At 7 months infants and distinguish emotions through voice
The brains of babies at 7 months shows a sensitivity to the human voice and the emotions communicated through the voice that is very similar to that observed in the brains of adults, according to a study by the University of London in United Kingdom published in the journal Neuron.
The study proves the origins of voice processing in the human brain and could provide information on neurodevelopmental disorders such as autism.
Scientists at the Center for Brain and Cognitive Development at the University of London, led by Tobias Grossmann, conducted their study in the laboratory of Angela D. Friederici Max Planck Institute in Cognitive Science and Human Brain in Germany. The researchers used near infrared spectroscopy to investigate when during development the regions of the temporal cortex became sensitive to the human voice. These specific cortical regions have had an important role in spoken language processing in adults.
Grossmann’s team found that children of seven months and not four months showed greater responses similar to those of adults in the temporal cortex as a result of the human voice compared with no vowel sounds, suggesting that sensitivity to voice emerges between 4 and 7 months of age.
Another important issue addressed by the study is whether the activity in brain regions sensitive to the voice in infants is modulated by emotional prosody, emotional rhythmic structure may reflect the sentiments of the speaker and helps convey the context of language. In humans, sensitivity to emotional prosody is crucial for social communication.
The researchers found that a region sensitive to the voice in the right temporal cortex showed increased activity when infants heard words of seven months with emotional prosody (anger or happiness). It is believed that such modulation of brain activity by emotional signals is a fundamental mechanism of the brain to prioritize the processing of meaningful stimuli in the environment.
“Our findings show that brain regions are sensitive to and specialized voice and modulated by emotional information at 7 months of age and raise the possibility that critical neurodevelopmental processes that underlie the alteration of the voice processing occurs in disorders such as autism could happen before the seven months, “said Grossmann.
Therefore, the researcher concludes that in future work the method will be used to assess individual differences in infants’ responses to voices and emotional prosody and could serve as one of the possible markers that may help early identification of infants with more risk of experiencing neurological developmental disorders.
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