Exposure therapy is currently considered the most successful treatment strategy for patients with anxiety and panic disorders. Yet more than a few patients fail to summon the emotional effort that exposure therapy inevitably brings along with it. Neuroscientists have now devised a method for deleting fear-afflicted memories from the brain of the patient without it being noticed.
“Decoded neurofeedback” is the name of the new method, the use of allows fear-filled memories to first be read and identified and later deleted. Using functional magnetic resonance imaging, scientists measure the activity in the brain and find complex patterns which represent a specific fear memory.
In their study, the researchers first created such a specific fear memory in 17 healthy volunteers. While the subjects looked at coloured patterns on a computer screen, they received in accompaniment with the red and green patterns a brief electric shock. The specific fear associated pattern which in this case originated in the visual cortex of the subjects was recorded by the scientists. At the same time, areas in the fear centre of the brain, the amygdala, were active and the subjects produced cold sweat on their skin. With yellow and blue patterns however, nothing happened. At the end of the first day of treatment, and in the absence of electric shocks, the subjects showed fear of the red and green patterns, but not of the blue and yellow.
Artificial intelligence image recognition can read angst loaded memories
Study author Dr. Ben Seymour from the University of Cambridge explains the process of “decoded neurofeedback”: “The way in which information is reproduced in the brain is very complicated. With the aid of artificial intelligence image recognition we can now identify content aspects of information. Using an AI-algorithm we managed to read weak fear afflicted memories quickly and unerringly. The big challenge was to then delete these anxiety-prone memories without creating a renewed awareness of the subjects”.
Small rewards at the right time override anxiety prone memories
After they had finished the fear-provoking electric shocks, the scientists observed their subjects for three days. Even in absolute rest periods the same fear brain patterns imprinted once again – albeit unnoticed by the subjects – on the researchers’ monitors.
And every time such a pattern was – at least partially – visible, the scientists rewarded the participants concerned with a small amount of money. They thus overwrote the fearful memories of the electric shock with a positive feeling. The scientists communicated to the subjects that small gifts of money would be given in the context of their brain activity. The nature of the connection was not exactly revealed by the researchers. By rewarding the always unconsciously emergent anxiety-prone pattern directly with a small amount of money, the researchers apparently succeeded in overriding the negative associations.
After 3 days: signs of fear significantly attenuated
The fifth day of the test series began with a few electric shocks not associated with the images, which in so doing would presumably recall memories of the experience. When the scientists followed up by showing their subjects the images which they had seen during the electric shocks, the following was observed: “Surprisingly, we could no longer measure typical angst associated sweat on the skin. In the fear centre of the brain, in the amygdala, things were very quiet as well”, says study leader Dr. Ai Koizumi from Advanced Telecommunicatons Research Institute International in Kyoto, Japan, adding: “This means that we have managed to extinguish the fear memory in our volunteers, without them noticing it at all”.
Library of fear codes
Despite the small number of subjects, the scientists hope that the technique tested in their pilot study could be further developed for clinical treatment of patients with post traumatic stress disorder or phobias. Therapy could look like this: “In order to make implementation applicable to patients, we have to create a library of information codes of the brain for the different factors which induce anxiety, such as spiders, but also for situations which burden patients”, says Dr. Seymour. “Then, the patient could basically go to regular ‘decoded neurofeedback’ sessions in which we remove the fear that is triggered by certain memories!” The stress of exposure therapy and side effects of drug therapy would then simply belong to the past. However will it really be so easy to get rid of one’s fears anytime soon?
“Probably not”, Seymour admits, because “the fears of real patients are 100 to 1,000 times stronger and also have existed far longer than the fears generated in the experiment. This could represent a significant hurdle, if we apply the method in practice”. Seymour assumes, however, that specific phobias, such as those of spiders, will soon be treated in a relatively uncomplicated manner. “It will however be more difficult with conceptual fears such as fear of heights or of flying”. As with exposure therapy, the patient here would also need to bring along some patience.
Fear reduction without fear through reinforcement of neural activity that bypasses conscious exposure
Koizumi et al.; Nature Human Behaviour, doi: 10.1038/S41562-016-0006