Roughly 1.8 million years ago, an early human ancestor started manufacturing hand-bashed, oval-shaped axes by knocking rocks together. These early tools, the most popular gadgets of the Pleistocene, triggered a revolution in the humanoid brain. New research suggests that the act of banging stones coincided with evolutionary growth in the neural network that activates when modern humans play the piano. These findings not only suggest a possible evolutionary link between stone tool technology and musical instrument use, but an alternative way of understanding how children develop musical ability.
“There is no specialized brain network that has evolved specifically for music,” Shelby Putt, a post-doc at Indiana University and coauthor on the study published in Nature Human Behavior, told Fatherly. “More likely, the cognitive network that allows a modern human musician to play a concerto has a long evolutionary history, one that extends back to around 1.8 million years ago.”
It’s obviously impossible to study the brains of extinct early humans but, for the study, Putt and her team turned to the next best thing—31 modern humans, who were shown videos of experts knapping stone and then told to try it themselves. As bone met rock, Putt and colleagues analyzed each participant’s brain activity using functional near-infrared spectroscopy, which measures blood flow to specific neurons and highlights the most active brain regions.
Prior studies had suggested that advanced tool making co-evolved with language, and that fine masonry could only develop within the neural networks set aside for speech. But the fNIR results suggest that Broca’s Area, the region of the brain linked to language, plays almost no role in the process. Instead, the results highlighted very specific regions of the brain—the temporal cortex for integration of visual, auditory, and motor information, the ventral precentral gyrus for visual memory, and the supplementary motor area for planning future actions.
The same regions are involved in modern piano playing. That’s no mistake, Putt says.
“A toolmaker needs to pay close attention to where she strikes the core with her hammerstone, and she must control how much force is used. Similarly, a pianist must pay attention to where she places her hands and how forcefully she presses the keys down,” explains Putt. “A toolmaker must read the stone to determine where to strike next, just as a pianist might read sheet music to know which note to play next. And both the toolmaker and pianist are listening to the sounds that their actions produce and relating these sounds back to this visual and tactile information.”
Putt hopes that her work will not only shed light on how our neural networks evolved, but also make strides in explaining how a child’s brain develops the ability to play music.
“The developmental stages that lead to adult working memory may, in some ways, parallel the evolutionary stages that led to modern human working memory,” she says.