Did walking upright make humans smart?
Watching their grandson and son learning to walk inspired a father and son academic team from the University of Sydney in Australia to write a paper that suggests standing up enabled humans to become smarter than other animals. They propose that bipedality - or walking on two legs - changed the human brain by liberating the cortex from the drudge of controlling routine tasks.
Dr. Mac Shine, a neurology researcher at the University's Brain and Mind Research Institute and his father, Rick Shine, Professor in Evolutionary Biology, describe how they came to their conclusions in the journal Frontiers in Neuroscience.
Tyler Shine, now 2 years old, is the inspiration behind his father and grandfather's ideas. When he was first learning to walk, they noticed how every step required the toddler's full attention.
But soon, as walking became routine, Tyler began to pay attention to his surroundings. He was also able to balance better, which helped free up his attention and focus on more interesting tasks.
As they observed Tyler's improved ability to walk and focus on his environment, and increased capacity to engage in mischievous behavior, the Shine team developed the idea that Tyler was transferring control of balance to "lower" parts of his brain. This released the cortex from the drudge of routine, lower order processes, freeing it up to focus on unpredictable challenges such as obstacles.
Tyler's father, Dr. Shine, says that at first all complicated tasks - for example driving a car or playing an instrument - take up our full attention, but they eventually become routine.
"Studies of brain function suggest that we shift the control of these routine tasks down to 'lower' areas of the brain, such as the basal ganglia and the cerebellum," he explains. "So, humans are smart because we have automated the routine tasks; and thus, can devote our most potent mental faculties to deal with new, unpredictable challenges."
Walking on two legs prompted evolutionary shift in way we use our brains
He and his father propose that the change from walking on all fours to walking on two legs - bipedality - was the key event in the early history of humans that prompted a change in the way we use our brains.
Dr. Shine believes that when our first pre-human ancestors started walking on two legs, it put evolutionary pressure not only on the body, but also on the brain.
Dr. Shine says suddenly the human brain was faced with the complex challenge of keeping balance, "and the best kind of brain to have, was one that didn't waste its most powerful functions on controlling routine tasks."
So he and his father believe that when our first pre-human ancestors started walking on two legs, it put evolutionary pressure not only on the body, but also on the brain.
They postulate that the onset of walking on two legs posed "massive neurocomputational challenges" to the brain, and this drove the "rapid expansion of human cognitive capacity."
"Specifically, the ability to rapidly 'delegate' well-learned behaviors into subconscious processes liberated higher neural centers to be available for flexible, 'online' processing of fitness-relevant stimuli," they note, adding that:
"Our ideas suggest several testable predictions and may clarify not only how human cognitive systems differ from those of other species, but also how the human brain works both in health and disease."
Dr. Shine says while new technology allows us to find out more and more about how the brain works by looking inside it, in order to interpret what we observe, we also need new ideas.
He says he is "delighted" that his son inspired one of these new ideas, and hopes perhaps one day, when he is watching his own son learning to walk, "we will be much closer to truly understanding the greatest mystery of human existence: how our brains work."
In 2012, Medical News Today learned of a US study that showed standing babies stay steady when focused. Researchers from Purdue University suggested that although babies learning to stand may look wobbly, they are more in control than they appear, especially when they focus on something they are holding - like a toy. They noted that the extent to which babies sway when standing reflects how they strategically adapt their posture as they learn about their environment.
Written by Catharine Paddock PhD
Copyright: Medical News Today
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