Positive emotions cause stronger connections in the brain activity of mothers and babies

Brain activity in mothers and their babies may be more strongly connected when the mother is happy, according to the University of East London’s Dr Sam Wass, one of the authors of a new study.

Researchers used a method called dual electroencephalography (EEG) to look at brain signals in mums and babies while they were interacting. They found that mums and babies tended to show synchronous patterns of brain waves – known as interpersonal neural connectivity - particularly in the frequency of 6-9 hertz, the infant alpha range.

The study, published in the journal Neuroimage, found that positive interaction, with lots of eye contact, increased the ‘oneness ‘of the mother-infant neural network, as opposed to being two functionally separate systems, which facilitates efficient sharing and flow of information between mother and infant.

Dr Sam Wass, who leads the BabyDev Lab at the University of East London, said, “During our early lives, in particular, our waking time is spent almost exclusively in the company of others, but almost everything that we know at the moment about how the brain develops comes from studying individual infants and children while they are on their own in a brain scanner.

“These new techniques, where we record from two brains at once during an interaction, can help us find out a lot more about how brains develop.”

Dr Vicky Leong from the University of Cambridge’s Department of Psychology, who led the study said, “Our emotions literally change the way that our brains share information with others - positive emotions help us to communicate in a much more efficient way.”

She added, “Depression can have a powerfully negative effect on the parent’s ability to establish connections with their baby. All the social cues that normally foster connection are less readily available to the child, so the child doesn’t receive the optimal emotional input needed to thrive.”

Dr Wass, a senior lecturer in the School of Psychology, recently secured a prestigious €1.5 million five-year grant from the European Research Council to find out more about how patterns of brain activity are ‘shared’ between infants and adults, using techniques similar to those in the current study.

Dr Wass and his collaborators are also looking at how the babies of depressed mothers may show less evidence of learning because of a weakened neural connection between mother and infant. Mothers who experience a persistently low or negative mental state due to clinical depression tend to have less interaction with their baby. Their speech is often flatter in tone, they make much less eye contact, and they are less likely to respond when their baby tries to get their attention.