Does the sight of soap bubbles, aerated chocolate or a lotus flower seed pod bring you out in a cold sweat and make you feel panicky? If so, you could be a sufferer of one of the most common phobias you have never heard of - trypophobia, or the fear of holes.
For trypophobes, the sight of clusters of holes in various formations can cause intensely unpleasant reactions - from serious migraines and panic attacks to hot sweats and increased heart rate.
New research by visual science experts Dr Geoff Cole and Professor Arnold Wilkins from the University of Essex suggests that trypophobia may occur as a result of a specific visual feature also found among various poisonous animals. The findings are published in Psychological Science, a journal of the Association for Psychological Science.
"These findings suggest that there may be an ancient evolutionary part of the brain telling people that they are looking at a poisonous animal," explained Dr Cole.
Although trypophobia has been widely documented by sufferers on the internet, it is still hardly known about and was only recently accepted by Wikipedia, who thought it was a hoax entry.
In one study, the Essex research team found that 16 per cent of participants reported trypophobic reactions. Despite this, there has been little scientific investigation of the phenomenon, leading Dr Cole to refer to trypophobia - which he suffered from himself - as "the most common phobia you have never heard of".
The research involved establishing if there was a specific visual feature common to trypophobic objects. They compared 76 images of trypophobic objects (obtained from a trypophobia website) with 76 control images of holes not associated with trypophobia. After standardising various features of the images, the researchers found that the trypophobic objects had relatively high contrast energy at midrange spatial frequencies in comparison to the control images. They had the same visual structure as stripes, which also cause migraines for some people.
The scientists then wanted to find out why this unique visual feature led to such aversive reactions. One trypophobia sufferer provided Dr Cole with a clue - he had seen an animal that caused him to experience a trypophobic reaction.
The animal in question, the blue-ringed octopus, is one of the most poisonous animals in the world, which led Dr Cole to a "bit of a Eurekamoment".