When your teens don’t seem to listen to you, it’s not just that they don’t want to clean their room or finish homework – their brains don’t record your voice like they did in the pre-teen years.
At the age of 13, children’s brains no longer find their mothers ’voices merely gratifying and more adaptable to unfamiliar voices, according to a new study from the Stanford School of Medicine.
The research, which was published on April 28 in the Journal of Neuroscienceused functional MRI scans to give the first detailed neurobiological explanation of how teens begin to separate from their parents.
“Just as a baby knows how to tune in to his mother’s voice, a teenager knows how to tune in to new voices,” said study lead author Daniel Abrams, PhD, clinical associate professor at psychiatry and behavioral sciences.
“As a teenager, you don’t know you’re doing this. It’s just you: you have your friends and new classmates and you want to spend time with them. Your mind is getting more sensitive and attracted to these unfamiliar voices.”
Somehow, the brains of teens are more receptive all Voices, including those of their mothers, rather than the brains of children under 12, were discovered by researchers, a finding that aligns with the growing interest of teens in many types of social signals.
However, in adolescents’ brains, reward circuits and brain centers that prioritize important stimuli are more activated by unfamiliar voices than by those of their mothers. Researchers said shifting the brain to new voices is an aspect of healthy maturation.
“A child becomes independent at some point, and this must be precipitated by an underlying biological signal,” said study lead author Vinod Menon, PhD, Rachael L. and Walter F. Nichols, MD. professor and professor of psychiatry and behavioral sciences.
“That’s what we’ve discovered: this is a signal that helps teens connect with the world and make connections that allow them to be socially fit outside of their families.”
Age-related change to new voices
The Stanford team found earlier that in the brains of children 12 and under, hearing their mother’s voice provokes an explosion of unique responses: a study published in 2016 showed that children can identify the voices of their children. with extremely high accuracy and that the special sound of The Mother indicates not only areas of auditory processing of the brain, but also many areas not activated by unknown voices, including reward centers, emotion processing regions, visual processing centers and brain networks that decide which incoming information is most important.
“The mother’s voice is the sound source that teaches young children everything about the socioemotional world and language development,” said Percy Mistry, PhD, co-lead author and researcher in psychiatry and behavioral sciences.
“Fetuses in the womb can recognize their mother’s voice before they are born, but with teenagers, even though they have spent even more time with this sound source than babies, their brains move away from it. in favor of the voices they have.
The new study is based on the previous study, adding data from adolescents aged 13 to 16.5 years. All participants had an IQ of at least 80 and were raised by their biological mothers. They had no neurological, psychiatric, or learning disorders.
Investigators recorded the mothers of the teenagers saying three meaningless words, which lasted just under a second. The use of meaningless words ensured that participants did not respond to the meaning or emotional content of the words. Two women who did not know the subjects of the study were recorded saying the same meaningless words.
Each adolescent participant listened to several repetitions of the meaningless word recordings of their own mother and unknown women, presented in random order and identified when they listened to their mother. Like younger children, teens correctly identified their mothers ’voice more than 97% of the time.
The teens were then placed on an MRI scanner, where they listened to the voice recordings again. They also listened to brief recordings of domestic sounds, such as a dishwasher in motion, to allow researchers to see how the brain responds to voices compared to other non-social sounds.
More activation in general
The researchers found that among adolescents, all voices caused greater activation in several brain regions compared to younger children: the selective upper temporal groove of the voice, an area of auditory processing; prominent processing regions that filter what information is important; and the posterior cingulate cortex, which is involved in aspects of autobiographical and social memory.
Brain responses to voices increased with the age of adolescents; in fact, the relationship was so strong that researchers could use voice response information on teen brain scans to predict how old they were.
What distinguished adolescents from younger children was that unfamiliar voices caused more activity than the mother’s voice in the accumbens nucleus of the reward processing system and in the ventromedial prefrontal cortex, a region involved in assigning value to social information. The shift to unknown voices occurred in these brain centers between the ages of 13 and 14, and there was no difference between boys and girls.
Research will help study the brains of teens with autism and other conditions that affect how they tune in with voices and other social stimuli. The Stanford team has found that younger children with autism do not have as strong a brain response in their mothers’ voices as children who tend to develop.
The team is excited to have discovered the basics of teens ’ability to tune in to new people, an important part of humans’ global engagement with voices. The fact that the brain is so attuned to the voices makes intuitive sense; just ask anyone who has ever felt an emotional shock when they hear the voice of a friend or family member after a long time, the researchers said.
“The voices around us are this incredibly rewarding sound source that allows us to feel connected, included, part of a community and part of a family,” Abrams said. “Voices are really what connects us.”
Children’s social interactions undergo a great transformation during adolescence. “Our results show that this process is rooted in neurobiological changes,” Menon said. “When teens seem to rebel against not listening to their parents, it’s because they’re wired to pay more attention to voices outside their home.”
The other authors of the Stanford article are former research assistant Amanda Baker and former scientific researcher Aarthi Padmanabhan, PhD.
The study’s authors are members of the Stanford Wu Tsai Institute of Neuroscience, Stanford Bio-X, and the Stanford Maternal and Child Health Research Institute.
Financing: The study was funded by the National Institutes of Health (grants K01 MH102428, DC011095, MH084164, DC017950 and DC017950-S1), the Brain and Behavior Research Foundation, the Singer Foundation and the Simons / SFARI Foundation.
The Stanford Department of Psychiatry and Behavioral Sciences also supported the work.
About this news of research in neurodevelopment
Author: Erin Digital
Contact: Erin Digital-Stanford
Image: Image is Stanford accredited
Original research: Closed access.
“A Change in Neurodevelopment in Mother-to-Family Voice Reward Circuits in Adolescence” by Daniel A. Abrams [Ph.D.]Percy K. Mistry [Ph.D.]Amanda E. Baker [M.A.]Aarthi Padmanabhan [Ph.D.] and Vinod Menon [Ph.D.]. Journal of Neuroscience
A change in neurodevelopment in the reward circuits of mother voices to unfamiliar voices in adolescence
The social world of young children revolves mainly around parents and caregivers, who play a key role in guiding the social and cognitive development of children. However, a hallmark of adolescence is a shift in orientation toward non-family social goals, an adaptive process that prepares adolescents for independence. Little is known about the neurobiological signatures underlying changes in adolescent social orientation.
Using functional brain imaging of human voice processing in children and adolescents (7–16 years), we demonstrate different neural signatures for mother’s voice and unfamiliar voices throughout child and adolescent development in reward systems and social assessment, instance in the nucleus accumbens and in the ventromedial prefrontal cortex. .
While younger children showed higher activity in these brain systems for the mother’s voice compared to non-familiar voices, older adolescents showed the opposite effect with higher activity for non-familiar voices. with the mother’s voice.
The results uncover a critical role for brain systems of reward and social appreciation in pronounced changes in adolescents ’orientation toward nonfamily social goals.
Our approach provides a template for examining developmental changes in reward and social motivation in individuals with pronounced social disabilities, including adolescents with autism.
Statement of importance:
Children’s social worlds undergo a transformation during adolescence. While the socialization of young children revolves around parents and caregivers, adolescence is characterized by a shift in social orientation toward non-family social partners.
Here we show that this change is reflected in neuronal activity measured from reward processing regions in response to short voice samples.
When younger children hear their mother’s voice, the reward processing regions show more activity compared to when they hear unfamiliar and unfamiliar voices.
Surprisingly, older teens show the opposite effect, with more activity for non-family members compared to the mother’s voice.
The findings identify the brainstorm of the changing social orientation of adolescents toward non-family social partners and provide a template for understanding neurodevelopment in clinical populations with social and communication difficulties.