A new study showed that scratching may not only relieve an itch but also temporarily block areas in the brain connected with unpleasant feelings and memories.
Such a surprising conclusion was made at Wake Forest University Baptist Medical Center in Winston-Salem, North Carolina. The scientists studied the processes happening in the brain when a person is scratched. 13 healthy people participated in the experiment, they were scratched with a soft brush on the lower leg on and off in 30-second intervals for 5 minutes. While being scratched they undergone a functional magnetic resonance – used to discover which areas of the brain are active.
The experiment showed that the activity of the anterior cingulate cortex and the posterior cingulate cortex was reduced. These areas are responsible for pain aversion and memory.
During the study the researchers also found out that scratching increased activity in the secondary somatosensory cortex and in the prefrontal cortex – responsible for compulsive behavior. That explains the desire to continue scratching once started.