Neural Bases of Emotional Language Processing in Individuals with and without Autism

Abstract

A fundamental aspect of successful social interactions is the ability to accurately infer others’ verbal communication, often including information related to the speaker’s feelings. Autism spectrum disorder is characterized by language and social-affective impairments, and also aberrant functional neural responses to socially-relevant stimuli. The main objective of the current research was to examine the behavioral and neural effects of making affective inferences from language lacking overt prosody or explicit emotional words in individuals with and without autism. In neurotypical individuals, the current data are consistent with previous studies showing that verbal emotional stimuli enhances activation of brain regions generally responsive to discourse, and also “social-affective” brain regions, specifically medial/orbital frontal regions, bilateral middle temporal areas, temporal parietal junction/superior temporal gyri and pCC/PC. Moreover, these regions respond differentially to positive and negative valence, most clearly in the medial frontal area. Further, results suggest that mentalizing alone does not account for the differences between emotional and neutral stories, as all of our stories required similar inferencing of the feelings of the protagonist. In autism, there is general agreement that the neurodevelopmental disorder is marked by impairments in pragmatic language understandings, emotional processes, and the ability to “mentalize,” others’ thoughts, intentions and beliefs. However, findings are mixed regarding the precise nature of emotional language understandings. Results of the present study suggest that autistic individuals are able to make language-based emotional inferences, and that like neurotypical controls, social-affective brain regions show task-related facilitation effects for emotional compared to neutral valence. However, the neural activations in the autism group were generally greater than controls, especially in response to emotion. Additionally, results showed greater difficulty with incongruent judgments in participants with autism. Together, these findings represent a first step toward revealing social-affective abilities in the language context in autism, despite irregular brain response. Such understandings are critical to generating effective intervention strategies and therapeutic practices for autistic individuals and their families. For remediation to be most beneficial, one must understand and utilize areas of skill, and leverage those to positively impact deficits.