Long-Term Memory Neural Circuits, Fast and Precise - Brain Theory from a Circuits and Systems Perspective - page 136

Fig. 8.8 Memorization enable circuit example for two rehearsals

amounts of memorization, topics full, that is apparently permanent. Therefore it is
assumed below that memorization is instant and permanent.
A blank word must have access to all possible attributes since, as is common
experience anything can be memorized. To reach each and every attribute, the same
circuits as for search and recall are assumed used for memorization.
Once a memory is formed, a vast number of possible attributes are unused, and
never will be used in conjunction with a given word and its image. Because of a
phenomenon known as neural plasticity unused neurons will reconstitute them-
selves as part of some other function. Perhaps they will serve in new blank words.
This suggests that words of long-term memory will be sparse, retaining only
essential attributes.

Memorization Enable

Memorization in the above system is triggered by a signal termed Memorization
Enable which is sensitive to recurring images in conscious STM, under specific
conditions: Memorization Enable is forced true with a digital filter whose output
goes true for a periodically repeated input image or action in consciousness. This
might be accomplished as in the example of Fig. 8.8 which requires two repeats
before memorization. At the same time there must be no matches (NoHit

¼ True)

from long-term memory. That is, the image must not already be in memory.
So if a given image is not in long-term memory and appears in conscious STM
repeatedly, it will be committed automatically to long-term memory. Note that a
digital comparator is a variation on the magnitude comparator discussed under
priority comparison in a previous chapter.