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and at the cognitive level this means some similar functions. After this, flexible elements
with new functions start interacting with each other also exchanging its characteristics. It is
reasonable to suggest that the more similar characteristics shared by some elements, the
more probability of its interactions. For example, if neuron A has a synapse with neuron B
then a probability that the discharge of neuron A results in the discharge of neuron B seems
more than the same probability for two neurons that do not share a common synapse. The
relationship between the similarity of elements and the probability of its interaction is the
substantiation of the criterion of minimal construction costs.
It is reasonable to expect that owing to interactions between elements, the resemblance of
elements can be increased. As a result, a pattern joining many elements with similar
characteristics gradually emerges and this pattern becomes sustainable. This indicates that
the construction of a new process is completed. Although, elements in the pattern have
something in common but there are some distinctions among them and this is a prerequisite
for the distributed representation for the goal and means.
It is suggested each pattern can be considered as a construction with two interconnected
components: one component is responsible for the goal and the other for the means. Such a
separation is based on the idea that some neurons in the pattern have mainly local
connections within the prefrontal cortex (they comprise the goal component). Other neurons
in the pattern are linked to other brain structures (those are the means component). Because
the activity of neurons within the PFC is likely more reverberatory and self-sustained than
that of neurons linked to other structures, the goal component can be more stable and
persistent than the means component.
Once a goal-directed process is constructed, some activation from the means component
propagates to other brain structures, which are able to carry out the process, and its
performance is initiated (B.T. Miller& D'Esposito 2005). Simultaneously, the components
interact with each other; this stabilizes the means component while it receives feedback
because of performing the process. Therefore, the fact that the process pursues the goal is a
result of the stability in the goal component produced by self-sustainable characteristics of
the PFC. It is possible to say that goal-directed processes are self-sustained gates, which
amplify appropriate information and diminish inappropriate one. The components are
constructed together but their architecture is slightly different. The functioning of
components gradually increases these differences and this change may be a basis for an
autonomous representation of goals and means in consciousness.
As is emphasized above I do not suggest that the brain includes a special comparator,
which monitors when the outcome of the process meets the goal, and then turns the
process off. Simply, with the achievement of the goal, the current situation undergoes
changes, thus not being able to support the ongoing process with appropriate
information. To meet novel requirements of the situation, the construction of another
process begins. Probably, more stable processes at a higher level of the goal-directed
hierarchy supervising short-term ones also participate in the completion of the ongoing
process. Free neural ensembles again become flexible components of the blackboard. It
can be hypothesized that a real goal-directed process is a hierarchical multilevel structure
joining many of such ideal processes.