Raw size of the brain of humans is about 1550 grams. Tursiops Truncatus(bottlenose) averages 1800 grams. Some researchers say raw size doesn't matter although there definately is a correlation between size and communications capacity. In microcephaliacs (undersized brains for humans) if the raw weight is less than 1000 grams it is unlikely the subject will ever gain verbal speech (as studied by Dr. John Cunningham Lilly M.D. who also writes about dolphins-see my other letter). Human babies are born with about 400 grams if I remember right, and around 800 grams they say their first word, 900 second word, and 1000 is the begennings of coherent speech. Chimpanzees/Greater Apes have been taught American Sign Language with around 350-450 grams brain weight likewise microcephaliacs. Dolphins are born with 1000 grams of weight.

Surface area/fold density/fissurisation is also another good area. Felines have very low density, Canines slightly more, Chimps/Great Apes are low to moderate, and Humans are high to very high(Einstein). Dolphins are usually at least as complex as humans, sometimes more so than Einstein according to my records. And we know fissurisation is a good sign that their brains are being used.

Neuronal density in cetaceans is usually as high as humans. Lamination (# of cortical layers) is also advanced. The complexity of cortical paterns, the specialization of cortical arrangements, and the amount of communication between cells are unknown.

Cetaceans have a very high ratio of cerebral cortex (silent associational areas) to motor cortex. Typically much higher than humans. For comparison macaque monkeys are almost all motor cortex, chimps have a higher level, and humans even higher yet. The only animals in the animal kingdom to have more than humans are the elephants and marine mammals. A higher percentage of cerebral to motor cortex in humans is related to creativity, higher abstract thinking, humor and memory. It is essentially what makes us human.

Cetaceans also have a high ratio of neocortical association neurons to limbic system brain stem neurons and the ratio is higher than even normal intelligent humans! A high ratio in humans is necessary for reality orientation, objectivity, humor, emotional self-control, and capacity for logically consistent abstract thought as well as higher forms of creativity. Low ratios typically mean impulsiveness, emotional instability, irritability, impaired memory, loss of objectivity and humor, marked egocentricity, stereotyped behavior, and sometimes mania, obsessions, delusions or hallucinations.

This is just the raw hardware they're packing so I'm sure you can see they have a lot of learning potential. Feel free to pass this around to anyone you wish, just leave my name on and add a note saying I'm trying to find other researchers (amateur/professional, orginizations/individuals) to talk with.

Mike Shawstad (contact through NEEPtursi@harmlesslion.com)

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