Comparisons of synaptic geometry, dendritic field density, and neural connectivity underscore the humbling revelation that the cetacean brain is superior to the human brain. In addition, the centralization and differentiation of the individual cerebral areas are levels higher than the human brain. Many of us may remember our lessons from Biology 101. We were shown illustrations of the brain of a rat, a cat, a chimp, and a human. We listened as the instructor pointed out the ratio of brain to body size and the increased convolutions on the neocortex of the human over the chimp, the cat, the rat. The simplistic conclusion was an understanding that humans were smarter. Of course, it was a human demonstration of intelligence, and the conclusion was arrived at by discrimination based on the selection of the examples. When the brain model of an orca is inserted into the picture, the conclusion based on the same factors places the human brain in second position. Unfortunately for the pride of humankind, this simple comparison is elementary compared to a truly astounding fact: whereas the human brain shares three segments with all other mammals, the cetacean brain is uniquely different in its physiology. Humans have the rhinic, limbic, and supralimbic, with the neocortex covering the surface of the supralimbic. However, with cetaceans we see a radical evolutionary jump with the inclusion of a fourth segment. This is a fourth cortical lobe, giving a four-fold lamination that is morphologically the most significant differentiation between cetaceans and all other cranially evolved mammals, including humans. No other species has ever had four separate cortical lobes. This well-developed extra lobar formation sandwiched between the limbic and supralimbic lobes is called the paralimbic. Considering neurohistological criteria, the paralimbic lobe is a continuation of the sensory and motor areas found in the supralimbic lobe in humans. According to Dr. Sterling Bunnell, the paralimbic lobe specializes in specific sensory and motor functions. In humans, the projection areas for different senses are widely separated from one another, and the motor area is adjacent to the touch area. For us to make an integrated perception from sight, sound, and touch, impulses must travel by long fiber tracts with a great loss of time and information. The cetaceans paralimbic system makes possible the very rapid formation of integrated perceptions with a richness of information unimaginable to us.
Posted on: Fri, 22 Aug 2014 07:16:00 +0000
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