If You Couldn’t Imagine Ghosts, Would They Still Be Scary?

Source: Pedro Figueras/Pixabay

For years, researchers have hypothesized that being able to recall imagery helps us link our thoughts with our emotions, and that makes it easier for us to consider future scenarios and then make better decisions in real time.

But that image recall is proposed to also have a dark side—it can make upsetting thoughts more overwhelming. In fact, it has been linked—as a driver of negative emotions—to illnesses like social phobia and posttraumatic stress disorder.

Researchers have now tested this theory with volunteers who aren't able to visualize mental images, a condition called aphantasia. These volunteers, and others without aphantasia, were presented with a series of short stories and photographs. The stories were scary, first-person, fictitious scenarios about 200 words long. One story, for example, began with "you are at the beach / in the water," and continued to build until, about halfway through, "suddenly a dark flash / in the distant waves / maybe it was a shadow." The story ultimately ended with "your legs flail / before white teeth / they disappear inside / cloudy red engulfs your vision / the surface above spins out of sight." Yikes.

While reading, the skin conductance level (SCL) of each volunteer was recorded. An increased SCL indicates a physiological change—enough of a change that your skin conducts more electricity. It's a major "tell" when it comes to an emotional response, and previous research has shown that it increases in response to frightening stimuli, even when they're imaginary.

Volunteers with aphantasia had much lower SCLs when reading these stories, compared to volunteers without aphantasia, but that didn’t hold true when they were presented with scary photographs.

There were 18 photos in total—the first five served as a neutral baseline (e.g. an umbrella), and the final 13 were frightening (e.g. a cadaver). There was no significant difference in response between people with and without aphantasia—both showed large increases in SCLs.

This work showed that mental imagery does, in fact, amplify our emotions, and reaffirmed that a lack of emotion from someone with aphantasia is not because they have a chronically dampened ability to respond emotionally or physiologically.

What I may have found most interesting about this work was its implications for how we think about mental health and therapy. There's evidence, for example, that positive mental imagery can help prevent depression, but for people with aphantasia that's often impossible, so bringing physical images into a talk therapy session could be highly beneficial.

Much more work needs to be done, but I love studies like this one, that help tease apart the complexity of our brains and remind us of the neural diversity that makes us all so wonderfully unique.