Science Uncovers Apes' Hidden Soul

Scientists have found the stongest evidence yet that some animals could have "souls".

They have located the cells responsible for self-consciousness in the human brain - and found similar clusters in great apes. The cells, named "self awareness neurons", appear to integrate the work of various parts of the brain - and create a sense of individuality.

The suggestion that consciousness is a physical process is certain to provole religious controversy as well as debate over the ethical treatment of great apes. The role of the neurons in humans has been confirmed in studies of patients in which the cells had been damaged by head injuries. Such patients lost all sense of being an individual and sank into a near-vegetative state.

Professor John Allman, of the California Institute of Technology, discovered the neurons in the frontal lobe of the brain. They are large and lie near the corpus callosum, which connects the brain's two halves.

More evidence comes from brain scans of people with mental illness. The anterior cingulate cortex - the area where the cells are found - becomes less active in depressed people and the cells may shrink. Conversely, in people with manic disorders, the cells enlarge and become more active.

Further evidence comes from studies of Alzheimer's disease. The cells appear to be especially vulnerable and patients' loss of self-identity correlates closely with the disappearance od the self awareness neurons.

Allman examined their role in animals by seeking the same cells in the brains of 28 primate species and 20 non-primates, including bats and dogs. The concentration of the neurons was greatest in humans, smaller in chimps and still less in gorillas. They could not be found in non-primates, though it is suspected that elephants and dolphins also have them.

-An article by Jonathan Leake in the Times of India