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...
What's your view?
There's precious little discussion of Coltheart's criticisms in the blogosphere and there's plenty of good neuroscience blogs around. Let me know what you think, leave a comment below.
References
Coltheart, M. (2004) Brain imaging, connectionism and cognitive neuropsychology. Cognitive Neuropsychology, 2, 21-25.
Coltheart, M. (2006). What has functional neuroimaging told us about the mind (so far)? Cortex, 42(3), 323-31.
Ramnani, N., & Miall, R. C. (2004). A circuit in the human brain for predicting the actions of others. Nature Neuroscience, 7, 85-90.
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I think the following recent paper in Cognition is relevant for the discussion.
MCCABE, D., CASTEL, A. (2008). Seeing is believing: The effect of brain images on judgments of scientific reasoning. Cognition, 107(1), 343-352
Basically they have found that when people read a science article, they rate the same (flawed) stories to be more scientifically sound when they are accompanied by a brain image, compared to a bar chart. The authors conclude that people have a "natural affinity for reductionistic explanations of cognitive phenomena".
This may also mean that it is easier to get money for this type of studies. If so, this also goes some way to explain some resentment from other scientists. In a world of finite resources, funding for an fMRI project may mean no money for tens of other projects (given how expensive fMRI can be).
cheers
The question "Can cognitive neuroscience tell us anything about the mind?" I find rather amusing when any ideas that may provide an answer are prevented from being put forward by such things as peer group review.
What is so amusing to me is that people in such positions with all of their qualifications, etcetera, can feel so threatened that they do not allow others to contribute to providing the answers they do not have.
Bronte
Jeremy, great post and I too share both a scepticism and fascination with neuroscience. I'm fairly certain that psychology is at the fringe of changing dramatically!
Mark
http://www.blognitions.com
Hello,
I am a PhD student and am about to embark on my own set of fMRI experiments into consciousness and attention. I have heard Max speak a number of times on the issue and should direct your attention to the replies by Rik Henson (they can be downloaded from his webpage).
Max however has clearly been selective in the examples he has provided. One of the great success stories of Cognitive Neuroscience has been understanding the neural processes involved in vision and attention. Pure cognitive models of vision have been built implicitly on the notion that vision is only ‘feedforward’ in that simple processes feedforward into more complicted ones and then eventually an attentional filter is met which only allows a restricted amount of information into consciousness.
Neurophysiologists and imagers over the past decade however have been wonderfully successful in largely dispelling that view held by old guard vision scientists. What we know now is that vision is massively interactive, with higher level processes feeding information back into lower level processes. In addition we now know that the correlate of attention is the feedback of information from decision related and spatial related areas of the brain into the visual areas. This massively interactive view of attention and perception has been carried along largely by physiologists and neuroimagers.
The future for cognitive neuroscientists is neurodistruption. Chambers and Mattingly (2005) suggest that neuroimaging is a liberal procedure, often detecting activation in regions of the brain that are not actually involved in the task under investigation. Chambers and Mattingly argue that imaging should be followed up by neurodistruption. Neurodistruption involves using Transcranial Magnetic Stimulation to excite populations of neurons in a very small region of the cortex. This wholesale excitation of this population renders the area computationally useless (similar to adding noise to an image). Eg., applying TMS to Broca’s area arrests speech (albetit very briefly). So by using TMS we can infer whether a reigion really is involved in a certain task. Best yet, TMS only disrupts neural activity for about 10ms, so the feedforward and feeback relationships can be determined (especially if you have two TMS coils!) You can see Pascal-Leone 2001 Science experiment showing the feedforward and feedback relationship between two visual areas.
Cognitive Neuroscience is only new, and already it has provided a wealth of evidence about how vision works.