Behavioral and physiological responses to child-directed speech of children with autism spectrum disorders or typical development.

Heinicke et al. (2012) watched preschool boys with and without autism while they heard child-directed speech. They tracked eye gaze and heart rate at the same time.

The team wanted to see if autistic kids look less at faces and if their bodies show more stress during speech.

Autistic preschoolers looked away from the speaker more often and had higher resting heart rates than typical peers.

Both signs point to trouble tuning in to speech, which could slow language growth.

Foody et al. (2015) found moms and dads of autistic kids also show high stress and low morning cortisol. The child data here match the parent pattern—autism families run on high arousal.

Laugeson et al. (2014) saw heart rate climb in older kids during speech, yet tics dropped. That seems opposite to our preschoolers, but age and diagnosis differ. High arousal can freeze little kids while it calms tics in older ones.

Root et al. (2017) later showed ADOS social scores predict real peer talk. Pair that with our gaze findings and you get a clear line: poor early attention to speech links to later social gaps.

Check both eyes and heart when you assess preschoolers with autism. If gaze drifts and heart rate stays high, simplify your voice, slow your pace, and add visual cues before you place language demands. These tiny fixes can lower arousal and boost attention in your next session.