Can Cognitive Neuroscience Tell Us Anything About the Mind?
Cognitive neuroscience –
essentially brain scanning – has become all the rage in psychology and related
fields. Given the headlong rush by, well, practically everyone, into cognitive
neuroscience I still entertain a quaintly unfashionable stance: I’m sceptical.
My scepticism is not total though, many cognitive neuroscientists claim that
there are many exciting findings to come. They’re probably right, but while
neuroimaging can certainly tell us much about the brain, there’s reason to
believe it hasn’t told us much about the mind. To understand what I mean by
this we need to go back to basics by asking what research is for.
“Does cognitive neuroscience
really have the power to distinguish between psychological theories?”Like all
scientists, psychologists are continually knocking out new theories to explain
the way we think and behave. One of the most important functions of research is
its ability to differentiate between two theories. If research doesn’t at least
provide a clue one way or the other then theoretically, and so practically,
it’s a waste of time. Does cognitive neuroscience really have the power to
distinguish between psychological theories? Is it any use to a cognitive
psychologist?
A
critic’s view
Max Coltheart is Professor of
Psychology at Macquarie University in Australia and in a recent journal article
he wonders whether cognitive neuroscience has really told us anything useful
about the mind so far (Coltheart, 2006). It’s important to realise that his
emphasis is on the mind, as in cognitive processes, as distinct from the brain,
as in physiological processes.
“Neuroscience’s strength is in
physiological processes…”There’s no doubt the mind’s cognitive processes are a
function of the brain’s physiological activity but these two things are nevertheless
(currently) separate questions. Cognitive neuroscience’s strength is in
physiological processes, and as imaging technology improves, so will the
importance of its findings in this area. But, again, why should a psychologist
care that much which part of the brain lights up in a scanner, if the mind’s
functioning is still so far removed from our understanding of its physiology?
An
example
All this can be difficult to
grasp in abstract. Take one of Coltheart’s examples. Suppose you’re a psychologist
interested in how people work out what other people are going to do. Their
intentions. Suppose there are only two competing theories that you’ve got to
choose between:
‘Simulation theory’: I
literally run a crude simulation of your mental state in my own mind. From this
I try and work out what you’re going to do next.
‘Theory theory’: I create a
theory about you, then try to work out what you’re going to do from that.
A recent neuroimaging study
claimed to be able to distinguish between these two theories. Ramnani and Miall
(2004) put people in the brain scanner, got them to carry out certain tasks and
predicted that if a particular part of the brain was activated it supported the
first theory, and if another, then it supported the second. What actually
happened was nowhere near this simple. Despite the claims of the study’s
authors, Coltheart argues that actually neither theory was substantially
supported or refuted by the findings.
“…evidence from cognitive
neuroscience fails to distinguish between theories.”This is just two theories
and one study – not exactly a scathing criticism of the whole of cognitive
neuroscience. But Coltheart does run through four other examples where evidence
from cognitive neuroscience fails to distinguish between theories. Again,
remember that we’re talking about relatively high level psychological theories
here, not low-level physiological processes.
Coltheart goes on to pull
quotes from a range of people who argue that, in principle, neuroimaging is
useless for psychological theory and understanding of the mind. Here’s a good
computing metaphor:
“No amount of knowledge about
the hardware of a computer will tell you anything serious about the nature of
the software that the computer runs. In the same way, no facts about the
activity of the brain could be used to confirm or refute some
information-processing model of cognition.” (Coltheart, 2004, p.22)
I personally don’t know enough
about cognitive neuroscience to argue whether or not this statement is true,
but it certainly has intuitive appeal. Considering the enormous quantity of
money going into cognitive neuroscience right now, it seems unlikely this would
be a majority view amongst psychologists. Not that scientist are slaves to
money, of course…Ahem…
About
the author
Psychologist, Jeremy Dean, PhD
is the founder and author of PsyBlog. He holds a doctorate in psychology from
University College London and two other advanced degrees in psychology.
He has been writing about
scientific research on PsyBlog since 2004. He is also the author of the book
“Making Habits, Breaking Habits” (Da Capo, 2003) and several ebooks.
SOURCE: PSYBLOG
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