Thursday, February 10, 2011

Phrenology, Then and Now

In the November 2010 issue of Perspectives in Psychological Sciences, a Special Section on "Neuroimaging: Voodoo, New Phrenology, or Scientific Breakthrough?" (Diener, 2010) looks back at the infamous paper by Vul et al. (2009) and forward into the future. In one of the articles, an extended analogy is made between modern neuroimaging and the phrenology of yore (Poldrack, 2010):
Imagine that fMRI had been invented in the 1860s rather than the 1990s. Instead of being based on modern cognitive psychology, neuroimaging would instead be based on the faculty psychology of Thomas Reid and Dugald Steward, which provided the mental “faculties” that Gall and the phrenologists attempted to map onto the brain. Researchers would have presumably jumped from phrenology to fMRI and performed experiments manipulating the engagement of particular mental faculties or examining individual differences in the strength of the faculties. They almost certainly would have found brain regions that were reliably engaged when a particular faculty was engaged and potentially would also have found regions in which activity correlated with the strength of each faculty across subjects.
Gall's ambition and vanity are now 'activation for judgment about self versus others', localized to medial prefrontal cortex. Friendly attachment/fidelity have been transformed into 'viewing a friend versus viewing a stranger', associated with right temporoparietal cortex.

-- click on image for larger view--



Table 1 (Poldrack, 2010). A Mapping of Gall's 27 Faculties to Potentially Related Neuroimaging Research.
Although few today would hold that 19th century faculty psychology is an accurate description of the structure of the mind, we can likely all agree that if the phrenologists had created task manipulations to isolate their proposed faculties using fMRI, something would have “lit up.” What would the patterns of activation associated with these faculties have looked like? If we believe, as I think most would agree, that each of the phrenologists' putative faculties relies in actuality upon a combination of basic mental operations, then we would likely expect that the maps obtained for a given faculty would include a large set of activated regions that would tend to overlap across tasks meant to tap into different faculties. Regardless, one can be almost certain that Gall and his contemporaries would have taken these neuroimaging results as evidence for the biological reality of his proposed faculties.
But we know better now, don't we? Because Neural Networks Debunk Phrenology!
The studies show that network interactions among anatomically discrete brain regions underlie cognitive processing and dispel any phrenological notion that a given innate mental faculty is based solely in just one part of the brain.
Does anyone really believe in phrenology any more? Who advocates such a view? Cognitive neuropsychologists? Single-unit neurophysiologists? OR has localization of function in discrete networks (rather than an individual structure or a bump on the head) become the new phrenology? I think the story goes like this: complex adaptive behavior is an emergent property of network interactions. This is certainly not a new idea (see any number of publications by Joaquin Fuster)...

According to Poldrack (2010), neuroimaging research strategies have evolved from “where” (blobology or neophrenology) to “what” (characterize function of a specific brain region) to “fractionation” (determine whether different mental processes engage different brain regions). Ultimately, localization of function is still the final goal... as it was for the original phrenologists:
Phrenology teaches us that in this life every act of the mind is performed through the instrumentality of the brain, and that peculiar states of this organ invariably accompany particular mental dispositions.

-M.B. Sampson Esq. (1842)

References

Diener E (2010). Neuroimaging: Voodoo, New Phrenology, or Scientific Breakthrough? Introduction to Special Section on fMRI. Perspectives on Psychological Science 5:714-715.

Poldrack, R. (2010). Mapping Mental Function to Brain Structure: How Can Cognitive Neuroimaging Succeed? Perspectives on Psychological Science, 5 (6), 753-761 DOI: 10.1177/1745691610388777

Sampson MB (1842). PHRENOLOGY IN ITS APPLICATION TO THE TREATMENT OF CRIMINALS. The Lancet 37:639-643.

Vul E, Harris C, Winkielman P, Pashler H (2009). Puzzlingly High Correlations in fMRI Studies of Emotion, Personality, and Social Cognition. Perspectives on Psychological Science 4:274-290.

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10 Comments:

At February 10, 2011 10:11 AM, Anonymous KevinH said...

The whole fMRI vs Phrenology thing is so rediculous. One is based on real, observer independent, significant data, and the other was based on random noise.

Similarity of goals is not a valid way to compare fields of knowledge. Are you willing to say that modern medacine is just as valid as homeopathy because they have similar goals? That psychology is equivalent to astrology? That intellegent design is equivalent to evolution?

It is methods, and data which separate the wheat from the chaff, not motivation or aim.

If what you are trying to say is that fMRI needs to move away from more descriptive studies to direct tests of hypothesis, then I'd fully support you. However, nothing is gained by trying to bias people against a valid scientific method by tying it to a ridiculous farce in the history of science.

 
At February 10, 2011 11:03 AM, Anonymous Thor said...

Been doing fMRI for 15 years. I know lots of people who believe in cognitive modules. Still. Lots.
Some believe they're distributed, some that they're localized to those blobs.

In some fields, it's difficult to publish unless you take a partially modularist view. For example in visual perception, people have to run some so-called functional localizers approach or risk getting attacked at review stage for showing random blobs which may or may not be this or that visual area. But the localizer approach assumes we can know and map the areas that we may be interested in a priori! Sometimes makes it difficult to do exploratory work. It's true that the visual system has specialization but I think the culture limits the way you can perform analyses (if you want to publish, which of course you do!).
There may be sub-fields where the opposite is the culture, I don't know... But how we conceptualize neuroimaging affects the kinds of questions we can productively ask so it's not an inert issue by any means.

 
At February 10, 2011 4:57 PM, Blogger Bradley Voytek said...

Very nice. I hadn't seen Poldrack's article. I like it a lot. Of course, I'm kinda biased on this matter:

http://blog.ketyov.com/2011/01/how-to-be-neuroscientist.html

And the author of that "Neural Networks Debunk Phrenology" piece was my PhD advisor.

 
At February 12, 2011 12:33 AM, Blogger Tara Maya said...

Hm, I found myself agreeing with KevinH, and then I found myself agreeing with Thor. Now I'm just going to sit back and see where it leads.

I do think that new tech--higher resolution--could either make the tendency more pronounced or blow away all present theories of localization.

Tara Maya
Conmergence

 
At February 14, 2011 4:01 AM, Anonymous Anonymous said...

Well, try getting a job at MIT without embracing a modular view! Nancy will set you butt on fire! :)

 
At February 14, 2011 4:42 AM, Blogger Ur23 said...

Sorry for posting a comment unrelated to this article, but I see no other way to contact you - everywhere on the Internet they are currently writing about this boy, Chase Britton, who lives quite normally without his cerebellum and pons:
http://www.aolnews.com/2011/02/12/chase-britton-boy-without-a-cerebellum-baffles-doctors/
Of course, this great opportunity for all kinds of people to deny neuroscience/physicalism... I would be very grateful if you could comment on this?

 
At February 17, 2011 7:47 AM, Anonymous Han said...

Seems like more prominence should be given to the fact that the BOLD signal cannot be mapped in a straightforward way to neural activity. There are studies showing firing in the absence of BOLD changes, and vice versa.

Also: have you ever looked at the methods section of an fMRI paper? The subtractions used are highly non-obvious. Assumptions about what brain regions are involved go into the subtraction, so there is an implicit model built into each brain image.

 
At March 22, 2012 8:36 PM, Anonymous Anonymous said...

Dear Blogger,
I'm a psychology undergraduate I'm writing a critical essay on Phrenology and I was hoping to reference your article. Could you please provide me with some more details so that I can cite your work.

Regards.

 
At March 23, 2012 5:58 PM, Blogger The Neurocritic said...

According to Purdue, the APA blog citation format is:

The Neurocritic. (2011, February 10). Phrenology, Then and Now [Blog post]. Retrieved from http://neurocritic.blogspot.com/2011/02/phrenology-then-and-now.html

OR it might be:

Neurocritic, T. Phrenology, Then and http://neurocritic.blogspot.com/2011/02/phrenology-then-and-now.html

[according to studenthacks.org]

 
At November 29, 2013 7:08 AM, Anonymous Anonymous said...

I'm a psychology undergrad and I just wanted to say thanks! ur blog supplied me with some great point to make!

 

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