Not that I'm calling anyone stupid. That's a reference, of course, to Clinton campaign manager James Carville's "It's the economy, stupid." It's a call to refocus the emphasis. Here we're talking cognitive science and the relation between computational theories and embodied theories of the mind and the need to refocus our emphasis on information processing.
I contend that embodied theories are, under the hood, computational (i.e., information processing) theories and that the embodied folks are mischaracterizing computational theories. Or at the very least they using one such theory (~Fodorian philosophy) as representative of the whole cognitivist/computational mindset. In fact, it’s always been about
information and how it gets processed.
It doesn’t matter how you process the information—neurons, electronic
switches, gears, pumps—it just matters that information (patterns of physical stuff
that correlate with the state of the world) is used in such a way as to guide
behavior. To try to make this clear, here’s an excerpt from The Myth of Mirror Neurons discussing some early conceptions of cognitive psychology.
Psychologist Ulric Neisser, who
literally named the field and wrote the book on it with his 1967 text, Cognitive Psychology, defined the
domain of cognition this way:
“Cognition” refers to all the processes by which the sensory
input is transformed, reduced, elaborated, stored, recovered, and used. … Such terms as sensation, perception, imagery, retention, recall, problem-solving, and thinking, among many others, refer to
hypothetical stages or aspects of cognition.[1]
Neisser’s table of contents
underlined his view that cognition was not limited to higher-order
functions. His volume is organized into
four parts. Part I is simply the
introductory chapter. Part II is called
“Visual Cognition” and contains five chapters.
Part III is “Auditory Cognition” with four chapters. Finally, Part IV deals
with “The Higher Mental Processes” and contains a single chapter, which Neisser
refers to as “essentially an epilogue” with a discussion that is “quite
tentative”. He continues,
Nevertheless, the reader of a book called Cognitive Psychology has a right to
expect some discussion of thinking, concept-formation, remembering,
problem-solving, and the like…. If they take up only a tenth of these pages, it
is because I believe there is still relatively little to say about them….
Most scientists today working
on perception or motor control, even at fairly low levels, would count their
work as squarely within the information processing model of the mind/brain and
therefore within Neisser’s definition of cognition. Consider this paper title, which appeared recently
in a top-tier neuroscience journal: Eye
Smarter than Scientists Believed: Neural Computations in Circuits of the Retina. If anything in the brain is a passive
recording device (like a camera) or a simple filter (like polarized sunglasses)
it’s the retina, or so we thought. Here’s how the authors put it:
Whereas the conventional wisdom treats the eye as a simple
prefilter for visual images, it now appears that the retina solves a diverse set
of specific tasks and provides the results explicitly to downstream brain areas.[2]
Solves a diverse set
of specific tasks and provides the results… sounds like a purpose-built bit
of programing—in the retina! We observe
similar complexity in the control of simple movements, such as tracking an
object with the eyes, an ability that is thought to involve a cerebral
cortex-cerebellar network including more than a half dozen computational nodes
that generate predictions, detect errors, calculate correction signals, and
learn.[3]
---end excerpt--
My former post doc advisor, Steve Pinker, who is
arguably today’s champion of the computational theory of mind and a staunch
defender of "symbolic processing" (it's not what you think!) reinforces the broad definition of computation
as just being about information processing:
the function of the brain is information processing, or computation… Information consists of
patterns in matter or energy, namely symbols, that correlate with states of the
world. That’s what we mean when we say that something carries information. A
second part of the solution is that beliefs and desires have their effects in computation—where
computation is defined, roughly, as a process that takes place when a device is
arranged so that information (namely, patterns in matter or energy inside the
device) causes changes in the patterns of other bits of matter or energy, and
the process mirrors the laws of logic, probability, or cause and effect in the
world. [4]
Notice that symbols are defined simply as patterns in matter
or energy, not x’s and y’s in lines of code. The patterns
“represent” (i.e., correlate with) states of the world. This constitutes information
that brains can make use of by changing the patterns, e.g., taking interaural
time difference and using that information to guide head movement. This is why
the embodied movement is so puzzling to me.
It’s fundamentally no different that the computational theory of
mind. Does the body contribute something to information processing? Of course! The brain evolved with the body to solve survival problems. The body shapes the input to the brain. But that doesn't mean that the brain isn't processing information.
1 Neisser,
U. (1967) Cognitive psychology.
Appleton-Century-Crofts
2 Gollisch, T. and Meister, M. (2010) Eye smarter than
scientists believed: neural computations in circuits of the retina. Neuron 65, 150-164
3 Wolpert, D.M., et al. (1998) Internal models in the
cerebellum. Trends in Cognitve Sciences
2, 338-347
4
Pinker, S. (1999) How the mind works. Annals of the New York
Academy of Sciences, 882:119-127.