The technique involves planned confrontation with the feared object, situation, thought or memory in order to help the individual overcome anxiety in a controlled, therapeutic environment. 

The new study involved 12 people with severe fear of spiders or arachnophobia who could not even get closer than 10 feet (3 meters) on average to a tarantula before the therapy session. 

“Before treatment, some of these participants wouldn't walk on grass for fear of spiders or would stay out of their home ... for days if they thought a spider was present,” said lead researcher Katherina Hauner. 

“But after a two- or three-hour treatment, they were able to walk right up and touch or hold a tarantula,” she added. “And they could still touch it [six months later]. They were thrilled by what they accomplished.” 

Functional MRI brain scans of the studied people revealed that at the beginning of the study, simply looking at photos of spiders triggered the activity of brain regions associated with fear response. 

But immediately after the treatment, those regions significantly decreased sending unwelcome “fight or flight” fear signals and also remained less active even after six months. 

The researchers were able to predict an individual’s long-term response to the treatment based on brain activity immediately after the therapy session. 

The finding shows that the brains of the treated people had reorganized in some way to maintain the improvement, the authors suggested in their report published in the Proceedings of the National Academy of Sciences.