Interoceptive Awareness, Alexithymia and Empathy in Autism

Background:  

Autism is often co-morbid with alexithymia, an impaired ability to recognise, describe and understand one’s own emotions. Considering inconsistent findings in emotion processing research in autism, it has been proposed that alexithymia may be a contributory factor to the emotional deficits of autism. Here, the role of interoception - the sense of one’s bodily state - in alexithymia and empathy was investigated in a sample of 52 adult participants (26 with high-functioning autism).

Objectives:  

To establish if people with autism differ in sensitivity to interoceptive signals compared to those without autism and if interoceptive sensitivity (IS) and interoceptive awareness (IA) are related to symptoms of alexithymia, empathy and autistic traits.

Methods:

IS was measured with heartbeat tracking and heartbeat detection tasks. Heartbeat tracking consists of counting one’s heartbeats during brief intervals, without taking one’s pulse. This count is compared to the actual number of heartbeats, giving an accuracy score. Heartbeat detection involves the identification of one’s own heartbeats from a series of sound beeps, which are synchronous or asynchronous w.r.t. one’s heartbeats. An emotion recognition task and an affective empathy task were also administered. Participants completed questionnaires measuring autistic traits, alexithymia, IA, empathy, and their sensory profile. Data was analysed for differences between people with and without autism, and regression-based conditional process analyses were conducted to investigate the relationships between IS, IA, alexithymia and empathy.

Results:  

Participants with autism were less accurate than the control group in the heartbeat tracking task, indicating lower IS. No differences were found in the heartbeat detection task. There was no difference between groups in identifying emotions and levels of affective empathy. Participants with autism scored significantly lower on the empathy questionnaire and significantly higher on the alexithymia questionnaire. All empathy scores were moderately correlated to autistic traits and alexithymia. While IS scores were not related to autistic traits, empathy or alexithymia, self-reported IA was related (r –values ranging from|.45| to |.57|), as were active and reactive strategies towards bodily feelings (r-values ranging from |.27| to |.57|). Conditional process analyses confirmed that reduced awareness of bodily feelings and a lower tendency for helpful strategies towards those feelings contribute to higher alexithymia, which in turn contributes to lower empathy (R² = .32). The negative effect of helpful strategies on alexithymia is moderated by autism, i.e. lower levels of helpful strategies is associated with a significantly higher level of alexithymia for people with autism compared to those without autism. 

Conclusions:  

These findings suggest that interoceptive awareness, but not interoceptive sensitivity, and active and reactive strategies towards bodily feelings contribute to empathy. Importantly, alexithymia fulfils a mediating role in this relationship, suggesting that understanding of one’s own emotions contributes to empathy. The data is also suggestive of an alexithymic subgroup in autism, whose emotion processing may differ from non-alexithymics with autism. Further research could examine whether interoceptive awareness training could be a beneficial intervention approach.