Infants at risk for autism rely on more information from the head when following gaze, according to a study published this January in Molecular Autism. The study highlights early disruptions to joint attention and provides the potential for identifying early signs of autism spectrum disorder (ASD) development.
Joint attention involves the sharing of attention between individuals toward a common object. It is especially important for infants in forming the basis for later development in social cognition and language. For example, a parent may look at their baby and then look towards a toy on the floor. By following their parent’s gaze along the floor, the baby is able to find the toy, and infants typically become competent at this before their first birthday. Later on, a child will learn that gaze direction often provides information as to what is going on inside someone’s mind.
Children with ASD display social communication impairments, and it has been proposed that this might be linked to disruptions to the development of joint attention. Given that ASD is rarely diagnosed before the age of 2–3 years, identifying impairments to joint attention provides the potential for identifying early signs of the disorder’s development.
The study, led by Emilia Thorup of Uppsala University in Sweden, used eye tracking software to assess the gaze following of 10-month-old babies with a familial risk for developing autism. 47 of the infants were high-risk (at least one older full sibling with an ASD diagnosis) and a control group of 17 infants were low-risk (no familial history of ASD). This was based on research indicating that in a family with one child diagnosed with ASD, the probability of an ASD diagnosis in a sibling is more than ten times higher than in the general population.
During the study, the experimenter performed a live puppet show while the baby’s gaze was recorded. There were two conditions: one in which the experimenter moved both their eyes and head between the two puppets, and one that involved movement of only the eyes.
The results revealed that the high-risk infants performed worse in the condition that involved only eye movement, whereas low-risk infants followed gaze as accurately in both conditions. The researchers concluded that “infants at risk for ASD may rely disproportionately on information from the head when following gaze”. The study also highlights the potential for identifying early signs of ASD development.