Xref: utzoo comp.ai:8261 sci.bio:4193 sci.psychology:3915 alt.cyberpunk:5413 Path: utzoo!utgpu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!caen!blue.engin.umich.edu!zarnuk From: zarnuk@caen.engin.umich.edu (Paul Steven Mccarthy) Newsgroups: comp.ai,sci.bio,sci.psychology,alt.cyberpunk Subject: Re: The Bandwidth of the Brain Summary: Photographic memory in practice. Keywords: photographic memory Message-ID: <1990Dec22.060218.22430@engin.umich.edu> Date: 22 Dec 90 06:02:18 GMT References: <37034@cup.portal.com> <1990Dec18.181935.23319@watdragon.waterloo.edu> <37111@cup.portal.com> Sender: news@engin.umich.edu (CAEN Netnews) Organization: University of Michigan Engineering, Ann Arbor Lines: 172 mmm@cup.portal.com (Mark Robert Thorson) writes: [ Discussion of master bricklayers' stunning ability to recall minute details about bricks layed 10 years earlier... Assertion that a master bricklayer uses extensive judgement and analysis when laying bricks ... ] >This is not at all the same thing as having a photographic memory >of the face of each brick. The bricklayer is remembering details >he used to make his decisions, so he is remembering the bricks at the >resolution at which for example a master chessplayer would >remember a chess position, rather than the detail of an actual mental >photograph (if such a thing could exist). Interesting to note here that master chess players "instantly" memorize _valid_ chess positions, but have trouble memorizing _invalid_ chess positions, implying that they have a better internal representation for valid chess positions. >The other phenomenon described by McCulloch is the more >well-known example of a person who claims to have photographic >memory. I believe this is nothing more than a person who has >developed a mental exercise which happens to be useful for >providing memory cues. He might even believe that he is viewing >the actual image of the document in his mind, but it is really nothing >more than an internally-generated synthetic image of what he >believes the document looks like Weeellll.... I am a very visual person. I often think by manipulating mental images. I was never partial to algebra -- but geometry has always held a special place in my heart. When they started teaching me how to interpret algebra geometrically, I did much better at it. I enjoy drawing and sketching, and do them well. I have at least partial photographic recall. Example 1: Highschool Civics (U.S. government) class My teacher gave us tests which consisted of topic sentences from the chapter with a key word (subject-noun, important adjective/adverb) missing. We were supposed to fill in the missing word. Each test would have about forty of these questions. I would look at the partial sentence and recall the page on which it appeared. I could tell you which column (the book was printed in double-columns), relative position vertically on the page, and whether it appeared on a left-hand (even-num- bered) or right-hand (odd-numbered) page. The recalled image was not like a rectangular photograph of the entire page set on a black background. It was more like a 4-inch circle centered on the sentence, with the peripheral image all there, but not accessible in detail. I could not recall the page number that the sentence was on unless it appeared near the corner where the page-numbers were printed. Needless to say, I got an A+ in that class. (Now if we could just convince _all_ educators to use this kind of test ... :) Now you may say that I "reconstructed" these images somehow, but from my vantage point, I was recalling a mental photograph. Even if he had actually composed original sentences, I would have done well, because I learned the material, but that would have been accessed from an internal representation of the knowledge -- not from a photograph. Example 2: Psychology Experiment in College No, I was not singled out for a special experiment. Various researchers offered nominal fees for participation as subjects in their experiments. I participated in half a dozen. Most were really sociological experiments, testing the subjects' preconceived notions about things. One was a memory experiment. We were given some whale-tale about "recognizing artists' styles"; told that we would be paid according to how well we scored; put into soundproof booths with a television-screen and two buttons (yes/no). It came in three sessions. Each session consisted of two parts: examples, then selections. First, 10 images were displayed on the screen for about 10 second each. These were "examples" of the "artist's" works. Then 50 images would be flashed on the screen, and we had about 10 seconds to decide whether this image was done by the same "artist". There was an audible beep indicating right/wrong decisions. The first session consisted of red, yellow and blue rectangles of different sizes stacked on top of each other. (Modern art?) I tried to sense a "style" from the 10 examples. There wasn't much to go on. They varied in color order (red,blue,yellow; yellow,red,blue; etc.) They varied in sizes (tall yellow, squat red, square blue; square yellow, tiny blue, large red; etc.) None were aesthetically pleasing. Then came the images. It took me a little while to get the pace. (Ten seconds is not long to make a "style" judgement.) I lost a few early ones by default. Some of the images displayed were from the examples -- those were easy. The others were just more of these random collections of red, yellow and blue rectangles of different sizes and orders -- some _very_ close to the examples. I tried answering "yes" to the duplicates and the close ones, and "no" to the ones that were not close. I got the duplicates right. I got the "not close" ones right. But all the "close" ones were wrong. -- I know, I'm slow. -- Ah Hah! Style, schmyle! They just want to know if I can remember a set of randomly colored/shaped blocks! I got nearly all of the rest right. (Under pressure, with 10 seconds to decide, sometimes you tell your left index finger to press the "yes" button, but your right index finger presses the "no" button instead.) Now I knew the game -- but they changed pitchers. Whereas the first session consisted of three large rectangles generally using the entire screen, the second session consisted of about 50 small, squares (two ibm-pc chr(219) full character-cell blocks), of red, blue and yellow scattered randomly on the screen (except no two squares touched sides, only corners if at all). Ten seconds is not long to "photograph" that much detail. Nevertheless, I had about a 90% hit-rate. In the third session, they threw in their fastball pitcher: the images were 100 single character-cell blocks randomly distributed on the screen. With the increased level of detail, my hit-rate fell to about 80%. For these high-detail sessions, I found that I scored better if I didn't try to think about them. I put myself in a semi-trance state and hit "yes" or "no" without really thinking about it. Afterwards, (getting my money), the researcher was stunned by my 79% overall score (I lost most of the first session before I learned the game.) Needless to say, I was never invited to participate in any more experiments. You may say that I developed a special skill to remember these random collections, but if so, I certainly did it quickly. I don't recall the researcher's name, but if you want verification, I'm willing to cooperate. I don't claim to have perfect photographic recall. But visual images are certainly an important element of whatever my brain uses for recall. I am also sensitive to recall through aromas and even more deeply by tastes. The sense of taste changes over time. If you enjoy a particular food or cigarette or anything, and you consume it constantly for a long period of time, it will not taste exactly the same to you now as it did when you first tasted it. There is a taste in your mouth at all times, but most of the time you ignore it. In fact, most of the time you cannot even perceive it, because it becomes part of the "background noise" that gets filtered out before it reaches the cognitive centers of the brain. This taste-in-the-mouth is primarily the result of your dietary habits for the period. If you're like me, then you go through phases when you're fond of Mexican food, then Itallian, then Chinese, etc.. At any one time, there is a relatively small number of dishes that you eat very regularly. The net result of all this is that there are "archetype" background tastes that are associated with different periods of your life. There are times when I have exceedingly intense instances of recall which actually carry this background taste along with them. There are times when a particular taste will initiate such an intense recall. These instances are quite rare for me, and they always bring along visual images, but they are generally not rooted to a specific instance, but rather to an entire period of my life. I will recall "global" information from the period. My feelings about myself and others at the time. I will _be_ the person that I was for a few moments. The moral of the story? Physical sensations play an integral role in recall. This includes visual images. Some people may be better attuned to their visual circuitry for recall than others. Personally, I recall most things by recalling actual visual "pictures". Sometimes the pictures contain enough detail to extract the necessary information. More often they just help me access the information that I need. Is this photographic recall? I don't measure up to the anecdote that you alluded to, but I do use pictures. ---Paul...