Investigating implicit emotion processing in autism spectrum disorder across age groups: A cross-modal emotional priming study

Cumulating evidence suggests that atypical emotion processing in autism may generalize across different stimulus domains. However, this evidence comes from studies examining explicit emotion recognition. It remains unclear whether domain-general atypicality also applies to implicit emotion processing in autism and its implication for real-world social communication. To investigate this, we employed a novel cross-modal emotional priming task to assess implicit emotion processing of spoken/sung words (primes) through their influence on subsequent emotional judgment of faces/face-like objects (targets). We assessed whether implicit emotional priming differed between 38 autistic and 38 neurotypical individuals across age groups as a function of prime and target type. Results indicated no overall group differences across age groups, prime types, and target types. However, differential, domain-specific developmental patterns emerged for the autism and neurotypical groups. For neurotypical individuals, speech but not song primed the emotional judgment of faces across ages. This speech-orienting tendency was not observed across ages in the autism group, as priming of speech on faces was not seen in autistic adults. These results outline the importance of the delicate weighting between speech- versus song-orientation in implicit emotion processing throughout development, providing more nuanced insights into the emotion processing profile of autistic individuals. Research is needed to know whether there are differences in how autistic and non-autistic individuals of different ages process emotions unconsciously. Our study shows that hearing emotionally spoken words unconsciously influenced how non-autistic people understood facial expressions across all age groups, while only non-autistic children were influenced by emotionally sung words. In contrast, only autistic children and adolescents, but not autistic adults, were influenced by emotionally spoken words when interpreting facial expressions. Autistic individuals of all age groups were influenced by emotionally sung words when interpreting faces. These results suggest that autistic people are less influenced by spoken information during unconscious emotion processing which can affect real-world social communication, as emotional cues in speech can be used to support judgment of facial expressions.