Imagining a threat can help you conquer your fear of it, according to research conducted at the Icahn School of Medicine at Mount Sinai and published November 21 in the journal Neuron. The study has strong implications for the treatment of anxiety and fear-related disorders.
The research focused on the difference between how fear is learned and unlearned. People quickly learn to fear a threatening or unpleasant experience, and the fear will recur when cues, like sights or sounds, associated with the bad experience are sensed. This can negatively impact quality of life and underlie emotional disorders like post-traumatic stress disorder, phobias, and anxiety.
One of the most effective ways to remove this fear is to experience the threatening cues without then having the bad experience, something known as "threat extinction" or "extinction learning." It is the most prescribed treatment for fear-related disorders.
But this type of therapy is impractical in some cases because the cues associated with a traumatic event may be difficult or unethical to reconstruct (e.g., a war zone) or because the intensity of re-exposure is overwhelming for the patient. In such cases, imagination, an internal simulation of real-life events, is a common treatment tool. But despite imagination's longstanding recognition in the clinic, it has received little attention from the neuroscientific learning community and, therefore, the neural processes through which imagination affects behavior are unclear.
To test the effectiveness of imagination in extinction learning and its neural mechanisms, Mount Sinai researchers exposed 68 study participants to auditory threat conditioning, which involved exposing them to two different sounds, one of which was paired with an uncomfortable electric shock. Next, the participants were randomized into three groups. The first group performed "imagined extinction": that is, they were directed to "play" the conditioned tones "in their head" to the best of their ability. The second underwent "real extinction," which consisted of actual exposures to the conditioned auditory stimuli. The third underwent no extinction; instead, they were directed to imagine two neutral sounds from nature ("birds singing" and "rain falling") as a control for the general effects of imagination on arousal. The threat memory was then reinstated in all participants through four unsignaled shocks, after which all participants were then re-exposed to the conditioned auditory stimuli. Functional MRI images were collected for each phase and skin conductance responses were recorded continuously.
"We found that imagined extinction and real extinction were equally effective in the reduction of threat-related neural and physiological responses elicited upon re-exposure to real-world threatening cues," says Daniela Schiller, PhD, Professor of Neuroscience and Psychiatry at the Icahn School of Medicine at Mount Sinai and senior author of the paper. "More specifically, neuroimaging results indicated that imagined extinction, like standard extinction, activated a network of threat suppression involving the ventromedial prefrontal cortex as a central hub."
The ventromedial prefrontal cortex is a key brain region involved in the ability to extinguish learned threat responses. It is often impaired in anxiety disorders. The current study shows that imagining threat-eliciting cues subjugates the same neural mechanisms as actual threat cues, achieving the same ability to inhibit and reduce responses to the threat in safe situations.
Researchers found that the effectiveness of imagined extinction corresponded to the strength of primary auditory cortex activation, indicating that imagining a sound activates the same neural circuits involved in actual hearing. By contrast, the neural network serving the non-specific imagination was not sufficient to prevent the expression of neural and behavioral threat-related response when confronting the real-life threatening stimuli.
"Our data indicate that an internal simulation of a real-world experience can alter the way one responds to that situation in the future," says Dr. Schiller. "These novel findings bridge a long-standing gap between clinical practice and cognitive neuroscience by validating the effectiveness of imagination-based therapies targeting anxiety disorders and extending our knowledge of how mental actions can influence basic neural circuits."
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This study was funded in part by The National Institute on Drug Abuse.
About the Mount Sinai Health System
The Mount Sinai Health System is New York City's largest integrated delivery system encompassing seven hospital campuses, a leading medical school, and a vast network of ambulatory practices throughout the greater New York region. Mount Sinai's vision is to produce the safest care, the highest quality, the highest satisfaction, the best access and the best value of any health system in the nation. The System includes approximately 6,600 primary and specialty care physicians; 10 joint-venture ambulatory surgery centers; more than 140 ambulatory practices throughout the five boroughs of New York City, Westchester, Long Island, and Florida; and 31 affiliated community health centers. The Icahn School of Medicine is one of three medical schools that have earned distinction by multiple indicators: ranked in the top 20 by U.S. News & World Report's "Best Medical Schools", aligned with a U.S. News & World Report's "Honor Roll" Hospital, No. 13 in the nation for National Institutes of Health funding, and among the top 10 most innovative research institutions as ranked by the journal Nature in its Nature Innovation Index. This reflects a special level of excellence in education, clinical practice, and research. The Mount Sinai Hospital is ranked No. 18 on U.S. News & World Report's"Honor Roll" of top U.S. hospitals; it is one of the nation's top 20 hospitals in Cardiology/Heart Surgery, Gastroenterology/GI Surgery, Geriatrics, Nephrology, and Neurology/Neurosurgery, and in the top 50 in six other specialties in the 2018-2019 "Best Hospitals" issue. Mount Sinai's Kravis Children's Hospital also is ranked nationally in five out of ten pediatric specialties by U.S. News & World Report. The New York Eye and Ear Infirmary of Mount Sinai is ranked 11th nationally for Ophthalmology and 44th for Ear, Nose, and Throat, while Mount Sinai Beth Israel, Mount Sinai St. Luke's and Mount Sinai West are ranked regionally. For more information, visit https://www.mountsinai.org or find Mount Sinai on Facebook, Twitter and YouTube.
Journal
Neuron