“I would describe my emotional ‘palette’ as very limited,” the research subject wrote. “The subtleties that other people seem comfortable with are really quite alien to me — the distinctions don’t make much sense to me.”
The person is describing alexithymia, a condition in which people have trouble identifying and describing their own emotions. It’s not a standalone psychiatric diagnosis but rather a component of many people’s personalities, to varying degrees: Studies have estimated it affects around 10 percent of people.
Now, a growing body of research is finding that individuals with alexithymia also have difficulties with non-emotional perception, such as telling when they’re hot, cold, hungry, or tired. And that reveals an interesting connection in all of our nervous systems, tethering our emotions to our awareness of things like heartbeat, temperature, and the rhythm of our breathing.
A new study surveyed 208 people with alexithymia, asking them if they struggled to interpret their bodily feelings and if they felt similarities between emotional and non-emotional states.
The results, published Wednesday in Royal Society Open Science, found a highly significant correlation between bodily confusion and alexithymia: People who had more trouble identifying their emotions also reported more similarities between physical and emotional sensations.
“People with alexithymia also may not know if they’re angry or just a bit hot because they ran up the stairs,” said Rebecca Brewer, a cognitive psychologist at the University of East London and the study’s lead author. “Or if their heart is beating harder because they just drank a cup of coffee or because they’re feeling fear.”
This ability to recognize what’s going on in the body is called interoception. Recent studies have shown that people with alexithymia have specific interoceptive problems, like perceiving their own heart rates, and can have erratic caffeine and alcohol consumption.
In contrast, Brewer said, their work suggests “that actually alexithymia might be synonymous with general difficulty understanding any interoceptive state in the body.”
For instance, one woman in the study wrote that she often got up to go to work, only to discover later that she was sick, and had to go home. “If my husband didn’t remind me about meals, I would forget to eat and drink,” she continued. “I get very hot or cold sometimes and don’t really notice until I get really uncomfortable. I often get dehydrated. I forget about going to the loo until it becomes uncomfortable.”
Biology of emotions
Beyond alexithymia, the findings highlight the biological connection between emotions, like love and anger, and physical sensations, like the pace of your breathing.
“This is very much in line with the way we view emotions and feelings,” said Jonas Kaplan, at the Brain and Creativity Institute at the University of Southern California. “Feelings come from the brain’s representation of the ongoing dynamics of what’s happening inside the body.”
Studying malfunctioning brain systems can often provide clues as to how the healthy brain works. More investigation in people with alexithymia could provide insight into how the brain differentiates signals to create sensations or interpretations in the healthy brain.
Kaplan said that further research was needed to understand how and where in the brain these perceptions broke down in those with alexithymia — for instance, the study doesn’t address whether subjects had trouble interpreting normal sensations, or if they had trouble feeling them at all. Pairing self-reports with imaging or physical monitoring could offer more conclusive answers.
For alexithymia, Brewer said that a part of the brain called the insula most likely plays a role. Studies have found that damage to the insula can cause acquired alexithymia, and that patients with alexithymia can have a different amount of gray matter in the insula. Brewer said that people with alexithymia often show abnormal fMRI results in the insula region, though from paper to paper, results are inconsistent.
Learning to discern
Have you ever felt like you couldn’t access higher-level emotions or thoughts when you were extremely tired or hungry? Mary Helen Immordino-Yang, a neuroscientist at USC who studies emotion, said that it’s because both of these types of feelings are partially processed in the insula.
Immordino-Yang has also found that activity in the insula, and its corresponding emotional recognition, varies culturally: The insula is functionally different in Beijing than in Los Angeles. That suggests that there isn’t a “normal” emotionally aware person and a person with alexithymia, but actually that all emotional cognition varies, and could possibly be a learned behavior.
If emotional and physical recognition can be learned, it could have therapeutic implications for other disorders. Patients with conditions like autism, eating disorders, and even diabetes (in which the body has trouble regulating blood glucose levels) have higher instances of alexithymia. Brewer believes that though these disorders are often seen at the same time as alexithymia, alexithymia stands alone as an independent condition. Alexithymia could even, in some cases, provide a causal role for someone’s inability to feel hungry or full. Further work needs to be done to see if improving interoceptive sensitivity through training could help any of those conditions.
“The main point to emphasize is that all of these feelings, everything that we feel is made up of different sensations inside the body,” Brewer said. “If we feel love, it’s difficult to explain how that feels, but you have physical sensations. You might say, I feel warm inside, tingly, things like this. … Every emotion that we feel and every state that we feel comes at least partially from signals inside the body.”