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To know anything well involves knowing ourselves well in relation to whatever else we wish to understand. Where does such knowing begin? At the beginning, perhaps? Here, Leela Zion serves as an able guide to the early stages of a lifelong journey whose full dimensions await scientific and philosophical investigation. - JK
WE LEARNED when young that there are only five senses: seeing, hearing, tasting, smelling, and touching. And even today most of the textbooks that deal with the senses still express this "only five senses theory."
We have many other senses, from the proprioceptive sensory system with receptors in the semicircular canals of our inner ears that tell us when our head is in motion and in which directions and planes it is moving, to senses involving feeling pain, heat, cold, discomfort, vibration, and pleasure. Today, we recognize that the senses are systems. A sense is not just a nose or an eye or an ear or two, but each is a very complex system involving several different kinds of sensory receptors and interpretations. When Van Gogh cut off his ear, he could still hear with that ear. All he cut off was the funnel that directs sound waves more easily into the various sensory receptors in the rest of the ear complex.
Hearing involves the onrushing and withdrawing of waves of air molecules that cause the ear drum to vibrate in various ways, and hence, the vibration of the hammer, anvil, and stirrup. These press fluid against the inner ear membranes with tiny nerve cells that send messages to the hearing center in the brain for translation. We can locate sounds in space and time, identify type, intensity, source, duration, and interpret these into song, talk, noise, laughter, or music.
Seeing involves neurons that pick up light, images, duration, and color. Neurons pinpoint objects in space and time, and enable the eye to focus. We measure light waves and judge them, compare them and revise our interpretation of them.
Through smell we can detect over 10,000 odorants, from minty, floral, ethereal, musky, resinous to foul and acrid. We have over 5,000 olfactory cells and 60 different sites of olfactory bulb surface resulting in spatial patterns or amplitude creating topographical mapping of odorants....