Identifying phenotypic and physiological subgroups of preschoolers with autism spectrum disorder.

Tessel Bazelmans,Tony Charman,Sarah Corrigan,Karen Toth,Sheila Ghods,Sara J Webb,Emily J H Jones

doi:10.1017/s0033291721003172

Abstract

To understand the emergence of symptoms in autism spectrum disorder (ASD), we need to identify the mechanisms that underpin the development of core social skills. Mounting evidence indicates that young children with later ASD attend less to other people, which could compromise learning opportunities with cascading effects. Passive looking behaviour does not tell us about engagement with visual information, but measures of physiological arousal can provide information on the depth of engagement. In the current study, we use heart rate (HR) and heart rate variability (HRV) to measure engagement with social dynamic stimuli in ASD. Sixty-seven preschoolers with ASD and 65 typical developing preschoolers between 2 and 4 years of age participated in a study where HR was measured during viewing of social and non-social videos. Using latent profile analyses, more homogeneous subgroups of children were created based on phenotype and physiology. Preschool-aged children with ASD, regardless of their non-verbal, verbal and social competencies, do not differ in overall HR or HRV compared to TD children. However, the ASD group showed a larger increase in HR (more disengagement) than the TD group to later-presented social stimuli. Phenotypic and physiological profiles showed this was primarily the case for children with below average verbal and non-verbal skills, but not necessarily those with more ASD symptoms. Children with ASD, especially a subgroup showing moderate cognitive delays, show an increase in HR to social stimuli over time; this may reflect difficulties re-engaging with social information when attention is waning.

Highlights

To understand the emergence of symptoms in autism spectrum disorder (ASD), we need to identify the mechanisms that underpin the development of core social skills
There was a significant effect of condition and a significant group-by-condition interaction effect (Fig. 1a); whilst the typical developing (TD) group showed an increase in heart rate (HR) from B1-Man to B2-Hungarian only [contrast = 2.50, p = 0.008, 95% CI (0.45–4.55)], the ASD group showed an increase in HR from B1-Man to the B2-Hungarian and B2-English conditions [respectively, contrast = 4.35, p < 0.001, 95% CI (2.20–6.50); contrast = 2.99, p = 0.001, 95% CI (0.90–5.08)] and an increase in HR from B1-Toy to the B2-Hungarian and B2-English conditions [respectively, contrast = 3.76, p < 0.001, 95% CI (1.62–5.91); contrast = 2.41, p = 0.014, 95% CI (0.32–4.50)]
Heart rate variability Age was a significant predictor of heart rate variability (HRV); older children had higher HRV when watching the videos (Table 2)

Summary

Introduction

To understand the emergence of symptoms in autism spectrum disorder (ASD), we need to identify the mechanisms that underpin the development of core social skills. We use heart rate (HR) and heart rate variability (HRV) to measure engagement with social dynamic stimuli in ASD. Sixty-seven preschoolers with ASD and 65 typical developing preschoolers between 2 and 4 years of age participated in a study where HR was measured during viewing of social and non-social videos. The ASD group showed a larger increase in HR (more disengagement) than the TD group to later-presented social stimuli. Phenotypic and physiological profiles showed this was primarily the case for children with below average verbal and non-verbal skills, but not necessarily those with more ASD symptoms. Children with ASD, especially a subgroup showing moderate cognitive delays, show an increase in HR to social stimuli over time; this may reflect difficulties re-engaging with social information when attention is waning

Results

Discussion

Conclusion