Intact Neural and Behavioral Processing of Vocal Emotional Expressions in Men with Autism

Human voices convey critical socio-affective information, including emotional states. Although autism has frequently been associated with difficulties in processing vocal emotional cues, findings remain inconsistent, particularly in adults. This study investigated neural and behavioral sensitivity to vocal emotion expressions in autistic adults using an objective auditory frequency-tagging EEG paradigm.

Twenty-five autistic adult men and 25 age- and IQ-matched non-autistic men completed an auditory frequency-tagging EEG task and an auditory and multimodal emotion-recognition assessment. During EEG recording, neutral vocal utterances were presented at 4 Hz, with emotional utterances (fear, anger, happiness, or sadness) inserted every third stimulus, generating an oddball frequency of 1.333 Hz indexing vocal emotion discrimination.

No significant group differences were observed in neural or behavioral measures of emotion processing. Robust oddball EEG responses were present in both groups, indicating automatic discrimination of emotional from neutral vocalizations. Fearful and angry vocalizations elicited the strongest neural responses. On the behavioral task, autistic and non-autistic participants showed comparable performance in the auditory modality as well as in the visual and audiovisual modalities, with auditory emotion recognition being the most challenging condition for both groups.

These findings provide converging neural and behavioral evidence for intact vocal emotion processing in autistic adult men and are consistent with the view that socio-affective processing differences may attenuate across development. Auditory frequency-tagging EEG shows promise as a sensitive tool for studying individual differences in socio-affective processing.