September 24, 2015

How do infants learn that when their mothers say “apple” they are referring to the round fruit that they are holding in their hand and not just making a strange sound? This is what a team from the International School of Advanced Studies and their colleagues from University of Padova set out to answer in a recent study. As the researchers told Science Daily:

A sensitivity to speech sounds is already present in newborns. These types of sounds are in fact perceived as special starting from the first days of life, and they are processed differently from other types of auditory stimuli.

The team explains that speech sounds signal social interaction, which is important for survival. But the researchers also hypothesized that infants must understand somehow that words are symbols that carry meanings and convey messages, even if they are not yet aware of it, or they wouldn’t be able to acquire language.

Try to imagine an infant who, on several occasions, sees his mother holding up a cup while uttering the word ‘cup’,” explains one of the researchers. “He could just think that this is something his mum would do whenever holding the cup, a strange habit of hers. But instead, in a short while he will learn that the word refers to that object, as if he were ‘programmed’ to do so.

To test their hypothesis, the researchers set up an experiment in which 4-month old infants watched videos where a person would utter a made-up name for an object and then an object would appear on the screen. Sometimes, however, the the person wouldn’t say anything before the object appears on the screen. The team monitored if and how quickly the infants would direct their gaze towards the object on the screen.

The researchers found that “in response to speech cues, the infant’s gaze would look faster for the visual object, indicating that she is ready to find a potential referent of the speech,” reports Science Daily, “However, this effect did not occur if the person in the video remained silent or if the sound was a non-speech sound”. As the scientists explain:

The mere fact of hearing verbal stimuli placed the infants in a condition to expect the appearance, somewhere, of an object to be associated with the word, whereas this didn’t happen when there was no speech.

They added:

This suggests that infants at this early age already have some knowledge that language implies a relation between words and the surrounding physical world. Moreover, they are also ready to find out these relations, even if they don’t know anything about the meanings of the words yet.

To learn more about this topic see full article in Science Daily.