I attended a free “consciousness-raising” workshop. The speaker, a woman named Slavica, performed a test to gauge our “level of consciousness.” She asked who among the group, without turning their heads, remembered the colour of the wall behind us? She informed us that a person of “very high consciousness” would be able to remember every visual detail they witnessed. If there was such a person in the room, she would bow to them and step aside to allow him or her to speak instead. I did not remember the colour, nor did anyone else. She did not indicate whether she was capable of this visual memory feat.
In fact, all people have limited visual memory. The human visual system only supports a small area of high resolution processing. The fovea is for sharp central vision, and is important in activities where visual detail is important, such as reading and driving. When the eyes scan a scene they do not take in every detail. The eye jumps to highlights, depending on what the viewer considers important. Changes outside the focus of attention are not noticed. Our visual memory seems real but it is an analog at best.
We have limits on our visual memory for efficiency, not because of our “low level of consciousness,” whatever that means. The brain stores just a rough outline of a scene and then uses knowledge of the world to fill in the detail.* If I can remember the peaks and valleys of a landscape I can fill in the rest with the laws of physics or simple interpolation.
We can store more information if we consider it important. Zen practitioners and visual artists have better visual perception than most people, not because they are more enlightened; it is their job to attend to visual detail. You may have a rich and accurate image of your lover’s face. Not everything is important to remember in detail, including the colour of the back wall. Clever trick, Slavica.
*Update 2017-10-04. Two types of evidence: 1) Andy Clark, Natural Born Cyborgs, reviews card tricks and studies that show the limits of visual memory. 2) David Marr, Vision, explains how the primal sketch on the retina gets built by the mind into a 2.5D sketch and then a 3D model.
Update 2017-10-05. Cognitive Bias Codex. An index of all our cognitive biases.