Autistic children may experience less variation in their bodily emotional responses

Research into emotion processing in autistic people has mainly focused on how they understand others' emotions.

A more limited body of work into how autistic people process their own emotions has, however, suggested difficulties identifying and describing emotional experiences, and distinguishing between emotional states.

The latter is potentially important, as it is associated with negative outcomes such as anxiety, depression, and self-injurious behavior, all of which have been suggested to occur more frequently in autism than in the general population.   

So far, studies of emotion differentiation in autism have tended to use language-based tasks. But now, a team led by Eleanor Palser from the University of California San Francisco has reported the first study looking at how autistic children map out where they feel emotions in their body.

The team finds that compared to non-autistic children, the bodily emotion maps of autistic children are more similar across different emotions, suggesting less variability in the way they physically experience different emotional states. The research, published in the journal Autism, was partly based on a 2016 report from the charity Autistica, in which members of the autistic community identified sensory processing and affective difficulties as key research goals.

A key aspect of emotional experience is the bodily sensation and change brought about by different emotions (e.g. sweaty palms when nervous, heart pounding when excited). Researchers have created detailed bodily maps of the regions and sensations associated with different emotional states, but no one had directly studied how — and where — autistic people experience emotion in their bodies.

In the new study, the researchers asked autistic and non-autistic children and adolescents to produce body maps of various emotions using a pen-and-paper version of the emBODY emotion colouring task.

The participants were asked to recall experiencing a particular emotion, then colour areas of stronger or faster resultant activity on one bodily outline, and those of weaker or slower activity on another. Six emotions — anger, fear, sadness, happiness, surprise, and disgust — were presented in a randomised order.

The team also used two tasks to measure interoception, one's own awareness of internal bodily responses. Interoceptive sensibility, participants' perceptions of their own interoception abilities, was assessed by asking them to indicate how often they feel common bodily sensations (e.g. goose bumps or stomach noises). A more objective measure of interoceptive accuracy was provided by examining how accurate participants were at a heartbeat-counting task.

On the colouring task, autistic participants showed less variability across emotions, with regard to the head, heart, and hands. In other words, they were more likely than non-autistic participants to colour these areas similarly, regardless of the emotion they were recalling.

Interestingly (and although the autistic group showed a lower level of interoceptive sensibility), these differences were not associated with interoceptive performance. This suggests that the bodily mapping task may tap into other aspects of emotion processing beyond simply the detection of one's own physiological changes.

The researchers also speculate that the reduced emotion differentiation in the autistic group may — even on a relatively non-linguistic colouring task — still have been affected by the difficulties with emotion-based language that many autistic people experience, rather than interoceptive problems.

Furthermore, the fact that this task involved the recall of emotional events raises the possibility that episodic memory deficits may have played a role.

The authors suggest that interventions focused on increasing children's emotion word knowledge, or improving their memory of emotional events, may help to increase emotion differentiation.

This is important because less variation in how people experience emotions has been linked to anxiety and depression, challenges which autistic people are more likely to experience.

Overall, this study offers the first indication that some autistic people may experience less variation in their physiological emotional responses.

Given that this may not be fully explained by interoceptive difficulties, future work could investigate other skills involved in distinguishing between the bodily sensations associated with different emotions.

Studies could also examine these abilities in other populations, to establish to what extent patterns may differ between groups.

Further reading

– Reduced differentiation of emotion-associated bodily sensations in autism

About the author

Dr Dan Carney is a UK academic psychologist specialising in developmental disorders. He undertook his post-doctoral research fellowship at London South Bank University, finishing in 2013. His published work to date has examined cognition, memory, and inner speech processes in Williams syndrome and Down syndrome, as well as savant skills in autism.