The most easily accessible examples of this for us to process can be found in the research of “split-brained” patients, individuals whose brain hemispheres were surgically disconnected. In work done by neuropsychologist Michael Gazzaniga, a patient would have images displayed to his right eye, which confers information to the left hemisphere of the brain, and he could easily identify and verbalize what he saw.
However, because verbal response is strongly reliant on the left-brain hemisphere, when the same patient had images displayed to his left eye, he would verbalize that he saw nothing. And to him, this was the absolute truth. But fascinatingly, when further prompted to draw with his left hand, the patient would sketch accurate pictures of the stimuli with which he had just been presented. So, verbally he would admit that he had seen nothing, when in fact, his right brain hemisphere would be able to communicate honestly what it had seen through a non-verbal medium. When further questioned by researchers about why he was drawing the particular objects he was, the patient again would answer “truthfully” that he had no idea.
How often do we consciously verbalize a truth that just isn’t so? It is likely impossible to know, given that we might interpret our words as objective truths, just as this patient had.