182 HOW THE BRAIN MAKES POTENTIALwhat is needed for defi nition of informational structures, as opposed to
mere assembly of features or other unitary ele ments.
Th e highly plastic brain, in other words, does not operate by fi xed rules
and would not have evolved in the fi rst place if it did. Th e standard model
has genet ically determined operations, with individual diff erences arising
from gene diff erences. What we really have is plastic networks abstracting
informational grammars from good- enough cir cuits pres ent in nearly every-
one. Th ey ensure far more diverse, and adaptable, individual diff erences.
COMPUTER SIMULATIONSOf course, actually analyzing the brain’s use of deep structure is not easy,
given the complexity of naturalistic stimuli and the numbers of cells and
synapses involved. So, as with the molecular biology of the cell, research-
ers increasingly resort to computer modeling. Th e rate of advance has
been enormous. It has been shown how artifi cial neural networks set up
on a computer with modifi able “synapses” can easily abstract the sta-
tistical structure in the inputs. Th e structure becomes assimilated in the
connection weights between the artifi cial neurons, refl ecting the relational
par ameters in experience.
In describing the assimilations in their own studies, Vincent Michal-
ski and colleagues have described networks that use “multiplicative inter-
actions to extract transformation... so that higher layers capture
higher- order transformations (that is, transformations between transfor-
mations).” Moreover, because the networks “encode transformations, not
content of their inputs, they capture only structural dependencies and we
refer to them as ‘grammar cells.’ ”^16 Th e transformations, of course, are
statistical par ameters abstracted from sensory inputs and not built-in (or
innate) rules.
As we saw in chapter 4, such structural grammars have been found in
the intelligent systems of single cells. Th ey have been further crucial for the
integration of cells and tissues in the origins of multicellular organisms.
Th ey fi gure in the remarkable pattern formations of bodily development
and in physiology. Here they are coordinating the ner vous system to deal
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