On November 30th, 2017 we learned about

Overactive olfactory abilities provide clues about people who can’t understand their own emotions

Many nursery rhymes are meant to teach simple lessons, but “If you’re happy and you know it” may also be a step towards diagnosing a neurological disorder. While most toddlers are probably more concerned with learning the order of hand-clapping and foot-stomping, the simple song’s question about knowing when you’re happy is actually a significant challenge for people with alexithymia. There’s a range of symptoms in alexithymic people, but they mostly revolve around difficulty identifying one’s own emotional state, from understanding what is being felt to figuring out how to express those feelings to others. Weirdly, the other major symptom associated with alexithymia was recently discovered to be an altered sense of smell, which may prove to be useful in understanding the neurology behind the condition.

Connecting odor and emotion

The nexus of smell and emotional awareness seems to be tied to where some of this mental processing takes place in the brain. Previous studies found that there was overlap in some of the brain areas that handle emotion and olfactory perception, prompting researchers to look at how alexithymic people might experience smell differently than the general population. If a pattern could be detected, it would hopefully shed light on the relationship between emotional and olfactory understanding, and why that overlap might exist in the first place.

The experiments divided alexithymic participants into various sub-groups. For instance, some people were found to struggle with identifying emotions to themselves, while others only had problems describing those emotions to others, and everyone operated on a spectrum of how severe the symptoms were. Once sorted, volunteers were asked to sniff and rate various smells from Sniffin’ Sticks, which are standardized odor samples for these kinds of experiments. Since reactions to many odors are specific to a person’s cultural background, researchers tried to avoid getting people’s opinions on smells. Instead, they asked them about how strong smells were while measuring physiological responses, such as heart rate and breathing, to each scent.

Doing less with more

The pattern that emerged was about as intuitive as the overlap between odor and emotional perception as a whole. People who had more severe alexithymia symptoms also had more acute senses of smell, detecting smaller traces of scents than people who had an easier time parsing their emotions. Instead of facing confusion because of muted odor and emotional response, researchers now believe that these people may have a hard time making sense of emotions because of an overwhelming amount of activity. If the olfactory and emotional centers in the brain are activated constantly, getting the signal from all that noise likely becomes difficult, leaving people with fewer cues about when exactly to clap their hands or stomp their feet, even if they can smell them across a room.

Source: The nose reveals our relationship with our emotions, EurekAlert!