Mothers and Strangers Voices: Impact on Newborns’ Brains

Fetus­es and new­borns react pref­er­en­tial­ly to their moth­er’s voice. A recent study looked for the first time at what is going on in a new­born brain when hear­ing his mother’s voice and a stranger’s voice. Results showed that not only new­borns process their moth­er’s voice more active­ly than that of a stranger but they also process it differently.

Researchers looked at the brain activ­i­ty in response to voic­es (moth­er and female stranger) in 16 new­born babies (mean age: 21 hours), by apply­ing elec­trodes to their heads while they were sleep­ing. Both the moth­er and a female nurse (who had vis­it­ed the moth­er sev­er­al times before the birth) were asked to make the short ‘A’ vow­el sound.

The moth­er’s voice pro­cess­ing ini­tial­ly acti­vat­ed the left pos­te­ri­or tem­po­ral lobe, an area par­tic­u­lar­ly involved in lan­guage com­pre­hen­sion in the adult brain. When the stranger spoke, the right tem­po­ral lobe was acti­vat­ed, an area asso­ci­at­ed with voice recog­ni­tion. Both voic­es sub­se­quent­ly acti­vat­ed a right motor region of the brain. This motor activ­i­ty may reflect the imi­ta­tive behav­ior observed in babies: When a baby hears the “B” sound for instance, he or she will make the mouth shapes need­ed to imi­tate this noise.

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Above is shown new­borns’ brain activ­i­ty when hear­ing their mother’s voice, and then the nurse’s voice. In the top row of each pan­el you can see the brain from the back and in the bot­tom row, pro­file views of the brain. Strong activ­i­ty is indi­cat­ed by the col­or red. The activ­i­ty is clear­ly on the left-side of the brain (lan­guage areas) when hear­ing the mother’s voice and most­ly on the right side of the brain (voice recog­ni­tion areas) when hear­ing the stranger’s voice. Cred­it: doi:10.1093/cercor/bhq242, Cere­bral Cor­tex, Oxford Uni­ver­si­ty Press.

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The pat­tern of brain activ­i­ty observed con­firms the idea that a mother’s voice acts as the pri­ma­ry ini­tia­tor of lan­guage. This is not new you may think, but it is the first time that this was observed live inside a baby’s brain.

Note also that the study was con­duct­ed while the babies were sleep­ing. Sleep­ing babies are very active: They can process exter­nal infor­ma­tion and learn… To keep in mind when we are around a sleep­ing infant!

Relat­ed posts:

• What is it like to be a vol­un­teer in a study in which elec­trodes are used?
• Top 10 Q&A about Child’s Brain Development