tony@rlgvax.UUCP (Tony Stuart) (11/02/88)
On the way into work this morning I was stopped at a light near an office building. They were washing the windows using a large crane. This lead me to think about the time that a light was out in CCI's sign and they used a crane to replace it. I began to wonder whether they replace all the lights while they have the crane up or just the one that is out. Maybe it depends on how close the lights are to the end of their rated life. This got me thinking about the lights in the vanity at home. Two of the four have blown in the last couple of weeks. I remarked to Anne how it was interesting that lightbulbs do start to blow out at around the same time. This lead me to suggest that we remember to replace the blown out lightbulbs. The point is that an external stimulus, seeing the men wash the windows of the building, lead to a problem to solve, replacing the lights in the vanity. I have no doubt that if I had replaced those lights already then the train of thought would have continued until I encountered a problem that needed attention. The mind seems optimized for problem solving and perhaps one reason for miscellaneous ramblings is that they uncover problems. On a similar track, I have often thought that once we find a solution to a problem it is much more difficult to search for another solution. Over evolutionary history it is likely that life was sufficiently primitive that a single good solution was sufficient. The brain might be optimized such that the first good solution satisifies the problem seeking mode and to go beyond that solution requires concious effort. This is an argument for not resorting to a textbook as the first line of problem solving. The textbook is sure to give a good solution but perhaps not the best. With the textbook solution in mind it may be much more difficult to come up with an original solution that is better than the textbook one. For this reason it is best to try to solve the problem internally before going to some external device. There may also be some insite into how to make computers think. Lets say I designed my computer to follow trains of thought and at each thought it looked for unresolved questions. If there were no unresolved questions it would continue onto the next linked thought. Otherwise it would look for the solution to the problem. If the search did not turn up the information in memory it would result in the formation of a question. Anne suggests that these trains of thought are often triggered by external stimulae that a computer would not have. She says that we live in a sea of stimulae. I've often wondered about the differences between short term and long term memory. Here's a computer model for it. Assume that short term memory is information stored as sentences and long term memory is information stored in data structures with organized field name/field value/relationship links. Information is initially stored in the sentence based short term memory. In a background process, or when our minds are otherwise idle, a task searches through the short term memory for data that might resolve questions (holes) in the long term memory. (Which is searched I don't really know.) This information in the short term memory is then appropriately cataloged in the long term memory. Another task is responsible for purging sentences from the short term memory. It could use a first in-first out or more likely a least frequently used algorithm. A side effect of this model is that information in short term memory cannot be used unless there is a hole in the long term memory. This leads to problems in bootstrapping the process, but assuming there is a solution to that problem, it also models behavior that is present in humans. This is the case of feeling that one hears a word or phrase a lot after he knows what it means. Another part of the side effect is that one cannot use information that he has unless it fits. This means that it must be discarded until the long term memory is sufficiently developed to accept it. -- Anthony F. Stuart, {uunet|sundc}!rlgvax!tony CCI, 11490 Commerce Park Drive, Reston, VA 22091
dharvey@wsccs.UUCP (David Harvey) (11/10/88)
In article <1020@rlgvax.UUCP>, tony@rlgvax.UUCP (Tony Stuart) writes: > > On a similar track, I have often thought that once we find a > solution to a problem it is much more difficult to search for > another solution. Over evolutionary history it is likely that > life was sufficiently primitive that a single good solution was > sufficient. The brain might be optimized such that the first > good solution satisifies the problem seeking mode and to go > beyond that solution requires concious effort. This is an > argument for not resorting to a textbook as the first line of > problem solving. > Usually, advances by humans comes on top of what has gone before, not inside a vacuumn. I realize that this is not exactly what you intended to present here, but it comes out that way regardless. As to the better solution, that usually is the way it happens. For examples, consider Keppler seeing inconsistencies between the model proposed by Aristotle and the calculations (just think how much faster his work would have been with a computer!) he made. This of course prompted him to devise a new model. Galileo and Newton also saw inconsistencies between what was commonly believed and the effects of gravity, ie, that accelaration was a constant not affected by the mass of the object. Einstein saw inconsistencies even in this model and developed the theory of relativity. In other words, these people KNEW the textbook solutions. What characterized them as being different from the masses is that they had the tenacity to reject the 'textbook' solution when a better model came to mind. Just how this can be emulated in a computer is not that easy. The only thing that can be said is that inconsistencies of data with the rule base must allow for a retraction of the rule and assertion for new ones. > > I've often wondered about the differences between short term > and long term memory. > Don't forget to include the iconic memory. This is the buffers so to speak of our sensory processes. I am sure that you have saw many aspects of this phenomenon by now. Examples are staring at a flag of the United States for 30 seconds, then observing the complementary colors of the flag if you then look at a blank wall (usually works best if the wall is dark). There are other ways of observing that there really is such a thing as iconic memory, but these must be performed in a lab setting with blind studies. I helped perform one of these at the University of Utah. How do you implement this into your model? I don't know, and I doubt anyone else does either since much research must yet be done to see the relationship between iconic, short term, and long term memory. Also, the differences between conscious and subconscious memory processes must be considered. Much of this iconic information makes its way into memory via the subconscious track, which I would cite as evidence the studies being performed by various researchers in Psychology. You have observed the linking process that takes place in our long term memories. This is of course a dandy model until you begin to look at some of our links. They have some of the following characteristics: [1] Some of them seem to link together totally randomly. I am sure you have observed the phenomenon that some of your own links are rather mysterious, where the items are not logically related at all. Nevertheless most of them ARE logically related. Maybe we can randomly throw in a time frame for the other links. This of course supposes that we can prove that time is indeed the model that determines them. By time I mean close time proximity for the linked structures. [2] There are a massive amount of them that we search, sometimes in vain. As witness to this consider the tip-of-the-tongue phenomenon that we are cursed with. I am sure that we all have experienced it. Perhaps those with photographic memory are not cursed with it, but not being so blessed I would not know. Also, some of these sturctures unlink with time and fall away. This last tidbit of course goes against the conventional textbook wisdom that they stay there forever. [3] Since there are so many, we MUST use parallel processing to search them all. Also realize that they are massive in nature, perhaps to the point of exceeding most mass storage devices (disks) in use today. The short term memory does not necessarily have to have a different data representation. It still has a linking type nature. The main difference I see between the two is that short term memory has far fewer links than long term. What needs to be done is to study why and how this short term memory links up with the long term memory. Perhaps frequency of use could be researched as the causal factor. Initially, we must establish a linking base for these short term facts to attach themselves to. As I see it there are several ways it will link into the established long term memory. First of course is the logical link. Another would be a time frame link where what was considered immediately before or after would be what we attach it to. Also, since it is a well established fact that we can chain things much better via poetry than prose, rhythm and actual morphemes must be considered for chaining. > A side effect of this model is that information in short > term memory cannot be used unless there is a hole in the long > term memory. This leads to problems in bootstrapping the > process, but assuming there is a solution to that problem, it > also models behavior that is present in humans. This is the > case of feeling that one hears a word or phrase a lot after > he knows what it means. Another part of the side effect is > that one cannot use information that he has unless it fits. > This means that it must be discarded until the long term > memory is sufficiently developed to accept it. > The problem is that there are more than enough holes for something to be fit in. Inconsistency seems to thrive in human beings. It is only when new information conflicts enough with old that we attempt to rationalize the two conflicting 'facts'. Unless the new information outweighs the old in some way it never replaces it. It can and does coexist with the old in tension in many cases. It is only when we reach the discomfort level that we attempt to resolve the disparity of the two in our fact base. Well, now that I have given enough for Psychologists and AI researchers to work on for the next 50 years (:-) I can go back to such mundane chores as homework and sleeping. Hmm, are we going to model the activity of sleeping in our machine? dharvey@wscss The only thing you can know for sure, is that you can't know anything for sure.
lammens@sunybcs.uucp (Johan Lammens) (11/14/88)
In article <778@wsccs.UUCP> dharvey@wsccs.UUCP (David Harvey) writes: >Don't forget to include the iconic memory. This is the buffers >so to speak of our sensory processes. I am sure that you have >saw many aspects of this phenomenon by now. Examples are staring >at a flag of the United States for 30 seconds, then observing the >complementary colors of the flag if you then look at a blank wall >(usually works best if the wall is dark). [...] Perhaps this question is a witness to my ignorance, but isn't the phenomenon you describe a result of the way the retina processes images, and if so, do you mean to say that iconic memory is located in the retina? ------------------------------------------------------------------------------ Jo Lammens Internet: lammens@cs.Buffalo.EDU uucp : ..!{ames,boulder,decvax,rutgers}!sunybcs!lammens BITNET : lammens@sunybcs.BITNET
paul@hpcehfe.HP.COM (Paul Sorenson) (11/22/88)
/ hpcehfe:comp.ai / lammens@sunybcs.uucp (Johan Lammens) / 7:42 am Nov 14, 1988 / In article <778@wsccs.UUCP> dharvey@wsccs.UUCP (David Harvey) writes: >Don't forget to include the iconic memory. This is the buffers >so to speak of our sensory processes. I am sure that you have >saw many aspects of this phenomenon by now. Examples are staring >at a flag of the United States for 30 seconds, then observing the >complementary colors of the flag if you then look at a blank wall >(usually works best if the wall is dark). [...] Perhaps this question is a witness to my ignorance, but isn't the phenomenon you describe a result of the way the retina processes images, and if so, do you mean to say that iconic memory is located in the retina? ------------------------------------------------------------------------------ Jo Lammens Internet: lammens@cs.Buffalo.EDU uucp : ..!{ames,boulder,decvax,rutgers}!sunybcs!lammens BITNET : lammens@sunybcs.BITNET ---------- No, you are correct and the example is wrong. Color after images like those described are NOT instances of iconic memory. Iconic memory is a theoretical stage of memory, patterned after short term memory, that functions as a limited capacity storage buffer for sensory information (just as STM serves as a limited [7 + or - 2] capacity storage for information prior to its being encoded into "Long Term Memory"). Presumably, Iconic memory preceeds STM, which preceeds LTM, which preceeds....(forgetting, making it up,?).