A notepad on proprioception: our sixth sense
I am spending a lot of time on the Internet learning more about proprioception. Here are some fun things I have read.
Proprioception is tested by American police officers using the field sobriety test, wherein the subject is required to touch his or her nose with eyes closed. People with normal proprioception may make an error of no more than 20 millimeters. People suffering from impaired proprioception (a symptom of moderate to severe alcohol intoxication) fail this test due to difficulty locating their limbs in space relative to their noses.
Proprioception is what allows someone to learn to walk in complete darkness without losing balance. During the learning of any new skill, sport, or art, it is usually necessary to become familiar with some proprioceptive tasks specific to that activity. Without the appropriate integration of proprioceptive input, an artist would not be able to brush paint onto a canvas without looking at the hand as it moved the brush over the canvas; it would be impossible to drive an automobile because a motorist would not be able to steer or use the foot pedals while looking at the road ahead; a person could not touch type or perform ballet; and people would not even be able to walk without watching where they put their feet.
Proprioception is occasionally impaired spontaneously, especially when one is tired. One's body may appear too large or too small, or parts of the body may appear distorted in size. Similar effects can sometimes occur during epilepsy or migraine auras. These effects are presumed to arise from abnormal stimulation of the part of the parietal cortex of the brain involved with integrating information from different parts of the body.
