Sunday, March 27, 2011

modern homunculism - the brain is not an explanation

APS | Brain scans pinpoint how chocoholics are hooked. This headline appeared in The Guardian a couple years ago above a science story that began: “Chocoholics really do have chocolate on the brain.” The story went on to describe a study that used functional magnetic resonance imaging (fMRI) to scan the brains of chocoholics and non-cravers. The study found increased activity in the pleasure centers of the chocoholics’ brains, and the Guardian report concluded: “There may be some truth in calling the love of chocolate an addiction in some people.”

Really? Is that a fair conclusion to draw from the fMRI data in this study, reported in the European Journal of Neuroscience? Brain stories have become very popular in the news pages in recent years—and brain imaging stories especially, in part because of the colorful “pictures” that often accompany the data and analysis. But how much can we really conclude from these images? How skeptical should we be, as readers of the science pages in the paper?

A growing number of scientists, including many who study the brain, are calling for more caution from scientists, both in reporting and interpreting fMRI data. Among them is University of Illinois neuroscientist Diane Beck, who in a recent article in Perspectives on Psychological Science discussed both the appeal and the pitfalls of popular stories about the brain and behavior.

The difficulties of these stories begin with the technology itself, the sheer complexity of which makes accurate reporting a challenge. Despite those colorful images in the journals and news pages, the fMRI is not a photograph—not even close. An fMRI image is actually constructed from the complex interplay of radio waves and the magnetic properties of hemoglobin. That familiar head-shaped image is the final product of highly sophisticated mathematics and modeling and statistical analysis—much of which neuroscientists themselves don’t fully understand.

Even this paraphrase of mine is a gross oversimplification. The problem is that the final product—the brain image—looks like a photograph, and that’s how most readers take it, as a simple snapshot of the brain in action. That’s in part because the simplicity of the message is appealing: Complicated behavior X lights up brain area Y. But such reductionism, Beck argues, lacks any explanatory power. Consider the chocoholic example again: Leaving aside the fact that chocoholic is not a recognized diagnosis, what does this study actually show? It shows that people who define themselves as chocolate cravers have more activity, relative to people who do not define themselves as chocolate cravers, is certain pleasures centers of the brain. That is, the sight and taste of chocolate activated the brain’s reward system in cravers, documenting . . . what? Well, documenting that some people find chocolate more rewarding than others. As Beck notes, we probably don’t need a brain scan to corroborate what most people probably already believe anyway.

But it’s the brain—it’s biological—which gives readers more confidence in a behavior than the behavior itself. Why isn’t it good enough to simply ask a lot of people if they crave chocolate? Chances are some would say yes and some would say no. The fact that the brain’s reward center is relatively more active in cravers doesn’t add much—and it certainly doesn’t verify that a self-proclaimed chocoholic is akin to a heroin addict or alcoholic.

25 comments:

Big Don said...

Recent brain PRR goodie... http://www.dailykos.com/story/2011/03/27/960535/-New-Research-on-Obesity-and-Brain-Function

nanakwame said...

Yes we have a working theory of the mind as in many other knowledgeable branches of sciences - to deny this is to step into the camp of the Creationist or play sophistry within your scientific community for personal biases or affinities. We have had the common unity today that absolute theory is dead and working and practical science is our benchmarks, at least since the end of the 1960’s. If we are to fight an attempt of fascist, we better understand what is known, what is unknown (for now) and what is unknowable in the present future. Otherwise we may be smart men, who unintentionally unite with the growing backward looking nostalgia, left or right. I firmly believe this. Paul Baran who has passed proves this to me, for his brilliance in networks and switching “packet switching”, gave the study of the mind a boost. Visualization and Imagination is such a boost to our working theories.

Anonymous said...

diazepam 5mg generic of valium - get prescribed valium anxiety

Anonymous said...

buy ativan online ativan seizures - ativan dosage long does last

Anonymous said...

xanax buy is xanax 1 mg strong - xanax side effects confusion

Anonymous said...

zolpidem 10 mg zolpidem tartrate sleep apnea - zolpidem coma

Anonymous said...

ambien cost ambien cr picture - ambien ld50

Anonymous said...

xanax without prescription drug interactions with trazodone xanax - xanax effects reviews

Anonymous said...

where can i buy xanax online xanax 2mg recreation - much does generic xanax cost walmart

Anonymous said...

xanax anxiety xanax drug contradictions - xanax side effects 2mg

Anonymous said...

cheapest ativan ativan 3rd trimester - ativan effexor withdrawal

Anonymous said...

buy diazepam cheap diazepam online no prescription - diazepam dosage forms

Anonymous said...

xanax online what generic xanax looks like - buy xanax online no prescription cheap

Anonymous said...

ambien ambien side effects suicidal thoughts - ambien flexeril drug interactions

Anonymous said...

buy ambien online ambien side effects headache - ambien sleep aid

Anonymous said...

ambien for sale no prescription buy ambien online from usa - ambien cr rooster

Anonymous said...

ambien zolpidem ambien 10 mg tablet - price of ambien cr 12.5

Anonymous said...

buy valium india valium 10mg uk - buy valium online legally

Anonymous said...

buy ambien online ambien pill blue - ambien overdose toxic level

Anonymous said...

cheap ambien online ambien cr doesn't work - ambien 10mg picture

Anonymous said...

soma buy generic soma markings - carisoprodol 350 mg buy online

Anonymous said...

where to buy valium online buy valium online cheap uk - buy 1000 valium

Anonymous said...

Pharmaceuticals Drugs Sales India Asia where can i buy acomplia online - buy generic acomplia http://www.buydiscountedisotretinoin.net/#buy-generic-acomplia

Anonymous said...

Drug Smuggling In The Bahamas phentermine 37.5 no prescription - order phentermine online http://www.intraart.com/ - [url=http://www.intraart.com/]buy cheap phentermine [/url]

Anonymous said...

Me and ozzy fucked more challenging, trying to show to my personal god!
FUCK YES!' right before cumming inside my warm pussy. were still fucking

my homepage ... hcg injections