Proprioception, Sensing Your Body in Space
Proprioception the Sixth Sense
If you were standing in a space with absolutely no external stimuli, no light, no air movement, temperature perfectly matched to your body and deprived of all external sensory input, you would still know that your hand was raised above your head and that your hand was holding up one finger and your head was turned upward. This is because of your proprioceptors.
We know that we have five identifiable senses. We have been taught them since elementary school; they are sight, smell, taste, touch and hearing. These all have an external component, however proprioception, our sense of orientation, has been spoken of as our sixth sense, and no it doesn’t make you see dead people. Proprioception is the sense of our selves, not dead people and not extra-sensory perception (ESP). It is not to be mistaken for our sense of movement although it does affect balance and coordination. It is the sense of our position and the position of our body parts.
Loss of Proprioception
In Oliver Sacks' book, The Man Who Mistook His Wife for a Hat, he describes one of his patients who had lost the faculty of proprioception. The segment is called “The Disembodied Lady”. This is an appropriate description of a person who loses their proprioception. The young lady, 27 years old at the time of her “disembodiment”, was hospitalized for gall bladder surgery and while awaiting the surgery, was given antibiotics as a precautionary measure. The day before her surgery, she developed a strange sense of disembodiment and was unable to control her movements, stand, sit up, speak naturally or even feed herself. Her hand would miss her mouth and her limbs flailed about. She was unable to locate where her arms were in space without seeing them.
When we wish to perform a task, the proprioceptor nerves in our muscles and tendons receive signals and return feedback to our brains regarding where the body is relative to itself. When these proprioceptors are destroyed, as in the case of a few unfortunate individuals, our brain does not register where our limbs are or what they are doing. So our brain cannot tell the muscle to stretch or contract according to the desire of the person wishing to perform any task at all.
The loss of proprioception is devastating. The description is a feeling of not really even knowing if you have a body except by visual recognition. Therapy includes teaching people to move their limbs and bodies according to visual feedback. It is a long and arduous endeavor and does not reach the level of natural intuitive movement. There is no cure for loss of proprioception. The reason and cause specifically are not definitive but a virus or illness is the initiating element of destruction.