1.   He studied neurons that should have responded to touch on the arm but could not because no information from the arm could reach the brain.

2.   Most animals have fast and slow pathways for responding to touch, Olausson said.

3.   Sensors in the head respond to touch.

4.   Some fibers were much slower to respond to touch than expected.

5.   To find out its purpose, the researchers blocked only the fast-acting fibers involved in nerves responding to touch.