しつこく書き直し。
dissociation and “dynamic core”
hypothesis
Okano (2019) approached the issue of neurological correlates of personalities in DID with the concept of “dynamic core (DC)” model proposed by Edelman and Tononi (2000) and Edelman (2005). DC represents a neural network system consisting of reentrant neural activity in the thalamo-cortical system which produces conscious existence (Edelman, Gally, Baars, 2011). In that network, bidirectional frequent information exchange in DC occurs, “strikes a optimal balance between segregation and integration on function.” (Edelman, Tononi, 2000, p.136)
What
is particularly relevant about their theory is their concept on in the mind and
consciousness. They especially stress the singleness of mind that each DC
harvors. Following W. James (1890) and C. Sherrington (1906)’s statement on the unitary and private
nature of consciousness being its foremost property, Edelman and Tononi (2000,
p.24) consider that “a conscious state is unified and integrated which simply
means that the whole experienced conscious state is always more than the sum of
its parts”. They propose a hypothetical N-dimensional neural space (N being a
large number representing the number of neural groups involved) and each
experience corresponds to a single point.
From
their standpoint of Integrated Information Theory, Tononi and Koch states the
same point as follows:
Consciousness
is unified; each experience is irreducible to non-interdependent subsets
of phenomenal distinction. (Tononi and Koch, 2016, p.6,
underline added by this author)
The
concept of DC presented by these authors give us a robust tool to consider
whether personalities can be partial and fragmented or irreducible and unified.
According to them, if a personality has an experience or a qualia, this attests
the wholeness of the neural network or DC involved. Based on their DC model, we
could assume that if a personality has an experience of something, that is
enough to have an integrated mind, if not altogether elaborated and sophisticated.
In fact, there could not be any partial or fragmentary consciousness
whatsoever, as a consciousness presumes an integrated N-dimentional neural space.
There
is another point to stress, which is that there is enough reason to believe
that the theory of DC can be applied to DID, as Edelman and Tononi themselves
suggest multiple existence of DCs. In their Information Integration
Theory (IIT), Tononi and Koch proposes multiple consciousness, stating that
IIT allows for the possibility of two or more complex within a single system.
It is to be reminded, however, that these consciousnesses are not partial or
fragment ; they stand alone as independent IIT. This view was echoed by Edelman
and Tononi who propose that mental disorders, such as dissociative disorders
and schizophrenia “should be reflected in abnormalities of the DC and
may result in the formation of multiple cores.”(Edelman, Tononi,
2000, p154, underline added by this author.)
Thus,
DC hypothesis practically anticipated two points that we dealt with so far;
Uniqueness and wholeness of the
personality, and their possible multiple existence in a condition such as DID.
