Humans perceive, react and think with a vast collection of neurons networked to the external world, and no study has ever shown that we receive or process information with any other capacities than our nervous systems. (Sorry, psychics: extra-sensory perception is still an unsubstantiated myth.) But what we do perceive extends far beyond our everyday understanding of the five human senses: sight, smell, taste, hearing and touch.
For one, our sense of touch is actually a variety of distinct sensations caused by different special-purpose neurons. Light touch, pressure, erotic sensation, vibration and various sensations of temperature and pain all result from differently-tuned sensory cells.
Humans also possess a host of other less obvious senses. Specific kinesthetic receptors exist for detecting stretching in muscles and tendons, helping us to keep track of our limbs. Other receptors are tuned to changes in head orientation, keeping us balanced. Still more detect levels of oxygen in certain arteries of the bloodstream. Let’s see Miss Cleo beat that.