Tuesday, April 11, 2006

Is fMRI Modern Phrenology? - What It Is & What It Isn't



The fMRI studies seem so beautiful, so could it really be just a modern-day phrenologist's toy? Phrenology, if you don't remember,was that pseudoscience of the past (for instance in Sherlock Holmes' day) that suggested that traits of personality, character, and even criminality could all be predicted by the shape of ones' skull.

The Cons on fMRI:

fMRI is not precise (it is blood flow, after all and not direct neuronal activity)
fMRI can be misinterpreted (very new science, many folks misinterpreting differences as indicating disease)
fMRI studies often require narrowing of tasks and experimental design decisions that affect degree of difference, location, and timing

The Pros of fMRI:

Don't knock localization - since it's humblest days of clinicians learning from individual brain injured patients or strokes, localization can tell you useful information about different components of cognitive processing
fMRI is not the same as descriptive anatomy - it is always associated with a behavioral task (and therefore behavioral data); why should this be worse than behavioral tasks alone?
fMRI has infused new ideas and hypotheses in to areas of developmental cognitive science, learning disabilities, emotional and social sciences, imagery, sensory processing, plasticity, autism, and psychiatric disorders - formerly untestable questions are now accessible to experimentation
fMRI studies have been correlated with physiological, clinical, and behavioral findings

Our conclusion: Don't throw out the baby with the bath water. fMRI is a valuable and fairly new tool, but one must be wary of generalizations and be aware of speculations when they are made.

As a neurologist, I'm used to having to be pragmatic. Literature and controlled studies are fine, but there are many individual features to a neurological presentation, and I need to know these as well as uncertainties when I make decisions about what to do. Neurologists work with scans all the time, and we know generally what they can do and what they can't do.

So will the fMRI replace clinicians? Nope. Will they replace a teacher's assessments? Nope. These either-or choices are just not going to happen.

Functional MRI is a remarkable technology - and although some might say it raises more questions than answers, it has already helped a lot of people, and it looks on pace to revolutionize the sciences of neurorehabilitation and psychiatry.

Brain Scans Prove Disease??
fMRI's Reckless?
Fact or Phrenology
Eide Neurolearning Blog: Neurolearning Epiphany
Eide Neurolearning Blog: Can Targeted Brain Therapy Correct Everything?
Stanford Links for the Great fMRI Debate
Comments and Controversies - Nervous System Development & Interpretational Challenges
Phrenology at Wikipedia

4 comments:

  1. very nice - thanks for addressing this point (I know that I might have teased you into it:)

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  2. yes, you certainly did! and it's an excellent point to discuss -

    Thanks very much.

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  3. fMRI is very popular in the press. It's a nice way of looking like you are explaining something without really explaining it. If fMRI is developing a bad reputation, I'm sure sloppy reporting is a major contributor.

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  4. That's true, and maybe it's the power of the image.

    fMRI is a great medium for blogs, though. It has the potential to go beyond the soundbyte or pictureblink of conventional news outlets, and we don't know of any other medium where the images of such studies can be directly compared, as in Money, Motivation, and ADHD

    I think some of the bad reputation was in the earliest years of this technology, but the net benefit has been a good one for the general public as a whole. More people from different walks of life are becoming aware of individual brain differences.

    Students are really empowered by seeing some of the studies (in the literature, not from themselves) - like looking at the dyslexia pics. The images of brains not "hearing" similar sounds gives affirmation of their problems in phonology - and visually they can see that this difference has nothing whatsoever to do with their intelligence.

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