Sensory Biology:
Windows on the World
Somewhere in the distance, an odd, rhythmic grumble imposed itself on the shark's consciousness. Although the Great White had no word for 'boat', it recognized the mechanical throbbing as a surface phenomenon that had rarely proven worthy of attention. But this time there was something familiar mixed in with the acrid, alien machine smells: the alluring scent of tuna oil. The great predator banked gracefully to investigate. As the shark continued its approach to the source of the piscine perfume, the mechanical throb ceased suddenly and was replaced by an un-natural clanging and chattering. Strange. Its curiosity aroused, Great White coursed toward this new disturbance. As the shark closed on the source of these strange sensations, a row of vibration-sensitive pits along its flanks added their collective voice to the sensory chorus. These signals intensified and re-enforced one another, compelling the Great White to accelerate in anticipation. Resolving specter-like from the underwater haze loomed a dark shadow, resembling a short, fat floating whale. The diffuse tuna scent was now everywhere and nowhere. As the shark ascended, its dorsal fin broke the surface momentarily. In response came an explosion of whoops and hollers from somewhere above the undulating liquid ceiling. The shark's large, sensitive eyes caught a silvery glint from a strange object. The Great White had never seen a shark cage before. It was half as tall as the shark itself was long, but much wider. The cage's surface was not curved and its volume seemed defined by empty spaces between vertical structural elements. As it swam past, the shark saw that there was something dark and moving inside, as though following it. Odd - and more than a little frightening. Yet all around it, the delicious tuna scent beckoned. Periodically a great flurry of bubbles spewed from the dark shape, as though it were drowning over and over again. As it neared the strange structure, the Great White's electrosensors tugged at it, inviting an exploratory nip. As the great predator's jaws clamped noisily onto the unyielding metal bars, several of its teeth broke free, spiraling gracefully as they sank . . .
Everything we are is experienced through the windows of our five senses. Sight, sound, smell, taste and touch not only define the nature of physical reality but also prescribe our place in it. Who we are is shaped as much by how we perceive the world as by its reactions to us. If, on the whole, people and fortune have been kind to us, we often perceive the world to be a pleasant place. Conversely, if we have been less fortunate, we may perceive the world as a hostile, indifferent, or altogether unpleasant place. In a deeply fundamental sense, each of us is the sum total of what we do and what is done to us. In constructing ourselves, our senses are the tools we use to experience, learn and remember. But how and what each of us perceives is the result of an absolutely unique combination of genes and experience. Yet, if experience is subjective, can there be such a thing as objective reality? To a large extent, we seek out friends and entertainments that validate our individual experience of the world . . . or, at least, the world as we want it to be. This is a 'natural' bias, but it is also a self-limiting one. Seeking out other perceptions, different ways of interpreting things is often frightening, but it can also be deeply rewarding. For such a perspective grants the courageous explorer a richer, far less parochial understanding of the world. If we are open to the experience, we can learn as much from contemplating the merkwelt (perceptual universe) of sharks as we can from comparing the experiences of fellow human beings. But one cannot hope to appreciate the sensory world of the White Shark from the safety of dry land. To begin grasping how the Great White perceives its environment - and human beings, when we enter its realm - we must first cast off the shackles of terrestrial thinking, and plunge receptively into this creature's alien, liquid universe.
