Remembered spaces

A poignant short essay from The New York Times on locations that only live in our memories.

It has the lovely image of cities that exist only in our minds, after buildings we knew so well have since been replaced.

Sort of nostalgic landscapes that we carry with us, long after the actual places have ceased to exist.

I’d might as well be looking at the people on the street and imagining all the buildings that have passed through them — places we knew almost by intuition until they vanished, leaving behind only the strange sense of knowing our way around a world that can no longer be found.

Link to NYT article ‘Remembered spaces’.

Encephalon 27 dashes by

A somewhat telegraphic 27th edition of the Encephalon psychology and neuroscience writing carnival has just been published on the new clean look Neurocontrarian blog.

A couple of my favourites include a brief investigation into a new skin patch to deliver drugs to patients with Alzheimer’s disease, and an article on punishment, morality and game theory, which sounds quite kinky now I come to think about it.

Needless to say, there’s plenty more kinky-sounding but scientifically respectable articles at the link below.

Link to Encephalon 27.

Hand actions fire mirror neurons in handless people

Science reports that people born without hands show ‘mirror neuron’ activity when they view hand actions, but in the area of the brain that controls the feet.

The ‘mirror neuron‘ system is a brain network that activates both when an action is being carried out, and when it is being observed, and has been hypothesised to be involved in perceiving and comprehending others’ actions.

The mirror neuron system is widely hyped but there’s no doubt it is an important brain function.

The researchers in this study were interested what sort of ‘mirror neuron’ activity would be apparent in people who had never had hands, while they watched hand actions.

The study, led by Dr Valeria Gazzola, recruited two people with arm aplasia, a developmental condition where the arms and hands are missing at birth, and sixteen comparison participants with normally developed hands.

The participants were brain scanned while being shown video of hands manipulating various objects (e.g. grabbing a glass or scooping soup out of a bowl) as well as still images of the hands resting behind the same objects.

Scans were also taken while participants completed actions with their lips, feet, and for the control group, with their hands – to see how this matched up with the ‘mirror neuron’ activity when watching the video.

When watching the hand actions, activity in the brain of two handless participants looked more like they were moving their feet.

As both participants use their feet to manipulate objects on a day-to-day basis, the researchers suggest that they are ‘mirroring’ the same goal, but using the brain systems that match how they would actually get the job done in everyday life.

One difficulty is that the activity from the two aplasic participants is quite variable, meaning the study really needs to be replicated to be sure of the effect.

However, if it bears out, it is a fascinating finding. It suggests that the mirror neuron system is much less action-based than we thought, and is, perhaps, equally as wrapped up with perceiving outcomes as movements.

Link to write-up from Science.
Link to abstract of scientific study.

Unconscious beauty primes positive emotions

We can correctly classify faces as attractive or unattractive, even when they appear so quickly that we’re not conscious of seeing them. This is according to a study that also found that subliminal attractive faces also prime positive emotions.

Profs Ingrid Olson and Christy Marshuetz flashed up photos of faces previously rated as either extremely attractive or extremely unattractive.

Each face stayed on-screen for only 13 milliseconds and was preceded by a picture of a scrambled face and was followed by a picture of a cartoon face.

Showing something just before or just after a briefly presented picture is known as ‘masking’ and helps to ensure that after it appears, the picture doesn’t stay in iconic memory – a very brief ‘after-image’ memory that extends our visual experience after something has gone.

Essentially, masking ensures the image doesn’t register consciously, and when participants were asked to classify the flashes as either attractive or unattractive faces they claimed they were just guessing because they couldn’t ‘see’ any photographs of faces.

But, on average, they managed to correctly classify the faces as attractive or unattractive, suggesting that facial attractiveness is something that is something that we process very quickly, so quick, it can happen before we’re consciously aware of it.

In another experiment, the researchers flashed up pictures of attractive and unattractive faces and houses, shortly followed by a word.

The word could either be linked to positive emotions (such as ‘laughter’) or negative emotions (such as ‘agony’) and participants were asked just to hit a button to classify the words as either good or bad.

The idea was to test whether attractive faces made participants react more quickly to positive words – strong evidence that these concepts had been ‘primed‘.

Priming is where one concept activates related concepts in the brain. So if you’re thinking of ‘football’, semantically related concepts like ‘game’, ‘crowd’ or ‘team’ will be made more available to your thoughts.

Psychologists know this because people will react more quickly to related concepts than to unrelated concepts if asked to identify them.

Olson and Marshuetz found that unconsciously presented attractive faces, but not attractive houses, primed positive emotions.

This suggests that attractive faces may have a particular attention and emotion grabbing effect. The effect seems so strong, it seems to work even when a face hasn’t registered in our conscious mind.

pdf of full-text paper.
Link to write-up from Science Daily.

Laugh and the world laughs with you

Discover magazine has an article that looks at the psychology of laughter and humour, noting that the two aren’t necessarily as linked as we’d normally think.

It seems the social context is as powerful as the content of the humour itself in driving our response, because laughter is a communication in itself.

Previous studies of laughter had assumed that laughing and humor were inextricably linked, but Provine’s early research suggested that the connection was only an occasional one. As his research progressed, Provine began to suspect that laughter was in fact about something else‚Äînot humor or gags or incongruity but our social interactions. He found support for this assumption in a study that had already been conducted, one analyzing people‚Äôs laughing patterns in social and solitary contexts.

“You’re 30 times more likely to laugh when you’re with other people than you are when you’re alone‚Äîif you don’t count simulated social environments like laugh tracks on television,” Provine says. Think how rarely you’ll laugh out loud at a funny passage in a book but how quick you’ll be to give a friendly laugh when greeting an old acquaintance. Laughing is not an instinctive physical response to humor, the way a flinch is a response to pain or a shiver to cold. Humor is crafted to exploit a form of instinctive social bonding.

Link to Discover article on laughter.

Brain toast t-shirt

If you’re a fan of toasting your brains, either literally or metaphorically, there’s now a t-shirt especially designed for you.

Belgian t-shirt label Carbone 14 have created some rather natty versions in red and white.

There’s also a skinny fit version if you like your toasted brains, well, skinny.

If on the other hand, you prefer your brains mashed, fried or baked, you’ll have to advertise your preference some other way, as they’ve yet to design shirts for the rest of the culinary range.

Thanks Laurie!

How gene therapy could cure brain diseases

Nature’s neurology journal has a freely available article on a technique that interferes with the translation of genetic information into proteins that may help prevent inherited brain diseases.

DNA has two main functions. The ‘template function’ of DNA is to pass on genes through generations and allow different traits to be inherited.

The ‘transcriptional function’ of DNA is to allow these genes to be expressed at appropriate times and places (and not expressed at others) to allow the cell to do its work.

‘Expression’ just means ‘turned into a protein’ and genes are just blueprints for proteins.

The blueprint gets turned into a protein by messenger RNA, which ‘reads off’ the information, then moves away to assemble the protein from a store of amino acid component parts.

As different cells in the body have different functions, and individual cells need to behave differently depending on what’s happening, different proteins need to be created at different times.

Disorders like Huntington’s disease result from genes that cause damaging proteins to be formed. These lead to the malfunction and death of brain areas that, in turn, leads to cognitive problems, movement difficulties, mental illness and eventual death.

Using a technique called RNA interference, researchers have found they can selectively interfere with the process where messenger RNA assembles proteins from the DNA’s genetic information.

Essentially, small chunks of gene-specific RNA are introduced into the cell, these find the messenger RNA and destroy the information before it gets turned into a protein.

In other words, it prevents specific genes from being turned into proteins.

This has caused a great deal of excitement because it could lead to treatments for disorders like Huntingdon’s by simply ‘silencing’ the rogue Huntingdon’s gene.

While you might have a rogue gene, RNA interference could essentially gag it, meaning it would never have a knock-on effect in the brain.

This has been demonstrated in very limited lab tests, and the Nature article examines the prospects for it being developed into a widespread treatment.

There are still some difficulties to overcome, however. One of which is how to get the interfering RNA into the right cells in the brain, a difficulty with many treatments owing to the filtering effect of the blood-brain barrier.

Another is how to make sure that the technique affects only the disease process. Researchers talk about proteins being involved in ‘chemical cascades’, meaning that they are involved in huge and complex mechanisms in the body.

It’s hard to predict exactly what effect silencing a gene will have, and whether your technique for doing so will also interfere with some other processes that use some of the same mechanisms, some of which we probably don’t even know about at the present.

RNA interference is still an experimental process, but it holds great potential for treating inherited brain diseases. The Nature article is a fantastic guide to the cutting edge of the science in this area.

Link to Nature Clinical Practice Neurology article on RNA interference.
Link to plain language guide to its use in Huntington’s.
Link to Wikipedia page on RNA interference.

Shifting eye therapy successfully treats trauma

A recent study has found that EMDR, a once suspect therapy that involves recalling traumatic memories while moving your eyes, is one of the most effective treatments for post-traumatic stress disorder (PTSD).

EMDR stands for Eye Movement Desensitization and Reprocessing. It’s a type of psychotherapy that, among other things, involves thinking about the traumatic event while attending to bodily reactions and moving your eyes left and right, usually following a light or the therapist’s finger.

It sounds bizarre and caused a great deal of suspicion when it first emerged, largely it was pretty much just ‘thought up’ by Dr Francine Shapiro and no-one really knows quite how it works.

However, several studies have found it to be one of the most effective treatments for post-traumatic stress disorder, and this new study, one of best to date, has repeated the finding.

This new study, led by Dutch psychiatrist Dr Bessel van der Kolk, compared EMDR, with SSRI drug fluoxetine (aka Prozac) and a pill placebo in a group of patients diagnosed with PTSD.

After the eight week treatment block, fluoextine and EMDR were equally effective,

However, six months later, 75% who had been traumatised in adulthood and were treated with EMDR reported having no symptoms. For people traumatised during childhood, a third treated by EMDR were symptom free by the same point.

In contrast, none of the people in either group treated with fluoxetine managed to free themselves from symptoms.

Most clinicians looking at the study might suspect that eight weeks of drug treatment wouldn’t be long enough as prescriptions are often recommended for six months to a year after stabilisation.

Nevertheless, it’s an impressive result, not least because of the short 8-week treatment time for EMDR and the strong recovery rate.

One of the criticisms of EMDR is that it’s still not clear what part the eye-movement aspect plays in the therapy and exactly how it works.

What this trial didn’t do is compare EMDR to cognitive behavioural therapy (CBT), a type of recently devised psychotherapy that is known to be one of the most effective treatments for anxiety disorders.

Both of these therapies focus on ‘reprocessing’ the trauma memories – essentially remembering and ‘reliving’ them, which seems to play a major role in preventing the uncontrolled memories and flashbacks that are part of the disorder.

This is also the focus of a recently devised combined drug and ‘reprocessing’ therapy we reported on earlier, which seems to work by dampening down bodily arousal when the memories are recalled due to the action of the drug propranolol.

Link to abstract of clinical trial.

Photographing delusions

Singapore art collective A Dose of Light exhibited some poignant and beautiful photographs by Wu Xiao Kang, a 26 year-old man with schizophrenia who later killed himself.

The show gained international acclaim and only later was it revealed that Kang was fictional, a creation of the collective who had taken the photos themselves.

The project consisted of 36 photos supposedly taken by Kang of an abandoned psychiatric hospital in which he was previously treated.

A Dose of Light designed the whole project as a conceptual artwork to portray the breakdown of reality that sometimes occurs in schizophrenia.

Several galleries and events hosted the exhibition in good faith, and one gallery has now pulled the exhibition in protest.

According to one newspaper report, the group decided to come clean on July 1st when a mental health charity wanted to use the images to promote awareness of mental illness in Singapore.

However, I first saw the photos at Bonkers Fest, an art and music event held in Camberwell, London on June 2nd, that also promotes awareness of mental health issues and is organised by a number of mental health charities.

In this case, there was no admission that the Kang was fictional and the photos were presented as genuine.

One member of the collective, Robert Zhao is a fine art student at Camberwell College of Arts, who were also partly involved in organising the festival.

Link to online ‘Wu Xiao Kang’ exhibition.
Link to Metafilter on the controversy.

Syd Barrett in the American Journal of Psychiatry

From the ‘images in psychiatry’ column from July’s American Journal of Psychiatry, written by Dr Paolo Fusar-Poli:

Roger Keith “Syd” Barrett was both the founding member of one of the most legendary rock bands and probably the most famous rock star to develop psychosis. He formed the band that would become Pink Floyd in 1965, amalgamating the first names of two American bluesmen, Pink Anderson and Floyd Council.

Recorded at Abbey Road Studios, inspired by LSD, and driven by Barrett’s songwriting, singing, and otherworldly guitar solos, the first album, “The Piper at the Gates of Dawn” (1967), alchemized the whimsical bohemian spirit of the “summer of love” and influenced generations of musicians with its sonic inventions and surreal lyrics.

Music journalists have called him “the golden boy of the mind-melting late-60s psychedelic era, its brightest star and ultimately its most tragic victim”. In fact after two haunting solo albums, “The Madcap Laughs” and “Barrett,” which showed the last flickering lights of his genius, his eccentric and creative personality drifted into a psychotic reclusive state, forcing him to withdraw from public view in 1974.

However, Pink Floyd would pay tribute to Barrett and would include madness as an ongoing theme on their best and most successful albums, “Dark Side of the Moon” (1973) and “The Wall” (1979), speaking to Syd directly in the songs “Wish You Were Here” and “Shine on You Crazy Diamond.” Barrett spent the rest of his life in his mother‚Äôs house in Cambridge, painting and gardening.

Link to AJP images in psychiatry column on Syd Barrett.
Link to Wikipedia page on Syd Barrett.

2007-07-13 Spike activity

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

For Certain Tasks, the Cortex Still Beats the CPU. Completely banal title obscures quite an interesting article on ‘human processing‘ in computer tasks.

Research suggests the biggest influence on how responsive we feel our partners are is actually how we respond to our partners.

The Washington Post reports on research linking the decline in criminal activity to a reduction in environmental lead poisoning.

People with autism do <a href="http://sciencenews.org/articles/20070707/fob4.asp
“>far better in certain non-verbal cognitive tests than you might expect from their IQ. Actually, similar findings, showing an advantage for visuospatial tasks, have been reported before.

CNN reports that antidepressants are the most prescribed drugs in U.S.

Dr Jerome Groopman writes in The New York Times about the cognitive biases that can lead to medical errors.

More on the ‘disease model’ of addiction: Dr Nora Volkow talks about the neuroscience of addiction on an NPR radio special.

Can nicotine be modified to make a useful cognitive enhancer? Wired investigates.

Hypnosis redux

alert_eye.jpgThanks to everyone who came along to discuss the neuropsychology of hypnosis last night. For anyone who wants to investigate further, here’s more on the psychology and neuroscience of hypnotic states.

Scientific American has a fantastic article on ‘The Truth and the Hype of Hypnosis’ that tackles some of the myths and covers some of the key scientific research.

Psychologist and hypnosis researcher Dr Peter Naish did a great talk last year on the science of hypnosis for the Dana Centre which is available online as an archived video webcast.

WNYC’s RadioLab had a special on placebo and the power of suggestion, which, to be fair, is light on science and heavy on anecdote, although it does make for an interesting listen.

And finally, Dr Matt Whalley’s site is a great guide to science of hypnosis. I keep mentioning it, because, well, it’s excellent.

Terrorism fails because we don’t see its purpose

In an article for Wired, security guru Bruce Schneier suggests that the reason terrorism fails is because it falls foul of a cognitive bias in how we understand people’s intentions from their actions.

Schneier bases his conclusions on a recent paper [pdf] by Max Abrahms who applies correspondent inference theory to terrorism and the political objectives of terrorist groups.

‘Correspondent inference theory’ suggests that we try and understand people’s intentions and character based on the most salient effect of their actions.

This can often lead us astray, as demonstrated by a regular plot line in soap operas where someone’s good intentions accidentally misfire and the person on the receiving end assumes they’re being deliberately malicious.

As noted by Schneier and Abrahms, this also leads us to misunderstand the goal that motivates terrorist acts:

The theory posited here is that terrorist groups that target civilians are unable to coerce policy change because terrorism has an extremely high correspondence. Countries believe that their civilian populations are attacked not because the terrorist group is protesting unfavorable external conditions such as territorial occupation or poverty. Rather, target countries infer the short-term consequences of terrorism — the deaths of innocent civilians, mass fear, loss of confidence in the government to offer protection, economic contraction, and the inevitable erosion of civil liberties — (are) the objects of the terrorist groups. In short, target countries view the negative consequences of terrorist attacks on their societies and political systems as evidence that the terrorists want them destroyed. Target countries are understandably skeptical that making concessions will placate terrorist groups believed to be motivated by these maximalist objectives.

In his paper, Abrahms examines the political objectives of terrorist groups and looks at how successful terrorism has been in obtaining them. He reckons, with a generous estimate, that only 7% of the stated goals have been achieved.

But he also notes that the stated goals rarely gets through to the people being targeted and that the political rhetoric of the terrorists’ target is littered with misunderstandings of their intentions.

I’m personally interested in how and why terrorists are labelled ‘mad’. It’s in the terrorists’ interest to be seen as sane, as part of the goal is to force concessions.

There’s no point conceding to someone who you think is unbalanced, because an irrational group might not stop the violence once they’ve achieved their aims.

The fact that violent protestors are so often labelled as ‘mad’ suggests, as per correspondent inference theory, that we assume their is no coherent intention behind their actions, contrary to what they are trying to achieve.

Anyway, an interesting look at the motivations and perception of political violence.

Link to ‘The Evolutionary Brain Glitch That Makes Terrorism Fail’.
pdf of Max Abrahms’ paper ‘Why Terrorism Does Not Work’

Magnetic brain stimulation not proven to fight depression

At a recent American Psychiatric Association meeting, commercial companies were showing off custom made magnetic brain stimulators as a treatment for depression. A review article in the latest Nature Reviews Neuroscience looks at the technology and finds there’s still no convincing evidence that it’s an effective treatment.

The technology is based on transcranial magnetic stimulation (TMS), essentially a large electromagnetic which is activated near the scalp.

As you might remember from high school physics, a magnetic field that moves over a conductor causes a current. As your brain is a conductor, a current is formed in the neurons which cause them to briefly activate.

After an area of brain is magnetically activated, there are a few hundred milliseconds of inactive ‘silence’, effectively switching the area off, albeit safely and temporarily.

Depending on how quickly these pulses are applied, over a short period of time (typically a few minutes), the overall level of activity in the targeted brain area can be increased, or decreased. A technique known as repetitive or rTMS.

It has been known for a while that patients with depression have reduced activity in the left frontal lobe.

Researchers thought that TMS could be used to increase activity in this area and treat the depression, and so a long series of controlled trials were started to see how effective it could be.

It turns out, TMS does seem to reliably increase activation in the left frontal lobe, but the evidence on whether it actually improves depression in mixed, so mixed in fact, it’s not clear whether overall, it’s an effective treatment at all.

One of the difficulties is that there are so many variables to test out.

TMS can be applied to anywhere on the cortex, at varying strengths, at varying frequencies, at varying angles, with different wave forms and with different shaped coils, just to name a few of the possibilities that don’t include variation in the patients themselves.

Ridding and Rothwell, authors of the review paper, are not impressed with the results so far, but note some areas are promising but under-researched:

It is a sobering conclusion. A new treatment that might help some patients slightly more than placebo, but for which we do not know the most effective dose nor the best group of patients to target. Yet this is not the most worrying thing about the depression story. The main problem is that none of these trials has advanced our understanding of how rTMS may be having any action at all in depression. Trials currently underway are being conducted with almost the same rationale as the initial trials more than 10 years ago. The only changes are in variables such as the subset of patients being studied, or the intensity of the stimulus with respect to the distance of the patient’s brain from the scalp surface. In effect, the science has stood still.

In retrospect, depression was probably a poor choice of condition in which to begin trials of rTMS. It is phenotypically diverse with difficult diagnostic criteria and a subjective clinical evaluation that makes it highly susceptible to any placebo effects of rTMS. Diagnostically simpler conditions that have been studied more recently, such as auditory hallucinations in schizophrenia and tinnitus may prove more tractable. In both cases, rTMS of areas of the parietal or temporal cortices, respectively, have reduced symptoms, in some cases for several weeks after treatment. However, the number of studies done so far is small, and any firm conclusions about efficacy await much larger controlled trials.

This hasn’t stopped a number of companies producing ‘off-the-shelf’ TMS devices to make the technology more accessible to work-a-day psychiatrists, rather than clinical researchers.

There are currently some large scale trials being conducted to test further whether TMS for depression is a useful treatment, but so far, the evidence just isn’t there.

However, one promising avenue might be using TMS as a treatment for stroke – brain damage caused by bleeds and blockages in blood flow.

A different, but perhaps equally effective approach has been driven by a model in which recovery after stroke is suppressed in some patients by input from an ‘overactive’ non-stroke hemisphere. Reduction of the excitability of this hemisphere by low-frequency rTMS has also been reported to increase function, in this instance in a group of chronic patients whose stroke had occurred at least 1 year previously

It’s still early evidence, but it might be that using TMS to target specific symptoms and selective disorders may be more effective than trying to treat the diverse conditions that make up the common psychiatric diagnoses, such as depression, bipolar and schizophrenia.

Link to abstract of TMS review paper (sadly, not open-access).

Synaesthesia in one language only

New Scientist have recently published a fascinating exchange on synaesthesia which has highlighted that some bilingual people with the condition experience the effect in one language only.

A reader wrote in to suggest that the consistently found associations of certain colours with specific letters of the alphabet may be due to with the way the letters are represented in children’s ‘ABC’ books.

Psychologist Dr Julia Simner replied, noting that research shows this wasn’t the case, but most interestingly, her letter indicates that some bilingual people only experience synaesthesia in one language:

Slessenger’s proposal that synaesthetes’ colours stem simply from childhood ABC books is sensible, but has been tested, and rejected, elsewhere. Anina Rich and colleagues traced 136 ABC books published as far back as 1862 – of which, surprisingly, only 38 used colour in any prominent sense. However, only 1 in 150 of their synaesthetes experienced colours consistent with any alphabet book [pdf].

Additionally, although Slessenger’s account is plausible for the examples he provided (eg, “A is for (red) apple, it’s less tenable when the entirety of alphabetic colours are considered. Indeed if synaesthetes’ colours were indicative solely of ABC learning, this would imply they lived in a world of green elephants (E), red mothers (M), black and blue tigers (T) and yellow cats (C).

Instead, our research indicates a different cause: synaesthetes colour their alphabets with a sophisticated, unconscious rule-system, in which, for example, associations are mapped according to the frequency with which letters and colour terms are encountered in the English language. High-frequency letters such as A are significantly likely to pair with high-frequency colour terms such as “red”.

Finally, Slessenger suggests our synaesthetes should be given symbols from an unknown language to test whether associations are independent of experience. This approach has been investigated and proved unhelpful. Strangely, depth of familiarity is not a strong predictor of synaesthetic colouring since some bilingual people have colour in only one language – and some monolinguals have colour for languages they do not understand.

In original letter was in response to a May article on the condition and some of Simner’s research findings. Unfortunately, the main article is behind a pay wall, but the letters are fascinating in themselves.

Link to original letter.
Link to Dr Simner’s reply.