Babies hear and react to human noises and emotions in their sleep, a new study reveals. Scientists saw increased brain activity in sleeping babies when they played a variety of noises and voices, showing that babies were using the same part of the brain that adults use when they’re awake, listening and responding to stimuli.
The babies, aged between 3 and 7 months, were monitored by an MRI scanner. Noises were then played to them while they slept. They listened to background noises such as coughs, sneezes and toys as well as sad, happy and neutral conversations that included laughing and crying sounds.
The study, from King’s College London, found that the babies responded similarly to happy and neutral sounds but had a much stronger reaction to the sad sounds, such as crying. This is the same as in adults who are awake, and uses the temporal cortex section of the brain.
“It’s fascinating that babies can do this. You’d think that a sleeping baby wouldn’t be able to hear you, but clearly their brains are processing sounds while they’re asleep,” Professor Declan Murphy from King’s College told New Scientist.
Murphy believes that this research can be used to discover the differences between how autistic brains and non-autistic brains develop.