These are excerpts and elaborations from my book "The Nature of Consciousness"
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The Reconstructive Memory A startling feature of our
memory is that it does not remember things the way we perceived them. Something
happens between the time we see or hear a scene and the time that the scene
gets stored in memory. I can tell you the plot of a
novel even if i cannot tell you a single sentence that was in the novel. If I
tell you the plot twice, i will use different words. It would be almost
impossible to use the same words. Nobody can remember all the sentences of a
book, but everybody can remember what the "story" is. Compare with a computer. A
computer can memorize the book page by page, word by word. Our memory does not
memorize that way. It is not capable of memorizing a book page by page, word by
word. On the other hand, it is capable of so many other things that a computer
is not capable of. For example, we can recognize a plot, told by somebody else,
as the plot of the same novel. That person's version of the plot and our
version of the plot probably do not share a single sentence. Nonetheless, we
can recognize that they are the same story. No computer can do that (yet), no
matter how big its memory is. Size is obviously not the solution. In the 1930s the British
psychologist Frederic Bartlett developed one of the earliest
models of memory. Bartlett studied how memory "reconstructs" the essence of a
scene. We can easily relate the plot of a movie, and even discuss the main
characters, analyze the cinematography, and so forth, but we cannot cite verbatim
a single line of the movie. We stored enough information about the movie that
we can tell what it was about and perform all sorts of reasoning about it, but
we cannot simply quote what a character said at one point or another. What Bartlett discovered is that events are
not stored faithfully in memory: they are somehow summarized into a different
form, a "schema". Individuals do not passively record stories
verbatim, but rather actively code them in terms of schemas, and then can
recount the stories by retranslating the schemas into words. Each new memory is
categorized in a schema which depends on the already existing schemas. In practice, only what is strictly necessary
is added. When a memory must be retrieved, the corresponding schema provides the
instructions to reconstruct it. That is the reason why recognizing an object is
much easier in its typical context than in an unusual context. The advantage of the
reconstructive memory is that it can fit a lot of information in a relatively
narrow space. Any memory that tried to store all the scenes, text and sound of
a movie would require an immense amount of space. But our memory stores only
what is indispensable for reconstructing the plot and other essential features
of the movie, thereby losing lots of details but at the same time saving a lot
of space. Back to the beginning of the chapter "Memory" | Back to the index of all chapters |
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