Page 93 - Artificial Intelligence in the Age of Neural Networks and Brain Computing

1. Dichotomies 81

mind, mostly as functionalists, as well as by biologically oriented thinkers. Bickle
[7] suggested that philosophers should adopt a “ruthless reductionist” approach by
learning molecular and cellular neurobiology. The multiple realizability thesis
(say Ref. [8]) emphasizes importance of hierarchical organization from molecules
to social interactions. Any nonreductionist physicalist theory should tell something
about “downward causation.”
“Downward causation” is a notion which suggests that higher level systems
influence lower level configurations. Classical molecular biology deals exclusively
with upward mechanisms of causation (from simple events to more complicated
ones) and neglects completely the explanatory role of downward causation. Since
we know that both molecules and genes form complicated networks or feedback
loops, it is difficult to defend the concept that there is nothing else in science than
a linear chain of elementary steps leading from cause to effects [9].
The methodologically successful reductionism is never complete, as Popper
suggested: there is always some “residue” to be explained.
“Downward causation,” that is, the mental agents can influence the neural func-
tioning was suggested by Sperry [10,11]. Sperry was criticized by stating that the
postulate that physiological mechanisms of the brain are directly influenced by
conscious processes is unclear [12,13]. Alternatively, it was cautiously suggested
by Ja ´nos Szenta ´gothai in a somewhat overlooked paper that the nervous system
can be considered as being open to various kinds of information, and that there
would be no valid scientific reason to deny the existence of downward causation,
or more precisely, a two-way causal relationship between brain and mind [14],
see Fig. 4.2.
On some similar way, Campbell and Bickhard [15] argue that “organization
principles” should have some priorities since our best physics tells us that there
are no basic particulars, only fields in process.” The relationship among free will,
downward causation, and the emergence of complexity is discussed in an edited
book from a broad perspective [16].
Twenty years ago it was argued [17] that the philosophical tradition of hermeneu-
tics, that is, the “art of interpretation,” which is a priori neither monist nor dualist,
can be applied to the brain. Even more is stated: on one side, the brain is an “object”
of interpretation, on the other side, it is itself an interpreter: the brain is a hermeneu-
tic device. In similar vein, in The Metaphorical Brain 2, Michael Arbib [18] argued
that our theories of the brain are metaphors, while the brain itself represents the
world through schemas, which may themselves be viewed as metaphors.

1.2 THE BRAIN-COMPUTER ANALOGY/DISANALOGY
Second, the problem of the brain-computer analogy/disanalogy was a central issue
of early cybernetics, in a sense revived by the neurocomputer boom. More precisely,
the two sides of the metaphor (“computational brain” vs. “neural computer”) should
be the subject of a brief discussion. There are several different roots of the early opti-
mism related to the power of the brain-computer analogy. We recall two of them.