Nov. 8, 2010 at 8:38 AM ETBill Briggs writes:What’s scarier than bats in the belfry? Easy: tarantulas in an MRI tube. To observe the brain’s panic-response network in full freak, British researchers asked 20 volunteers to lie inside a functional magnetic resonance imaging machine. One by one, the scientists then had each person view a screen that showed a tarantula crawling closer ... and ... closer to the subject’s feet. As the spider advanced, MRI scans allowed researchers to see flashes of activity switch from the volunteer’s prefrontal cortex – a region associated with anxiety – to a spot in the midbrain known to involve intense fear. But the neural terror waned when the tarantula retreated, “regardless of the spider’s absolute proximity,” wrote the study’s authors. In other words, as long as the spider was moving away, no matter how close it still was, the volunteers relaxed. Titled “Neural Activity associated with monitoring the oscillating threat value of a Tarantula,” the study was published today by the National Academy of Sciences. They could simply have dubbed their paper: “Watching the Willies.” What the researchers glimpsed, they say, was the brain’s danger-tracking system at work. Before you brand the scientists as sadists, you should know two things. First: the findings may make it easier to diagnose and treat patients who suffer from clinical phobias, said Dr. Dean Mobbs, one of the authors. “We first show that multiple (brain) systems are involved in fear and that a goal of future research should be to try and understand which parts of the system break down,” said Mobbs, who works at the MRC-Cognition and Brain Sciences Unit at the University of Cambridge Medical School. “If we can understand this, then we can better engage people with phobias and other types of fear. To cure we must first understand.” Second: the volunteers were actually watching pre-recorded images of the spiders walking to and fro. The MRI tubes never contained real critters. But why tarantulas? Why not rats or bats or scorpions? “The UK has one of the highest amounts of spider phobics in the world. This is despite the fact that we have no deadly spiders in the UK,” Mobbs said. He then admitted: “I mainly used spiders because I have a slight fear of them.” What scares you the most? Tell us about it in the comments.Find The Body Odd on Twitter and on Facebook.