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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Hi,
I do not know a lot about neuroscience, but as a computer engineer I could not help noting the wrong analogy. One can get a lot of information about the software by studying the hardware. All programs are finally translated into a series of zeros and ones and by looking into these machine instructions, one can infer a lot about the software.
It is a very common practice in cracking/ reverse engineering to study the machine instructions and memory contents in order to get insite into a software without source code.
And in reality, your hardware and software are not very different, there are microcircuits that do the same job as a software and they all work on the same mathematical principles. Software is just more flexible ( easier to change ) than hardware.
I do not see any logical principle preventing people from understanding mind by studying the brain, though practically it may be impossible ( which I hope might someday be overcome by new technologies ).
Thanks and regards,
RayS
Cognitive neuroscience is clearly not just about studying the brain-- else there would be no need for the "cognitive" part. On the other hand, I don't think it will ever be a stand-alone tool to study the mind. Any conclusions about the operation of the mind hinted at by brain activations or whatever must ultimately be validated by more traditional kinds of behavioral data to gain real traction.
I think the relevance of cognitive neuroscience is not in studying the mind or brain separately, but in studying the relationship between the two. If the mind is what the brain does, cognitive neuroscience studies how the brain does the mind. It's shedding light on the age old mind body problem.
Of course, in addition to the philosophical insights, there are straightforward practical applications. Knowing how the brain does the mind allows one to treat the impaired mind by means of changing something about the brain.
The analogy of brain/mind hardware/software is naive. In fact, sufficient knowledge of computer hardware could but upper limits on the software's performance or size, for example, among other things.
The analogy could be better drawn if I were to compare the ability to take measurements of the activity of the computer while it is in operation to fMRI. In that case it might indeed be possible, given sufficient knowledge of the constituent parts, to deduce the code the machine is using and understand quite a bit about not only what kind of software is running, but if it similar to other kinds running on different machine.
At the very least neuroimaging, electrophysiology, MEG etc give us a chance to fill in some of those squares the cognitive scientists (such as myself) like to draw.
Thanks for your comments Rays and the two anonymouses. Following on from what you're saying I thought you might find this post at MindHacks of interest about Dr Brad Pasanek who has created a database of metaphors of the mind.
I just like to add a quick comment regarding the perceived hostility towards fMRI approaches both from neuroscientists and from cognitive scientists.
I do not think that there is something fundamentally wrong with fMRI and clearly some results are important (if neither for neuroscience nor for cognitive science at least for medicine). However I guess the reason why many people feel deeply uncomfortable about fMRI approaches is that a technique that has neither had great impact on our understanding of the brain nor had great impact on our understanding of the mind all of a sudden is the most successful approach in terms of funding and visibility.
Clearly fMRI promises new progress in a range of fields. However, there are fundamental dangers. fMRI tends to encourage a way of thinking about the brain as a set of little specialized processors connected to one another. Because fMRi can only visualize localization of function it makes many people believe that the brain is radically localized, an idea that is not supported by electrophysiology. The kind of theory that many scientists derive from fMRI may be neither helpful for neuroscience nor for cognitive science.
Thanks anonymous, I think there's a lot of truth in what you say.
I wouldn't dare disagree with an eminent psychologist but I think Coldheart is wrong. You can tell a great deal about the software on a computer from examining the hardware. Hardware determines the characteristics of the software - apple hardware won't run microsoft software (for example). So by determining that the harware is apple, you can also determine that the software is not microsoft.
In the same way the physical characteristics of the neural network constrain and define what can and cannot be done by the brain (e.g telepathy and telekenisis are impossible because the brain is insufficently sensitive to magnetism).
I simply dont't beleive that the brain and the mind are 2 separate entities. The "mind" is just what the brain does, it's our subjective experience of a particular pattern of neural activation at a particular point in time. Many parts of the body are not fully understood - yet medicine does not see the need to invent metaphysical constructs to fill the knowledge gaps - why does psychology ?
Matt, like earlier commenters, I think we might have pushed this software/hardware metaphor further than it really goes. Also I don't think anyone is suggesting brain and mind are separate. But, as you say there does seem to be a temptation to invent something to bridge the gap between the two.
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For example, if I were to try and write a top ten list of cog-neuro studies as I've done for psychology in general, what would be on there?-----
For example, kandel (nobel prize 2000)
for discoveries concerning signal transduction in the nervous system.
I know he didnot use fMRI but he is a neuro scientist.
Author of:
Principles of Neural Science, 4th Edition
I'm no neuroscientist, but you could call me an interested student of this stuff as it applies to my coaching practice.
I'm currently reading Dan Goleman's "Social Intelligence", which as far as I've read is trying to make the information we get from imaging useful, maybe you've already read it, if not it may be worth checking out.
Other thing I thought of is this video of a TED speech by V.S. Ramachandran that also is trying to make the connection between physiology and psychology. Here's the web address: http://www.spring.org.uk/2007/10/ramachandran -on-capgras-syndrome.php
Thanks Hatsch and Thomas.
I'm an italian student, I'm graduated in experimental psychology. I read all your comments.
But there is an experimental technique, TMS (i.e. transcranial magnetic stimulation) that allows to understand both the brain and the mind. It isn't a brian imaging technique but It can "read" the brian functions. The TMS create a magnetic field that modifies the electric field of brian iterferring with the brian activity. If we stimulate a particular area involving in a particular task we observe an interference in that task. So we can acquire information about localization of cognitive functions. But also...
we can analyze the chronometry of mind. With a single-pulse TMS, we can give a single stimulation in a fixed temporal window. If the process occurs in that time it would be modified, if it occurs before or after the stimulation, it would be unmodified. So we can know when a cognitive process is involved.
If you are interest, I suggest a paper: "Studies in cognition: the problem solved and created by transcranial magnetic stimulation" by E.M. Robertson et al.
P.S. I'm sorry for my bad english
Here's the problem as I see it.... using current cognitive neuroscience techniques to understand brain-behavior relationships is currently like trying to understand the functioning of a car's motor by measuring the heat patterns on the hood of the car. We can tell when it's working harder (and which areas show the biggest changes), but that's a far cry from truly understanding motor function.
Claim are often overstated and the work has been too exploratory for too long. Unfortunately, trying to understand an engine while it's working is darn near impossible.
It's hard for me to foresee the future of this work until the technology proceeds much farther. However, precise measurement may simply highlight another problem - no two brains work exactly alike.
Cheers,
Mike
Mike, I couldn't agree more!
For the "pro neuroimaging point of view" check out a recent article by Jason Mitchell that outlines areas in which neuroimaging has contributed to research in social cognition:
http://www.blackwell-synergy.com/doi/abs/10.1111/j.1467-8721.2008.00564.x
A few other places where I think neuroimaging can help understand things that previous psych work has not:
-How do implicit and explicit attitude interact to result in our ultimate evaluations/ attitudes/ behaviors? See Cunningham & Zelazo (2007) for an overview of one theory that integrates past work in psych, cognitive science, and insights provided from neuroimaging.
-On a related point, how do people control race bias? See work by Phelps and colleagues.
-Distinctions between internal and external focus: see review article by Lieberman (2007) on core processes in social cognitive neuroscience.