Mind, Body, World- Foundations of Cognitive Science, 2013a

Indeed, the interactions between a universal Turing machine’s machine head
and its ticker tape are decidedly of the sense-act, and not of the sense-think-act,
variety. Every possible operation in the machine table performs an action (either
writing something on the ticker tape or moving the tape one cell to the right or to
the left) immediately after sensing the current symbol on the tape and the current
state of the machine head. No other internal, intermediary processing (i.e., thinking)
is required.
Similarly, external scaffolding was characteristic of later-generation relay computers
developed at Bell labs, such as the Mark III. These machines employed more
than one tape reader, permitting external tapes to be used to store tables of precomputed
values. This resulted in the CADET architecture (“Can’t Add, Doesn’t
Even Try”) that worked by looking up answers to addition and other problems
instead of computing the result (Williams, 1997). This was possible because of a
“hunting circuit” that permitted the computer to move to any desired location on
a punched tape (Stibitz & Loveday, 1967b). ENIAC employed scaffolding as well,
obtaining standard function values by reading them from cards (Williams, 1997).
From an engineering perspective, the difference between externally controlled
and stored program computers was quantitative (e.g. speed of processing) and not
qualitative (e.g. type of processing). In other words, to a computer engineer there
may be no principled difference between a sense-act device such as a universal
Turing machine and a sense-think-act computer such as the EDVAC. In the context
of cognitive control, then, there may be no qualitative element that distinguishes
the classical and embodied approaches.
Perhaps a different perspective on control may reveal sharp distinctions
between classical and embodied cognitive science. For instance, a key element in
the 1945 description of the EDVAC was the component called the central control
unit (Godfrey & Hendry, 1993; von Neumann, 1993). It was argued by von Neumann
that the most efficient way to control a stored program computer was to have a
physical component of the device devoted to control (i.e., to the fetching, decoding,
and executing of program steps). Von Neumann called this the “central control
organ.” Perhaps it is the notion that control is centralized to a particular location or
organ of a classical device that serves as the division between classical and embodied
models. For instance, behaviour-based roboticists often strive to decentralize
control (Brooks, 1999). In Brooks’ early six-legged walking robots like Attila, each
leg of the robot was responsible for its own control, and no central control organ
was included in the design (Brooks, 2002).
However, it appears that the need for a central control organ was tied again
to pragmatic engineering rather than to a principled requirement for defining
information processing. The adoption of a central controller reflected adherence to
engineering’s principle of modular design (Marr, 1976). According to this principle,
Marks of the Classical? 331