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Article 6545 of comp.ai.philosophy:
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>From: bill@nsma.arizona.edu (Bill Skaggs)
Newsgroups: comp.ai.philosophy
Subject: Re: Memory and store/retrieve.
Message-ID: <BILL.92Aug2121827@ca3.nsma.arizona.edu>
Date: 2 Aug 92 19:18:27 GMT
References: <1992Jul30.152320.2247@puma.ATL.GE.COM> <1992Jul31.160209.26718@mp.cs.niu.edu>
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	<1992Aug1.132812.12457@mp.cs.niu.edu>
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Organization: ARL Division of Neural Systems, Memory and Aging, University of
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In-Reply-To: rickert@mp.cs.niu.edu's message of 1 Aug 92 13: 28:12 GMT

rickert@mp.cs.niu.edu (Neil Rickert) writes:

    >The problem with episodic memory is that it is so difficult to
    >measure.  It is, for example, very difficult to tackle that most basic
    >question: "if we did not have language, what would episodic memory be
    >like?"

I agree that it's difficult, but it isn't quite impossible.  For
psychologists trying to study episodic memory in animals, the most
commonly used experimental paradigms are variants of "delayed match to
sample", in which the animal is shown an object, then after a delay is
presented with the same object together with another one, and must
choose the one it saw before in order to obtain a reward.

   >The appearance of discrete items in the memory is then mostly a
   >reflection about how language works, rather than about how memory
   >works.

The real question, I think, is whether the brain uses attractor neural
networks (such as, for example, Hopfield nets) for memory.  If it
does, then creation of a new attractor is naturally described as a
"storage" operation, and convergence to an existing attractor is
naturally described as "retrieval".  My work on the hippocampus has
led me to believe that it is an attractor neural network, used to
store episodic memories for a duration of weeks to months.  (This
theory was first proposed by Marr in 1971.)  Your intuition, I guess,
is that memory works differently.  But maybe we can both agree that in
the end it comes down to an empirical question, and there is not yet
enough data to really be sure either way.

	-- Bill


