Emotions such as happiness, anger, sadness, fear, and anxiety, among many others, are usually triggered by events around us. These are said to be our direct subjective response to a particular stimulus, such as heights causing acrophobes sudden panic.
However, is it also possible that some emotions are caused by abnormalities in parts of our body? This seemed to be the case of a man whose long history of fearing spiders suddenly vanished when part of his brain, the left amygdala, had been surgically removed.
The man, who had been suffering from a rare disease known as granulomatous encephalitis, causing his seizures, admitted to having arachnophobia all his life until the surgical procedure.
His debilitating seizures forced him to have himself checked by physicians who found abnormalities in his amygdala, the portion of the brain that controls fear. The almond-shaped structure is just over an inch long, and about one particular inch in diameter. His doctors recommended removal of this particular part of his brain, which he agreed to undergo.
The surgery was a success; his seizures stopped, and in an unexpected turn of events, his fear of spiders disappeared. Scientists said his fear turned into "fascination" of the creature. However, he also developed a deep aversion to music, which eventually waned. And while his fear of spiders never returned, his other fears such as fear of speaking in public did not disappear.
The Consultant Neuropsychiatrist suggested the removal of his amygdala affected one type of fear - the panic-type kind.
Reports said that according to his doctor Nick Medford at the Brighton and Sussex Medical School, UK, "neuralpathways related to the panic-type fear response were eliminated while parts of the amygdala responsible for generalised fear remained intact."
"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," Dr. Medford told New Scientist. "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."
It has not been exactly identified though which portion of the brain, or the amygdala in particular, such fear of spiders resides. Medford said the neural pathway associated with his patient's arachnophobia must have resided somewhere in the portion of the amygdala that was surgically removed.
"It's not uncommon for people to have temporal lobe surgery for severe epilepsy. And arachnophobia is supposed to be reasonably common. So we might be able to test people for that phobia, or any other kind, before and after surgery," he said.
While further studies are needed to identify which portion of the brain has dominion on what specific fears, this study could be the beginning of an exploration to brain surgery in the elimination of certain fears or anxieties.
