This game test your memory, and, ultimately, your sanity. The object of the game
is to memorize sequence of lights. On that note, does anyone remember those Simon
commercials in the '80s? How could you forget! :). Use your mouse to click start
and click the color bars.
What is the basis behind a photographic memory?
Scientists who study memory phenomena generally believe that eidetic memory (more
popularly known as "photographic memory") does not exist. Early experiments on eidetic
memory were intriguing, but could not be replicated.
People do show extraordinary memory performance in certain circumstances. For example,
expert chess players can typically play blindfolded chess against several opponents
at the same time, easily memorizing many chessboard configurations. Others use special
tricks to memorize long lists of randomly selected numbers.
Impressive as these feats are, scientists attribute them to specialized ways
of thinking about the information, not to any kind of enhanced visual memory. One
interesting experiment that makes this point was performed by a cognitive psychologist
named DeGroot.
Expert chess players were shown a chess board with pieces on it for a brief period,
such as 15 seconds, and then asked to reconstruct what they had seen on a new chess
board. That is, they were asked to place chess pieces in the same positions as they
had appeared on the board they'd been shown. The expert players were very good at
this, much better than novice players. One hypothesis was that the experts had developed
an enhanced ability to memorize visual information.
In the next experiment, the expert chess players were asked to do the very same
thing; butt this time, they were shown boards whose pieces were arranged in ways
that would never actually occur in a game of chess. Not only did their ability to
remember the positions go down, but it went down all the way to the level of the
novice players. We can conclude that the original, enhanced performance at remembering
chess positions came from the experts' ability to mentally organize the information
they had observed, not from any ability to "photograph" the visual scene.
Eidetic Images
Historically, one of the most controversial forms of mental imagery is the so-called
eidetic image. An eidetic image is one that, for the subject, reputedly bears remarkable
stimulus-like properties. The subject claims to LITERALLY SEE, in exceptional detail
learning ability, an image of some recently-seen object. Although the image is "mental"
it appears to be in physical space. Although eidetic images share features with
memory images and projected images, they are distinct in that they can, according
to the reports of subjects, be
INSPECTED FOR NEW DETAIL IN THE MANNER OF A PHYSICALLY-PRESENT STIMULUS OBJECT.
The investigation of eidetic images poses special problems for psychology. The principal
problem is how to characterize the subjective reports of eidetic imagery. Both the
reliability of subjective reports and the precise nature of the supposed "inspection"
of the images present problems, particularly if psychology is understood to be a
science with quantifiable parameters. These problems have led many physcologists
to question the existence, in the strict sense required by science, of eidetic images.
Descriptivist and strict behaviorists claim there is no way to differentiate performances
consistent with so-called eidetic images from performances consistent with extraordinary
descriptive memory. According to some, then, eidetic images are just memory images.
Eidetic images are distinct from after-images. Typically, after-images are an involuntary
reaction brought about as a result of over stimulation of the retina. A flash of
light, intent staring at a bright color patch, and similar events overload the retinal
tissues, causing them to send signals to the brain after the source of the stimulation
is removed. After- images often appear to be floating space before the eyes or to
be on nearby surfaces. They do not appear to be in a fixed in a physical location.
An after-image will appear to move when the eyes focus on a different location.
Eidetic images, on the other hand, can be triggered by what appears to be simple
visual inspection of a physical object. No overloading of the retinal tissues appears
to occur, since the visual study of the object usually lasts several minutes and
eye movements are continuous during the process. When the object is removed, a person
capable of forming an eidetic image will retain a detailed memory image that (according
to the subject) appears to be relatively stable in physical space. Often, it appears
to be in the same physical space independent of eye movements. If, for example,
a figure or painting is shown on a wall or desk top and then removed, the eidetic
subject will point to the appropriate surface area location when describing the
details of the eidetic image "seen" in the vacated space. (See Stromeyer and Psotka,
1970, p. 346 and A. Richardson, 1969, pp. 29-44 for more on the distinction between
eidetic images and after-images.)
Eidetic imagery is generally reputed to exist in a significant percentage of children
between the ages of seven and fourteen. Eidetic imagery, particularly in children,
has been studied at least since 1819 (Purkinje), and several other important studies
were made near the turn of the century. The topic fell out of favor with the advent
of behaviorism. The few contemporary studies made have tended to confirm (via subjective
reports of children) the findings of older, traditional psychology. Haber and Haber
(1964) found that 8% of children between the ages of 7 and 12 appeared to have eidetic
imagery (Haber and Haber in A. Richardson, 1969, p. 37). Eidetic imagery tends to
disappear with age and is very rare among adults.
Eidetic images are usually generated spontaneously in children and by choice in
adults. Maintaining an eidetic image, in either case, requires both interest and
effort on the part of the subject. Despite this, eidetic images appear to fade in
most cases at rates that are not fully controllable by the subject. It is therefore
a judgment call as to whether to list eidetic images as under conscious control
or not. (In my work, I have indicated that they are not, because the greatest incidence
of eidetic imagery is among children.)
