Fathers' and Non-Fathers' Physiological Responses to Distress Vocalizations of Infants with Autism Spectrum Disorders

Background:   Children with ASD, even before receiving a formal diagnosis, express atypical patterns of cry (higher fundamental frequency and shorter inter-bout pauses) in response to social and non-social stressors. Cries of children with ASD are also perceived differently from other cries, and these perceptual differences may alter parent-infant interaction.

Objectives:   To test multiple physiological responses to atypical distress vocalizations (crying of ASD children) acoustically matched with typical distress vocalizations (crying of typically developing children) and with positive vocalizations (laughter of typically developing children).

Methods:   The experimental procedures were designed measure how components of the autonomic nervous system respond to typical and atypical infant distress vocalizations. We employed three convergent methodologies. (i) Emotional arousal was assessed using the Galvanic Skin Response (GSR). (ii) Assessments of excitability were conducted monitoring cardiac dynamics via Inter-Beat Interval (IBI). (iii) Promptness to action was measured as temperature increases of the right hand (Right Hand Temperature Change – RHTC), which is associated with arousal and activation. These physiological assessments were performed on two groups with contrasting caregiving experience: fathers (n=10) and non-fathers (n=10).

Results:   Inferential analysis was performed considering two groups (fathers vs non-fathers) and three stimulus types (ASD cry, TYP cry, laughter) for the three measures (GSR, IBI, RHTC). Both fathers and non-fathers showed greater negative response (increased GSR) to ASD cries compared to TYP cries and laughter (p < .001). Fathers showed higher IBI compared to non-fathers while hearing both typical and atypical crying  (p < .05), and for the RHTC fathers showed greater temperature increases than non-fathers while listening to typical and atypical cries (p < .05).

Conclusions:   In agreement with behavioral studies that have been conducted mainly in females and mothers, fathers and non-fathers show more emotional arousal mediated by sympathetic activation (measured as increased GSR) while listening to cries of children with ASD. In other terms, it seems that ASD cries are processed as more negative. This result is likely driven by specific characteristics of ASD cries (high frequency and shorter pauses). Fathers were calmer (lower IBI) than non-fathers while listening to cries, perhaps because fathers have more experience in caring for crying infants. Fathers were more prompted to act (increase of the RHTC) than non-fathers while listening to cries. However, we found no differences between fathers and non-fathers in reaction to non-distress vocalizations. Sensitivity to infant cries may be tuned by fathering experience. These findings highlight both similarities and differences in fathers’ and non-fathers’ physiological responsiveness to crying of children with ASD and can provide information to guide specific intervention programs for parents of children at high-risk of ASD.