Scratching That Awful Itch February 4, 2008Posted by Mrs Weird Scientist in Human Body, Psychology and Behavior, Think About It.
Tags: itch, memories, scratch
Scratch. Scratch, scratch. Scratch, scratch, scratch. When you have an itch, scratching it can bring some desperately needed relief. Now, we might actually know why scratching feels so good. A study led by dermatologist Dr Gil Yosipovitch at Wake Forest University Baptist Medical Center in North Carolina suggests that by scratching an itch, you momentarily turn off parts of the brain linked with bad feelings and memories. The full study can be seen in the Journal of Investigative Dermatology.
Calling All Scratchers
To check out their theories around scratching, Yosipovitch and his team of researchers scratched each of 13 test subjects with a soft brush on the lower part of their leg in 30-second intervals for 5 minutes. Then, they investigated what was going on in the brain by using a technique called functional magnetic resonance imaging. What were the results? Scratching reduced activity in two parts of the brain that are associated with pain aversion and memory. The more intensely a person was scratched, the less activity there was in the anterior cingulate cortex and posterior cingulate cortex. Yosipovitch thinks that scratching might prevent the emotional aspects of an itch, which is why people feel relief.
The Scratching Doesn’t Stop
So you have an itch – but why can’t you seem to stop scratching it? You can blame your good ol’ secondary somatosensory cortex. Say what? It’s a long, complicated-sounding word for your pain centre, which is linked with compulsive behavior. This helps to explain why people scratch so compulsively when they get an itchy spot on their body. It’s a bit confusing actually! On one hand, you feel relief each time you scratch because the two parts of the brain linked to icky feelings and memory are less active. But wait – you also have the secondary somatosensory cortex getting all riled up and encouraging that repetitive, compulsive scratching.
Fixing The Itch
Studies like this one are really important. Not just to satisfy our curiosity about why we get itchy and tend to scratch so much, but because it can help to treat different medical conditions. Some people suffer from skin disorders such as eczema, which can leave them with chronic itchy skin. This type of study can help us to figure out just what is happening in the brain when an itch strikes. This means that researchers can use this newfound understanding to develop effective treatments. For the rest of us, we will likely continue to scratch our itches. Since the study shows that this action shuts off the areas of the brain connected to unpleasant feelings and memories, it’s not too surprising that scratching feels so nice!