Imagine my astonishment and yes, unease, when in my very own house a circle of light appeared on a white wall. In that circle, a few seconds later, a most familiar face materialized in that circle before gradually fading away. Had I been woefully wrong all these years about mystical events?
It all began when a friend E-mailed me the strange image reproduced below, along with a short list of instructions:
1. Stare intently at the four dots in the image for no less than 30 seconds.
2. Then, stare at a nearby white wall and begin blinking.
3. What, and whom, do you see? Well? I don't know what you see, but after staring at the wall a few seconds, I saw a bright circle appear in which as image of Jesus then materialized. Not, as news items occasionally relate, a questionable and hardly recognizable image of Christ on, say, a potato chip or a mildewed potato, but an unmistakable likeness right there on my wall.
I called my sources at The Neurosciences Institute in La Jolla, California, and described the phenomenon. What was going on? Researchers at the Institute, somewhat amused, suggested answers and also referred me to the Illusion Works L.L.C. website. My illusion was quickly demystified.
What I had seen, apparently, was an "afterimage." In our retinas are photoreceptors, cells that convert light into electrical impulses that are transmitted to the brain. When I focused intently for 30 seconds on the image above, these photoreceptor cells became fatigued, or desensitized. This desensitization was most pronounced for the receptors on which the white part of the image was focused, but far less so for those viewing the black areas. Then, when I looked at the white wall, the least depleted receptors responded strongly, producing bright images, while the largely depleted and inactive cells transmitted little to the brain, producing the dark areas of the image on the wall. The result was an afterimage, in which the white areas of the original had turned black and the black areas white. Blinking apparently helped the process by stimulating the receptor response. Within several seconds, as the photoreceptor cells readjusted to their normal state, the afterimage faded away.
In other words, I had not undergone a mystical experience, but rather one that is rationally and fully explainable by science. Relieved, and with renewed confidence, I look forward to continuing a campaign of skepticism against irrational and mystical claims.