brain complexity

Brain size

With a large body comes a large, complex brain. Despite being the largest living terrestrial mammal, very little is known about the elephant brain. Indeed, until recently, only a few original articles had specifically focused on the elephant central nervous system (Cozzi et al. 2001). The brains of Asian and African elephants rank among the highest for absolute and relative mass, cortical expansion. Their brains exhibit features comparable to those of some of the Cetaceans and the Great Apes, including humans. Averaging about 5 kilograms, the adult African elephant brain is the largest among living and extinct terrestrial mammals. The brain of a newly born elephant is approximately 50% its adult weight, indicating a prolonged developmental period for the brain wherein the environment will significantly shape neuronal microstructure.

One way of comparing the brains of different animals is to use the Encephalization Quotient (EQ). EQ is the ratio of the observed brain mass to the expected brain mass of a typical animal of that size (Jerison, 1973). Looking at brain size in this way, an EQ equal to 1.0 is an average mammalian brain. Theoretically, the larger the brain is relative to body size, the more the neural