For us, one aspect of imagination is creating something that doesn’t already exist; in terms of the brain this is thinking. And seems simple when you do just that and put some thought to these findings. However, it’s fascinating that thanks to evidence of blood flow we might know more about how our ancestors practised varying levels of thinking. And so perhaps imagining.
How did human intelligence evolve? Anthropologists have studied this question for decades by looking at tools found in archaeological digs, evidence of the use of fire and so on, and changes in brain size measured from fossil skulls.
However, working with colleagues at the Evolutionary Studies Institute of the University of the Witwatersrand in South Africa, we have found a new way to estimate the intelligence of our ancestors.
By studying fossil skulls, we determined how much blood – and how much energy – the brains of ancient hominins required to keep running. This energy use gives us a measure of how much thinking they did.
We found the rate of blood flow to the brain may be a better indication of cognitive ability than brain size alone.