Encephalon 57 on Mind Hacks

Welcome to the 57th edition of the Encephalon psychology and neuroscience writing carnival, where we have the honour of hosting the best in the last fortnight’s mind and brain writing, here on Mind Hacks.

We start off with two great interviews. The first is a video interview with pioneering neuroscientist Rodolfo Llin√°s, known for his radical ideas on consciousness, picked up by Channel N. One of the great names in cognitive science makes an appearance on Sharp Brains as Michael Posner is the subject of a recent interview.

One of Posner’s great achievements, along with Marcus Raichle was to invent the subtraction method for the analysis of brain imaging data to allow us to make inferences about how the mind is working. The Neurocritic has an excellent piece on some of the state-of-the-art work which is attempting to advance this technology, almost 30 years after the original breakthrough, by looking at links between electrical activity in the cortex and spontaneous fluctuations in signals from fMRI scanner.

Also on a neuroimaging tip, Pure Pedantry covers a recent study on the neuroscience of hypothesis generation, or how we think up possible explanations to explain causality in our booming, buzzing confusion of a world.

The masters of making sense of out of confusion are, of course, children, and a couple of great articles look at some of the latest research showing how the developing brain seems to work its magic. Looking at the remarkable development of language, the consistently excellent Cognitive Daily discuss a child’s use of gesture to communicate and whether it slows language learning. Songs from the Wood has a great piece on infantile amnesia – that curiosity of development where we typically cannot remember anything that happened before the age of 3-4 years.

But if you want to learn more about what makes memories stick, Physiology Physics looks at long-term potentiation – one of the most important neuroscience discoveries in the last fifty years and one of the cornerstones of remembering.

If you’re interested in where all this childhood experience ends up, one destination is our personality or personal style of interacting with each other and the world. The Mouse Trap looks at some of the most influential of these theories in <a href="
http://the-mouse-trap.blogspot.com/2008/09/cloningers-temaparements-and-character.html”>three great posts that discuss character traits, emotional maturity and emotional intelligence.

Obviously, if you’ve been reading the same dodgy research that Dr Shock has, you’ll know that one part of emotional maturity is saying no to computer games because THEY BURN YOUR SOUL. Or, maybe they don’t and the researchers are trying to spin a positive result into a negative one to get their unsupported point across. Ah, the joys of science.

Entering more unusual territories, Brain Blogger has a brief guide to the syndrome where people lose control of their hands after brain injury, carious known as anarchic or alien hand syndrome. PodBlack stays with the uncanny in a post about sex differences in superstitions and paranormal beliefs. It’s actually the last part of the four part series looking at superstitions and all are well worth a read.

Equally mysterious and no less controversial is the placebo effect and Brain Health Hacks has an interesting piece on what the the science of placebo might tell us about the neuroscience of hope. I’m sure there’s an election joke in their somewhere but I’ll leave that as a exercise for the reader.

Talking of culture in a more general sense, the newly launched Culture and Cognition blog has an interesting piece that discusses a recent Nature paper on culture and the brain and another on what can only be described as culture hacking.

From culture hacking to baseball hacking as sports psychology blog 80 Percent Mental looks at the cognitive science of baseball including some illustrative videos and perfect timing for the World Series.

From the best in baseball, to the best in online writing about Bipolar Disorder (calling Liz Spikol…) as PsychCentral ranks its Top 10 Bipolar Blogs for 2008. Keeping with the positivity, Brain Blogger looks at tetrabenazine, a drug which shows promise in treating Huntingdon’s disease.

Finally, we finish with some articles about our animal friends. The always thought-provoking Neuroanthropology which provides two posts with video footage of cooperative hunting in chimpanzees. As they say – “The videos raise questions about our own animal nature, as well as what is the dividing line between our own minds and the minds of some of our closest relatives.”

Obviously, none of those chimpanzees have robotic cyber-implants, unlike the monkey discussed in a Pure Pendantry piece on a recent Nature Neuroscience article. But it’s not just cyber-monkeys, it’s also radioactive mice! Neurotopia has the low-down on the effects of exercise on hippocampal cell proliferation in irradiated mice. I’m sure there’s a Marvel comic that starts like that but I dread to think which one.

Along the same lines of a science-fiction plotline become reality, Neurophilosophy looks at recent research on how individual memories were erased in mice. And if your hero needs a daring getaway, there’s more from the same source on staggering escape mechanism of the crayfish.

Synaesthesia induced by hypnosis

Wired Science has an interesting preview of an upcoming study that used hypnosis to induce colour-number synaesthesia in highly hypnotisable participants.

Synaesthesia is where the senses merge, and in colour-number synaesthesia, the affected people experience colours associated with specific numbers.

This new study used hypnosis to induce exactly this experience in people who didn’t have it before:

The researchers, led by Roi Kadosh of University College, London and Luis Fuentes of Spain’s University of Murcia, put three women and one man under hypnosis, then instructed them to perceive digits in color: one as red, two as yellow, three as green, and so on.

Upon waking, the subjects found it difficult to find numbers printed in black ink against correspondingly colored backgrounds. The numbers seemed to blend in — a telltale sign of synesthesia. When the hypnosis was removed, the ability vanished.

How the synesthesia formed so suddenly isn’t clear, but the researchers said that new neural connections are probably not responsible. “Such new anatomical connections could not arise, become functional, and suddenly degenerate in the short time scale provided by the current experiment,” they wrote.

Instead they suggest that hypnosis broke down neurological barriers between sensory regions. Marks agreed, but cautioned against extrapolating the findings too broadly: Many different varieties of synesthesia exist, from seeing emotions to tasting sounds, and may have different neurological and psychological origins.

Hypnosis has been studied before for it’s ability to induce anomalous colour experiences.

In a study published in 2000, the researchers used hypnosis to induce the experience of colour when the participants were viewing a black and white image, as well as the reverse.

What was most fascinating about this particular study was that it was run in a PET scanner and the researchers discovered that the colour-based focused hypnotic suggestions actually altered the function the colour perception areas in the visual cortex, which is known to be involved in the perception of colour.

In other words, it is likely that hypnosis was not simply leading the people to make false claims, but was actually affecting what they perceived.

Link to ‘Hypnosis Lets Regular People See Numbers as Colors’.
Link to PubMed entry for colour study (with full-text link).

I am a committee, chaired by a hedonist

Psychologist Paul Bloom has written a wonderfully eclectic article for The Atlantic magazine about the psychology of pleasure and why it suggests that we have multiple situation-specific selves.

The piece is a little disjointed in places but it is packed full of information and if nothing else you get a good sense of the enthusiasm for this developing field.

One area of pleasure research not mentioned in Bloom’s piece is the fascinating work of Michel Cabanac, who has a theory that pleasure is the decision-making currency of the brain.

New Scientist had an excellent article on Cabanac’s work which you can read online, and makes an excellent complement to The Atlantic piece.

However, Bloom is more concerned with how we resist the temptation of pleasure using ‘self-binding’ – in other words, doing things that will reduce the chances of us succumbing to temptation later on. Like getting someone to hide your cigarettes if you’re trying to give up.

For adult humans, though, the problem is that the self you are trying to bind has resources of its own. Fighting your Bad Self is serious business; whole sections of bookstores are devoted to it. We bribe and threaten and cajole, just as if we were dealing with an addicted friend. Vague commitments like “I promise to drink only on special occasions” often fail, because the Bad Self can weasel out of them, rationalizing that it’s always a special occasion. Bright-line rules like “I will never play video games again” are also vulnerable, because the Bad Self can argue that these are unreasonable—and, worse, once you slip, it can argue that the plan is unworkable.

For every argument made by the dieting self—“This diet is really working” or “I really need to lose weight”—the cake eater can respond with another—“This will never work” or “I’m too vain” or “You only live once.” Your long-term self reads voraciously about the benefits of regular exercise and healthy eating; the cake eater prefers articles showing that obesity isn’t really such a problem. It’s not that the flesh is weak; sometimes the flesh is pretty damn smart.

Link to Atlantic article ‘First Person Plural’.
Link to NewSci piece ‘The Pleasure Seekers’.

Milgram’s culture shock

ABC Radio National’s Radio Eye has one of the best documentaries on Milgram’s conformity experiments that I’ve ever heard. It follows up several of the people who took part in the original experiment and weaves their stories into the audio from the original and chilling tapes of the actual sessions.

You’ll have to be quick because the audio is only online for another week or two and it’s a 50-minute must-listen programme that is wonderfully produced.

The tapes of the actual sessions are remarkable and you can feel the psychological tension as the study progresses.

As well as being a detailed guide to the study, it’s a fascinating look at the experience of taking part in a process that had as much impact for the ethical changes that it triggered as for the implications for what we know about conformity and social pressure.

Link to Radio Eye ‘Beyond the Shock Machine’ (via AITM Blog).

Creationists unaware of past, doomed to repeat it

New Scientist has an article on a group of creationists who are attempting to argue that we have a soul based on the difficulty of reducing mental events to neurobiology. The article makes out that this is a new front on the ‘war on science’ but I wouldn’t be manning the barricades quite yet, as the issue has been around as long as neuroscience itself.

The creationist-affiliated researchers suggest that the ‘mind-body problem‘ – the difficulty in explaining subjective mind states in terms of objective biological processes – means that the mind must be partly non-material and, therefore, have some spiritual aspect to it (i.e. the soul).

What’s interesting in this debate as many scientists respond by simply denying there is a problem and suggesting that this is just a issue of progress and eventually we will be able to explain every mind state in terms of brain function.

This is unlikely, however, owing to the fact that the mind and brain are described with different properties and so cannot be entirely equivalent. Therefore, one will never be completely reduced to the other.

This does not imply that there must be a soul or non-material mind at work. If this doesn’t seem obvious to you, try this example.

Why does Elvis not want you to step on his blue suede shoes? You buy a copy of the track on CD but analysing the physics of the sound waves in the song will not fully answer your question.

You might find out that the volume or pitch increases at specific points to highlight certain key phrases, but you can’t fully understand why Elvis is so protective of his new shoes through physics alone.

In other words, you can’t explain everything about the song through objective scientific methods. This does not mean your CD, or the sound waves, have a soul.

The same goes for the mind and brain. There are some things we talk about in terms of experience, mental events and thoughts that will not be adequately explained at the level of objective biological measures. Similarly, this does not imply the existence of a soul.

Importantly, it doesn’t disprove the existence of a soul either, because unless you make specific falsifiable statements about what a soul actually does in the brain in an empirically testable way, science can’t test it one way or another. It can only make inferences.

On the basis of the fact that no proposed ‘soul effect’ has ever been detected, most neuroscientists think that a non-material aspects to the mind doesn’t exist. The mind, like Elvis songs, are just part of the world, even if we need to use different levels of meaning to fully explain them.

However, some neuroscientists think different, and have done for as long as neuroscience has been around, and this is why this ‘new’ development is unlikely to be a big threat.

In fact, Nobel-prize winning neuroscientist Sir John Eccles believed until his dying day that there was a non-material aspect to the mind. Dana Magazine has a great article on Eccles’ dualism which is well worth reading if you want a summary of his views.

But this just illustrates the point that the recent claims by creationist-affiliated researchers are neither new nor particularly threatening. Neuroscience has not come crashing to the ground, and science seems remarkably untroubled.

UPDATE: The Neurologica Blog also has some great coverage of the NewSci piece and has more of an in-depth analysis.

Link to NewSci piece ‘Creationists declare war over the brain’.
Link to Dana article on Eccles’ dualism.

2008-10-24 Spike activity

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

Being altruistic makes you hot, finds new research covered by Medical News Today.

Neuronarrative is a high-quality new mind and brain blog. Highly recommended.

The San Franciso Chronicle has an excellent piece on the place of brain scans in the courtroom.

In light of the recent controversy over a murder conviction in India where ‘brain scan lie detection’ was admitted as evidence, Wired covers the aftermath and the protest of Indian scientists.

BBC News has a video on research looking at the link between dancing style, attractiveness and ‘fitness’ as a potential mate.

Hypnosis, memory and amnesia are discussed by one of the leading hypnosis research groups in the Scientific American Mind Matters blog. This see post for our own coverage of the this fascinating study.

BBC News covers new research that finds mentally demanding jobs may protect against Alzheimer’s. More evidence that staying active keeps the brain healthy.

Creationist ‘fossilised brain‘ ridiculousness is covered by Pharyngula. Looks more like a cauliflower to me.

But wait, brain found inside watermelon. The final nail in the coffin for evolutionary theory.

Alternet has an extended article on the Johns Hopkins research into the medical benefits of the hallucinogenic drug psilocybin (thanks Sandy!).

Neuroanthropology previews an upcoming conference on the ‘encultured brain‘.

The Top 10 Bipolar Blogs of 2008 are presented by PsychCentral.

Being a <a href="
http://women.timesonline.co.uk/tol/life_and_style/women/families/article4962480.ece”>daddy makes you kinder and smarter, reports the Times. Presumably, this helps make up for the sleep deprivation.

New Scientist reports that a computer circuit has been built from brain cells. NetBSD port to follow shortly.

Paul Bloom is interviewed by The Boston Globe about the psychology of believing in the soul. Presumably it refers to the eternal soul rather than Marvin Gaye.

The BPS Research Digest covers an interesting study on social norm violations in fans queuing for a U2 gig.

A funky guide to all things dopamine is provided by Neurotopia.

Submit your entries for Encephalon, this Monday

The next edition of the Encephalon psychology and neuroscience writing carnival will be hosted here on Monday 27th October, so submit your best mind and brain writing from the last fortnight if you’d like it featured.

You can email me directly via this web form or you can email your links to encephalon.host [at sign] gmail.com.

Please put the word ‘Encephalon’ in the subject line. I look forward to reading all the submissions!

False advertising statistics effective, say 9 out of 10 cats

Ars Technica has a fantastic article on a recent study that found that numerical specifications in adverts have a huge effect on our choices, even when they’re meaningless.

The numbers can be ratings, technical details, supposed representations of quality – it doesn’t seem to matter. In general, bigger is better and the study found that we tend to be swayed by the numbers even when it directly contradicts our experience.

The first test involved megapixels. The authors took a single image, and used Photoshop to create a sharper version, and one with more vivid colors; they told the students that the two versions came from different cameras. When told nothing about the cameras, about 25 percent of the students chose the one that had made the sharper image. But providing a specification reversed that. When told that the other model captured more pixels using a figure based on the diagonal of the sensor, more than half now picked it. When it comes to specs, bigger is better, too, even if the underlying property is the same. Given the value in terms of the total number of pixels captured, the preference for the supposedly high-resolution camera shot up to 75 percent.

The researchers thought this might be a problem with the fact that not everyone is technically minded, so they tried various other experiments with everything from scented oil to ice-cream – all with the same effect.

To quote the researchers “even when consumers can directly experience the relevant products and the specifications carry little or no new information, their preference is still influenced by specifications, including specifications that are self-generated and by definition spurious and specifications that the respondents themselves deem uninformative.”

Link to Ars Technica write-up of study.
Link to study paper.
Link to DOI.

Pentagon requests robot packs to hunt humans

New Scientist reports on a new Pentagon request to develop a pack of robots “to search for and detect a non-cooperative human”.

I am a strong believer in the fact that everyone who takes a course in artificial intelligence should be made to watch post-apocalyptic film The Terminator as a stark warning, in the same way that everyone who works with MRI scanners is made to watch serious videos about ‘what can go tragically wrong and how you can prevent it’.

I also suspect though, that the students who come out of those lectures rooting for the robots are recruited into military research teams.

From the Pentagon document:

Typical robots for this type of activity are expected to weigh less than 100 Kg and the team would have three to five robots.

PHASE I: Develop the system design and determine the required capabilities of the platforms and sensors. Perform initial feasibility experiments, either in simulation or with existing hardware. Documentation of design tradeoffs and feasibility analysis shall be required in the final report.

PHASE II: Implement the software and hardware into a sensor package, integrate the package with a generic mobile robot, and demonstrate the system‚Äôs performance in a suitable indoor environment. Deliverables shall include the prototype system and a final report, which shall contain documentation of all activities in this project and a user’s guide and technical specifications for the prototype system.

PHASE III: Robots that can intelligently and autonomously search for objects have potential commercialization within search and rescue, fire fighting, reconnaissance, and automated biological, chemical and radiation sensing with mobile platforms.

PHASE IV: Die puny humans die!

PHASE V: To the bunkers! Run for your lives! Arggghhhhh!

PHASE VI: Sarah Connor, we’re going to send you back in time to make a movie to warn everybody about the coming annihilation of the human race. Recruit a political leader so people will take it seriously – like Governor Schwarzenegger, for example.

Earlier this year, Israel announced that they want to develop an AI-controlled missile system that “could take over completely” from humans. If you’re still chucking, the UK military satellite system is called Skynet.

Link to NewSci on Pentagon opening Pandora’s box.
Link to Pentagon solicitation request.

Towards a neuropsychology of religion

This week’s Nature has a fascinating essay by anthropologist Pascal Boyer discussing the quirks of spiritual belief and how they may result from the evolution of our mind and brain.

Boyer is best known for his book Religion Explained: The Evolutionary Origins of Religious Thought where he argued that religion can be understood as where the cognitive abilities we’ve developed through evolution are applied to things like group identity, ritual, or the explanation of otherwise mysterious things, such as weather or disease.

Essentially, Boyer argues that there are cognitive restraints on religious practice and belief, which he illustrates by pointing out some interesting inconsistencies in our intuitive ideas about spiritual agents. According to Boyer, this suggests that our mental capacities define what are supposed to be all-powerful or all-knowing entities.

This clip of Boyer being interview by Jonathan Miller is fascinating because he points out, contrary to popular belief, what most religions are concerned with. He notes most religions do not concern themselves with the creation of the world or the afterlife, while the presence of unseen agents is almost universal.

There is now a growing interest in the cognitive science of religion and one of my favourite articles is by psychiatrist Quinton Deeley who discusses how different form of religious ritual may influence specific cognitive functions to pass on religious teachings and commitments (full disclosure: Deeley is a friend and research collaborator).

Deeley argues that the well-known distinction between ‘doctrinal’ rituals which are frequent and low intensity (such as everyday prayers or practices), and ‘imagistic’ high-intensity, less-frequent rituals (such as exuberant religious celebrations) serve different psychological purposes.

‘Doctrinal’ rituals help create semantic memories of key concepts and emotional response through associative learning, while ‘imagistic’ rituals help create episodic memories of specific situations that may involve altered states of consciousness and the experience of other realities.

Deeley also did a fascinating talk on ‘Ritual, Possession Trance, and Amnesia’ where he discusses some of the neuropsycholgical mechanisms that might underlie trance and possessions states.

Link to Boyer’s Nature essay ‘Religion: Bound to believe?’.
Link to brief interview with Boyer on religion.
Link to Deeley’s article ‘The Religious Brain’.
Link to video of talk ‘Ritual, Possession Trance, and Amnesia’.

Neuropsychiatry in Venezuela

Apologies for the lack of posts, but I’ve just arrived in Punto Fijo in Venezuela, as I’ve kindly been invited to be a guest of the Venezuelan Psychiatric Society at their annual conference, where I shall be talking about the cognitive neuropsychiatry of psychosis later in the week.

Unfortunately it’s dark and I’ve been travelling since yesterday, so all I know about Punto Fijo is that it is supposed to be remarkably beautiful and it’s incredibly humid.

However, I spent a fantastic day in Caracas with Jorge, a superb colleague from Medellín, and Jose and Claudia, a Venezuelan psychiatrist and psychologist couple who graciously toured us through the city and showed two weary travellers some warm Venezuelan Hospitality.

Updates to follow shortly (after some well deserved sleep).

Monochrome dreaming

Watching black and white television as a child may explain why older people are less likely to dream in colour than younger people, according to new study reported in New Scientist.

The study is from psychologist Ewa Murzyn, who was interested in how early experience could affect our dream life.

She first asked 60 subjects – half of whom were under 25 and half of whom were over 55 – to answer a questionnaire on the colour of their dreams and their childhood exposure to film and TV. The subjects then recorded different aspects of their dreams in a diary every morning.

Murzyn found there was no significant difference between results drawn from the questionnaires and the dream diaries – suggesting that the previous studies were comparable.

She then analysed her own data to find out whether an early exposure to black-and-white TV could still have a lasting effect on her subjects dreams, 40 years later.

Only 4.4% of the under-25s’ dreams were black and white. The over-55s who’d had access to colour TV and film during their childhood also reported a very low proportion of just 7.3%.

But the over-55s who had only had access to black-and-white media reported dreaming in black and white roughly a quarter of the time.

It’s an interesting study because, as we recently discussed, philosopher Eric Schwitzgebel argued that exposure to TV was an unlikely explanation for the effect where we’ve tended to report more coloured dreams in modern times and suggested this actually showed we’re not very good at introspecting into our own minds.

This study provides some evidences that the effect may be more reliable than we think.

However, I’m still puzzled by why television would seem to have such a big influence so many years later when most of the visual experience the person would have received as a child, even if a heavy TV watcher, would be from the ‘real’ coloured world.

Curious.

Link to NewSci on black and white dreams study (thanks Laurie!).
Link to scientific paper.
Link to PubMed entry for same.

Colombian Congress of Psychiatry report

I recently got back from the Colombian Congress of Psychiatry and was incredibly impressed both by the high standard of scientific work and the wonderfully welcoming people I met.

I have to say, I didn’t see quite as much of the conference as I normally would owing to the rather relentless pace of partying that seems to occur in Bogot√° (things I haven’t seen at UK psychiatry conferences: the president of the national psychiatric association stood atop a table getting everyone to wave their hands in the air like they just don’t care).

For me, one of the academic highlights was actually from a Spaniard, Julio Sanju√°n, who talked about some innovative research he’s doing on auditory hallucinations.

In one elegant study, Sanju√°n and his team decided to look at what sort of brain activation is triggered by neutral and emotional words in patients with schizophrenia who hear voices.

It’s remarkably how many studies in schizophrenia have been done of changes in visual perception when one of the major problems for many people with the diagnosis is that they hear intrusive and unpleasant hallucinated voices.

Sanju√°n came up with the idea of simply looking at how the brains of people with schizophrenia react to hearing emotional words (such as swear words) compared to neutral words – matched for word type and frequency.

The image on the right shows the remarkable difference, whereby emotional words cause a much larger response in the brain. In fact, they found they triggered much greater frontal lobe, temporal cortex, insula, cingulate, and amygdala activity, largely on the right.

It’s a ‘why didn’t I think of that’ study that might help explain why people with schizophrenia often find their voices so disabling when other people in the population can hear voices and remain undisturbed.

In terms of drug company ridiculousness that often appears as part of the ‘educational effort’ in European Conferences (i.e. models on bikes), it was remarkably muted in comparison.

However, one particular lowlight was finding out the session I was speaking at was being used by Janssen to advertise their ‘new’ antipsychotic paliperidone – which is actually little more than a repackaged risperidone.

Did I mention risperidone has just gone out of patent and can now be produced much more cheaply by other drug companies? Obviously nothing at all to do with Janssen having a newly patented drug to sell I’m sure.

Wave your hands in the air like you just don’t care.

Link to Sanju√°n study on emotional word reactivity.
Link to PubMed entry for same.

The sexual distractions of cheese crumbs

Another fantastic quote from Bonk, a book about sex research by science writer Mary Roach, this time about the effects of distraction on female sexual arousal (from p251):

A thousand images can play on a woman’s mind: work, kids, problems with Ultrasuede. One nonpharmaceutical solution is to teach women to redirect their focus and pay more attention to physical sensations – a practice called mindfulness.

A pilot study – meaning it’s a preliminary investigation with no control group – by Lori Brotto and two colleagues at the University of British Colombia had promising results. Eighteen women with complaints about their ability to become aroused participated in mindfulness training. Afterward, there was a significant jump in their ratings of how aroused they’d been feeling during sexual encounters.

If it’s any solace, even female rats have trouble focusing. I give you a sentence, my favourite sentence in the entire oeuvre of Alfred Kinsey, from Sexual Behaviour in the Human Female: “Cheese crumbs spread in front of a copulating pair of rats may distract the female, but not the male”.

Full disclosure: I was sent a free copy of the book by the publishers about six months ago but I’ve only just got round to reading it.

Link to Mary Roach’s website.
Link to previous Mind Hacks review of Bonk.

Looking for the mind in a haystack of words

The New York Times has an article on the simple but effective idea that a statistical analysis of word frequency in written text can be a guide to the psychological state of the author. It’s a technique that’s been pioneered by psychologist James Pennebaker who has conducted a considerable amount of intriguing research to back up his technique.

In fact, he’s completed a huge number of studies looking at word frequency in everything from bereavement to suicidal and non-suicidal poets.

However, some of his most impressive work has focused on the benefits of getting distressed or ill people to write, finding that it benefits recovery from trauma, but perhaps more surprisingly seems also to boost immune system function in HIV patients.

The evidence and theory behind the work was described in a great 2003 review article which notes that the importance lies not so much in the subject or action words, but in the ‘bitty’ parts of speech, such as the use of pronouns (I, you, we and so on).

These seem to relate to the focus of the thoughts and Pennebaker was asked by the FBI to apply the technique to the communications of Al Queda:

Take Dr. Pennebaker’s recent study of Al Qaeda communications — videotapes, interviews, letters. At the request of the F.B.I., he tallied the number of words in various categories — pronouns, articles and adjectives, among others.

He found, for example, that Osama bin Laden’s use of first-person pronouns (I, me, my, mine) remained fairly constant over several years. By contrast, his second-in-command, Ayman al-Zawahri, used such words more and more often.

“This dramatic increase suggests greater insecurity, feelings of threat, and perhaps a shift in his relationship with bin Laden,” Dr. Pennebaker wrote in his report [pdf], which was published in The Content Analysis Reader (Sage Publications, July 2008).

Interestingly, the FBI have their own in-house text analysis technique but I’m damned if I can remember the name or find it on the net. Answers on an encrypted telegram please…

Link to NYT piece ‘He Counts Your Words (Even Those Pronouns)’.
Link to review article ‘Psychological aspects of natural language’.
Link to PubMed entry for same.