Exploring the links between brain function and parent-infant interaction: A longitudinal study

Autism is a neurodevelopmental condition characterised by impaired social interaction, impaired communication and restrictive and repetitive behaviours and interests with prevalence around 1% in the UK school population. Due to its high heritability, siblings of children with autism have 50% risk of developing the disorder or autistic traits compared to infant siblings without autism.
Prospective longitudinal studies of infants with an older sibling with autism have shown that a behavioural diagnosis is rarely observable before the age of two to three years, while brain function measures have been able to identify early subtle differences within the first year of life. For instance, it has been shown that infant siblings who later receive a diagnosis exhibit altered event-related potential (ERP) responses to eye gaze and faces as well as a decreased brain activation to socially relevant visual and auditory stimuli. By the second year, overt behavioural signs include a gradual decrease in social and communicative behaviours, such as reduced joint attention, shared smiles and vocalisations. However, whether early brain function changes are linked to subsequent atypicalities in social behaviours is not yet clear and may have important implications for early intervention.
Transactional models of development support the idea that early subtle disruptions in infants' social competence may alter parental responses towards the infant and subsequent mutuality in parent-infant social interactions. Early brain function differences may be exacerbated by atypicalities in interactions within different brain regions and the child's social environment, thereby producing a pattern of socio-cognitive development that gradually deviates from a healthy phenotype. For instance, atypical early social communicative skills are likely to influence parental responses which may inadvertently decrease social attention in infants with pre-existing genetic vulnerability, leading to an increasingly atypical developmental route. In support of this idea, research has identified clear relationships between brain responses to eye gaze (ERPs) and quality of parent-child interaction (PCI) in at-risk infants relative to those at low risk of autism at 7 months of age. Links between these two measures have also been found in a similar study undertaken by the researcher involving 8-month old infants at-risk, distinguishing later diagnosed from non-diagnosed infants, and yielding promising results for future investigation.
The current project seeks to extend on this research, proposing to follow a longitudinal design in order to examine whether different measures of brain function in response to social stimuli are related to unstructured PCI in infants at high and low risk of autism over developmental time, and how this association is linked to autism outcome. Particularly, the PCI measure will focus on parental directiveness, sensitive responsiveness, infant attentiveness to parent, infant affect and mutuality variables. These variables have distinguished at-risk from low-risk groups, with the latter three variables predicting those who were later diagnosed with autism. Additionally, research has found links between ERP responses to eye gaze and infant affect and attentiveness in infants at-risk.
Taken together, this project will offer significant insights into the possible risk factors leading to autism outcome and the role that PCI could play in these children's developmental trajectories, which could form the basis for identifying new targets for supportive early interventions for vulnerable infants. It will also provide a stepping stone towards a better understanding of how measures of brain function relate to naturalistic interactions between infants and their parents and whether they could both play a predictive role in assessing the risk of clinical diagnosis in early childhood.