People don’t usually think of touch as a temporal phenomenon, but it is every bit as time-based as it is spatial. You can carry out an experiment to see for yourself. Ask a friend to cup his hand, palm face up, and close his eyes. Place a small ordinary object in his palm ― a ring, an eraser, anything will do ― and ask him to identify it without moving any part of his hand. He won’t have a clue other than weight and maybe overall size. Then tell him to keep his eyes closed and move his fingers over the object. He’ll most likely identify it at once. By allowing the fingers to move, you’ve added time to the sensory perception of touch. There’s a direct analogy between the fovea at the center of your retina and your fingertips, both of which have high acuity. Your ability to make complex use of touch, such as buttoning your shirt or unlocking your front door in the dark, depends on continuous time-varying patterns of touch sensation.

* analogy: 유사 ** fovea: (망막의) 중심와(窩) *** retina: 망막