Eq. 3.\(\psi\left(\text{PCC}\right)=\sum{MI(}X_{j}^{k};PCC-X_{j}^{k})\)
Footnote 6. Edelman
and Tononi offer a similar measure (Edelman and Tononi 2001, p. 130), described as
“neural complexity,” but neither this measure nor their theory more
generally have a direct bearing on phenomenal content. This is the
case because despite their assertions that their theory explains qualia as well as the workings of the brain, their theory is expressly
materialist in nature and offers no link between functional
explanations of the brain and phenomenal content/experience. They do not offer
any psychophysical laws or bridging principles between the physical
and phenomenal realms.
PI and CI will entail complicated calculations in any biological
structure because of the physical complexity involved in any biological
structure. I discuss this limitation further below.
Looking again to the fruit fly as an example for applying the framework,
the fruit fly’s brain is mostly devoted to visual processing and
contains about 100,000 neurons. (Rein, K., et al., (2002).
Chiang, et al., (2010)). If we assume an average 100 dendrites for
each neuron, we have about 10,000,000 synapses, which are the internal
connections quantified by CI in this case. We would also, to be
comprehensive, have to determine what neural subunits exist in the fly
brain and quantify interconnections between neural subunits in addition
to the simple internal connectivity of all synaptic connections; these
data are steadily being discovered in work on the various
“connectomes” in different organisms. We would also need to consider
other relevant information flows at the subneuronal level, as explored
by Craddock et al. 2017 and Hameroff and Penrose 2014, and other
publications. The complexity in quantifying these levels of connectivity
is daunting.
For the purposes of this example, however, we can translate this
calculation to an estimated normalized CI value of 4. Again, the
specific value doesn’t particularly matter at this time since it’s only
an example to show how the framework works.