Your brain on imagination: It’s a lot like reality, study shows

0
119
A study subject undergoes a brain scan in a functional magnetic resonance imaging (fMRI) machine. CREDIT/CU Boulder

IMAGINE a barking dog, a furry spider or another perceived threat and your brain and body respond much like they would if you experienced the real thing. Imagine it repeatedly in a safe environment and soon your phobia–and your brain’s response to it–subsides.
That’s the takeaway of a new brain imaging study led by University of Colorado Boulder and Icahn School of Medicine researchers, suggesting that imagination can be a powerful tool in helping people with fear and anxiety-related disorders overcome them.

“This research confirms that imagination is a neurological reality that can impact our brains and bodies in ways that matter for our wellbeing,” said Tor Wager, director of the Cognitive and Affective Neuroscience Laboratory at CU Boulder and co-senior author of the paper, published in the journal Neuron.

About one in three people in the United States have anxiety disorders, including phobias, and 8 percent have Post Traumatic Stress Disorder. Since the 1950s, clinicians have used “exposure therapy” as a first-line treatment, asking patients to face their fears – real or imagined – in a safe, controlled setting. Anecdotally, results have been positive.

But until now, very little has been known about how such methods impact the brain or how imagination neurologically compares to real-life exposure.

“These novel findings bridge a long-standing gap between clinical practice and cognitive neuroscience,” said lead author Marianne Cumella Reddan, a graduate student in the Department of Psychology and Neuroscience at CU Boulder.

“This is the first neuroscience study to show that imagining a threat can actually alter the way it is represented in the brain.”

For the study, 68 healthy participants were trained to associate a sound with an uncomfortable, but not painful, electric shock. Then, they were divided into three groups and either exposed to the same threatening sound, asked to “play the sound in their head,” or asked to imagine pleasant bird and rain sounds – all without experiencing further shocks.

The researchers measured brain activity using functional magnetic resonance imaging (fMRI). Sensors on the skin measured how the body responded.

In the groups that imagined and heard the threatening sounds, brain activity was remarkably similar, with the auditory cortex (which processes sound), the nucleus accumens (which processes fear) and the ventromedial prefrontal cortex (associated with risk and aversion) all lighting up.

After repeated exposure without the accompanying shock, the subjects in both the real and imagined threat groups experienced what is known as “extinction,” where the formerly fear-inducing stimulus no longer ignited a fear response.
Essentially, the brain had unlearned to be afraid.

“Statistically, real and imagined exposure to the threat were not different at the whole brain level, and imagination worked just as well,” said Reddan.

Notably, the group that imagined birds and rain sounds showed different brain reactions, and their fear response to the sound persisted.

“I think a lot of people assume that the way to reduce fear or negative emotion is to imagine something good. In fact, what might be more effective is exactly the opposite: imagining the threat, but without the negative consequences,” said Wager.