Sensory Differences,Alexithymia and Neural Activity During Emotion Observation in Youth With Autism Spectrum Disorder (ASD)

PURPOSE: Previous work has indicated that alexithymia — trouble recognizing, describing, and distinguishing emotions in oneself — may contribute to deficits in empathic processing in Autism Spectrum Disorder (ASD; Bird et al., 2010). Furthermore, alexithymia is associated with atypical responses to sensory input (Kano et al., 2007). Individual differences in alexithymia may also be associated with the increased rates of sensory sensitivities in ASD (Milosavljevic et al., 2016). To date, only one study has explored the relationships between alexithymia, sensory sensitivities, and empathic processing in youth with ASD (Milosavljevic et al., 2016), and there is little understanding of the neural mechanisms involved. The objectives of the current study are: (1) to assess the relationship between scores on The Alexithymia Questionnaire for Children (AQC) and the Short Sensory Profile Second Edition (SSP-2); and (2) to assess how performance on these scales relate to neural activity during an emotional face processing task in a sample of typically developing (TD) youths and youths with ASD. Understanding the relationship between sensory and emotion processing is a vital concern in occupational therapy for improving theoretical basis, mechanistic understanding, and evidence-based practice in sensory based therapy in ASD.

DESIGN: Participants were recruited for this quantitative experimental study through social media, schools, parent groups, clinics, and community events. Participants were 8-17 years old, English speaking, right handed, and had no intellectual disability.

METHODS: Data from 27 high-functioning participants with ASD (mean age=11.90±2.13), and 29 TD participants (mean age = 12.0±2.36) were analyzed. AQC was completed by participants and the SSP-2 was completed by parents. fMRI data was collected on a 3-T Siemens MAGNETOM Prisma scanner while participants watched videos of emotional faces presented in a block design. Standard preprocessing was applied, and whole brain analysis of the neural response to emotional faces compared to rest were made controlling for age, sex, and IQ. Parameter estimates from a functional ROI in the inferior frontal gyrus (IFG), a region involved in empathy processing, was extracted using FSL’s featquery. Pearson partial correlation was used to assess the associations between IFG activity, AQC, and SSP-2 scores.

RESULTS: In the TD group, no significant correlations were observed between the SSP-2 and the AQC. In the ASD group, the SSP-2 register score was significantly positively correlated with the AQC identifying emotions score (R=.414, p=.044). In a whole brain correlation across all participants, increased alexithymia scores were correlated with significantly reduced activation in a large cluster of the left IFG pars opercularis (Z>2.3). In the ASD group, a significant negative correlation was observed between activation of the left IFG and the SSP-2 register subscale (R= -.409, p=.047).

CONCLUSION: In our ASD sample, we observed a significant correlation such that as alexithymia scores became more severe, individuals also displayed increased hypo-responsive profiles, as measured by the SSP-2 register score. Furthermore, across all groups, we found that in an emotional face processing task, individuals showing high activity in the left IFG tend to be less alexithymic and, in the ASD group, less hypo-responsive. This work suggests a relationship between sensory functioning, alexithymia severity, and IFG activation during an emotion processing task. These findings offer new insights for occupational therapists to deliver more client-centered care for social-emotional processing needs by being able to better identify individuals who may benefit most from sensory based therapy.

References

Bird, G., Silani, G., Brindley, R., White, S., Frith, U., & Singer, T. (2010). Empathic brain responses in insula are modulated by levels of alexithymia but not autism. Brain, 133(5), 1515-1525.

Kano, M., Hamaguchi, T., Itoh, M., Yanai, K., & Fukudo, S. (2007). Correlation between alexithymia and hypersensitivity to visceral stimulation in human. Pain, 132, 252–263.

Milosavljevic, B., Leno, V. C., Simonoff, E., Baird, G., Pickles, A., Jones, C. R., ... & Happé, F. (2016). Alexithymia in adolescents with autism spectrum disorder: its relationship to internalising difficulties, sensory modulation and social cognition. Journal of autism and developmental disorders, 46(4), 1354-1367.