Posts Tagged ‘Mary Ann Raghanti’

“I Get By With A Little Help From My Friends”

April 3, 2018

2-19-18 WKSU’s Jeff  St. Clair did a radio report entitled Monogamy and Smiles are the Results of a Neurochemical Change That Made Us Human. It was recently rebroadcast. Analysis found it very compelling. From the broadcast: “Kent State professors Owen Lovejoy and Mary Ann Raghanti worked together on a recent paper that looks at how a neurochemical change in our brains became the turning point in human evolution.” ““Cooperation is something that’s very uniquely human. We start cooperating by the time we’re 1 year old. This doesn’t happen in other ape species, so it’s hard wired.” Raghanti believes that early in our history something switched-on in our brains that sent us on a different path than our closest relatives, and it wasn’t our smarts. “Our brain was the size of the chimpanzee. We hadn’t expanded the cerebral cortex yet,” says Raghanti, “so whatever it was that changed our personality occurred without that cerebral cortex.” Raghanti has been dissecting the brains of humans, chimpanzees and other primates over the past decade to see what could account for the differences in our behavior. She looked at the chemicals that trigger our thoughts and actions – the neurotransmitters – and where they’re active in the brain. It was a lot of work counting all the neural connections. “We very laboriously section every single brain into very thin sections, and then we stain it, and put it under the microscope and we have special software where we can quantify the number of axons which gives us a measure of the enervation.” She didn’t see many differences, until she got to the part of the brain called the striatum. Nestled deep in the brain, the striatum plays an important part in decision-making and is home to the all-important reward system, the same system that gets hi-jacked by drug addiction. But Raghanti found that in early human ancestors that reward system developed for another purpose. “Our reward system gets triggered by helping other individuals,” says Raghanti. The chimpanzee is our closest living relative, but we differ in how part of our brain is wired. In humans dopamine is dominant in the striatum, which coordinates social interactions, while in chimps acetylcholine, key for aggression, dominates. That pathway is missing in apes. Instead, Raghanti found they’re hard-wired for aggression.” “Lovejoy says if evolution is survival of the fittest, it doesn’t make sense if instead of competing, you’re helping each other, which is what humans do. “Why do you cooperate with other people unless it gives you more offspring? I’ve never really understood that on a basic selection basis, until Mary Ann made this discovery.” For Lovejoy, all the pieces come together knowing that the human brain is hard-wired for teamwork.” ““Hominids have a form of social structure that no other primate has,” says Lovejoy. “We have something we call social monogamy.”” Analysis finds it intriguing that “the same system… gets hi-jacked by drug addiction.”