The Broader Autism Phenotype As It Relates to Interoception, Alexithymia, and Emotion Processing

Background: The ability to process information from our internal bodily state has been found to relate to socio-emotional competence (Ferri et al., 2013). Neurotypical adults who show high interoceptive accuracy (IA) in sensing and tracking bodily signals such as heart rate are found to experience emotions with heightened intensity (Pollatos et al., 2007), and work with individuals with ASD has also examined IA, though results are mixed. Some studies have found increased IA in ASD (e.g., Schauder et al., 2015), while others have found impaired IA (e.g., Garfinkel et al., 2016). Recent studies have suggested that alexithymia, a personality construct characterized by impairments in sensing, identifying, and describing one's emotions, might mediate associations between ASD and IA (Shah et al., 2016) as well as ASD and emotion processing (Cook et al., 2013). More work is needed to understand how the associations among these factors might relate to the broader autism phenotype (BAP).

Objectives: The present study investigated the relations between characteristics of the BAP, IA, alexithymia, and emotion recognition in the general population.

Methods: The present sample included 36 undergraduate students (14 male). Participants completed a heartbeat perception task, where they were asked to silently count their heartbeats without physically feeling their heart or pulse. Heart rate was recorded using a Biopac MP150WSW system. After this task, participants completed a series of questionnaires to measure aspects of socio-emotional competence. Characteristics of the BAP were measured through the Social Responsiveness Scale, Second Edition (SRS-2; Constantino & Gruber, 2012); alexithymia was assessed with the Toronto Alexithymia Scale (TAS-20; Bagby et al., 1994); and emotion recognition was assessed using the Reading the Mind in the Eyes Test (RMET; Baron-Cohen, et al., 2001). Based on prior work by Pollatos et al. (2007), IA was calculated as the mean accuracy in heartbeat perception across three randomly-ordered time intervals.

Results: Characteristics of the BAP were found to be positively related to alexithymia, r(33) = .648, p < .001, and a trend towards a negative association with emotion recognition was also found r(34) = -.321 , p = .056. Alexithymia was negatively related to emotion recognition, r(33) = -.373, p =.027, and on further analysis, when controlling for alexithymic traits, the marginal association between BAP and emotion recognition disappeared (r(32) = -.113, p = .525), consistent with previous work. When examining these aspects of socio-emotional processing in relation to IA, only the RMET was found to be significantly associated, r(34) = .411, p = .013, such that those who were more accurate in detecting their heartbeats also showed better accuracy in recognizing others emotions.

Conclusions: Consistent with past work in ASD, the present study found a) increased BAP characteristics were associated with higher levels of alexithymia, b) higher levels of alexithymia were associated with worse emotion recognition, and c) relations between BAP and emotion recognition were mediated by alexithymic traits. Further, better interoception related to better emotion recognition. Future work will expand the present sample to further explore the relationship between IA and socio-emotional competence as it relates to the BAP.