Neuroscientist Beau Lotto’s entire presentation below is entertaining and informative, but take note in particular of his yoked prism demonstration from the 4:00 to 6:09 mark:
Lotto’s latest book is revelatory on many levels (including overcoming extreme anxiety attacks, leveling him with headaches and a host of neurological symptoms that originated in his mind until he learned to shed all his troubles and cares in Petula Clark-like fashion). With regard to vision, consider Lotto’s following observation (p.110):
“All perception is just your brain’s construction of past utility (or ’empirical significance of information’). This is a scientific fact, and admittedly quite a strange one. But how does this happen? Where does the construction take place? The answer becomes clear once you understand how our senses rely very little on the external world, but more on our internal world of interpretation … Only 10 percent of the information your brain uses to see comes from your eyes. The other 90 percent comes from other areas of the brain. This is because for every one connection from the eyes (via the thalamus) to the primary visual cortex, there are ten connections from other cortical regions. Moreover, for every one connection going to the visual cortex from the eyes (again via the thalamus), there are ten going back the other way, dramatically affecting the information coming from the eyes. In terms of information flow, then, our eyes have very little to do with seeing. The seeing is done by our brain’s sophisticated network making sense of the visual sensory information. This is why the adage seeing is believing gets it all wrong.
I was struck by Lotto’s elaboration on the balance – on the dynamic equilibrium, if you will – between excitation and inhibition. His style triggered thoughts about the utility in developing the dynamic equilibrium we call visual facility, toggling between accommodative stimulation and relaxation; between convergence and divergence. The state and position of our eyes can reveal our mental and emotional states. Too much excitation and we’re driven toward eso posture; too much inhibition and we’re released into exo posture.
Lotto’s ultimate lesson is that, to understand human perception, neuroscientists must get out of the traditional laboratory and into more naturalistic settings. To explore these realities he has created The Lab of Misfits – helping to understand why we see what we do, a modern day version of “vision is motor”.
I have no doubt that Lotto would find our vision therapy rooms intriguing.