oh my god i've got the perfect hat for this!

Family Guy's Stewie Griffin, on the animated set of The Hills, in the episode We Love You Conrad.

"What's everybody looking at? The salesman told me it was unisex."

double entendre

postcards from nowhere

...or triple entendre, or even more [depending on your source].

Stolen from Neuroanthropology's Wednesday Round Up #62:

Research Digest, It’s Those Voodoo Correlations Again … Brain Imagers Accused of “Double Dipping”
More methods problems for imaging researchers – using the same data twice, first to find the area and then to show that area is really the one responsible for whatever hypothesis is at stake. For more commentary, see Neuroskeptic, Mind Hacks, and Newsweek.

Others have already written about the new voodoo-esque paper by Kriegeskorte et al. (2009). Having blogged extensively about the original controversy, I don't have anything to add... other than the links above... and some fun and wholesome pictures.

Reference

Kriegeskorte N, Simmons WK, Bellgowan PS, Baker CI. (2009). Circular analysis in systems neuroscience: the dangers of double dipping. Nat Neurosci. 12:535-40.

A neuroscientific experiment typically generates a large amount of data, of which only a small fraction is analyzed in detail and presented in a publication. However, selection among noisy measurements can render circular an otherwise appropriate analysis and invalidate results. Here we argue that systems neuroscience needs to adjust some widespread practices to avoid the circularity that can arise from selection. In particular, 'double dipping', the use of the same dataset for selection and selective analysis, will give distorted descriptive statistics and invalid statistical inference whenever the results statistics are not inherently independent of the selection criteria under the null hypothesis. To demonstrate the problem, we apply widely used analyses to noise data known to not contain the experimental effects in question. Spurious effects can appear in the context of both univariate activation analysis and multivariate pattern-information analysis. We suggest a policy for avoiding circularity.

The Constant State of Desire

Karen Finley in The Constant State of Desire
Photo by Donna Ann McAdams

If you are better at exerting self-control by choosing less pleasurable but more healthy options, do you live in a constant state of (suppressed) desire? If you feel like you're always sacrificing and denying yourself what your brain's "valuation system" indicates is worth more, does the craving eventually go away? Or are you more likely to binge in a moment of weakness? Isn't this why most diets fail? Wouldn't it be better to have that candy bar every once in a while? (or else, learn to love cauliflower more than Cadbury)?

However, this constant state of desire is not what the mad lib Science paper (Hare et al., 2009) is about. It's not even about dieting at all, despite what the press release says.

Caltech Researchers Pinpoint the Mechanisms of Self-Control in the Brain

Study of dieters shows how two brain areas interact in people with the willpower to say no to unhealthy foods

PASADENA, Calif.--When you're on a diet, deciding to skip your favorite calorie-laden foods and eat something healthier takes a whole lot of self-control--an ability that seems to come easier to some of us than others. Now, scientists from the California Institute of Technology (Caltech) have uncovered differences in the brains of people who are able to exercise self-control versus those who find it almost impossible.

The key? While everyone uses the same single area of the brain to make these sorts of value-laden decisions, a second brain region modulates the activity of the first region in people with good self-control, allowing them to weigh more abstract factors--healthiness, for example--in addition to basic desires such as taste to make a better overall choice.

To start, let's look at the subject selection criteria (Hare et al., Supporting Online Material - PDF):

"We recruited two types of subjects: 1) individuals who self-reported being on a diet to lose or maintain weight and 2) individuals who self-reported no current monitoring of their diet. All subjects reported that they enjoyed eating sweets, chocolate, and other “junk food” even though they might be restricting them from their current diet.

. . .

Subjects were classified as self-controllers (SC) or non-self-controllers (NSC) based on their behavior during the experiment, and not on their self-reports about diet status during the recruiting process."

So really, the study isn't about dieting at all,¹ because one could be a "self-controller" in the experiment and yet report no dietary restrictions in real life. And actually, the study may not even say much about food choices in the real world, because a participant could say she'd choose the broccoli over the brownie to gain the experimenter's approval, but then go home and eat ice cream for dinner.

Back to the subject selection:

"Fifty-two subjects participated in the experiment. However 15 subjects did not meet our a priori inclusion criteria based on their behavioral data [they fell into a gray zone]. 37 subjects were included in the analysis. Subjects were divided into two groups based on their behavioral data: successful self-controllers (SC) and non-self-controllers (NSC). The SC group included 19 subjects (14 female ... mean BMI = 24.8 ± 5.2) and the NSC group included 18 subjects (6 female ... mean BMI = 23.2 ± 5.1)."

There's a lot more pressure on women to diet and to give the appearance of restraint, and 70% of them were in the SC group. So who knows, it might be true that the female subjects felt more compelled to choose the healthy choice than they would have in real life.

Anyway, the experimental design is illustrated below:


Fig. 1A. The task proceeded in three parts: taste ratings, health ratings, and decisions.

The subjects viewed pictures of 50 different food items and rated them on a 5 point scale for health and taste in two separate blocks. After this, one food item rated as neutral on both dimensions (e.g., crackers, jello) was selected as the reference item, and subjects had to choose between it and another item on each trial.

"Subjects cared about their choices because they were required to eat the food that they chose in a randomly selected trial at the end of the experiment.² Note that because subjects did not know which trial would count, their optimal strategy was to treat each decision as if it were the only one that counted. Although this is a binary decision task, subjects were asked to express the strength of their preferences using a five-point scale: Strong No (=choose reference) [to] Strong Yes (=choose shown item)."

The participants were sorted into SC and NSC groups according to their behavioral performance during the decision phase. The SC subjects chose food items on the basis of both health and taste, but the NSC group chose on the basis of taste alone. What were the investigators looking for in the fMRI data? They assumed at the outset that the brain's "value assigner" is located in the ventromedial prefrontal cortex³ (vmPFC), and the "self-controller" (in the dorsolateral prefrontal cortex, DLPFC) modulates value signals in vmPFC.

For fear of beating a dead horse, I won't get into the fMRI data analysis methods here (5 pages in the supplementary methods) and whether there were any "Voodoo Correlations" (or rather, "Puzzlingly High Correlations" - PDF). But here's a figure from Hare et al. with r=.847.


Fig. 2E. Robust linear regression showing a strong relationship between a measure of the effect that health ratings have on vmPFC activity and a measure of the effect that the health ratings have on decisions.

Below is another figure showing that Beta values in vmPFC increased with goal values, regardless of self-control. The legend was taken from Hare et al., Supporting Online Material (PDF).


Fig. 2B (Left). Estimated betas in the vmPFC for each of the regressors. This plot was constructed as follows. First, for each individual and type of trial we measured the associated beta value at the peak voxel for the goal value contrast (GLM 1) inside the vmPFC ROI shown in Fig. 2A (Right). The individual subject peaks were selected from within this ROI to allow for variability between subjects. Second, the mean and standard error of these betas were computed for each type of trial.

Now what about self-control in the DLPFC? A region in the left middle and inferior frontal gyri (IFG/BA 9) was more active during "self-control" trials in both groups, with the SC group showing this to a greater extent than the NSC group. And finally there was the requisite functional connectivity analysis (PDF) to explain the inverse relationship between greater activation in IFG/BA 9 and reduced activation in vmPFC. But since these two regions did not exhibit task-related functional connectivity, another area (IFG/BA 46, of course) had to be mediating the self-controlling effect of IFG/BA 9 on vmPFC. Got that? Hmm.

One of the things that struck me about this paper⁴ is the remarkable lack of scholarship, particularly when concluding in such a grandiose fashion:

"Lastly, an improved understanding of the neurobiology of self-control in decision-making will have applications to clinical practice in domains such as obesity and addiction, to economic and public policy analysis in problems such as suboptimal savings and health behaviors, and to legal thinking about which criteria should be used in determining if an individual is in full command of his decision-making faculties and thus accountable to the law."

Let's take the applications for obesity as our most relevant example here. Were there any citations of the literature on neurodegenerative disorders and appetite? Case studies of brain lesions and appetite? Studies of obese vs. lean individuals? Eating disordered vs. normal weight people? No, no, no, and no. Since they didn't cite any papers in these important [and more ecologically valid, if you really want to learn about self-control over food choices] areas of inquiry, here's what I learned from a PubMed search. A voxel-based morphometry study in patients with frontotemporal dementia demonstrated that binge eating was associated with greater degeneration in the right ventral insula, striatum, and orbitofrontal cortex (Wooley et al., 2007). Conversely, tumors in the right lateral frontal cortex have been associated with anorexia in several case reports (Houy et al., 2007; Trummer et al., 2002). In healthy subjects, transcranial direct current stimulation over DLPFC (specifically to increase neuronal firing over the right and to decrease it over the left DLPFC) was shown to reduce food cravings (Fregni et al., 2008). Neuroimaging studies have observed less activation in the left DLPFC of obese participants after a meal than was observed in lean participants (Le et al., 2006, 2007). There's even a right PFC hypothesis of obesity (Alonso-Alonso & Pascual-Leone, 2007).

You'd think all of this might have been relevant to an article on the neurobiology of self-control over food choices, but apparently not. Time for some chocolate cake. I just can't help myself...

Footnotes

¹ The writer of the press release can be excused for getting this wrong because in the main article, Hare et al. lead the reader to believe that the subjects are all dieters:

To test these hypotheses, we recruited self-reported dieters and used functional magnetic resonance imaging (fMRI) to study the neural activity in vmPFC and DLPFC while the participants made real decisions about which foods to eat.

² At the end of the experiment, were the participants asked how much they really cared about their choices, or is that just a proclamation?

³ The words dopamine, nucleus accumbens, and basal ganglia did not appear in the article (ignoring previous studies on the topic). The phrase "vmPFC-striatal network" appears once but is dissed right away.

⁴ ...besides everything else I've said thus far...

Additional Reading

Alonso-Alonso M, Pascual-Leone A. (2007). The right brain hypothesis for obesity. JAMA 297:1819-22.

Fregni F, Orsati F, Pedrosa W, Fecteau S, Tome FA, Nitsche MA, Mecca T, Macedo EC, Pascual-Leone A, Boggio PS. (2008). Transcranial direct current stimulation of the prefrontal cortex modulates the desire for specific foods. Appetite 51:34-41.

Houy E, Debono B, Dechelotte P, Thibaut F. (2007). Anorexia nervosa associated with right frontal brain lesion. Int J Eat Disord. 40:758-61.

Le DS, Pannacciulli N, Chen K, Del Parigi A, Salbe AD, Reiman EM, Krakoff J. (2006). Less activation of the left dorsolateral prefrontal cortex in response to a meal: a feature of obesity. Am J Clin Nutr. 84:725-31.

Le DS, Pannacciulli N, Chen K, Salbe AD, Del Parigi A, Hill JO, Wing RR, Reiman EM, Krakoff J. (2007). Less activation in the left dorsolateral prefrontal cortex in the reanalysis of the response to a meal in obese than in lean women and its association with successful weight loss. Am J Clin Nutr. 86:573-9.

Trummer M, Eustacchio S, Unger F, Tillich M, Flaschka G. (2002 ). Right hemispheric frontal lesions as a cause for anorexia nervosa report of three cases. Acta Neurochir (Wien). 144:797-801

Woolley JD, Gorno-Tempini ML, Seeley WW, Rankin K, Lee SS, Matthews BR, Miller BL. (2007). Binge eating is associated with right orbitofrontal-insular-striatal atrophy in frontotemporal dementia. Neurology 69:1424-33.


Reference

Hare, T., Camerer, C., & Rangel, A. (2009). Self-Control in Decision-Making Involves Modulation of the vmPFC Valuation System. Science, 324 (5927), 646-648. DOI: 10.1126/science.1168450

Introduction: The concept of self-control in decision-making has occupied philosophers and scientists throughout recorded history because the ability to exercise it is central to human success and well-being. Behavioral studies have examined the problem of self-control and provided valuable insights that suggest it is exhaustible in the short term (1–3), can be enhanced by cognitive strategies (4–7), and is correlated with measures of intelligence (8–10). However, little is known about the neurobiological underpinnings of self-control and how these neural mechanisms might differ between successful and unsuccessful self-controllers.

I told myself it would be different when I had children. We'd share our experiences and feelings together. We'd be so close. But I'm just like my father, a drunken slob. And the only feelings I share are no, no feelings at all. The only feelings I share are no feelings at all.

-Karen Finley, The Constant State of Desire (from Shock Treatment)

Science Paper Mad Libs (Cog Neuro Edition)

mad libs, by roboppy

Want to get published in Science? Try using this template:

The concept of _____________ has occupied philosophers and scientists throughout recorded history because the ability to _________ is central to human ________ and ________. Behavioral studies have examined the problem of ________ and provided valuable insights that suggest it is __________ (1–3), can be enhanced by ___________ (4–7), and is correlated with _____________ (8–10). However, little is known about the neurobiological underpinnings of ___________ and how these neural mechanisms might differ between ___________ and __________.

Yes, that's right, a sure-fire formula to a better CV and Google Magic! Rank on Google's 1st Page in as little as 24 hours! Not only that, you can learn how to be SEO friendly: descriptive keywords with high search frequency this tool will tell u if ur website keywords r hot or not.

You can trust us. We Are Scientists.

Twitter as an Incubator of Swine Flu Misinformation

xkcd

Randall Munroe is not that far off... Foreign Policy's net.effect blog is one of many blogs with a story about this:

Swine flu: Twitter's power to misinform

Sat, 04/25/2009 - 5:56pm

Who knew that swine flu could also infect Twitter? Yet this is what appears to have happened in the last 24 hours, with thousands of Twitter users turning to their favorite service to query each other about this nascent and potentially lethal threat as well as to share news and latest developments from Mexico, Texas, Kansas and New York (you can check most recent Twitter updates on the subject by searching for “swine flu” and “swineflu”). And despite all the recent Twitter-enthusiasm about this platform's unique power to alert millions of people in decentralized and previously unavailable ways, there are quite a few reasons to be concerned about Twitter's role in facilitating an unnecessary global panic about swine flu.

. . .

However, in the context of a global pandemic – where media networks are doing their best to spice up an already serious threat – having millions of people wrap up all their fears into 140 characters and blurt them out in the public might have some dangerous consequences, networked panic being one of them. If you think that my concerns about context are overblown, here are just a few status updates from random Twitter users that would barely make you calmer (or more informed) about what's going on:

I'm concerned about the swine flu outbreak in us and mexico could it be germ warfare? (link)

In the pandemic Spanish Flu of 1918-19, my Grandfather said bodies were piled like wood in our local town....SWINE FLU = DANGER (link)

Good grief this swine flu thing is getting serious. 8/9 specimens tested were prelim positive in NYC. so that's Tx, Mexico and now Nyc. (link)

Short Ribs! How long before the Swine Flu hysteria crashes the pork market? 2 hours? 3? (link)

be careful of the swine flu!!!! (may lead to global epidemic) Outbreak in Mexico. 62 deaths so far!! Don't eat pork from Mexico!! (link)

Swine flu? Wow. All that pork infecting people....beef and chicken have always been meats of choice (link)

SIMPLE CURE FOR THE NEW BHS (BIRD/HUMAN/SWINE FLU) AS REPORTED ON TV LAST NIGHT IS THE DRUG TAMIFLU....ALREADY A PRESCRIPTION ON THE MARKET (link)

Be careful...Swine Flu is not only in Mexico now. 8 cases in the States. Pig = Don't eat (link)

Don't follow that crowd, follow @CDCEmergency instead:

Swine flu - 40 confirmed cases. New York count now at 28. http://bit.ly/KO5pA
about 3 hours ago from web

20 confirmed cases of swine flu in U.S. 1 hospitalized. All have fully recovered. http://bit.ly/uycgL #swineflu
about 20 hours ago from web

someecards

"All I need is a TV show..."

A Warm TV Can Drive Away Feelings of Loneliness & Rejection

Studies find that illusionary relationships with TV characters can give us real pleasure

Release Date: April 22, 2009

BUFFALO, N.Y. -- Not all technology meets human needs, and some technologies provide only the illusion of having met your needs.

But new research by psychologists at the University at Buffalo and Miami University, Ohio, indicates that illusionary relationships with the characters and personalities on favorite TV shows can provide people with feelings of belonging, even in the face of low self esteem or after being rejected by friends or family members.

The findings are described in four studies published in the current issue of the Journal of Experimental Social Psychology [Derrick et al., 2009].

However, after some sleuthing to uncover the classical literature on the topic, I've discovered that Rutherford et al. (1980) described this phenomenon nearly 30 years ago:

You're just another face that I know from the TV show
I have known you for so very long I feel you like a friend
Can't you do anything for me, can I touch you for a while
Can I meet you on another day and we will fly away

Turn It On Again
------Rutherford et al. 1980

Derrick et al., 2009 replicated this finding in a series of four experiments, all of which supported the Social Surrogacy Hypothesis, i.e.,

...that parasocial relationships provided by television programs can yield the experience of belonging. Specifically, we drew three primary predictions from the Social Surrogacy Hypothesis. If favorite television programs can yield the experience of belonging, we hypothesized that (1) events that typically elicit belongingness needs (e.g., threats to a relationship, a rejection experience) would elicit a desire to experience a favored television program, (2) thinking about a favored television program could buffer against threats to real-world belongingness, and (3) thinking about a favored television program should reduce the accessibility of loneliness related concepts.

In Study 1, 701 college students completed the lonely activities scale and the likelihood of feeling lonely scale. These scales were developed for the current study by asking 12 other undergraduates to list non-social activities that people might do when they feel lonely. A final list of 31 activities was given to the larger group, who were asked to rate the items on a scale of 1 (would definitely not do) to 7 (definitely would do). The top six items were:

• Listen to music – a particular CD/tape
• Watch television – a favorite TV program
• Sleep
• Surf the web
• Eat
• Exercise

Participants were also asked to rate their likeliness of feeling lonely when doing these activities, on the same 7 point scale. And not surprisingly (since we already know that all of the experiments supported the hypothesis), people felt significantly less lonely when watching TV.

Of course, this result was only correlational in nature, so Study 2 manipulated "belongingness needs". Half of the participants were asked to write an essay about a fight with a close other, and the other half were asked to list as many items at home as they could remember. I would have suggested a better neutral essay-writing condition than the residental list, along with a condition to deliberately reduce "belongingness needs" (like an essay about an enjoyable shared experience with a close other). But then again, I'm not a social psychologist, so what do I know?

After the first writing exercise, subjects were asked to write another essay about watching either a favorite show, or whatever was on at the time.

Participants in the Favored condition wrote about a time they watched their favorite television program, describing it in as much detail as possible. Participants in the Control condition wrote about a time when they had watched “whatever was on” television, describing it in as much detail as possible. Participants were asked to describe as much as they could about the content of the program and their experience watching it. Length of time writing this Parasocial essay served as the primary dependent measure.

Lo and behold, the predicted Belongingness Needs × Parasocial Essay interaction was obtained:


Fig. 1 (Derrick et al., 2009). Length of time spent writing television essay as a function of social needs condition and type of television program.

Study 3 was nearly identical to Study 2, except the Parasocial Essay component was limited to 6 min, and the dependent measures were self-esteem, mood, and feelings of rejection. Again, the predicted Belongingness Needs × Parasocial Essay interactions were obtained for state self-esteem, mood, and a trend for feelings of rejection.

Now the authors need to extend these findings to actually watching a favorite vs. a random TV show, instead of just thinking about watching.

See also:

TV Relieves Loneliness

Does Your TV Give You the Warm Fuzzies?

References

Derrick, J., Gabriel, S., & Hugenberg, K. (2009). Social surrogacy: How favored television programs provide the experience of belonging. Journal of Experimental Social Psychology, 45 (2), 352-362. DOI: 10.1016/j.jesp.2008.12.003

Rutherford M, Collins P, Banks T. (1980). Turn It On Again. Duke.

All I need is a TV show, that and the radio
Down on my luck again, down on my luck again
I can show you I can show you some of the people in my life
I can show you I can show you some of the people in my life
It's driving me mad just another way of passing the day
I, I get so lonely when she's not there

Turn It On Again
------Rutherford et al. 1980

Neural Correlates of Admiration and Compassion and Envy and Schadenfreude

In light of all the sensationalistic press coverage about a journal article that wasn't publicly available last week, it's worth taking a moment to look at the actual experiment. Of course, the savvy skeptics know by now that the paper in question (Immordino-Yang et al., 2009) has absolutely nothing to do with Twitter (see Recommended Reading below for a recap). Instead, the authors conducted a neuroimaging study to examine the brain's response to stories designed to elicit the emotions of admiration and compassion. To do this, the participants (n=13) first watched a series of mini-documentary narratives about real people (who were not celebrities). Each of the 50 narratives was 60-90 sec long, and incorporated audio, video, and still images to convey stories categorized as:

1. Admiration for virtue (AV), which involved people performing highly virtuous, morally admirable acts. The narratives emphasized the virtuous and morally admirable nature of the protagonist, such as dedication to an important cause despite difficult obstacles, and did not include displays of notable skill.

2. Admiration for skill (AS), which involved people adeptly performing rare and difficult feats, e.g., an athletic or musical performance, with both physical and cognitive components. No physically or socially painful acts were shown, and the skillful feats, although amazing, did not imply a virtuous protagonist or reveal a virtuous act.

3. Compassion for social pain (CSP), which involved people in states of grief, despair, social rejection, or other difficult psychological circumstances. No physical pain was evident in these narratives, and the troubling circumstances were discerned from the descriptions, rather than being apparent in the images shown.

4. Compassion for physical pain (CPP), which involved people sustaining a physical injury. The injuries were caused by sports and other mishaps and had no moral or social implications. The injuries were not the result of malevolence, and the participants were reassured that the injuries had no long-term implications....

5. Control narratives, which involved comparable living, mentally competent people engaged in or discussing how they felt about typical activities under commonplace social circumstances. These circumstances were engaging but not emotion provoking.

After each of the narratives, the subjects were asked to discuss how they felt about the protagonist's situation. This part of the study took 2 hrs, and was conducted outside the scanner. For the fMRI portion of the protocol, 5 sec recaps of all 50 scenarios were presented, and the task was to:

induce in themselves for each story, as strongly as possible, a similar emotional state to the one they had experienced during the preparation session and to push a button to indicate the strength of the emotion they achieved in the scanner (from 1 to 4...). Participants were asked to report candidly on the strength of their current feelings in the scanner, rather than on the strength of feeling they remembered from the preparation session.

OK, so the subjects were first asked to remember how they felt 2 hrs ago, then try to duplicate that feeling, and then report on how they feel now (rather than before). So there's a memory component and a decision component (i.e., to not confuse past feelings with the present). Each trial was sorted post hoc on the strength of the reported emotion, and only the effective trials were included in the analysis.

The comparisons of interest were pain (compassion) vs. non-pain (admiration), and emotional responses to other peoples’ social/psychological conditions (AV, CSP) vs. to their physical conditions (AS, CPP). One of the first issues discussed is the recruitment of homeostatic mechanisms when experiencing these social emotions:

It is well known that basic emotions such as fear, sadness, and happiness and limited social emotions such as moral indignation engage neural systems concerned with sensing and regulating body function with varying patterns, and it has been hypothesized that among those systems, the insula plays an especially prominent role. It is also known that engagement of social emotions and the consequent feeling for another’s social/psychological situation are described by poets and lay people alike in visceral and bodily terms and in terms of their heightening effect on one’s own self-awareness or consciousness.

Basically, people may have visceral responses to the circumstances of others. How do these responses differ across physical vs. psychological situations? For example, admiring a gymnast's skill on the balance beam vs. admiring a student's charity work with Habitat for Humanity? Or feeling compassion for a single mother who loses her job vs. feeling compassion for one who sprains her ankle? Although it's not mentioned in the paper, this idea draws on Antonio Damasio's somatic marker hypothesis (e.g., Damasio, 1996). Perhaps this omission occurred because two of the main regions implicated -- the ventromedial prefrontal cortex (VMPFC) and the amygdala -- were not discussed in the paper [however VMPFC is difficult to image using fMRI because of susceptibility artifacts]. The somatic marker hypothesis is succinctly described by the title of one of Damasio's books: The Feeling of What Happens: Body and Emotion in the Making of Consciousness (1999).

Other components in the somatic marker circuit include the insular cortex, a region implicated in interoceptive awareness of bodily states (Craig, 2009), and somatosensory cortices responsive to external stimuli. Because activity in the anterior insula features primarily in the Twitter-warped distortion of the story, I'll start here with the authors' third hypothesis:

3. that activation in the anterior insula would peak and dissipate more quickly for CPP than for CSP or varieties of admiration.

In a way, this is a trivial prediction, because one can evaluate the sprained ankle narrative more quickly than the job loss scenario. In fact, I will argue below that simple behavioral response time might be a more precise measure of how long it takes to generate the emotion in question than is the hemodynamic response (blood flow changes, measured by the BOLD signal in fMRI) in the insular cortex. One reason for this is because of the significant delay (5-6 sec at least) between initial neural firing and the peak of the hemodynamic response, which is estimated using a procedure that is not trivial for something as complex as an emotional response (for a more detailed discussion of this issue, I recommend this PPT file from Jodi Culham's excellent fMRI 4 Newbies site).

Let's start with a simpler example. The figure below shows the averaged hemodynamic response function (HRF) in the primary visual cortex to a series of flashes. The HRF peaks at ~5 sec after the flash, whereas neurons in primary visual cortex fire within 50 msec and drop off shortly thereafter. Thus, the hemodynamic response to even a simple sensory stimulus lags behind neuronal firing by 5 sec.


Fig. 2 (Calhoun et al., 1998). Time courses from four regions in the calcarine cortex (Pl-P4) and the averaged response (CIRQ). Amplitude units are normalized to a maximum of one and a baseline of zero.

The next example shows the HRFs in occipital regions and the insula while subjects viewed rotating objects. The precise details aren't important here, but note the peak latency for the HRF in the insula is around 6-8 sec, with the later peak for novel objects (compared to repeated objects).


Fig 2C (Weigelt et al., 2007). Event-related deconvolved BOLD fMRI responses (GLM parameter estimates averaged across trials and subjects for all voxels in each ROI) reported against time for each of the experimental conditions.

That brings us back to Immordino-Yang et al. and the emotional narratives. In the figure below, note that the HRF time course does peak earlier for the CPP condition compared to the others, as predicted. However, the CSP condition rises at the same time, albeit with a later (very broad) peak.


Fig. 3 (Immordino-Yang et al., 2009). Event-related averages for the time courses of admiration and compassion in the anterior insula, with standard errors. Units are percentage change in BOLD signal and time in seconds; time courses are not corrected for hemodynamic delay. For display purposes, BOLD data have been linearly interpolated to 1-s resolution. The volume of interest is displayed in pink. Conditions: AV (green): admiration for virtue; AS (yellow): admiration for skill; CSP (blue): compassion for social pain; CPP (red): compassion for physical pain. Note the rapid rise and dissipation of CPP versus the slower and more sustained rise of CSP, AV, and AS.

It's critical to note that the onset of a felt emotion is not as easy to determine as the onset of a visual object. Although more detailed methods are in the Supplementary Materials not available as of this writing, it seems that respiration and heart rate data were obtained in 7 of the 13 subjects to help with this. I would say these psychophysiological responses, in concert with the participants' own reaction times for rating their subjective responses, would provide a more accurate measure of how long it takes to feel an emotion than the fMRI data. It's hard to know what an insular HRF of 6 sec vs. 10 sec means when watching a fast-paced movie or reading the CNN news crawl or yes, spending too much time on Twitter. Nonetheless, on the basis of these imprecise latency measures, the authors speculate:

If replicated, this finding could have important implications for the role of culture and education in the development and operation of social and moral systems; in order for emotions about the psychological situations of others to be induced and experienced, additional time may be needed for the introspective processing of culturally shaped social knowledge. The rapidity and parallel processing of attention-requiring information, which hallmark the digital age, might reduce the frequency of full experience of such emotions, with potentially negative consequences.

And there's your "Twitter is evil" angle.



I'll leave you with this final thought: where's the line between admiration and envy, between compassion and schadenfreude? There actually is a recent paper on the Neural Correlates of Envy and Schadenfreude (Takahashi et al., 2009), and for now I'll refer you to this nice summary in Pure Pedantry.

ADDENDUM (Monday 4:20 PM): You can read more details about the Methods in the Supporting Information, which is now freely available to all on the PNAS website, as is the open access article itself.


Recommended Twitter Reading:

Social media threats hyped by science reporting, not science (Ars Technica)

Experts say new scientific evidence helpfully justifies massive pre-existing moral prejudice. (Bad Science)

For the last time: that "Twitter is Evil" paper is not about Twitter! (Bioephemera)

Is Twitter evil? (Cosmic Log at MSNBC - despite the ridiculous headline, it's one of the few popular science articles to talk about the actual study... it even included a figure from the paper)

The Neurology of Twitter (The Neurocritic proposes an actual fMRI study of Twitter, complete with predicted results)

The Neurology of Twitter, Part 2 (Yet another recap of the media circus, with a time line of certain events)

References

Craig AD. How do you feel--now? The anterior insula and human awareness. (2009). Nat Rev Neurosci. 10:59-70.

Damasio AR. (1996). The somatic marker hypothesis and the possible functions of the prefrontal cortex. Philos Trans R Soc Lond B Biol Sci. 351:1413-20.



Mary Helen Immordino-Yang, Andrea McColl, Hanna Damasio, and Antonio Damasio. (2009). Neural correlates of admiration and compassion. Proceedings of the National Academy of Sciences.