Our sense of stimuli originating outside of the body.  For example:  Vision, Smell, Hearing, Taste, Touch, Temperature, and Pressure

Our sense of stimuli originating inside the body.  For example: Heart rate, blood pressure, oxygenation, pH, other organ functions.

“Plasticity, then, in the wide sense of the word, means the possession of a structure weak enough to yield to an influence, but strong enough not to yield all at once. Organic matter, especially nervous tissue, seems endowed with a very extraordinary degree of plasticity.” (William James, 1890).

Our sense of our body’s position in space and time, essentially our movement and awareness map.  For example:  Joint angles, position, tension, speed, quality of movement, etc.