PALO ALTO, CALIFORNIA — A new study from the Stanford University School of Medicine has found that a much larger area of the brain is activated when children hear their mother’s voice, compared to when they hear other unfamiliar voices. Beyond the auditory regions, areas of the brain involved in emotion and reward processing, social functions, detection of what is personally relevant and face recognition, all responded more strongly to the mother’s voice.
The study, published in Proceedings of the National Academy of Sciences, is a first of its kind evaluation looking at brain scans of children listening to their mothers’ voices.
Of note, the study also found that the strength of connections between the brain regions activated by the voice of a child’s mother could “predict that child’s social communication abilities”
“Many of our social, language and emotional processes are learned by listening to our mom’s voice. But surprisingly little is known about how the brain organizes itself around this very important sound source. We didn’t realize that a mother’s voice would have such quick access to so many different brain systems.”
Hearing Mom’s Voice
While it has been known through research for many years, that babies and young children prefer to hear their mother’s voice, the reason behind the preference had yet to be defined prior to this study.
In the study, a total of 24 children (ranging from 7 to 12 years old) had their brains scanned with an MRI while they listened to nonsense-word recordings. The nonsense words were either read by their mother, or by a control.
According to Vinod Menon, PhD, one of the study authors, “we wanted to know: Is it just auditory and voice-selective areas that respond differently, or is it more broad in terms of engagement, emotional reactivity and detection of salient stimuli?”
Amazingly, even with short audio clips of less than 1 second long, the children studied were able to identify their own mothers’ voice with more than 97% accuracy.
Brain regions found to be more engaged by the mother’s voice surprised Dr. Menon and his colleagues. Areas that were more responsive to the mother’s voice were found to go well beyond auditory areas such as the primary auditory cortex. Other areas being engaged by the mother’s voice included areas of the brain responsible for emotions, including the amygdala; areas of the brain that detect and assign value to rewarding stimuli, such as the mesolimbic reward pathway and medial prefrontal cortex; areas of the brain that process information about the self, including the default mode network; and regions involved in perceiving and processing of faces.
Researchers discovered that children who had the strongest social communication abilities were also those that exhibited a stronger degree of connection between regions of the brain when hearing their mother’s voice.