Electromyographic responses to emotional facial expressions in 6-7 year olds with autism spectrum disorders.

Researchers stuck tiny EMG sensors on the faces of 6- and young learners. Half had autism, half were typical.

Kids watched happy, angry, and fearful faces on a screen. Sensors caught micro-movements in their own cheek, brow, and eye muscles.

Overall, both groups copied the faces the same amount. Kids with autism moved the right muscles just as fast.

But inside the autism group, one thing stood out. Children who copied fearful faces less had worse social skills on the ADOS.

Eussen et al. (2016) looked deeper with fMRI. They saw slower amygdala habituation to fearful faces in autism. The two papers seem to clash—same emotion, opposite results. The fix: EMG catches surface mimicry; fMRI catches brain habituation. The face can copy while the brain still lags.

Lemons et al. (2015) used eye-tracking and also found no group difference in arousal to eye contact. Together, these nulls chip away at the old idea that autistic kids simply avoid social input.

Kaartinen et al. (2016) link less autonomic habituation to direct gaze with worse social scores. Both studies tie a physiological measure to real-world social trouble, just with different sensors—EMG versus skin conductance.

Do not assume a child who looks engaged is processing fear normally. Watch for flat or delayed responses to distress cues—crying, scared faces, sirens. If you see low fear mimicry, add emotion-labeling drills and practice reading worried faces. Targeting this micro-skill may boost broader social responding.