Marcia Haskell

“OUR ABILITY TO RECOGNIZE FAMILIAR THINGS
At first glance our ability to recognize familiar things may not seem so unusual, but brain researchers have long realized it is quite a complex ability. For example, the absolute certainty we feel when we spot a familiar face in a crowd of several hundred people is not just a subjective emotion, but appears to be caused by an extremely fast and reliable form of information processing in our brain. In a 1970 article in the British science magazine Nature, physicist Pieter van Heerden proposed that a type of holography known as recognition holography offers a way of understanding this ability. * In recognition holography a holographic image of an object is recorded in the usual manner, save that the laser beam is bounced off a special kind of mirror known as a focusing mirror before it is allowed to strike the unexposed film. If a second object, similar but not identical
* Van Heerden, a researcher at the Polaroid Research Laboratories in Cambridge, Massachusetts, actually proposed his own version of a holographic theory of memory in 1963, but his work went relatively unnoticed.
to the first, is bathed in laser light and the light is bounced off the mirror and onto the film after it has been developed, a bright point of light will appear on the film. The brighter and sharper the point of light the greater the degree of similarity between the first and second objects. If the two objects are completely dissimilar, no point of light will appear. By placing a light-sensitive photocell behind the holographic film, one can actually use the setup as a mechanical recognition system.7 A similar technique known as interference holography may also explain how we can recognize both the familiar and unfamiliar features of an image such as the face of someone we have not seen for many years. In this technique an object is viewed through a piece of holographic film containing its image. When this is done, any feature of the object that has changed since its image was originally recorded will reflect light differently. An individual looking through the film is instantly aware of both how the object has changed and how it has remained the same. The technique is so sensitive that even the pressure of a finger on a block of granite shows up immediately, and the process has been found to have practical applications in the materials testing industry.”
― Michael Talbot, The Holographic Universe