How do babies figure out what they need to learn amid the countless sounds and words flooding their environment?

Research has shown that when an infant makes eye contact with a speaker, such as a parent, their brain activity synchronizes, sending a signal that the information is important and enabling them to selectively learn language.

A research team led by Professor Victoria Leong of the University of Cambridge in the UK and Nanyang Technological University (NTU) in Singapore announced on the 28th that they confirmed this through an experiment involving 8-to-10-month-old infants in the UK and Singapore.

The research team stated that this study demonstrates how simple social cues, such as making eye contact or calling a baby's name, go beyond merely capturing an infant's attention to actually activate the learning process itself, providing evidence that supports the importance of early language development and parent-child interaction.

Although infants are equipped with remarkable learning abilities from birth, numerous stimuli—including visual information, sounds, and human voices—exist simultaneously around them, requiring a process of selecting what constitutes important information.

The research team pointed out that while it was previously known that social cues such as eye contact, infant-directed speech with exaggerated tones, and calling a baby's name help infants learn, it was not yet clear how these cues translate into learning within the brain.

To investigate this, the research team conducted an experiment exposing 47 infants aged 8 to 10 months in the UK and Singapore to three types of artificial languages that were not real words.

The person delivering the artificial languages was the same in all cases, but appeared on a computer monitor wearing glasses where their eyes were fully visible, partially visible, or completely invisible depending on the language.

The research team compared how well the infants learned the artificial languages presented under the three different conditions of eye exposure.

During the presentation of the languages, the team measured the infants' brain activity using electroencephalography (EEG) and analyzed the degree of synchronization between the speaker's brain activity—measured when the video was recorded—and that of the infants.

Next, the infants were played words from the previously heard language alongside newly created fake words, and the duration of their gaze toward each side was measured.

Looking at new words longer than already familiar words was taken as an indication that the infants had learned the previously presented language.

The analysis showed that although the infants heard all three languages, they significantly learned only the language presented when the speaker's eyes were fully visible.

On the other hand, when the speaker's eyes were partially or completely obscured, the learning effect was not statistically significant.

In particular, stronger neural coupling—the connection of brain activity flowing in the direction from the speaker to the infant during the language learning process—was associated with greater learning effects.

In fact, the neural coupling between the speaker and the infant predicted learning outcomes better than the infant's brain activity alone.

The research team explained that the duration of time infants spent looking at the screen showed almost no difference regardless of whether the speaker's eyes could be seen, meaning that rather than simply staring at a screen for a long time, the process of grasping the speaker's intent and synchronizing brain activity through eye contact plays a crucial role in actual learning.

They added that eye contact is one of several social cues conveying the speaker's intention that "what I am saying right now is important," noting that smiling, pointing, or calling the baby's name can serve the same function.

Professor Leong said, "When teaching something to a child, rather than speaking while looking at a cell phone, putting the phone down and speaking while looking into the child's eyes will make the child take it more seriously and be more likely to learn."

(Photo: Provided by Victoria Leong/University of Cambridge, Yonhap News)