ULTIMATE COMPUTING - Quantum Consciousness Studies

From Brain to Cytoskeleton 73
Figure 4.3: Brain memory bank based on “conventional” notions of dendritic
spine synapses. Input lines (B 1-3 ) are axons which branch and synapse on
dendritic spines (E) connected to output lines (C). “File dump lines” (A, d 1-3 ) direct
spine activities to “copy” or “dump.” Such a configuration allows each spine to
hold about 3 bits of information, remarkably low when compared to the capacities
of biomolecules such as DNA or microtubules. Cytoskeletal activities within
dendritic spines may contribute. By Paul Jablonka.
4.3.5 Synaptic Mechanisms of Learning and Memory
Memory processes have traditionally been divided into two classes; short
term and long term. Short term memory, or working memory, is apparently how
we remember telephone numbers from the time we look them up in the directory
until we dial them. Long term memory or reference memory is used in recording
information for long term reference. Short term or working memory is thought to
be of relatively small capacity with a maximum of 5 to 9 items at any one time. It
is labile and easily disrupted if attention is diverted and it automatically erases
within minutes. Continual verbal rehearsal counteracts erasure and re-enters the
contents as long term memory. Once laid down, long term memory can endure for
a long time—perhaps an individual’s lifetime. Long term memory has a large
capacity, and difficulty in recalling specific items arise not because memory
traces fade, but rather because their address is lost. Well practiced access routes to
long term memory items include “nmemonics,” easily remembered reference
clues. Items which have been stored and then not used will become increasingly
difficult to recall. Once they are retrieved, such seemingly forgotten memories
become again accessible. Conventional wisdom has held that items become stored
in long term memory only after they have been first held in short term memory.
This is a process known as consolidation which is thought to require a finite