Investigating the Association of Early Attentional Control and Autonomic Arousal in a Sample of Low- and High-Risk Infants
Objectives: The objective of this study was to examine the association between autonomic arousal and attentional control in a sample of high-risk infants.
Methods: Data from a sample of participants from an ongoing longitudinal study of ASD were used for the analyses. The data included infant behavioural and physiological data at three time points: 6 (n=12), 12 (n=23), and 18 months (n=8) of age. Participants were designated as high risk if they had an older sibling with ASD (n=36) or as low risk if they did not (n=7). Behavioural data included scores on items related to engagement, disengagement, and sustaining of attention on the Autism Observation Scale for Infants (AOSI; items 2 and 19) and the Autism Parent Screen for Infants (APSI; item 20). Physiological data consisted of heart rate and heart rate variability extracted from electrocardiography signals collected as participants watched a 2-minute calming video clip. Repeated measures linear regression was used to examine the association between heart rate /heart rate variability and the behavioural scores.
Results: There were no significant effects of group (high risk/low risk) or visit (6, 12, 18) on the APSI or AOSI items. The low-risk group had significantly higher heart rate variability compared to the high-risk group (low-risk: 6.1(0.6) (CL: 4.9-7.3); high-risk: 4.7(0.3) (CL: 4.2-5.2); p=0.04). Parent-reported levels of sustained attention (APSI item 20) were significantly correlated with heart rate variability (beta=-1.4(0.4); p=0.006), with lower levels of sustained attention associated with lower heart rate variability. Associations between heart rate variability and engagement/disengagement of attention scores of the AOSI were not significant. No significant associations were found between heat rate and any of the behavioural scores.
Conclusions: Consistent with findings in non-ASD samples, our preliminary results suggest that decreased levels of sustained attention may be associated with decreased heart rate variability in a sample of low- and high-risk infants. Replication with larger sample sizes is needed. Our analyses are a first step in understanding physiological underpinnings of attentional control difficulties in ASD. If replicated in a larger sample, these results may also suggest physiological differences in high-risk infants.