![]() On the other hand, I must admit to having been a tad chagrined when I first discovered that the humble mantis shrimp (which isn’t actually a shrimp or a mantid) has the most complex eye known in the animal kingdom. From one point of view (no pun intended), I’m riding the crest of the wave that represents the current peak of human evolution, as are you of course, but this is my column, so let’s stay focused (again, no pun intended) on me. I don’t know about you, but I’m tremendously impressed with the wealth of information provided to me by my eyes. By comparison, in the dim lighting conditions when rods come into their own, cones shut down and provide little or no useful information. Cones require bright light to function, while rods are saturated in a bright light environment. The bottom line is that rods and cones simply don’t play together in the same lighting conditions. In reality, rod cells are much more sensitive than cone cells, to the extent that attempting to contrast their sensitivity on the same chart would result in a single sharp peak for the rods contrasted with three slight bumps for the cones. Also, I’ve normalized the curves on the vertical axis (i.e., I’ve drawn them such that they all have the same maximum height). There are several things to note about this illustration, including the fact I’m rather proud of this little scamp, so please feel free to say nice things about it. Typical humans have three types of cone photoreceptors (think “color”) along with rod photoreceptors (think “black-and-white”) We also have rod photoreceptors that are extremely sensitive in low levels of light, that cannot distinguish different colors, and that provide what is known as scotopic vision (the sensitivity of our rods peaks at 498 nm). In my Evolution of Color Vision paper, I make mention of the fact that the typical human eye has three different types of cone photoreceptors that require bright light, that let us perceive different colors, and that provide what is known as photopic vision (the sensitivity of our cones peak at wavelengths of 420, 534, and 564 nm). As we discussed in an earlier column - Are TOM Displays the Future of Consumer AR? - “Eighty to eighty-five percent of our perception, learning, cognition, and activities are mediated through vision,” and “More than 50 percent of the cortex, the surface of the brain, is devoted to processing visual information.” In the case of humans, one of our most powerful and pervasive senses is that of sight. What about senses we do not have, but that occur in other animals, such as the fact that some creatures can detect the Earth’s magnetic field, while others can perceive natural electrical stimuli? Wouldn’t it be appropriate to class these abilities as being extra-sensory perception as compared to our own sensory experience? For example, if my wife (Gina the Gorgeous) ever discerns the true purpose of my prognostication engine, I foresee that I will no longer need it to predict her mood of the moment. ![]() Actually, I may have a touch of precognition myself, because I can occasionally see a limited way into the future. ![]() Returning to ESP, the official definition goes something along the lines of, “claimed reception of information not gained through the recognized physical senses, but rather sensed with the mind.” Alternatively, the Britannica website defines ESP as “perception that occurs independently of the known sensory processes.” Typical examples of ESP include clairvoyance (supernormal awareness of objects or events not necessarily known to others) and precognition (knowledge of the future). Contra wise, if you hold your hand over something cold, you can detect the lack of heat.) But we digress… (*Even if you are blindfolded, if you hold your hand close to something hot, you can feel the heat in the form of infrared radiation. This is also referred to as the “sixth sense” based on the fact that most people think we (humans) are equipped with only five of the little rascals: sight, hearing, touch, taste, and smell.Īs an aside, we actually have many more senses at our disposal, including thermoception (the sense by which we perceive temperature*), nociception (the sense that allows us to perceive pain from our skin, joints, and internal organs), proprioception (the sense of the relative position of the parts of one’s body), and equilibrioception (the part of our sense of balance provided by the three tubes in the inner ear). I was just perusing and pondering the official definition of extrasensory perception (ESP). ![]()
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