Automatic processing of emotional faces in high-functioning pervasive developmental disorders: An affective priming study.

Kamio et al. (2006) showed faces with happy or angry expressions to teens with high-functioning autism. The faces flashed so fast that the kids could not tell what they saw. Then a second picture appeared and the kids had to say if it was good or bad.

The team also ran a slow version where faces stayed on screen long enough to see. Both tests checked whether the emotional face primed, or sped up, the next answer.

Typical teens answered faster when the first face matched the feeling of the second picture. Autistic teens showed no speed-up at all, even when the face was invisible.

The result means their brains did not pick up emotional meaning from faces automatically.

Stel et al. (2008) saw the same blank response in a different task. They asked autistic teens to hold a pencil in their teeth, forcing a smile. Typical teens felt happier; autistic teens felt nothing. Together the two studies show the social signal never gets in.

Hartston et al. (2023) and Hartston et al. (2024) explain why: autistic adults form weak, unstable pictures of faces in the first place. If the brain sketch is blurry, emotional tags never stick.

Spriggs et al. (2015) trace the trouble back to babyhood. Infants later diagnosed with autism start out looking at eyes, then steadily stop. The priming failure in Yoko’s teens fits this early drop-off.

Do not assume your client will read your smile, your frown, or even your wide-eyed surprise. Pair faces with clear words or gestures. Teach emotion with explicit rules—"wide eyes plus open mouth means scared"—and give many examples. Check understanding by asking the learner to label the feeling instead of waiting for a spontaneous reaction.