February 28, 2009

intimacy can be expensive

What does "intimate" mean?

Recently, we received a letter from one JoAnn LaBrecque-French, Director of Marketing and Communications of the Washington National Opera, telling us that the price for renewing our opera subscription would increase. 

Ours are among the best seats in the cheapest section: Front-row aisle, way up in the second (top-most) balcony. Turns out that WNO is, quite reasonably, carving out a new "second tier premium" section, so they can charge more for such seats. Good for them.

But, how did they choose to communicate this? Ms. LaBrecque-French wrote:
In an effort to create a more intimate opera experience, Washington National Opera observed the seating preferences of its partrons and made some adjustments to the seating and price charts for the upcoming 2009-10 season.
Well. Since when does "intimate" mean costly?

February 24, 2009

investment is a good thing

One might think that obliging people to specify hypotheses about the way their data are caused is a good thing; but it does require a lot more investment and prior knowledge.

February 19, 2009

everything you always wanted to know about...

The wikipedia page on hippocampal anatomy is less than one year old, and it's great. The editors who created it did so in part to shorten wikipedia's (much larger) main hippocampus page. 

February 18, 2009

"The green-eyed monster that lives in your brain."

Yesterday I asked whether the New York Times headline concerning the recent neuroimaging study of envy was silly.

But the coverage in the UK's Daily Mail is even sillier. They report that scientists have found the brain's "jealousy lobe," and announce that the "area of the brain which controls jealousy has been found." Yeah, sure. And every crowing rooster "controls" the rising sun.

brain knitting – is that like brain mapping?

[Source: The UK's Daily Telegraph.]

February 17, 2009

um, what would be the alternative?

I would generally like to write only positive, affirmative, things here. But sometimes, you just gotta wonder...

An interesting functional imaging study of envy appears in this week's issue of Science, and is written up in today's New York Times. The headline in the Times is: "In pain and joy of envy, the brain may play a role." 

Well, really. Um, what precisely would the alternative be, that the brain does not "play a role" in envy? 

February 16, 2009

congratulations!, you have answered the question, What's a nice physicist doing in a hospital-based brain scanning center?

one more thought on flexibility

Because MRI is so flexible – because it allows us to sensitize images to various physical, physiological, pathological, and functional properties of the brain – we sometimes call it an employment program for physicists, who are relied upon to make, and implement, the necessary choices.

February 15, 2009

thumb's up for so what

A few years ago, I was giving a talk at UMBC, hosted by the Department of Electrical Engineering. Early on, I caught a student giving a "thumb's up" sign to his professor. Not bad feedback! 

But afterwards, I asked whether there was a reason for that feedback at that moment, and I received an interesting answer. Recently, the same group of students had received a talk on how to give talks, by a devotee of Edward Tufte. One of Tufte's rules of presentation is that the title of a slide should state not merely the "what" but rather the "so what?" 

So, this introductory slide got a thumb's up for its title, which, after all, could have been something boring like "Brain Images Sensitized to Different Contrasts."

February 14, 2009

brains, bends, & bikes

The differences between a rat and a lawyer include the lawyer's cephalic flexure, or "head bend." 

The long axis of the rat's head lines up with the long axis of the rat's body; the rat's gaze direction lines up with his spine. Whereas, when standing, the lawyer's gaze direction is at right angles to her spine. 

When you hold your arm and your hand out straight in front of you, your hand lines up with your arm like the rat's head lines up with his body. Whereas, the front of the human brain is related to the human body the way your hand is related to your arm, when you hold your arm straight up but with your hand bent, with palm parallel to the floor.

[The cephalic flexure is a potential source of confusion in neuroanatomy, because the relationship between reference systems changes as you move around it. At the base of the brain, the ventral/dorsal (front/back) directions of the brain line up with the ventral/dorsal directions of our body; at the front of the brain, the ventral/dorsal directions of the brain line up with the inferior/superior (bottom/top or foot/head) directions of our body.]

I saw a few fast cyclists on road bikes this morning, all low, flat-backed, and aerodynamic. To me they looked like atavistic critters, human seeking to deny their cephalic flexure, and line up their gaze direction with their spine. I suppose that practice is good because, in the short run, it makes 'em faster, and in the long run, it provides business for chiropractors.

February 11, 2009

voodoo baloney

You may have noticed recent media coverage of the charge that functional brain imaging in social neuroscience is beset by "voodoo correlations".

Without addressing the questions about statistics & etiquette that have been raised, let me just say that I am very grateful to Ed Vul for providing on his website a marvelous (he calls it "charming") 1950 paper (reporting on a talk given in 1949) that brilliantly and succinctly states the problem. The problem was the same, but the context was different: Sixty years ago, the context was not neuroimaging but rather personality tests, and the phrase wasn't "voodoo" but rather "baloney."

Edward Cureton's 1950 paper, entitled "Validity, Reliability, and Baloney," is only three pages long, and well worth the read.

February 10, 2009

mishaps in neuroanatomical nomenclature

If it is true, as has been said, that all of science is either mathematics or stamp collecting, then the question must sometimes arise, how are we to tell the two apart?

One way is mistakes. Because mistakes, such as the inverted jenny, are prized by stamp collectors, but stamped out (sorry!) by mathematicians.

Here are my favorite mistakes in neuroanatomical nomenclature:
  • The optic nerve is not a nerve. Because by definition, "nerves" exist only outside the skull. How about optic tract?
  • The basal ganglia are not ganglia, and are not strictly basal. Because by definition, ganglia exist only outside the skull. You could call 'em nuclei.
  • "Pons" means "bridge" but the pons does not bridge the two cerebellar hemispheres; it only appears to.
  • The substantia innominata (literally stuff with no name) has got a name.
Okay, maybe the last one isn't so much wrong as recursive or self-referential.

February 6, 2009

$10,000.00 prize offered for the human connectome

Today the 2009 Pittsburgh Brain Connectivity Competition was announced, with a $10k first prize:

What's very cool is that the competition organizers provide all the data. So, this is not a contest to build a better device or design a better experiment; it is a contest in analysis. Everybody analyzes the same data. This contest is to best see what's in those data.

The data are not yet available, but they promise to be diverse magnetic resonance images sensitized in clever ways to various aspects of anatomical and functional connectivity. The competition is to best use those data to map brain connections.

$10k! You can't win if you don't play!

February 5, 2009

pluralism & plurality

Yes to pluralism! This year marks the tenth anniversay of a really great paper, from a bunch of really smart people, called Plurality and resemblance in fMRI data analysis

A challenge in functional MRI is figuring out what's in our data. Our raw data are like 3D movies. They have three spatial dimensions, plus time; they are motion pictures or moving pictures of the brain. But in one sense they are worse than a real movie, in that a frame or still from a real movie has got information about the movie, while any one of the images we acquire has no information about brain function. That's because the information about brain function is contained solely in how our images change with time. The challenge then is to analyze these weird brain movies to get, y'know, fMRI activation maps, the familiar (color!) glamour pix. 

How do we do this? Mostly by asking, "When you do something in the scanner – like tapping your fingers – where in the brain does the MRI signal time course resemble the time course of that activity?" By the way, this approach is usually called the General Linear Model (GLM). It works. It may be fair to say that it was the predominant approach ten years ago, when the Plurality & Resemblance paper came out, and it may be fair to say that it is still the predominant approach to fMRI data analysis today.

The GLM is, as you said, like, "putting a frame down on the landscape." It's seeing things in one way, and asking, simply, how much of that one way there is at each brain location. The problem with this is that it does not tell us how well that one way matches or describes what's really going on at each brain location. Fitting a model does not validate it. 

What to do? Why not try different models, and also try approaches that are, say, more loosely framed in the first place, or more exploratory in nature? Why not try a bunch of different appproaches, and compare results? In their paper, Lange et al did just that! They provide:
"... comparisons of results across methods includ[ing] a voxel-specific concordance correlation coefficient for reproducibility, and a resemblance measure...  These measures can assist researchers by identifying groups of models producing similar and dissimilar results, and thereby help to validate, consolidate, and simplify reports of statistical findings. "
Ten years later, it's still a great paper.

February 4, 2009


So, are we now talking about "neuropluralism"? This allows us to get ahead of new developments, and leave ourselves open for anything and everything that might come.

On another note, thanks for the tip on Hebbian networks. Which lead me to associative learning. Which gets me geeked about how, in so many ways, brain researchers, educators, communications experts, are all talking about the same things, and we have so much to share with and learn from each other.

Also, Hebbian is just a swell word. Fun to say, and fun to look at.

re: another SHOCK

Yes, it was simple for a while: Neurons ruled! The story was that brain activity = neuronal activity; that neurons were the only cells that really mattered; that changes in metabolism & blood flow were merely (but reliable) downstream consequences of changes in neuronal spiking.

But now we know that things are more complicated.

The latest finding is that blood flow anticipates stimuli; that areas of visual cortex containing neurons tuned for a location in visual space where a stimulus is expected, literally blush due solely to that expectation, even when the stimulus fails to appears, and the neurons do not increase their activity.

Recently we saw another finding that diminishes the supremacy of the neuron; namely that another population of brain cells, the astrocytes, have their metabolism tuned to stimulus attributes.

Can we call the old oversimple view, imputing dominance to only one type of cell, "neuronist"? I call for us to come together, put neuronal chauvinism (neuronism?) behind us, and celebrate the diversity of our cerebral cell communities!

February 3, 2009

another SHOCK for brain imaging research...


Brain Tutor 3D for iPhone

I put Brain Innovation's amazing new free Brain Tutor 3D app on my iPhone, and I just love it. 

You may be interested in Rainer Goebel's blog post on its development. Turns out, to squeeze a whole brain into that little phone, they did reduce the spatial resolution to 2 mm in each direction, compared to the 1 mm of their other (non-iPhone) products. But wow, what an amazing thing, to have a labeled brain to slice & twirl, on a phone. 

And did I mention that it's free?


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