Neuroscientists may have found a way to recondition the brain into overcoming fear.
Although some phobias develop in childhood, most phobias appear to emerge unexpectedly and without explanation in adolescence or early adulthood.
Common specific phobias include those centered around animals or insects, germs, heights, open spaces, closed spaces, medical procedures, or flying.
Although most people manage to carry out their daily activities despite their phobias, for others, these fears can be debilitating. Although patients realize their fear is irrational, this does not make their fear any less extreme.
Post-traumatic stress disorder (PTSD) reportedly affects 7.7 million adults, or 3.5 percent of the American population. Experiencing sexual abuse, either in childhood or adulthood, seems to be a main trigger of PTSD.
Overall, anxiety disorders cost the United States healthcare system more than 42 billion dollars every year.
Usually, the recommended form of treatment for phobias is exposure therapy, where patients are gradually exposed to the object of their fear. However, this type of therapy is not very pleasant, and as a consequence, it is often avoided by patients.
A team of international researchers may have found a more effective way to reduce fear, which could ultimately have a positive impact on treatment options for patients with phobias.
Studying brain representations of fear
Using a combination of artificial intelligence and brain-scanning technology, a team comprising of researchers from Great Britain, Japan, and the U.S. may have discovered a way to unconsciously remove specific fear memories.
The team was led by Dr. Ai Kozumi, from the Advanced Telecommunications Research Institute International in Kyoto and the Centre of Information and Neural Networks in Osaka - both in Japan.
The results were published in the journal Nature Human Behaviour.
The team used a new technique called "Decoded Neurofeedback" to read and identify fear memories. The technique uses brain scanning to monitor brain activity and identify complex patterns of activity that indicate a fear memory.
Researchers created fear memories in 17 healthy individuals by administering an electric shock every time they saw a certain computer image.
Dr. Ben Seymour, of the Engineering Department at the University of Cambridge in the United Kingdom and one of the researchers on the team, explains how using artificial intelligence image recognition enables scientists to recognize the content of neurological information picked up by brain scanners.
"The way information is represented in the brain is very complicated, but the use of artificial intelligence (AI) image recognition methods now allow us to identify aspects of the content of that information. When we induced a mild fear memory in the brain, we were able to develop a fast and accurate method of reading it by using AI algorithms. The challenge then was to find a way to reduce or remove the fear memory, without ever consciously evoking it."
Dr. Ben Seymour
When they were able to identify the neurological pattern for representing fears, researchers tried to override the bad memory by giving their subjects a reward.
"We realized that even when the volunteers were simply resting, we could see brief moments when the pattern of fluctuating brain activity had partial features of the specific fear memory, even though the volunteers weren't consciously aware of it," says Dr. Seymour.
"Because we could decode these brain patterns quickly, we decided to give subjects a reward - a small amount of money - every time we picked up these features of the memory," he continues.
The team repeated the procedure for 3 days. They told the participants that the reward depended on their brain activity, but they did not tell them how.
By repeatedly connecting the patterns of brain activity related to electric shocks with a positive reward, scientists were aiming to gradually recondition the brain into reducing the fear memory.
The team then tested what happened when participants were again shown the set of pictures previously associated with electric shocks and fear.
Dr. Kozumi explains the positive outcome of the experiment.
"In effect, the features of the memory that were previously tuned to predict the painful shock, were now being re-programmed to predict something positive instead. Remarkably, we could no longer see the typical fear skin-sweating response. Nor could we identify enhanced activity in the amygdala - the brain's fear center. This meant that we'd been able to reduce the fear memory without the volunteers ever consciously experiencing the fear memory in the process."
Dr. Ai Kozumi
Although the sample size for this study was limited, researchers hope that through a concerted scientific effort, neuroscientists will gradually build a database of people's brain representations of fear, which would eventually enable them to come up with tailored treatment against phobias.
"To apply this to patients, we need to build a library of the brain information codes for the various things that people might have a pathological fear of, say, spiders," says Dr. Seymour.
"Then, in principle, patients could have regular sessions of Decoded Neurofeedback to gradually remove the fear response these memories trigger."
Such a reconditioning-based treatment, if effective, would be preferable to existing drugs and exposure therapies.
As it bypasses the conscious experience of fear, Decoded Neurofeedback treatment would allow patients to completely avoid the stress associated with exposure therapy. Additionally, the new treatment would avoid any side effects from drugs.