The human voice preactivates the neural circuits of face perception already at 4 months of life

This study published in «Scientific Reports» demonstrates the ability of 4-month-old infants to anticipate an event according to the sound heard. In particular, the authors showed that a voice is able to pre-activate the neural circuits involved in the visual perception of faces about a second before seeing them appear. It is the first scientific demonstration that very young children can prepare themselves for the encounter of socially relevant stimuli.

When we perceive sounds or identify images, the activity of our brain is not all used to process the physical characteristics and meanings that arise from them. On the contrary, only a small part of our brain activity (from 1 to 5% approximately) is mobilized in response to external events, in the remaining 95% the brain is continuously involved in various activities including formulating probabilistic predictions on the events that could occur in the environment. These hypotheses are then systematically, and often unconsciously, compared with reality in order to arrive at a correct interpretation of what has been heard or seen. But from what age are we able to predict what will happen in the environment depending on what we perceive? The team of researchers from the University of Padua in the study entitled "Face specific neural anticipatory activity in infants 4 and 9 months" published in the journal "Scientific Reports" answered this question for the first time.
In this research, brain activity was reconstructed in three classes of subjects - adults, 9-month-old children and 4-month-old babies - starting from their cortical electrical activity (EEG) during the presentation of faces or objects respectively preceded by a human voice or from non-human sounds.
The results suggest that even in the group of 4-month-old children there is a neural activation that reflects the ability to anticipate the event depending on the sound heard. In other words, the simple sound of a human voice is able to pre-activate the neural circuits involved in the visual perception of faces about a second before seeing them appear on a screen.

Link: https://www.nature.com/articles/s41598-022-17273-1
Title: “Face specific neural anticipatory activity in infants 4 and 9 months old” - «Scientific Reports» - 2022
Authors: Giovanni Mento, Gian Marco Duma, Eloisa Valenza & Teresa Farroni