Isolated words in infant-directed speech

Imagine you’re a small baby who hasn’t yet learned to talk. 

• When people around you speak, what do you hear? 

It’s probably quite like listening to people speaking a language you don’t know.

• If you don't know Gaelic, try listening for individual words in this video of Iain speaking Scottish Gaelic. 

How can we work out what babies do or don't remember?

The Head-Turn Preference procedure is a well-established method of measuring what babies and infants pay attention to. The video explains how the procedure works.

In order to focus on whether babies do in fact learn better from hearing isolated words than words in running speech, Keren-Portnoy, Vihman and Lindop Fisher adopted a different approach from previous experimental attempts.

Instead of exposing babies to target words in a "special" or lab setting, they designed a picture book and asked the caregiver to read the book to babies at home, twice a day for three weeks. 

• The book contained a number of unfamiliar animal names 

  • e.g., dassie, dugong, fennec, pudu (these are real animal names!)

Some of the animal names were presented in isolation in the book and some in a sentence. 

• After three weeks, the children were brought to the lab and the researchers used the Head-Turn Preference procedure to see which words were more familiar.

The results of the Head-Turn Preference test showed that the babies remembered the names they had heard in isolation better than the names they heard in running speech. 

• Keren-Portnoy, Vihman and Lindop Fisher concluded from this that isolated words are disproportionately useful to the baby for language learning, especially in the earliest stages.