Why make us comfortable scratching?

Scratching the itch will temporarily turn off areas of the brain associated with feelings and unpleasant memories, so make us relax and feel more comfortable . " Our study for the first time explains how scratching reduces itching ," said Gil Yosipovitch, a dermatologist at Wake Forest University in North Carolina, USA.

Previous studies have shown that pain, caused by strong scratching, will inhibit itching. Yosipovitch and colleagues figured out what happens in the brain when people scratch. The team used magnetic resonance imaging to find out which areas of the brain work when scratching. They used a soft brush to scratch the legs of 13 healthy people, every 30 seconds for a total of 5 minutes.

The team found scratching reduced the activity of the frontal cortex and the pericardial cortex - these areas involved in hate hatred. And the more a person scratches, the less activity there is in these areas of the brain.

" Being able to scratch can overwhelm the feelings of itching and bring comfort, " Yosipovitch said.

But they also found that once scratched, people wanted to scratch more. Increasing activity in the secondary sense cortex - the center of pain, and the prefrontal cortex, involves impulsive behavior."This explains why people are even more motivated to continue scratching."

Researchers have found that understanding how the brain works will help find ways to treat people with chronic itching, such as eczema.