How exposure therapy enables even people with life-long arachnaphobia to hold a tarantula after just two hoursDuring therapy participants were taught about tarantulas which helped them challenge their catastrophic thoughts
14:14 GMT, 22 May 2012
Adults with a lifelong debilitating spider phobia can hold a tarantula after just two hours of therapy as it changes their brains' response to fear, scientists say.
A study from Northwestern Medicine study found the exposure therapy was so successful that the adults were able to touch or hold a spider in their bare hands even six months after the treatment.
Cured: Subjects were able to hold a tarantula in their bare hands after a lesson helped them challenge false catastrophic thoughts about them
'Before treatment, some of these participants wouldn't walk on grass for fear of spiders or would stay out of their home or dorm room for days if they thought a spider was present,' said lead author Katherina Hauner, whose paper is published in Proceedings of the National Academy of Sciences.
'But after a two or three-hour treatment, they were able to walk right up and touch or hold a tarantula. And they could still touch it after six months. They were thrilled by what they accomplished.'
The study found exposure therapy works by making immediate and long-term changes to the brain in how it responds to fear.
The team studied 12 adults affected by arachnophobia. It is a type of specific phobia which is one of the most common anxiety disorders. Before the therapy session participants could not get closer than 10 feet on average to a tarantula.
When they were even shown a picture of one the regions of the brain associated with fear response – the amygdala, insula, and cingulate cortex – lit up with activity in an fMRI scan.
During the therapy, participants were taught about tarantulas and learned their catastrophic thoughts about them were not true.
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'They thought the tarantula might be capable of jumping out of the cage and on to them,' Hauner said.
'Some thought the tarantula was capable of planning something evil to purposefully hurt them. I would teach them the tarantula is fragile and more interested in trying to hide herself.'
They gradually learned to approach the tarantula in slow steps until they were able to touch the outside of the terrarium. Then they touched the tarantula with a paintbrush, a glove and eventually pet it with their bare hands or held it.
'They would see how soft it was and that its movements were very predictable and controllable,' Hauner said.
'Most tarantulas aren't aggressive, they just have a bad reputation.'
Immediately after the therapy, an fMRI scan showed the brain regions associated with fear decreased in activity when people encountered the spider photos, a reduction that persisted six months after treatment.
When the same participants were were asked to touch the tarantula six months later, 'they walked right up to it and touched it,' Hauner said.
'It was amazing to see because I remembered how terrified they were initially and so much time had passed since the therapy.'
Hauner also could predict for whom the therapy would be most effective based on an individual's brain activity immediately after the treatment.
Participants with higher measurements of activity in brain regions associated with visual perception of fearful stimuli immediately after the treatment were much more likely to show the lowest fear of spiders six months later.
'This suggests that observations of brain activity immediately after therapy may be a useful future tool in predicting an individual's long-term outcome,' Hauner said.