Brain Architecture for an Intelligent Stream of Consciousness - Brain Theory from a Circuits and Systems Perspective - page 18

memory search in the background for forgotten information such that forgotten
things sometimes appear in one's consciousness minutes or hours later.
Mental confusion might result from multiple returns for a given set of cues, a
common situation when an inadequate number of cues are used to call forth
memories, and many different images are returned at once. For survival, and
fundamental to any system of associative memory, human memory included, is
multiple match resolution. First of all, it must prevent basic memory breakdown
because of multiple returns on the same neural paths. Secondly, a basic recall
referee is essential, including a processor that assigns priority to memory returns
and then chooses the highest priority image to be gated into conscious STM.
A basic recall referee is proposed in this topic.
Decisions are important to a successful life form, and are shown to be choices
made mainly by the brain, and not the person involved, based on past experiences
logged in LTM. However, other types of decisions are only influenced by past
memories, but not determined by past memories, such as random decisions. These
are important when guessing a solution to a mysterious problem, for instance, as
discussed below.
It continues to be a mystery how a person achieves inspired choices, such as
common sense, truth judgment, intuition, and artistic appraisal. These seem to
differ significantly from decision based logically on past memories, and decisions
based on a random variable. In view of this mystery this topic leaves open the
possibility of subneural computing of some sort, possibly quantum computing, or
quantum-like computing without an actual quantum system, since a quantum might
be difficult to achieve biologically. Quantum computing, however unlikely it seems
to skeptics, is too important to ignore completely, and so is introduced below and
expanded in later chapters.
Classification of Neural Signals
There are many types of signals in neurons and synapses; the most important are
illustrated in Fig. 2.1 .
The weak synapse is one that results in a single pulse in the dendrite. Single
pulses are needed in a practical system for accurate timing, as explained in
subsequent chapters. For example, single pulses are needed in those situations in
which sequential logic is necessary, for instance, when there are multiple returns
from associative memory arriving sequentially that need to be parked in separate
holding areas.
In contrast, a regular synapse produces a pulse burst of about ten pulses and is
often used for neural logic. Neural logic here refers to neurons that compute
Boolean combinational logic, equivalent to a network of AND, OR, and NOT
gates. Included under logic are buffers and delay lines with a simple connective
purpose.