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Posts Tagged ‘fMRI’

It would seem that the concerns depicted in our previous post are widespread indeed!

Martha Farah

Martha Farah

The last issue of the Journal of Cognitive Neuroscience, published by the MIT Press, is just out. Martha Farah introduces it with an editorial, basically a two-page warning. Abstract:

Unrealistic, financially motivated claims about functional brain imaging can have a negative impact on society at large and on our field. If too much is promised and not delivered, funders may become wary of cognitive neuroscience and skeptical about its genuine potential. Bad advice given to businesses concerning marketing and personnel selection could lead to expensive mistakes, and bad advice given to governments concerning security screening and interrogation could lead to far worse. Yet imaging is being offered for these applications now, with scant evidence of validity.

NeuroFocus CEO displays an examinee's brain waves chart as she watches a commercial film wearing a EEG headset. YOSHIKAZU TSUNO/AFP/Getty Images

NeuroFocus CEO displays an examinee's brain waves chart as she watches a commercial film wearing a EEG headset. YOSHIKAZU TSUNO/AFP/Getty Images

Pr. Farah, Director of the Center for Cognitive Neuroscience at U Penn, recommends several tactics to the neuroscientists eager to stand up against bad neuroscience, suggesting to “inoculate our students against brain imaging overclaim” or “blogging and posting reactions to blogs“. And I imagine that implicitly, this editorial will also act as a stop-sign to those neuroscientists who entertained the thought of doing profitable consulting jobs for neuromarketing private firms.

I don’t have a clear enough view of the fields of neuroeconomics and neuromarketing to be able to judge if commercial uses of fMRI / EEG have already proved harmful in any manner to scientific research. Has any grant application been rejected with referee reports mentionning the wrong commercial uses of brain scans? Is there any informal, unexpressed mood in scientific circles that “cognitive neuroscience” is somewhat dodgy, because of the bad press it is given?

What are your experiences in your universities, in your research labs? (you can post your reactions to this post, as recommended by Martha Farah, or contact me privately to help me in my research!)

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mere voodoo?

Statistics in fMRI studies: mere voodoo?

“Do you think the media are partly responsible for sensationalizing the findings of social neuroscience? And how can the media do a better job of reporting on brain scanning data?

Ed Vul: In general, I would advocate a bit more skepticism on the part of reporters, with respect to all scientific findings. I think reporters generally try to write up conclusions in slightly grander terms than the scientists used originally. What they may not realize is that scientists themselves have often oversold the implications of their findings a bit. You put these things together and you can end up with really overblown coverage. (On the other hand, perhaps if this advice were followed, science columns would end up dull and unread, so perhaps I should withdraw the suggestion.).”

This is from an interview of Ed Vul, a graduate student with an inquisitive mind.

Ed Vul

Ed Vul

He has an article in press which caused big waves in the small community of social neuroscientists and neuroeconomists. In this paper, he makes a strong critique of the statistical methods used to correlate a behavioral trait with a particular brain region – which is the bread and butter of fMRI studies. For the interested readers, here is the exchange in chronological order:

Ed Vul and al., article in press: Voodoo Correlations in Social Neuroscience

Original Rebuttal by incriminated scientists (including Tania Singer, a neuroeconomist at Zurich), new version of their rebuttal – and they work on an article-length version as well.

Rejoinder by Ed Vul (to the first version of the rebuttal)

Interview of Ed Vul for Scientific American

My bet on the final issue of this debate, for what it is worth? From the quick look I had on the papers, it seems that “regression to the mean” is a central issue in this statistical debate. And ah! if there is one topic where nobody agrees on (among and between statisticians, biologists, and economists), this is this one.* So in my humble opinion, the debate is ripe for taking a turn that is very common in these cases: “It always ends in statistics“. Participants will retort with increasingly sophisticated and intractable analytical refinements, obfuscating the core issue that draw a large audience to the debate in the first place.

* See an article by Stephen Stigler on the topic

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That’s the 2nd part of a three-easy-steps-guide to neuroeconomics (see previous post).

Image with fMRI

Image with fMRI

As is obvious if you ever perused through an article in neuroeconomics, brain images have a central role in social neuroscience. So a question that is often asked in the corridors and conference rooms is how trustful those visual representations are. In particular, how trustful are the visuals showing well-defined zones of activations in the brain?

An entry point to this issue can be to develop a critical comparison between the localizationist view of brain activity (cognitive skills would be organized in independent scattered patches) and the old-time phrenology.

Brain in the phrenology mode

Brain in the phrenology mode

This is the view suggested by the cognitive neuroscientist Guy Tiberghien, who recently made a presentation “against spectacular neuroimaging” (in French), indicting the simpleness of the localizationist view. Clever replies to this argument exist (the connectivist, network view), but it remains that by definition, brain images display a very static snapshot of the mind-in the-brain.

anne-beaulieu

Anne Beaulieu

A different perspective consists in studying the emergence of brain imaging technologies from the sociological and historical point of view, focusing on the transformations in their use since the 1970s. This is precisely the topic of Anne Beaulieu‘s PhD dissertation (2000). In “The Space Inside the Skull“, she unraveled the “archeology” of brain functional imaging (mainly PET at the time). She shows how in the late 70s and 80s, brain imaging was conceived primarily or exclusively for clinical applications, like for mapping the brain of a patient before surgery, or to obtain a standardized brain atlas. It is almost as an afterthought that in the late 80s, functional imaging technology was used to trace “mind” activities, diverging then from the agenda of the clinicians.

This history of functional brain imaging is supplemented by a reflection on the epistemic status of the visuals, drawing on the work of Michael Lynch and Karen Knorr-Cetina. Doing anthropological field work in the McConnell Brain Imaging Centre at McGill University, the center which designed maps of “average” brains, Anne Beaulieu reveals in detail how neuroscientists build a justification for their use of brain images. In interviews, they display a love-hate relationship with images: both useful for synthesizing large amounts of data, convenient to communicate results to a large audience, but also threatening the seriousness of science because of their non-quantitative nature, and their aesthetic properties.

I find this approach promising: instead of attempting to define a border separating “real” from “fake” science in brain imaging, as the title of this post would provocatively suggest, I believe rather that tracing the changing practices and conventions in the field allows for a deeper understanding of the meanings of brain images.

The next step probably consists  in comparing the epistemic status of images in neuroscience, with their status in economics. To do that, you’d have to read another PhD dissertation (in French) by my colleague Yann Giraud, precisely asking “Is Economics a Visual Science? (1932-1969)“. But that’s enough dissertations for today.

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