How 'baby talk' may give infants a cognitive boost

NHS. UK: Say 'mama'! Talking to babies boosts their ability to make friends and learn,” the Mail Online reports. In a review, two American psychologists argue that even very young infants respond to speech and that "baby talk" is essential for their development. It is important to stress that a review of this sort is not the same as fresh evidence.
The review must largely be considered to be the authors’ opinion based on the studies they have looked at. The methods and quality of these underlying studies informing this review are also unknown, so we cannot say how solid this evidence is.
That said, the authors’ arguments would chime with most parents’ instinctive beliefs: regularly talking to your baby is a “good thing”. Regularly talking to your baby is likely to have many benefits, not least in helping their understanding of speech and strengthening the bond between parent and baby.
However, whether talking to your baby has greater effects on their learning capacity or ability to make friends in the future is something that cannot be proven by this review.

Where did the story come from?

The study was written by two psychologists from New York University and Northwestern University in the US. The work was supported by the Eunice Kennedy Shriver National Institute of Child Health and Human Development of the National Institutes of Health, and the National Science Foundation. It was published in the peer-reviewed scientific journal Cell.
The Mail Online reports the review accurately, but doesn’t recognise the important limitations of this review in relation to its absent methods, which means it must largely be considered to be the authors’ opinions.

What kind of research was this?

This was a narrative review discussing a selection of evidence about the effects of exposure to human speech during the first year of a baby’s life. They discuss how this affects not only their speech and language development, but potentially their cognitive ability and social capacity as well.
The authors provide no methods for their review. This does not appear to be a systematic review, where the authors have systematically searched the global literature to identify all evidence related to this topic. It is not known how the authors selected the studies they chose to discuss, and whether other relevant evidence was left out. Therefore, this review must largely be considered to be the opinion of the authors.
While we find the possibility highly unlikely, this sort of unsystematic review may have been subject to what is known as “cherry-picking” – where evidence that does not support the authors’ arguments is deliberately ignored.

What do the authors discuss?

The researchers say it has been thought that listening to speech is mainly beneficial for infants in helping them to develop language. However, they say that new evidence suggests that benefits lie beyond just language acquisition. 
They say that from the first months of life, listening to speech promotes the acquisition of fundamental psychological processes, including:

• pattern learning – the ability to recognise both visual and verbal patterns, such as “ma-ma-ma”
• the formation of object categories – the ability to place external objects into categories, such as being able to tell the difference between a white van and a white sheep
• identifying people to communicate with
• acquiring knowledge about social interactions
• development of social cognition – the ability to interpret, recognise and respond appropriately to other peoples’ feelings and emotions

They also discuss the idea that as babies grow, they specifically favour human speech over other vocalisations, such as laughing or sneezing. They discuss the different nerve cell responses to human speech compared with other sounds, and how speech particularly activates certain areas of the brain. The researchers then go on to discuss the more intricate patterns of how babies learn the rules and patterns of speech as they grow, such as understanding repetitive sequences of different syllables.
The authors present findings of some experiments that aim to see how speech helps babies to learn object categorisation. Babies aged three to 12 months viewed different objects (such as animals) accompanied by listening to either speech or sounds/tones. This found that those listening to speech were better able to categorise similar objects than those who had heard only tones accompanying the objects.
The discussion then turned to how speech may enable babies to identify “potential communicative partners”. That is, they develop the knowledge to treat people and objects differently (for example smiling and making sounds at people). Babies also develop an understanding of how speech conveys information and intentions, even if they cannot understand what is being conveyed. 

What do the authors conclude?

The authors conclude: “Before infants begin talking, they are listening to speech. We have proposed that even before infants can understand the meaning of the speech that surrounds them, listening to speech transforms infants’ acquisition of core cognitive capacities […]. What begins as a natural preference for listening to speech actually provides infants with a powerful natural mechanism for learning rapidly about the objects, events and people that populate their world”.
They say that further research is needed into the range of cognitive and social processes that are and are not facilitated by speech, and the mechanisms underlying this.

Conclusion

This is an interesting narrative review that challenges the belief that speaking to babies is only beneficial in terms of their own speech and language acquisition. The discussion presents what they describe as new evidence, suggesting that the benefits may extend far beyond this. They argue that speaking to babies may have benefits in terms of developing their cognitive abilities, such as the tests where accompanying speech helped babies better categorise objects. The review suggested that it may enhance their social capacity, such as recognising people to talk to and understanding the nature of speech and how it conveys thoughts and intentions.
Much of this discussion is plausible, but the limitations of this review must be noted. The authors provide no methods on how they have searched for, reviewed and selected the evidence they discuss. We don’t know whether all evidence relevant to the topic has been considered, or whether a biased account has been given. Therefore, this review must largely be considered to be the authors’ opinions based on the studies that they have looked at. The methods and quality of these underlying studies informing this review are also unknown, so we cannot say how solid the evidence is.
It makes sense that regularly talking to your baby is beneficial, not least by helping their understanding of speech and strengthening the bond between the two of you.
There is also evidence that babies born into “speech-poor” environments, where they do not receive regular exposure to spoken language, may have delayed development.
However, whether talking to your baby will turn them into a new Mozart or Einstein, or make them super-popular in later life, cannot be proven by this review.
Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.