Insufficient Sleep Makes Learning Words Harder for Babies
We already know that sleep deprivation affects the brain and makes us more emotional. Research now suggests that sleep deprivation affects the memory and language development of babies who are less than seven months old.
A 2017 study published in the journal Brain & Language set out to determine the effect of sleep on language learning in infants. Researchers divided 37 six-and-a-half month-old infants into two groups.
Babies in the nap group listened to a stream of artificial words for seven minutes roughly half an hour before their estimated nap time. Once the babies fell asleep, they were placed in a crib and their sleep was monitored until they naturally awoke.
Babies in the no-nap group listened to the same stream of words for the same amount of time but were then quietly entertained with toys for a period of time that matched the nap duration of babies in the nap group.
Word retention was measured using the Headturn Preference Procedure, which is recognized as an effective way to investigate infant speech perception.
Benefits of sleep on infant language development
Researchers found that the infants who slept were better at remembering the words they were exposed to than the babies who did not sleep. This led the authors of the study to suggest that sleep benefits language encoding and retention, and that this benefit should accumulate over time.
An earlier study published in 2015 found that infants between nine and 16 months of age who napped were better at remembering words and understanding their meaning compared to infants who stayed awake. The authors of this study concluded that infant sleep enables the retention and organization of recent memories.
The power of a short nap
The 2015 and 2017 studies were particularly interesting since the nap durations were not particularly long. In the earlier study, infants performed better after an average nap duration of just 45 minutes. In the latter study, the average nap duration was just 64 minutes.
The importance of sleep in childhood
These aren’t the first studies to confirm just how important a role sleep plays in childhood development. A 2007 article published in the journal Sleep pointed out that short sleep duration in the first three years of life is associated with hyperactivity and lower cognitive performance on developmental tests at the age of six.
In other words, poor sleep in early childhood may have long-term negative effects.