This is the second in a series of posts exploring the scientific data behind often-quoted stats around visual thinking and the use of images in learning. You can read the first one here.
So far, a pretty strong case has been made for visuals as learning and teaching tools, but now let’s look at the actual make up of our brain tissues.
True or false? 90% of information entering the brain is visual.
We couldn’t verify this, even though it seems to be all over the web. The only source that mentions this fact is a book by Eric Jensen called Brain-Based Learning: The New Science of Teaching & Learning, and we haven’t been able to access the footnotes to see where the citation comes from.
We do know that when our eyes our open, our vision accounts for two-thirds of the electrical activity of the brain — a full 2 billion of the 3 billion firings per second — which was the finding of neuroanatomist R.S. Fixot in a paper published in 1957.
True or False? 40% of all nerve fibers connected to the brain are linked to the retina.
True — in fact, half of all neural tissue deals with vision in some way.
The nerve fibers statistic is also cited by Eric Jensen in Brain-Based Learning. In that same paper from 1957 that R.S. Fixot published in the American Journal of Opthamology (summarized here), 50% of our neural tissue is directly or indirectly related to vision.
True or False? More of our neurons are dedicated to vision than the other four senses combined.
True — in fact, we may be out-evolving our sense of smell.
According to John Medina in his book Brain Rules, in the fight for more neural real estate that’s going on between our olfactory cortex and the visual cortex, vision is winning. He writes: “about 60 percent of our smell-related genes have been permanently damaged in this neural arbitrage, and they are marching toward obsolescence at a rate fourfold faster than any other species sampled.” Why? “In the crowded, zero-sum world of the sub-scalp,” Medina says, “something has to give.” So smell those rosebuds while ye may.
More interesting and surprising factoids on the relationship to vision and memory in our next and final post in this series. Stay tuned.