Tracked with pain

Today’s Nature has an excellent piece about an increasing and currently not well-researched trend for fMRI brain scan ‘neurofeedback’ treatments, where the patient is shown a visual representation of the activity of a certain brain area in the hope of learning to control it.

In this case, the big idea is that a patient with chronic pain is shown real-time activity in their anterior cingulate cortex, an area in the frontal lobe associated with the ‘unpleasantness’ of pain (rather than just its physical sensation), and they can see when they doing something to successfully reduce the activity and can try and learn to do it reliably.

The article looks at the work of Sean Mackey who researches the area but is appropriately skeptical about a number of companies who have recently sprung up offering this as a treatment, despite the lack of firm evidence.

As you may recall, this premature commercialisation is a bit of a pattern with fMRI research, as you can also buy the services of companies offering ‘lie detection’ and ‘neuromarketing’ despite a similar lack of evidence for their usefulness.

However, the piece also looks more generally at the neuroscience of pain which is, if you’ll excuse the pun, becoming a hot area, both as the understanding of pain moves away from the idea that it happens ‘in the body’ to the idea that it is handled by numerous brain circuits, each which may be involved if different aspects of the experience and our behavioural reaction to it.

In some of his other work, Mackey’s laboratory has used fMRI to explore these connections between pain processing and cognitive processes. Fear of pain, for example, can increase the pain itself, and Mackey’s group studied some of the brain regions involved in this anticipation. In another study he showed that watching someone else in pain activates brain areas that are fairly distinct from those active during one’s own pain. And in unpublished work he has found that romantic love can lessen the experience of pain. Mackey says these connections demonstrate how strong an influence conscious thought may have over pain processing.

Link to Nature article ‘Shooting pain’.

Visual illusions can be caused by imagination

Photo by Flickr user Arnar Valdimarsson. Click for sourceA fantastic study just published in Cognition reports that the motion aftereffect illusion, where staring at something constantly moving in one direction causes illusory movement in the opposite direction when you look away, can be caused just by imagining that the movement is happening.

The effect is occasionally called the ‘waterfall illusion’ because it can be triggered by staring at a waterfall for a few minutes and then looking at the nearby bank, which will seem as if it is moving upward, in the opposite direction to the falling water.

It was traditionally explained by the fact that direction-specific motion-detecting neurons in the brain’s visual areas ‘habituate’ or adapt to constant movement by slowly becoming less active, as if they barely need to keep reporting with the same vigour because they’re just detecting more of the same.

According to this explanation, when you look away, these ‘habituated’ neurons are caught off guard and the neurons that look out for motion in the opposite direction are relatively stronger and so, until the balance is readdressed, give the impression that the world is moving contrary to your past experience.

As with most of these things, it turns out not to be quite so simple, but the effect is so easily invoked that it is used widely in vision and motion research.

One of the key findings in this area is that visual imagery activates some of the same areas as actually seeing what you’re thinking of. In other words, the brain seems to simulate the visual experience actually in the visual system.

Or at least, that’s what it looks like from the brain scans, but just because the same areas are active during both tasks, it doesn’t mean the same neurons are being used. It could be completely different processes at work that just happen to share the same neural office space.

So here’s the cool bit. This new study, led by psychologist Jonathan Winawer, asked participants to briefly view a moving pattern. It only appeared briefly, not long enough to cause the effect, and then disappeared.

Then were then shown the same pattern, without any movement, and were asked to imagine that it was moving in the same way. After a short while, the pattern was replaced by a picture of motionless dots, and they were asked to indicate if they saw the dots moving in a particular direction.

If the effect appeared, participants should see the dots moving in the opposite direction.

The participants were asked to imagine different directions and types of motion and then were given the same task but where they didn’t need to imagine anything, as the pattern moved by itself.

As expected, the moving pattern caused a clear motion aftereffect, but rather wonderfully, the effect appeared after participants had simply imagined the movement. It wasn’t as strong but it was clearly there.

They researchers also asked the participants after which direction would they expect the dots to go in, to check they hadn’t heard about the effect or were just doing what they thought was expected of them, and they couldn’t reliably give the correct direction that the effect would cause.

This provides good evidence that when imagine visual experiences we’re actually running a simulation in the same parts of the brain that are used to actually see the world.

Link to PubMed entry for study.
pdf of full text paper.

Brain stories and neuronovels

Photo by Flickr user William Forrester. Click for sourcen+1 has an excellent article on how neuroscience is making an increasing appearance in novels, not only as a subject, but also as a literary device to explore characters and explain their motivations.

It marks the start of the trend from Ian McEwan‚Äôs Enduring Love and notes that in more recent years books such as Richard Powers‚Äôs The Echomaker, Mark Haddon‚Äôs Curious Incident of the Dog in the Night-Time and Rivka Galchen’s Atmospheric Disturbances have all drawn heavily from the medical and brain science literature for their main hooks.

What makes so many writers try their hands and brains at the neuronovel? At the most obvious level, the trend follows a cultural (and, in psychology proper, a disciplinary) shift away from environmental and relational theories of personality back to the study of brains themselves, as the source of who we are. This cultural sea change probably began with the exhaustion of “the linguistic turn” in the humanities, in the 1980s, and with the discredit psychoanalysis suffered, around the same time, from revelations that Freud had discounted some credible claims of sexual abuse among his patients. Those philosophers of mind who had always been opposed to trendy French poststructuralism or old-fashioned Freudianism, and the mutability of personality these implied, put forth strong claims for the persistence of innate ideas and unalterable structures.

And in neuroscience such changes as the mind did endure were analyzed in terms of chemistry. By the early ’90s, psychoanalysis—whether of a Lacanian and therefore linguistic variety, or a Freudian and drive-oriented kind—was generally considered bankrupt, not to mention far less effective and more expensive than the psychiatric drugs (like Prozac) that began to flow through the general population’s bloodstream. The new reductionism of mind to brain, eagerly taken up by the press—especially the New York Times in its science pages—had two main properties: it explained proximate causes of mental function in terms of neurochemistry, and ultimate causes in terms of evolution and heredity.

It’s really well researched piece and neatly outlines the play between literature, science writing, culture and neuroscience through the development of numerous popular novels in the area.

Link to n+1 article ‘The Rise of the Neuronovel’.

Dramatic sexuality changes after brain disturbance

The Neurocritic has compiled a collection of interesting neurological studies where a number of patients seems to have experienced a profound change in their sexual preferences as a result of brain disturbance.

One of the most well-known of these studies is a recent case of a man who was convicted of paedophilia late in life, but was later found to have a brain tumour, and on removal of the tumour his sudden interest in children disappeared. It reappeared again when the tumour once more began to grow.

The case has raised questions about free will and self-determination in light of the fact that such morally reprehensible acts seemed only to occur when a tumour was affecting brain function.

It’s importantly to mention that brain damage rarely causes such tragic events, although sexual difficulties, in general, are not uncommon. Problems can range from difficulties with arousal and enjoyment, to behavioural disturbances and inappropriate behaviour.

In some rare cases, preferences themselves seem to be affected, although it’s never clear whether it’s actually that the person has different desires, or whether they always had them but now are, perhaps, less able to stop themselves acting on them.

It’s easier to think that damage has changed people’s desires when the behaviour markedly unusual, such as this case of a man who was, to put it bluntly, screwing the coin return tray of a public telephone after brain deterioration.

But one thing we know from the forensic literature and cases of healthy people who accidentally die during sexual practices (for example, these two), is that no matter how strange the attraction seems to you, someone is out there expressing it.

Not all of the cases of changes sexuality after brain damage are where people act outside of the norm, of course. In one, admittedly, not brilliantly detailed case, an apparently exclusively homosexual man found he developed heterosexual attraction after a stroke.

Sadly, this area is massively under-researched so we really know relatively little about how different aspects of desire, emotional attachment and sexual behaviour are handled by the brain, but these case studies give us a window into the possibilities.

Link to The Neurocritic on ‘Unusual Changes in Sexuality’.

Face of the giant panda sign

I’ve just discovered a curious medical finding that can be detected on MRI brain scans called the ‘face of the giant panda sign’ where, quite literally, it looks like there’s a panda face in the middle of the brain, indicating a specific pattern of neural damage.

The image you can see on the left is the ‘face of the giant panda sign’ that appeared in a brain scan of a patient with multiple sclerosis who started showing unusual sexual behaviour and is taken from a 2002 study. Click the image if you want to see the whole scan.

The pattern is apparently caused by “high signal in the tegmentum, normal signals in the red nuclei and lateral portion of the pars reticulata of the substantia nigra, and hypointensity of the superior colliculus”.

It is most associated with Wilson’s disease, a genetic condition which causes a toxic build-up of copper in the body, but obviously can appear in other disorders as well.

Thanks to Twitter user @sarcastic_f for alerting me to this.

It’s not just pandas that appear in brain scans of course, the Virgin Mary has also been known to make an appearance.

Link to PubMed entry for MS study.
Link to brief description from Neurology.

A poster to remember

While strolling through town the other day, I came across this fantastic memory and brain-themed poster.

It’s from the University of Antioquia’s museum who are holding an art and literature competition to celebrate 200 years of Colombian independence.

Click the image for a bigger version or hit the link below if you want to see it in all its glory.

Link to bigger version.

2009-10-23 Spike activity

Quick links from the past week in mind and brain news:

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The single best article you’ll read on technology and the brain for a while is published in The Times. 300 words of sense.

The Sydney Morning Herald covers an inattentional blindness study in mobile phone users and asks ‘Did you see that unicycling clown?’ I’m more interested to know whether the unicycling clown saw the psychologist following him around all day.

Apart from the fact that she seems to be labouring under the misapprehension that the right temporal parietal junction is not used for anything else (it is) there’s an excellent TED talk by Rebecca Saxe on ‘theory of mind‘ and the neuroscience of inferring others’ mental states.

Neurophilosophy covers on how electrodes planted into the open brain of an awake patient reveals the neural dynamics of speech. Accompanied by an equally as awesome image.

The anthropology song is featured on Neuroanthropology.

The Neurocritic finds an intriguing film about a professor who believes she has found a way of determining scientifically whether someone is in love.

Philosopher Stephen Stich gives four lectures on ‘Moral Theory Meets Cognitive Science’ which are collected at 3 Quarks Daily.

Dr Petra has been upgraded!

Another good TED talk, this time by Beau Lotto on what optical illusions tell us about perception.

Science News on research that a gene involved in vocal cord development may be a factor in a inherited speech disorder.

There’s a brief Q&A on the science of persuasion over at Nature.

The BPS Research Digest covers some heart-warming research on how a heated room makes people feel socially closer.

You can read a free taster issue of November’s The Psychologist here. Enjoy!

Scientific American’s Mind Matters blog has a great piece on making errors and learning.

Another good Neurophilosophy post, on how immediate goal kicking performance in American ‘foot’ ‘ball’ affects the perception of how big the goal seems.

Science News reports that ‘People can control their Halle Berry neurons‘. Neurons? I have enough trouble trying to control my Halle Berry thoughts. Don’t think of Catwoman. Damn.

The National Alliance on Mental Illness (NAMI) is an American nonprofit, grassroots, self-help, support and advocacy organization of consumers, families, and friends of people with severe mental illnesses that happens to receive 75% of its funding from Big Pharma, according to The New York Times.

Cognitive Daily asks What does it take to get kids to eat healthy foods? Personally, I bribe them with cans of Red Bull.

There’s on excellent piece on how antidepressant sales are rising despite depression diagnoses falling in the UK over at Neuroskeptic. Apparently, longer-term treatment is now the norm.

FAILBlog has a hilarious duck phobia fail.

To the bunkers! H+ Magazine reports on robots controlled by human brain cells. Let’s hope they’re not the Halle Berry neurons.

Slashdot commentor kindly lists all the Doctor Who references to robots controlled by organic brains.

I found this great article on drug counterfeiting from a 1961 edition of Popular Mechanics.

BoingBoing has an interesting snippet on a new NIH study which will deploy robo-calling for boozers and stoners. Press 1 if you’re taking a bong hit?

Happy belated Fechner Day.

Language Log asks ‘Is irony universal?’. Rather ironically, asked by Americans. Also some interesting observations in the comments from Danny O’Brien.

Insecurity + power = boss rage, according to a new study covered by Neuronarrative.

The New York Times has a piece by David Brooks who marvels at how “damned young, hip and attractive” neuroscientists are. I would just like to disavow this dreadful stereotyping and point out that, like myself, many competent neuroscientists look pretty rough and find being deeply unfashionable quite groovy (by still using words like ‘groovy’ for example).