Less is more: Exposure to stimuli for overcoming phobia

February 6, 2017, Children's Hospital Los Angeles
Brain activity of spider phobic people during repeated presentation of pictures of spiders -- when they were aware of them (left column), and when they were not aware of them (right column). The phobic people processed the spider pictures significantly more when they were not aware of them, particularly in brain systems (including frontal cortex and caudate nucleus) that support regulation of fear and its associated behavioral responses? These are 2-D slices positioned parallel to the floor in a standing person, with the forehead at the top and the back of the head at the bottom of each slice. Credit: Bradley Peterson, MD

A team of investigators, led by Bradley S. Peterson, MD, director of the Institute for the Developing Mind at Children's Hospital Los Angeles, and Paul Siegel, PhD, associate professor of psychology at Purchase College of the State University of New York, have found that exposure to phobic images without conscious awareness is more effective than longer, conscious exposure for reducing fear. The investigators used fMRI to determine that areas of the brain involved in fear processing were much more strongly activated by unconscious exposure. Results of the study will be published in the journal, Human Brain Mapping, on February 6, 2017.

"Although we expected - and observed - activation of the neural regions that process fear," said Peterson, who is also professor of pediatrics and psychiatry at the Keck School of Medicine of the University of Southern California, "we also found activation in regions that regulate the emotional and behavioral responses to fear—reducing the of fear."

While "phobia" is often defined as an irrational fear, many of the stimuli that produce a phobic response actually have an evolutionary basis that biologically prepares humans to fear them. For this study, the investigators used spiders - a common fear stimulus. They enrolled 21 spider-phobic and 21 non-phobic control participants, all young adult women. Women were selected because previous research has shown that 75 to 80 percent of all people who experience phobias are women.

All participants experienced three conditions that included viewing control images not associated with phobias (flowers) and phobia-inducing images (spiders) at two levels of exposure - very brief (without awareness) and longer duration (clearly visible). The very brief exposure was accomplished through a technique known as backward masking, where a target image is shown very briefly and then immediately followed by a non-target image or "mask" that prevents recognition of the target.

In participants with phobia, very brief exposure to spider images strongly activated the subcortical regions of the brain involved in immediate fear processing. Yet they did not experience fear consciously, apparently because the very brief exposures also activated brain regions that regulate fear. Clearly visible to the spider images, by contrast, deactivated areas of the brain that regulate , inducing the conscious experience of .

"Counter-intuitively, our study showed that the brain is better able to process feared stimuli when they are presented without ," said Siegel, who is first author on the study. "Our findings suggest that phobic people may be better prepared to face their fears if at first they are not consciously aware that they've faced them."

Peterson added that he saw potential for using this technique to treat children and adolescents with anxiety disorders. Current therapies are based on directly confronting the feared stimulus, which can cause young people to experience significant emotional distress.

Explore further: Memory activation before exposure reduces life-long fear of spiders

Related Stories

Memory activation before exposure reduces life-long fear of spiders

August 25, 2016
Many people suffer from anxiety and fears, and a common treatment for these problems is exposure therapy. In a new study published in Current Biology, researchers at Uppsala University have shown how the effect of exposure ...

The itsy bitsy spider? Arachnophobes overestimate spider sizes

February 16, 2016
Ben-Gurion University of the Negev researchers have discovered that arachnophobes overestimate spider size compared with other neutral animals that do not elicit fear, which could be useful in treating phobias.

Understanding fear means correctly defining fear itself, study concludes

February 4, 2014
Understanding and properly studying fear is partly a matter of correctly defining fear itself, New York University neuroscientist Joseph LeDoux writes in a new essay published in Proceedings of the National Academy of Sciences. ...

New treatment for childhood phobias

June 20, 2012
Australia’s leading support, treatment and research facility for anxiety and emotional disorders, the Centre for Emotional Health at Macquarie University, is trialing a new treatment for childhood dog and spider phobias. ...

Recommended for you

Intensive behavior therapy no better than conventional support in treating teenagers with antisocial behavior

January 19, 2018
Research led by UCL has found that intensive and costly multisystemic therapy is no better than conventional therapy in treating teenagers with moderate to severe antisocial behaviour.

Research reveals atomic-level changes in ALS-linked protein

January 18, 2018
For the first time, researchers have described atom-by-atom changes in a family of proteins linked to amyotrophic lateral sclerosis (ALS), a group of brain disorders known as frontotemporal dementia and degenerative diseases ...

Fragile X finding shows normal neurons that interact poorly

January 18, 2018
Neurons in mice afflicted with the genetic defect that causes Fragile X syndrome (FXS) appear similar to those in healthy mice, but these neurons fail to interact normally, resulting in the long-known cognitive impairments, ...

Babies' babbling betters brains, language

January 18, 2018
Babies are adept at getting what they need - including an education. New research shows that babies organize mothers' verbal responses, which promotes more effective language instruction, and infant babbling is the key.

College branding makes beer more salient to underage students

January 18, 2018
In recent years, major beer companies have tried to capitalize on the salience of students' university affiliations, unveiling marketing campaigns and products—such as "fan cans," store displays, and billboard ads—that ...

Inherited IQ can increase in early childhood

January 18, 2018
When it comes to intelligence, environment and education matter – more than we think.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.