Science "explains" the visual system in simplistic terms that are quite inaccurate. Photons of light are focused on the retina where they form an image of the external world. The "pattern" of this image is transferred to impulses in the optic nerves, and it is ultimately expressed as a similar pattern on the optic cortex at the back of the brain. This process is much like the process a computer uses to form a graphic image on the screen. This graphic image is expressed as a specific collection of individual dots: the more dots there are and the closer together they are, the more realistic the image will be. We call this "image digitizing."
If things were this simple we should be able to electrically stimulate the optic cortex with a pattern of electrodes arranged, for example, in the shape of the letter A, and the subject would report seeing the visual image of the letter A. The fact of the matter is that even the letter A cannot be perceived in this way; the patient merely reports the sensation of light. We expect that somewhere in the brain such a patterning is expressed--on the "computer screen of the mind," for example. But we have not found the screen. This may be because it exists only in the state of consciousness, not in the physical brain.
I know of one experimental circumstance in which simple images can be impressed on the conscious mind without going through the visual system at all. This technique was discovered by Dr. Elizabeth Rauscher, a physicist, and William Van Bise, an engineer. It uses magnetic fields generated by two coils of wire, each pulsing at a slightly different frequency and directed so as to intersect at the head of the subject
When two beams of electromagnetic energy with different frequencies intersect at some point in space, a third frequency is formed. This frequency is the difference between the two original frequencies and is called either the "difference" or the "beat" frequency. For example, if one beam had a frequency of 100 kHz and the other a frequency of 99.99 kHz, the difference would be 0.01 kHz, or 10 Hz. This is a useful technique for producing extremely low frequencies (ELF) within a small volume located a distance away from the original transmitters. In Van Bise and Rauscher's experiment, the difference frequencies were always in the ELF range. The size of the volume in which this occurs depends upon the diameter of the two beams. (This technique will be discussed further in a later chapter.)
Van Bise and Rauscher's blindfolded subjects "saw" such simple figures as circles, ellipses, or triangles, which could be changed by altering the frequency of one of the coils. The coils were several feet from the subject's head. The magnetic field strength from the coils were so small that no electrical currents could have been generated in the brain, and the control electronics were located in another room.
This technique seems to bypass the entire visual system as we know it, acting directly at the interface between the organic brain and the conscious perception of visual images. If this supposition is even partially correct, it is highly unlikely that the conscious perception level is based upon a digital or nerve-impulse system. The technique could not possibly have stimulated nerve impulses in any part of the brain, because the field strengths were far too low and the ELF frequency cannot produce such stimulation. It is probable that this sensitivity to such low-strength, low-frequency magnetic fields requires the presence of semiconducting DC elements.[12]
