October 27, 2021


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Tags: Autism, decades, skewed, Spectrum, Studies, trait, understudied


Categories: autism

How an understudied trait has skewed autism research for many years | Spectrum

About 15 years ago, psychologist Geoff Bird began questioning a longstanding tenet in autism research: the idea that all autistic people struggle with empathy.

It just didn’t make sense to Bird. In his experience, both autistic and non-autistic people differ greatly in their ability to sense or feel another person’s emotions – the scientific definition of empathy. Yet there has been a body of research that has suggested that people with autism are often unable to recognize what another person is feeling.

Two of Bird’s colleagues suggested a solution to the riddle: What if some autistic people fail to recognize their own emotions instead of a lack of empathy, a little-known trait called alexithymia? Wouldn’t that affect their ability to share someone else’s?

Bird was skeptical, but joined them in a research project – the results of which, published in 2010, shocked him: in both autistic and non-autistic men, those with a weaker brain response to images of another person with pain had higher levels Alexithymia. After adapting to alexithymia – which was not done routinely – the empathic brain reactions in the two groups showed no differences at all.

“I immediately thought ‘wow’ and realized that this alexithymic hypothesis has the potential to be incredibly important in autism,” says Bird, professor of cognitive neuroscience at Oxford University in the UK.

The “alexithymia hypothesis,” if correct, may not only explain the wide range of emotion processing difficulties autistic people seem to have – sometimes none. It could also shock the way autism is studied, diagnosed, treated, and even defined.

Listen to a Spectrum webinar with Zachary Williams about measuring alexithymia.

“It’s a pretty new concept,” says Stephen Edwards, senior lecturer in psychology at Federation University Australia at Ballarat, who is developing therapy to reduce the features of alexithymia. And it comes with an important implication: Any research into emotion processing in autistic people must measure alexithymia and control how it is done with intelligence quotients, say Bird and others. Otherwise, alexithymia – which occurs in about half of autistic people compared to 5 percent of neurotypical people – could be a major confounding factor in many autism studies.

Despite the prevalence of alexithymia in autistic people, it may be unfamiliar to many autism researchers, Bird says. But a number of new tools are poised to help them measure the trait more routinely – and possibly reshape emotion research in the process. Teams who have already answered the call discover that addressing alexithymia removes some of the obvious differences in emotion processing between autistic and non-autistic people.

Test a hypothesis:

Two psychiatrists coined the term “alexithymia” in 1972 and created a mixture of Greek words that mean “lack of words for emotions”. Today it is defined by three characteristics: difficulty identifying and describing one’s feelings and, although most research has focused on the former, a thought pattern that emphasizes the outer world over the inner one. Alexithymia can affect all elements of emotion processing, including recognizing facial expressions and other people’s emotions, and even emotional responses to music.

Years after these initial surprising results, Bird and a colleague hypothesized that alexithymia might explain some of the difficulties in processing emotions associated with autism – and how they differ in autistic people.

“It was the step from simply saying ‘shrug your shoulders, all autistic people are different’ to ‘OK, what explains the variance?'” Says Bird.

Since then, researchers have found that alexithymia – more than autism traits – can predict a person’s gaze patterns, the intensity of their reaction or ability to recognize facial expressions, and even their tendency to share resources, a marker of prosocial behavior.

Bird is married to Jennifer Cook, a Senior Fellow at the University of Birmingham in the UK. The two lead separate research lives, they say, but when Cook started her own laboratory three years ago, measuring alexithymia became a rationale. “Accounting for alexithymia is one of the things we do in our studies now,” she says.

Cook’s work supported Bird’s theory. In a study published earlier this year, she and her colleagues asked 60 autistic and non-autistic adults with alexithymia to look at a series of animated points like moving faces and rate them as angry, happy, or sad. The team found that both groups were equally good at detecting most emotions. Notably, autistic people struggled more to identify anger than their non-autistic peers, suggesting that something about this emotion is different for people with autism.

Illustration by Alexander Glandien

“Alexithymia is really responsible for many of the difficulties autistic people have in recognizing emotions,” says Connor Keating, a PhD student in Cook’s laboratory at the University of Birmingham in the UK who worked on the animation study and is doing his PhD. Testing of the alexithymic hypothesis. “And maybe that can explain many of the difficulties we had in literature before we knew about alexithymia.”


Keating and others usually measure alexithymia using a self-report questionnaire called the Toronto Alexithymia Scale (TAS-20), which was developed in 1994 for Personal Emotions.

However, this is not so easy with autistic people. Researchers validated the tool on a small group of autistic people in 2005, but an independent team was unable to replicate these results earlier this year. This team found that a condensed, eight-question version of the scale they called the General Alexithymia Factor Score (GAFS-8) performed better than the TAS-20 in autistic adults.

Two more recent scales, the Toronto Structured Interview for Alexithymia and the Perth Alexithymia Questionnaire (PAQ), are potentially even more accurate, says Zachary Williams, a medical and graduate student at Vanderbilt University in Nashville, Tennessee who helped create the GAFS-8 was.

A comparison of several alexithymia measurements in 2020 shows this: The results of the TAS-20 may at least partially reflect a person’s current stress level, as the study showed, and not their basic emotion processing – a problem that was not or was not observed with the PAQ another screen, the Bermond Vorst alexithymia questionnaire.

Regardless, researchers need to analyze how different interventions affect their results, says Williams, who is himself autistic. “Whether alexithymia is more likely to predict group difference than autistic traits depends heavily on the measures used to quantify autistic traits, alexithymia, and the outcome of interest.”

All of these measures are based solely on self-disclosure – a method that can be unreliable. Therefore, some researchers are working to develop more objective tools based on physiological responses. For example, people with larger spikes on the skin – known as skin conductivity – also score higher on the TAS-20 after viewing emotional images, even after being checked for signs of autism, as Cook and Keating demonstrated earlier this year.

The results are consistent with theories that people with alexithymia have difficulty distinguishing which situations require strong emotional responses and are therefore often in a state of high stress. But they also contradict the popular notion that alexithymic people are out of tune with their physical responses to emotions: people with high levels of alexithymia rated their emotional responses just as well as people with lower scores based on their skin conductance responses.

Bird, who is developing a measurement based on skin conductivity, heart rate, and pupillary dilatation, found that people who report alexithymic characteristics themselves have a greater difference between their own ratings of their emotional responses to images and pupil dilatation.

Ideally, researchers can combine questionnaires and other measures into a standardized set of alexithymia tests, says Keating. “There is still a long way to go to measure alexithymia. We all need to come together and find better ways to measure it. “

Improving health:

Even with better tools for measuring alexithymia, researchers face a challenge: recruiting autistic and non-autistic people who match on this trait. Still, it is worth the effort, say proponents of the alexithymia hypothesis. Failure to accurately measure and account for alexithymia can cloud our understanding of autism itself, which could affect who will be referred for diagnosis and who will be included in research studies.

Because alexithymia appears to induce some characteristics of autism, some professionals who refer children for assessment, such as teachers or pediatricians, might miss autistic children with no difficulty processing emotions, says Andrew Surtees, a lecturer in psychology at the University of Birmingham in the UK

And while alexithymia is not measured as part of the autism diagnostic process, high alexithymic traits alone can put someone above the clinical limit of the gold standard autism diagnostic observation scale (ADOS), as Bird has shown. As a result, studies that only use the ADOS to identify autistic participants may inadvertently include non-autistic people with alexithymia in their cohort.

Differentiating between the two conditions can be difficult for diagnosticians, Surtees says, but adding an explicit alexithymia screen to the process could help – which would benefit not only research projects but these people as well.

“For the people who are working with this autistic person and trying to improve their lives or help them improve their lives,” says Surtees, “this information can really be critical.”

Detecting and combating alexithymia in autistic people could also improve their mental health, as the property has been linked to increased rates of social communication difficulties, anxiety, and depression. And it could help clinicians figure out who would benefit from which support, especially because some forms of therapy like cognitive behavioral therapy are less effective in people with high levels of alexithymia, says Surtees. Edwards starts a study to assess whether a mimicry task can increase the ability to recognize emotions and thereby relieve stress in people with alexithymia and autism.

“If we can say that this autistic person has alexithymia and they don’t, and we know that this person with alexithymia will have their whole set of problems that the person without alexithymia doesn’t,” says Bird, “we’re better able to help these two people. “

Quote this article: https://doi.org/10.53053/GNRQ3144


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