Neurosurgeon/Terrorist?

Via The Null Device:

Al-Qaeda's best and brightest

Apparently, one of the suspects in the recent UK terrorist attacks was a neurosurgeon. I guess this shows that suicide bombing isn't brain surgery.

Also of note:

A Surgeon’s Trajectory Takes an Unlikely Swerve

. . .

He [Simon Plant, landlord] said that the Ashas were model tenants, but that Dr. Asha, a Palestinian with Jordanian citizenship, had something of a condescending manner. "He got a slight attitude," said Mr. Plant, an elevator engineer. "He had a sense of self-importance about being a doctor. You could definitely feel it."

. . .

Dr. Asha, 26, whose specialty is neurosurgery, recently started work at the North Staffordshire Hospital in Stoke-on-Trent. According to the General Medical Council in Britain, Mohammed Jamil Abdelqader Asha completed his medical studies in Jordan in 2004. His limited registration allowed him to work for the National Health Service under supervision. Until last July, he worked as a doctor at Royal Shrewsbury Hospital and the Princess Royal Hospital, both in Telford.

A 26 year old neurosurgeon? OR was he a mere neurologist?

A photo of suspect Mohammed Asha, shaking hands with Jordan's Queen Noor

Faces ARE Really Special, After All

OR: Bentin, Taylor, Rousselet, Itier, Caldara, Schyns, Jacques, & Rossion respond to Thierry et al.


from Bentin et al. (2007): Supplementary Figure 4. B. These histograms derived from Thierry et al.'s (2007) data provides the best illustration that ISPV cannot account for N170 amplitude, showing an inverse relationship between within-category picture similarity (highest for faces) and N170 amplitude (highest for cars) in the low ISPV condition and similar N170 amplitudes for faces and cars in the high ISPV condition despite lower picture similarity for faces than cars (Experiment 1).

The Phineas Gage Fan Club has noted the publication of a letter to the editor in Nature Neuroscience that's critical of the ISPV paper published by Thierry et al. (2007a) in April. What's ISPV? That's interstimulus perceptual variance, and it was a factor purportedly uncontrolled in prior studies of the N170, an electrophysiological signal thought to be selective for faces (see Are Faces Special?). The specificity of the N170 for faces (vs. other objects) is part of a larger debate on whether faces have a privileged processing status or not (the latter view being that faces are just one example of a stimulus class that requires substantial expertise in order to distinguish between similar exemplars). Then the recent NN paper added more fuel to the fire.

Briefly, in their original article, Thierry et al. argued that previous studies of the N170 component did not adequately control for variability across stimulus classes, i.e., face stimuli were much more similar to each other than the non-face stimuli. When ISPV was more tightly controlled, the selectivity of N170 for faces (vs. cars) went away.

Then, Bruno Rossion, from the Face Categorisation Lab in Belgium, commented that these experiments were kind of... bad and (ironically) failed to adequately control for interstimulus variance, among other things (see also C'mon, Aren't Faces REALLY Special?). The correspondence from Bentin, Rossion, and six more authors (along with a reply by Thierry et al.) appears in the July issue of NN. Johan has done a nice job summarizing the debate in N170 face controversy continues, so I'll only add a few choice quotes:

Here we [Bentin et al.] demonstrate that ISPV was actually controlled in many studies, yet the N170 effect remained conspicuous (Fig. 1 and Supplementary Figures 1,2,3 online). Evidently, Thierry and colleagues' claim is wrong and misleading.

Continuing merrily along:

In addition to their factual error, they failed to note the striking contradiction between their hypothesis and the existing literature. Most notable are the larger N170 for inverted than for upright faces, the larger N170 for upright than for inverted Mooney faces..., [etc.] All these modulations of N170 are robust despite identical stimuli in different conditions, hence identical ISPV.

My favorite, however, is the title for Supplementary Figure 4: "Self-contradictions in Thierry et al.":

Supplementary Figure 4. A. While Thierry et al. claimed to have controlled for inter-stimulus similarity between pictures of faces and objects (exact values not reported), their own data suggest otherwise.

And the debate continues...

References

Bentin S, Taylor MJ, Rousselet GA, Itier RJ, Caldara R, Schyns P, Jacques C, Rossion B. (2007). Controlling interstimulus perceptual variance does not abolish N170 face sensitivity. Nature Neurosci. 10:801-802.

[apparently, the original title for this submission was "Much ado about nothing: controlling interstimulus perceptual variance does not abolish N170 face sensitivity," as listed in the publications of the Face Categorisation Lab. I would imagine the editors at NN did not take too kindly to the "much ado" part...]

Thierry G, Martin CD, Downing P, Pegna AJ. (2007a). Controlling for interstimulus perceptual variance abolishes N170 face selectivity. Nature Neurosci. 10:505-511.

Thierry G, Martin CD, Downing P, Pegna AJ. (2007b). Is the N170 sensitive to the human face or to several intertwined perceptual and conceptual factors? Nature Neurosci. 10:802-803.

Captain My Captain

Walt Whitman (1819–1892). Leaves of Grass. 1900.

193. O Captain! My Captain!

1

O Captain! my Captain! our fearful trip is done;
The ship has weathered every rack, the prize we sought is won;
The port is near, the bells I hear, the people all exulting,
While follow eyes the steady keel, the vessel grim and daring.
But O heart! heart! heart!
O the bleeding drops of red!
Where on the deck my Captain lies,
Fallen cold and dead.

Brain's voluntary chain-of-command ruled by not one but two captains

By Michael Purdy

June 18, 2007 -- A probe of the upper echelons of the human brain's chain-of-command has found strong evidence that there are not one but two complementary commanders in charge of the brain, according to neuroscientists at Washington University School of Medicine in St. Louis.

It's as if Captains James T. Kirk and Jean-Luc Picard were both on the bridge and in command of the same starship Enterprise.


In reality, these two captains are networks of brain regions that do not consult each other but still work toward a common purpose — control of voluntary, goal-oriented behavior. This includes a vast range of activities from reading a word to searching for a star to singing a song, but likely does not include involuntary behaviors such as control of the pulse rate or digestion.

So there you have it. The captains don't talk to each other. This article (of course) is in reference to the paper by Dosenbach and colleagues (2007),¹ in which they described two distinct task-control networks:

A frontoparietal network included the dorsolateral prefrontal cortex and intraparietal sulcus. This network emphasized start-cue and error-related activity and may initiate and adapt control on a trial-by-trial basis. The second network included dorsal anterior cingulate/medial superior frontal cortex, anterior insula/frontal operculum, and anterior prefrontal cortex. Among other signals, these regions showed activity sustained across the entire task epoch, suggesting that this network may control goal-directed behavior through the stable maintenance of task sets.

Scientists exploring the upper reaches of the brain's command hierarchy were astonished to find not one but two brain networks in charge, represented by the differently-colored spheres on the brain image above. ... The regions in each network talked to each other often but never talked to brain regions in the other network. [from the wustl "two captains" news release by M. Purdy]

Shouldn't they be talking to each other at some point?

These two independent networks appear to operate on different time scales and affect downstream processing via dissociable mechanisms. [from Dosenbach et al., 2007]

If they're not talking directly to each other², how does the sustained control network communicate the need to adjust performance on a moment-to-moment basis, and how does making a mistake (for instance) engage the sustained control network?

For possible answers to those questions, one is drawn to a popular model of discrete regions for cognitive control³ and conflict monitoring (Botvinick et al., 2001), which has been discussed at Developing Intelligence. Interestingly, Botvinick and colleagues seem to have located the areas for errors/trial adjustments and the areas for sustained task performance in the opposite structures from Dosenbach et al. (2007) [...sort of]. Namely, the conflict monitoring hypothesis (see also Botvinick et al., 2004; Yeung et al., 2004) places "watching out for response conflicts" (e.g., naming the ink color here -- BLUE -- as in the Stroop task) and "watching out response gaffes" (e.g., saying "blue" instead of "red" to the word above) in the anterior cingulate cortex. These functions would be part of the frontoparietal network for Dosenbach et al. (2007). Meanwhile, for Botvinick et al., the dorsolateral prefrontal cortex (PFC) implements "control"⁴ on a trial-by-trial basis and maintains task set on a sustained basis. Similarly, as part of the frontoparietal network, the dorsolateral PFC is involved in implementing adaptive control on a trial-by-trial basis for Dosenbach et al. In the longer run, however, this latter scheme puts another network (anterior cingulate/frontal operculum/anterior PFC) in charge of maintaining task set.

How do these views relate to other recent studies that emphasize the brain's network properties? As reviewed in the June 15 PERSPECTIVES in Science, 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), as stated in a prior post by The Neurocritic:

In contrast to the outdated (Fuster, 2000) Modular Paradigm (in which cognitive functions and the contents of cognition are localized in discrete regions [discrete networks??] dedicated to the specific functions and domains), Fuster has long supported the Network Paradigm where higher cortical functions are distributed across brain regions, showing extensive intersection and overlap. In this scheme, one neuron can be part of many networks.

Fuster's unique twist is his emphasis on "extensive intersection and overlap," particularly at the highest levels of the hierarchy [where things are most distributed, rather than orchestrated by a single "central executive"].

To be fair, novel approaches by the non-Fuster investigators (reviewed by Knight in the Debunking Phrenology commentary) include characterizing the nature of neuronal oscillations that synchronize activity across cortical regions [but even aspects of that research are not all that new, of course; the recent Science article by Womelsdorf, Singer et al. certainly builds on their prior work dating back to the late 80's-early 90's].

At the end of the day, however, a lot of time and effort and money is still spent in search of the captain(s).


Footnotes

¹ See also The New Neuroscience Party Game.

² But see this quote on page 11077: "The frontoparietal and cinguloopercular control networks were strongly intraconnected and quite separate from each other, suggesting that they carry out dissociable control functions. The networks may nonetheless communicate with each other."

³ The function formerly known as "executive control."

⁴ It would be good to listen to The Faint's The Conductor (Thin White Duke Mix), but I couldn't find the mp3 online. Imagine "control control control control control control..." repeated 100 times to an electroclash beat. Other tracks available here, though.


References

Botvinick MM, Braver TS, Barch DM, Carter CS, Cohen JD. (2001). Conflict monitoring and cognitive control. Psychol Rev. 108:624-52.

Botvinick MM, Cohen JD, Carter CS. (2004). Conflict monitoring and anterior cingulate cortex: an update. Trends Cog Sci. 8:539-46.

Dosenbach NU, Fair DA, Miezin FM, Cohen AL, Wenger KK, Dosenbach RA, Fox MD, Snyder AZ, Vincent JL, Raichle ME, Schlaggar BL, Petersen SE. (2007). Distinct brain networks for adaptive and stable task control in humans. PNAS 2007 Jun 18; [Epub ahead of print].

Fuster JM (2000). The module: crisis of a paradigm (book review, The New Cognitive Neurosciences Second Edition, M.S. Gazzaniga, Editor-in-Chief, MIT Press). Neuron 26:51-53.

Knight RT. (2007). Neural networks debunk phrenology. Science 316:1578-9.

Womelsdorf T, Schoffelen JM, Oostenveld R, Singer W, Desimone R, Engel AK, Fries P. (2007). Modulation of neuronal interactions through neuronal synchronization. Science 316:1609-12.

Yeung N, Cohen JD, Botvinick MM. (2004). The neural basis of error detection: conflict monitoring and the error-related negativity. Psychol Rev. 111:931-59.

The New Neuroscience Party Game: Six Degrees of Steve Petersen

A new article in PNAS identified two distinct task-control networks by "applying graph theory to resting state functional connectivity MRI data" (Dosenbach et al., 2007). A press release from Washington University in St. Louis includes this quote from one of the authors (Steven Petersen, Ph.D.):

To enhance their analysis [resting state functional connectivity MRI], Dosenbach and Petersen turned to graph theory, a branch of mathematics that visually graphs relationships between pairs of objects.

"A similar approach is used in the party game Six Degrees of Kevin Bacon," Petersen notes. "You use paired connections — appearances in the same movie, marital relationships — to go from one actor or actress to another until you've identified a chain of connections linking Kevin Bacon and another performer that wasn't immediately obvious."

How many degrees away are you?

Steven E. Petersen, Ph.D., the James S. McDonnell Professor of Cognitive Neuroscience and director of the Division of Neuropsychology in Neurology in the School of Medicine, was elected as a fellow of the American Association for the Advancement of Science (AAAS).
Individuals are elected as AAAS fellows in recognition of their efforts toward advancing science or fostering applications that are deemed scientifically or socially distinguished.

Reference

Dosenbach NU, Fair DA, Miezin FM, Cohen AL, Wenger KK, Dosenbach RA, Fox MD, Snyder AZ, Vincent JL, Raichle ME, Schlaggar BL, Petersen SE. (2007). Distinct brain networks for adaptive and stable task control in humans. PNAS 2007 Jun 18; [Epub ahead of print].

Control regions in the brain are thought to provide signals that configure the brain's moment-to-moment information processing. Previously, we identified regions that carried signals related to task-control initiation, maintenance, and adjustment. Here we characterize the interactions of these regions by applying graph theory to resting state functional connectivity MRI data. In contrast to previous, more unitary models of control, this approach suggests the presence of two distinct task-control networks. A frontoparietal network included the dorsolateral prefrontal cortex and intraparietal sulcus. This network emphasized start-cue and error-related activity and may initiate and adapt control on a trial-by-trial basis. The second network included dorsal anterior cingulate/medial superior frontal cortex, anterior insula/frontal operculum, and anterior prefrontal cortex. Among other signals, these regions showed activity sustained across the entire task epoch, suggesting that this network may control goal-directed behavior through the stable maintenance of task sets. These two independent networks appear to operate on different time scales and affect downstream processing via dissociable mechanisms.

Danah Boyd on the Social Networking Class Divide

myspacebook

From the Annals of the Ever-Expanding Universe of Danah Boyd¹ comes an article from the BBC:

Social sites reveal class divide

Fans of MySpace and Facebook are divided by much more than which music they like, suggests a study.

A six-month research project has revealed a sharp division along class lines among the American teenagers flocking to the social network sites.

The research suggests those using Facebook come from wealthier homes and are more likely to attend college.

By contrast, MySpace users tend to get a job after finishing high school rather than continue their education.

. . .

Broadly, Ms Boyd found Facebook users tend to be white and come from families who are keen for children to get the most out of school and go on to college.

Characterising Facebook users she said: "They are in honors classes, looking forward to the prom, and live in a world dictated by after school activities."

By contrast, the average MySpace teenager tends to come from families where parents did not go to college, she said.

Ms Boyd also found far more teens from immigrant, Latino and Hispanic families on MySpace as well as many others who are not part of the "dominant high school popularity paradigm".

"MySpace has most of the kids who are socially ostracised at school because they are geeks, freaks, or queers," she said.

Teenage users of both sites have very strong opinions about the social network they do not use, she noted.

. . .

..."This division is just another way in which technology is mirroring societal values."

via The Null Device

Footnote

¹ 522,000 hits and counting

See also:

viewing American class divisions through Facebook and MySpace

One Word.

Scared. Angry. Putting a one word label on the face to the left by pressing one of two buttons was an experimental task performed by participants in a recent study by Lieberman et al. (2007). That's the same as years of talk therapy, according to science writers and even Lieberman himself. For example,

Adapted from Fig. 1 of Lieberman et al. (2007).

Talking the pain away ...

[...after reading about this horribly, horribly overinterpreted study...]

by Lea Winerman
[APA] Monitor Staff [they should know better! one word: shame!]

Tell your troubles to a Guatemalan worry doll, place it beneath your pillow and, according to legend, those worries will be gone by morning. That’s just one example of the culture-spanning idea that putting problems into words can blunt those problems’ emotional impact. Centuries of thinkers—from Spinoza to William James to every psychologist who practices talk therapy—have recognized this peculiar power of language, according to UCLA psychologist Matthew Lieberman, PhD.

. . .

Using fMRI, the researchers found that when the participants labeled the faces’ emotions using words, they showed less activity in the amygdala—an area of the brain associated with emotional distress. At the same time, they showed more activity in the right ventral lateral prefrontal cortex...

...this suggests that verbalizing an emotion may activate the right ventral lateral prefrontal cortex, which then suppresses the areas of the brain that produce emotional pain. [because deciding whether a face is angry or scared is so emotionally wrenching.]

"[In talk therapy] we tend to focus primarily on content and enhanced understandings and changed understandings," said Lieberman. "But it’s not entirely irrelevant that they all involve putting feelings into words."

One word.

...is a bomb in your hands.

-- Scrawl, One Word

What was the study about? The researchers compared "affect labeling" (shown above) to other kinds of tasks to see which brain regions were specifically active when people pressed a button to indicate whether a facial expression conveyed fear or anger [for instance; "happy" and "surprised" were other possibilities, but these occurred only 20% of the time]. What were the other tasks? The five control conditions were "affect matching"(choosing which of two faces matches the expression of the target), "gender matching" (choosing which of two faces matches the gender of the target), "shape matching" (with simple geometric shapes) "gender labeling" (choosing the gender-appropriate name), and "observe affect" (just look at the emotional face without making a response). The most important contrast was affect labeling vs. gender labeling.


Adapted from Fig. 1 of Lieberman et al. (2007).

What were the results, and how should we interpret them? Mind Hacks is most certainly on the right track (bold emphasis mine):

The VLPFC increases its activity to dampen down the emotions triggered by the amygdala.

However, it's not clear whether this happens equally for both positive and negative emotions, as 80% of the faces in the study had expressions of anger or fear, while only 20% displayed happiness or surprise, so this data only really tells us about unpleasant feelings.

We know that observing emotion in others makes us more likely to feel the same thing ourselves, but it's not the same as experiencing an emotion 'first-hand', so we need to be a bit careful in assuming that this study fully represents the more everyday experience of talking about our emotions.

This experiment gives us a good understanding of the brain circuit involved reducing emotional impact via naming, but it doesn't tell us much about why this occurs.

This is one of the major drawbacks of neuroimaging studies. They often just redescribe an effect in terms of brain activity.

Yes. But that doesn't stop journalists from wild extrapolation (see blogosphere debate on the conflict between scientists vs. science journalists).

Name that feeling: You'll feel better

By Julie Steenhuysen
Thu Jun 21, 12:31 AM ET

CHICAGO (Reuters) - Putting feelings into words makes sadness and anger less intense, U.S. brain researchers said on Wednesday, in a finding that explains why talking to a therapist -- or even a sympathetic bartender -- often makes people feel better.

They said talking about negative feelings activates a part of the brain responsible for impulse control.

"Anger." There. I wrote it. Press the right button. Do I feel better now? Do you?

You're scaring me now in the new year
You're scaring me now
You're scaring me now
One word is a bomb in your hands
One word becomes a bomb in your hands
One word is a bomb in your hands

-- Scrawl, One Word

Reference

Lieberman MD, Eisenberger NI, Crockett MJ, Tom SM, Pfeifer JH, Way BM. (2007). Putting feelings into words: affect labeling disrupts amygdala activity in response to affective stimuli. Psychol Sci. 18(5):421-8.

Putting feelings into words (affect labeling) has long been thought to help manage negative emotional experiences; however, the mechanisms by which affect labeling produces this benefit remain largely unknown. Recent neuroimaging studies suggest a possible neurocognitive pathway for this process, but methodological limitations of previous studies have prevented strong inferences from being drawn. A functional magnetic resonance imaging study of affect labeling was conducted to remedy these limitations. The results indicated that affect labeling, relative to other forms of encoding, diminished the response of the amygdala and other limbic regions to negative emotional images. Additionally, affect labeling produced increased activity in a single brain region, right ventrolateral prefrontal cortex (RVLPFC). Finally, RVLPFC and amygdala activity during affect labeling were inversely correlated, a relationship that was mediated by activity in medial prefrontal cortex (MPFC). These results suggest that affect labeling may diminish emotional reactivity along a pathway from RVLPFC to MPFC to the amygdala.


If I give it a name it wouldn't be love
If I give it a name it wouldn't be love
IT WOULDN'T BE LOVE

-- Scrawl, One Word

Not A Family Blog, After All

This rating was determined based on the presence of the following words:

> p**** (26x) - all but one in the recent homunculus post
> s** (5x)
> g** (4x)
> b*mb (3x)
> or*f*ce (1x)

[And that's not even including death or suicide or endophenotype or melanocortin receptor.]


via the NC-17 rated A Blog Around The Clock.