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

it—as an affordance, a set of possible behaviors” (Metzinger, 2009, p. 167). In short,
while embodied and classical cognitive scientists seek implementational evidence,
they are likely to interpret it very differently.
The materialism of embodied cognitive science leads naturally to proposals
of functional architectures. An architecture is a set of primitives, a physically
grounded toolbox of core processes, from which cognitive phenomena emerge.
Explicit statements of primitive processes are easily found in embodied cognitive
science. For example, it is common to see subsumption architectures explicitly
laid out in accounts of behaviour-based robots (Breazeal, 2002; Brooks, 1999, 2002;
Kube & Bonabeau, 2000; Scassellati, 2002).
Of course, the primitive components of a typical subsumption architecture are
designed to mediate actions on the world, not to aid in the creation of models of
it. As a result, the assumptions underlying embodied cognitive science’s primitive
sense-act cycles are quite different from those underlying classical cognitive science’s
primitive sense-think-act processing.
As well, embodied cognitive science’s emphasis on the fundamental role of an
agent’s environment can lead to architectural specifications that can dramatically
differ from those found in classical cognitive science. For instance, a core aspect
of an architecture is control—the mechanisms that choose which primitive operation
or operations to execute at any given time. Typical classical architectures will
internalize control; for example, the central executive in models of working memory
(Baddeley, 1986). In contrast, in embodied cognitive science an agent’s environment
is critical to control; for example, in architectures that exploit stigmergy
(Downing & Jeanne, 1988; Holland & Melhuish, 1999; Karsai, 1999; Susi & Ziemke,
2001; Theraulaz & Bonabeau, 1999). This suggests that the notion of the extended
mind is really one of an extended architecture; control of processing can reside outside
of an agent.
When embodied cognitive scientists posit an architectural role for the environment,
as is required in the notion of stigmergic control, this means that an agent’s
physical body must also be a critical component of an embodied architecture. One
reason for this is that from the embodied perspective, an environment cannot be
defined in the absence of an agent’s body, as in proposing affordances (Gibson, 1979).
A second reason for this is that if an embodied architecture defines sense-act primitives,
then the available actions that are available are constrained by the nature
of an agent’s embodiment. A third reason for this is that some environments are
explicitly defined, at least in part, by bodies. For instance, the social environment
for a sociable robot such as Kismet (Breazeal, 2002) includes its moveable ears, eyebrows,
lips, eyelids, and head, because it manipulates these bodily components to
coordinate its social interactions with others.
256 Chapter 5