When a baby cries we react quickly to the needs of the child. A team of researchers from the University of Toronto and the National Institute for child health and human development (Maryland) studied the effects of infant vocalizations on adult cognitive performance. What happens to the brain when a new born baby laughs or cries?

While the majority of publications have emphasized the role of the baby’s face as a powerful means of attracting adult attention, the sounds of a baby’s cry are also significant. The acoustics of a baby’s cry trigger vigilance, and research on brain imagery shows that infant vocalizations activate cortical regions affecting cognitive control and attention. Further studies have also indicated the negative impact of infant vocalization on cognitive control by reducing concentration.

In current research, Joanna Dudek and her colleagues have tried to identify the effects of two different baby sounds, cries and laughter, on the concentration of an adult during a cognitive task. In the first experiment, 15 participants listened to these sounds before doing a Stroop exercise on the computer (to identify the color of a word as quickly as possible). Seven of the participants were female, none of them had children and the average age was 20.9 years. In the second experiment, 20 female participants with an average age of 20.6 years and without children, did the same exercise while simultaneously listening to the infant cries or laughter. To evaluate the influence of infant vocalization on cognitive control, neural responses to the Stroop exercise were recorded using an electroencephalography (EEG).

In both situations the babies’ cries interfered with performance by slowing down adult cognitive activity, with participants performing the task more slowly when listening to babies’ cries than to their laughter. In addition, the results of the participants’ EEGs highlight what is known as ‘cognitive conflict,’ which is essential to learning and also promotes decision making by focusing attention primarily on (negative) emotional stimuli.

The results of the study, published in the review Plos One, show that cerebral recognition of infants’ cries is a reality and that it concerns parents and non-parents alike. Understanding this mechanism will help to improve care for newborns as parents responding to multiple stimuli can develop their cognitive flexibility to enable rapid decision making.