Thursday, October 06, 2011

New York Times on Addiction and The Insula

In Clue to Addiction, Brain Injury Halts Smoking

Published: January 26, 2007

Scientists studying stroke patients are reporting today that an injury to a specific part of the brain, near the ear, can instantly and permanently break a smoking habit. People with the injury who stopped smoking found that their bodies, as one man put it, “forgot the urge to smoke.”

The finding, which appears in the journal Science, is based on a small study [Naqvi et al., 2007]. But experts say it is likely to alter the course of addiction research, pointing researchers toward new ideas for treatment.

While no one is suggesting brain injury as a solution for addiction, the finding suggests that therapies might focus on the insula, a prune-size region under the frontal lobes that is thought to register gut feelings and is apparently a critical part of the network that sustains addictive behavior.

Hey, wait a minute!

Didn't the NYT just publish an authoritative piece to the contrary? In You Love Your iPhone. Literally., Martin Lindstrom claimed the insula was a signifier of love and compassion, not addiction:
WITH Apple widely expected to release its iPhone 5 on Tuesday, Apple addicts across the world are getting ready for their latest fix.

But should we really characterize the intense consumer devotion to the iPhone as an addiction? A recent experiment that I carried out using neuroimaging technology suggests that drug-related terms like “addiction” and “fix” aren’t as scientifically accurate as a word we use to describe our most cherished personal relationships. That word is “love.”

. . .

But most striking of all was the flurry of activation in the insular cortex of the brain, which is associated with feelings of love and compassion. The subjects’ brains responded to the sound of their phones as they would respond to the presence or proximity of a girlfriend, boyfriend or family member.

OK, OK, we all know by now that royal proclamations of brain function based on logical fallacies and unpublished (and never-to-be-peer-reviewed) commercial studies are not to be believed. NYT did publish a retort to this silliness, a Letter to the Editor (The iPhone and the Brain) in which "Forty-five neuroscientists respond to a recent Op-Ed about using brain imaging to analyze our attachment to digital devices." We also know that the insula is activated in a substantial percentage of all neuroimaging studies (Yarkoni et al. 2011; PDF). Reflecting this ubiquity, The Neurocritic blog archive contains 73 unique posts with the word "insula."

But what of addiction and the insula? In their 2007 Science paper, Naqvi and colleagues performed a retrospective study of 69 stroke patients (all smokers): 19 with lesions in the insula and 50 with lesions elsewhere. The color coding in the figure below depicts the number of individuals with damage in specific brain regions.

Fig. 1 (Naqvi et al., 2007). Number (N) of patients with lesion in each of the regions identified in this study, mapped onto a reference brain. Boundaries of anatomically defined regions are drawn on the brain surface. Regions not assigned a color contained no lesions. (Top) All patients. The horizontal line marks the transverse section of the brain shown in the top row. The vertical line marks the coronal section shown in the bottom row. (Middle) Patients with lesions that involved the insula. (Bottom) Patients with lesions that did not involve the insula.

The likelihood of post-stroke smoking cessation did not differ between the insula and non-insula groups, but those with insula lesions who did quit smoking reported that it was easy to do so. The authors concluded that...
...smokers with brain damage involving the insula, a region implicated in conscious urges, were more likely than smokers with brain damage not involving the insula to undergo a disruption of smoking addiction, characterized by the ability to quit smoking easily, immediately, without relapse, and without persistence of the urge to smoke.
The problem with this assertion is that it relies on memory for events that occurred an average of 8 yrs earlier, which could be subject to recall bias (Vorel et al., 2007). A better design would be a prospective study that follows patients from the time of stroke and then assesses subsequent smoking behavior. In fact, Bienkowski et al. (2010) performed such a study and failed to see a difference between their insula and non-insula groups at a 3 month follow-up. This suggests that the insula does not play a special role in addiction.

What does this mean for iPhone love? Is Lindstrom right? Unlikely! He would have to demonstrate that insular strokes cause an inability to feel love for iPhones (or anything else, for that matter). Such a finding would suggest that an intact insula is necessary for the experience of love and compassion, and that the activity in his fMRI experiment was not a mere epiphenomenon.

In the real world of peer-reviewed neuroimaging research, however, that sort of converging evidence is rarely obtained.

Further Reading

NYT Editorial + fMRI = complete crap

the New York Times blows it big time on brain imaging

Neuromarketing means never having to say you're peer reviewed (but here's your NYT op-ed space)

fMRI Shows My Bullshit Detector Going Ape Shit Over iPhone Lust

...and pollyannaish comment by Martin Lindstrom

NYT Letter to the Editor: The uncut version

Articles on insular cortex from The Amazing World of Psychiatry: A Psychiatry Blog

The Insula Is The New Black...

No Longer an Island, the Insula Is Now a Hub of High Fashion


Bienkowski P, Zatorski P, Baranowska A, Ryglewicz D, Sienkiewicz-Jarosz H. (2010). Insular lesions and smoking cessation after first-ever ischemic stroke: a 3-month follow-up. Neurosci Lett. 478:161-4.

Naqvi, N., Rudrauf, D., Damasio, H., & Bechara, A. (2007). Damage to the Insula Disrupts Addiction to Cigarette Smoking. Science, 315 (5811), 531-534 DOI: 10.1126/science.1135926

Vorel SR, Bisaga A, McKhann G, Kleber HD.(2007). Insula damage and quitting smoking. Science 317:318-9; author reply 318-9.

Yarkoni T, Poldrack RA, Nichols TE, Van Essen DC, Wager TD. (2011). Large-scale automated synthesis of human functional neuroimaging data. Nat Methods 8:665-70.

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At October 07, 2011 11:59 AM, Anonymous Anonymous said...

So couldln't we do a test with the low voltage therapy on the insula, and see if it helped folks quit?

At October 11, 2011 7:33 AM, Blogger jonathan said...

If I remember correctly, the insula connects the frontal lobes to the limbic system, two areas that have been implicated in autism. My twiddling (self-stimulatory behaviors) seem analogous to an addiction, and I wonder if something along those lines could be implicated in the etiology of autism.

At October 12, 2011 8:10 AM, Anonymous brain shirts said...

Thank you for this post, and I think more people need to read this. I would imagine that if the insula was involved in addiction, it is likely part of a larger network including the basal ganglia, rather than a cortical area which is both necessary and sufficient for "additive" behavior. This seems to be such a common thing is science not to make the distinction about whether a brain region is necessary for a particular function, whether it is sufficient for that function, or whether it the activity seen in neuroimaging is simply an epiphenomenon and simply correlated but not causal. Thanks for the interesting post and keep up the good work!

At December 25, 2011 4:08 PM, Anonymous Anonymous said...

The link goes to the abstract only, with a paywall blocking access to the article. Any chance you might have a link to the full article?


At December 25, 2011 8:16 PM, Blogger The Neurocritic said...

Anonymous of December 25, 2011 4:08 PM - which article? Three of the four refs have links to their PubMed abstracts. All of the articles are behind a paywall, there's no link to a free version. There's a link to a free PDF of Yarkoni et al. in the post, however.

At June 11, 2013 2:11 AM, Blogger Fallen Leaf said...

latest one, i think. follows up on the Naqvi and Bienkowski paper.


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