer says. “As we mature, our survival depends less on maternal support and more on our group affiliations with peers.”
It is not clear how universal this neural shift is. Seltzer says this finding can turn up in different mother-child relationships, including those with different parenting styles or even a history of neglect or abuse.
So while teens and parents can sometimes feel disheartened by missed messages, take heart, Abrams says. “That’s how the brain gets wired, and there’s a good reason for that.”