November 3, 2014
Man Loses Fear Of Spiders After Brain Surgery
April Flowers for redOrbit.com - Your Universe Online
We all have fears, rational or not. Some fear the dark, some fear snakes, and some fear the unknown. No matter what the fear, we all have them. Most of us just have to accept our fears and try to live with them. Except, perhaps, if you are a certain 44-year-old business man in the UK.The man in question had arachnophobia, the fear of spiders. He also suffered from a rare condition called sarcoidosis which damages the skin, lungs and sometimes the brain. Brian Stallard of Nature World News reports that the disease, which resulted in granulomatous encephalitis, had caused damage to the left side of his amygdala and was causing severe and sudden seizures.
His doctors decided the best course of action would be to remove the affected part of the amygdala, which is the region of the brain most closely associated with emotional reactions. The surgery stopped his seizures, but caused two very interesting side effects. He lost his fear of spiders, and gained a fear of music (Melophobia) — particularly the music of a certain TV ad.
He hasn't noticed the lessening or increasing of any other fears. He is still just as afraid of public speaking as he was before the surgery. The fear of music has waned over time, but the arachnophobia has stayed away. Before the surgery, he threw tennis balls at spiders, or vacuumed them up. Now, he is willing to touch them and finds them fascinating, according to Helen Thomson of New Scientist.
Nick Medford, a senior lecturer in psychiatry at the University of Sussex, observed the patient at the Brighton and Sussex Medical School. Medford says understanding how the surgery affected only a single phobia is very difficult, but it might have something to do with the two types of fear responses humans seem to have.
"It's like when you see a snake and you jump back in alarm, but when you look back you realize it's just a stick," he says. "That's your quick-and-dirty panic response: it isn't very accurate but it's necessary for basic survival. And then there's the more nuanced fear-appraisal which takes longer to process but is more accurate."
Medford hypothesizes that the neural pathways related to panic-type fear have been eliminated by the surgery, while leaving the generalized fear pathways intact. He can't know for sure because the man reports no other phobias and has refused further testing.
The Daily Mail's Madlen Davies reports that Medford would like to test his theory in other patients. Temporal lobe surgery for epilepsy is not uncommon, and it is possible some of those patients would have arachnophobia as well. By testing for phobias before and after the surgery, Medford would be able to assess the strength of his theory.
A paper detailing the surgery and the astonishing results has been published in Neurocase: The Neural Basis of Cognition.