Boing Boing 

Wide awake during brain cancer surgery

This fascinating video from the Mayo Clinic explains how 28-year-old Mary Meixner went through "awake surgery" during which surgeons used an intra-operative MRI to target her brain tumor.

At the end of the operation, she slept. Then, she says, "I woke up and I was so excited, and I was like, yes! I'm not dead! I can talk! I can think! Because you never know, right?"

Transcript here (PDF).

(via @thespeachgal)

Forecast uncertain: Chaos theory, weather prediction, and brain cancer

A diagnosis of brain cancer is basically a death sentence. It’s a terrible thing for anyone to deal with, and it’s only made worse by all the uncertainty.

Read the rest

Why we love food porn

Turns out, we like food porn for the same reason we like such things as the art of Tom of Finland and certain parts of Dolly Parton. There's a big connection between the way we're attracted to exaggerated sexual characteristics, and the way we're attracted to exaggerated food characteristics.

In a post at Smart Planet, Christopher Mims explains this phenomenon, called supernormal stimuli:

Pioneered in field studies by the ethologists Tinbergen and Lorenz, supernormal stimuli is any phenomenon in which the features of an object — be it a parent, mate, or food — are exaggerated to make an animal respond more strongly to them. In her 2010 book Supernormal stimuli: how primal urges overran their evolutionary purpose, Deirdre Barrett explored the ways in which movie makers, advertisers and fast food companies exaggerate the parts of things we already like in order to hijack our emotions and cravings.

Baby chicks presented with parents with exaggerated versions of the features they’re homing in on — the color of a parent’s beak, say — will respond more strongly to an exaggerated, but artificial, version of their parent than to the real thing. In the same way, humans home in on versions of reality in which the most enticing features are enhanced. In food, that’s texture, color, and anything else we associate with nutrient density, mouth feel and general deliciousness.

That video might not actually be safe for work, by the way.Video Link

The connections between "itch" and "ouch"

The biology of itching and the biology of pain are intertwined in interesting ways, writes graduate student and science blogger Aatish Bhatia. Understanding itching can help us better understand how to treat pain. I'd not seen Bhatia's blog before, but I'm really liking his style. He does a great job of breaking down the science in a clear way.

... In the last decade, researchers have learned about receptors in the nerves under our skin that react specifically to itchy substances. When these receptors fire, they send a signal racing up our spinal cord, headed to our brain where it creates an urge to scratch. Scientists now have a basic map of the roads that an itch takes on its way to our brain. And they have even been able to block some of these roads in mice, essentially preventing them from feeling an itch.

...The picture that is emerging is a complex one, where pain and itch signals are distinct yet subtly intertwined. Of the nerve cells under our skin, some are involved only in signalling pain, and they have pain receptors. Others are responsible for signalling different types of itches, and they have both itch and pain receptors. If the same cell has both receptors, how do we distinguish itch from ouch?

... As the biology of itching becomes better understood, the benefits are making their way from the lab to the clinic. The drug morphine is a powerful painkiller, but has a common side effect of itchiness. Women taking opiates to relieve their labour pain often experience a similar side effect. Zhou-Feng Chen and Yan-Gang Sun, authors of the GRPR receptor study, teamed up with colleagues at the newly founded Center for the Study of Itch and managed to tackle this problem. Their results, published in the current issue of the journal Cell, show that the benefits of morphine can be separated from the itch.

Via Greg Laden

Image: llama itch, a Creative Commons Attribution (2.0) image from davedehetre's photostream

Where does pain happen?

Someone stubs her toe. Where is the pain? In her mind ... or in the toe? In a recent study, laypeople indicated that they thought the pain was in the toe. (Via Scientific American Mind)

The illusory cow

Richard Wiseman found a cow that may have a vase on its face. Or ... maybe ... it has two faces on its face. Is your mind blown yet?

Via Dimitrios Diamantaras

What reward does your brain actually seek?


Dopamine Jackpot! Sapolsky on the Science of... by FORAtv

Dopamine does a lot of things, but you're probably most familiar with it as the chemical your brain uses as a sort-of system of in-game gold coins. You earn the reward for certain behaviors, usually "lizard-brain" type stuff—eating a bowl of pudding, for instance, or finally making out with that cute person you've had your eye on. And, as you've probably heard, there's some evidence that we can get addicted to that burst of dopamine, and that's how a nice dessert or an enjoyable crush turns into something like compulsive eating or sex addiction.

Neurologist Robert Sapolsky puts an interesting twist on this old story, though. What if it isn't the burst of dopamine that we get addicted to, but the anticipation of a burst of dopamine? It's a small distinction. But it matters, he says, if our reward system is based less on happiness than on the pursuit of happiness.

For more on this, check out David Bradley's post on this video, which also links back to a more-detailed discussion of the basics of dopamine addiction.

No such thing as "neurotypical"?

"The distinction between neurodiverse and neurotypical is too simplistic. There is certainly a great deal of structural variability between individuals, and that's compounded by structural changes that go on across the lifespan. I'm sure [the extent of brain variability is] a lot more than most people realise." — Jon Simons, senior author on a recently published research paper looking at structural variation in the human brain, and its influence on the ability to distinguish between stuff that actually happened, and stuff we imagine. As quoted by Mo Costandi in The Guardian.

Can magnets make you lie?

A small Estonian study is offering some hints that our brains could be even weirder than we'd imagined. Researchers found that magnetic pulses directed at a certain part of the frontal cortex affected whether people were more willing to fib, or more likely to tell the truth. Only 16 people were involved in the study, so these results are more something potentially cool to follow up on than a definitive declaration about brain function. There's a good chance this could turn out to be a statistical fluke. But it is worth researching further. If the effect is real, it could have some really interesting ethical, legal, and neurobiological implications.

Say it with me now: "F***ing magnets, how do they work?" Mo Costandi explains:

Inga Karton and Talis Bachmann of the University of Tartu adopted a different and novel approach, by examining the natural propensity to lie spontaneously during situations in which deception has no consequences. They recruited 16 volunteers, and showed them red and blue discs, which were presented randomly on a computer screen. The participants were asked to name the colour of each disc, and that they could do so correctly or incorrectly at their free will.

The researchers used a technique called transcranial magnetic stimulation (TMS) to disrupt the participants' brain activity during the task. TMS is a non-invasive technique in which pulses of electromagnetic radiation are targeted to a specific brain region, inducing weak electrical currents that can either inhibit or enhance activity in that area.

They split the participants into two groups of eight for the experiment. Half of the participants in one group received magnetic pulses to the dorsolateral prefrontal cortex (DLPFC) in the left hemisphere of the brain, while half in the other received them to the DLPFC on the right side. The rest of the participants acted as controls, and TMS was targeted to either the left or the right parietal cortex.

Statistical analysis of the results revealed that magnetic stimulation directed at the left DLPFC slightly increased the participants' tendency to lie about the colour of the discs, whereas stimulation of the right DLPFC slightly reduced it. By contrast, stimulation of the left or right parietal cortex had no effect on the participants' propensity to lie.

Costandi has actually made his full interview with the primary researcher in this study available online. In it, he gets a bit more into the nuance of what happens when you turn up a result as odd as this one, why scientists conduct such small studies, and what they do with the results of those studies.

Beautiful paintings of neurons

That's no dandelion. It's a painted close-up of a slice of human hippocampus. Jessica Palmer at the Bioephemera blog introduced me to the gorgeous artwork of neuroscience grad student and painter Greg Dunn. His images of different neurons are really lovely. And you can buy prints.

Via Elizabeth Sears

The science of near-death experiences

Some recent research is confirming what a lot of us have probably long suspected—there's a pretty reasonable scientific explanation for near-death experiences.

Recently, a host of studies has revealed potential underpinnings for all the elements of such experiences.

For instance, the feeling of being dead is not limited to near-death experiences—patients with Cotard or "walking corpse" syndrome hold the delusional belief that they are deceased. This disorder has occurred following trauma, such as during advanced stages of typhoid and multiple sclerosis, and has been linked with brain regions such as the parietal cortex and the prefrontal cortex—"the parietal cortex is typically involved in attentional processes, and the prefrontal cortex is involved in delusions observed in psychiatric conditions such as schizophrenia," Mobbs explains. Although the mechanism behind the syndrome remains unknown, one possible explanation is that patients are trying to make sense of the strange experiences they are having.

This story, by Charles Q. Choi, breaks down several common elements of near-death experiences the same way. But the fact that I found most interesting relates to who has "near-death" experiences. Turns out, it's not limited to people who are actually near death. Choi reports that a study of 58 patients who had had near-death experiences found that 30 of them weren't actually in danger of dying. They just thought they were.

The neurobiology of politics

What, if anything, should we make of studies that purport to find neurological differences between people who self-identify as "conservative" and people who self-identify as "liberal?" You've seen studies like that in the paper. You've heard them argued about on radio and TV shows. But what do they actually mean? Is this just so much high-tech phrenology? Is it a smug way for one group to make snide commentary about the other group under the guise of "science?" Is your political affiliation determined by your mind, or by your brain?

Behavioral therapist Andrea Kuszewski has a great guest post up at The Intersection blog, looking at what we can (and can't) learn from the handful of studies that have attempted to link politics and neurobiology. None of these studies have been perfectly well-done, she writes. But, despite being flawed in different ways, they're coming to some of the same conclusions—conservatives seem to have a more active amygdala and liberals seem to have a more active anterior cingulate cortex. You can shorten that into a headline-grabbing statement about conservatives being driven more by emotions and liberals by logic. But it's really, really not as simple as that.

If you're going to talk about these studies at all, Kuszewski writes, you're going to have to understand the context behind them. In other words: This is an issue chock full of yesbuts. And, without them, you're going to come to some very wrong conclusions.

This is definitely a story worth reading all the way through. It is, however, a difficult story to excerpt ... at least, without committing the very sins the article is meant to correct. But out of all the yesbuts Kuszewski identifies, I'd like to highlight this one, in particular, because I think it's often overlooked in many popular discussions of neurobiology and culture.

1. The brain is plastic. Meaning, every time we engage in any activity, our brain changes somewhat, even if only to a very small degree. In fact, your brain is a little bit different right now than when you started reading this article. And a little different now. Engaging in any activity excessively or intensely over a long period of time changes your brain even more—such as training for a sport or spending a long time practicing and becoming proficient at a skill. Conversely, if you stop using an area of your brain to a significant degree, it will probably shrink in size due to lack of connectivity, similar to the atrophy of muscles. When it comes to the brain areas measured in these studies, we aren’t sure how much of the difference was there to begin with, or to what degree the brain changed as a function of being in a particular political party. I suspect both things contribute somewhat. How much? We have no way of knowing at this point. To say conclusively, we need a longitudinal study, with control groups, measuring brain volume before and after joining, leaving, or participating in a political party’s activities or ideologies.

How the human brain lies to us

Even in important moments, our brains are not as good at creating accurate memories as we think they are.

This clip from the World Science Festival features two stories that show how easily the brain can be manipulated. In the first, writer Jonah Lehrer describes how he remembers his cousin ruining his 8th birthday party (except, that, he later found out, this incident never happened). The second is significantly more rattling, as Harvard psycholigst Daniel L. Schacter describes a case of mistaken identity that could have led to an innocent man being tried for rape.

This tendency of the brain to naturally distort memories has been studied in relation to what people believe they remember about September 11th. It turns out, even memories that we think of as being seared into our brains aren't as accurate as they're often treated as being, writes Greg Bousted in a piece for Scientific American. Human memory simply isn't that reliable.

Memories of tragic public events have been of interest to researchers for years. Dubbed as “flashbulb memories” for their extraordinary vividness of detail and photographic recall, these emotionally charged memories are described as being “burned” into one’s mind. Knowing exactly where one was or what one was doing during the assignation of John F. Kennedy, the Challenger disaster, or now, the September 11 attacks has become a quintessential phenomenon of the past few generations. In 1977, a pair of Harvard psychologists studied the reported memories of the JFK assassination. Participants had “an almost perceptual clarity” for recalling when they learned about the assassination and during the immediate aftermath, noting even trivial details with impressive accuracy. The researchers concluded that flashbulb memory is more detailed and accurate than memories of ordinary daily events. The defining characteristic of these types of emotionally charged, shared memories is that one’s confidence in their accuracy tends to be unshakable. But does that really make them more accurate?

In an attempt to answer that, Duke University’s Jennifer Talarico and David Rubin conducted a study on the day after the 9/11 attacks. They gave volunteers a questionnaire about their memories of the morning of September 11 as well as some other unremarkable event a day earlier. They later followed up with the questionnaires at several intervals up until almost a year later. What the researchers found is that the memories of the individuals’ goings-on during the events of September 11—the vivid and picture-like ones—were in fact no better than their recall of, say, lunch the day before. Like most memories, they predictably declined in accuracy over time.

I certainly have very detailed childhood memories that, upon reflection, can't possibly be true—in particular, I remember cooking soup for my mom while she was sick in an apartment that we moved out of somewhere around the time I was 4 years old. Obviously, she didn't actually let a toddler stand over the stove with chicken soup. But my brain "remembers" it. Maybe, at the time, that was simply something I wanted to do and my brain mixed that desire up with later memories of cooking in other, similar, kitchens.

What false memories has your brain concocted up?