Detecting suicidal intent in the unconscious mind

The Situationist has just alerted me to a fantastic article in the Boston Globe on the development a cognitive test for suicidal thoughts that doesn’t rely solely on the conscious mind.

The test is a variant of the Implicit Association Test (IAT) that has been used to look at our automatic associations between different concepts, based on how quickly we can categorise them.

We’ve discussed in it more detail previously but it essentially relies on the fact that if you have an pre-existing association between two concepts, say, the concepts ‘blonde’ and ‘stupid’, making similar associations will be faster than associating ‘blonde’ and ‘clever’ because you’re going to be quicker doing whichever classification best matches associations you already have.

Most of the research has been done on implicit social biases, finding that even people who have no explicit prejudices against blondes, foreigners, men or whomever, might find they automatically associate certain negative concepts with these groups.

However, as the test purely measures associations between concepts, it can be used to look for other implicit biases. In fact, the researchers featured in the Globe piece have used it to test for implicit associations between the concept of self and suicide.

Most suicidal patients will admit they are at risk of harming themselves. Contrary to popular belief, suicidal patients don’t necessarily want to die, they just want the pain to stop and will be upfront if they think professionals can help.

Some, however, may have decided that death is the only relief, or they may be unable to see clear alternatives owing to the effects of mental illness on thinking.

Suicide risk is assessed on the basis of people’s actions and what they say, so a completely determined person can talk their way through a risk assessment.

This new research is testing the IAT as a way of assessing suicide risk, even if the person is denying they are suicidal.

The study, led by Dr. Matthew Nock, an associate professor in the psychology department at Harvard University, is called the Suicide Implicit Association Test…

But critics question whether the test is actually practical, and up until now no one has tried to apply it to suicide prevention. As part of his training, Nock worked extensively with adolescent self-injurers – self-injury, such as cutting and burning, is an important coping method for those who engage in it, though they are often unlikely to acknowledge it. Nock thought that the IAT could serve as a behavioral measure of who is a self-injurer and whether such a person was in danger of continuing the behavior, even after treatment.

In their first major study, Nock and Banaji asserted that the IAT could be adapted to show who was inclined to be self-injurious and who was not. And more important, they said, the test could reveal who was in danger of future self-injury.

It’s an interesting idea and the early results look intriguing, although as the article notes, the proof will be how well it actually works in practice.

One difficulty with risk assessment in psychiatry is its almost impossible to do ‘ideal’ outcome studies because of the ethical implications.

For example, lets say your new risk measure predicts someone will kill themselves. From a statistical point of view, you’d want to wait and see if they do, so you can compare these positive predictions with the negative predictions and get an accuracy measure.

But from a purely humane point of view, you’re going to intervene and try and help the person, meaning risk assessments are not always based on ‘ideal’ statistical information.

The article has an excellent discussion of some of the wider ethical and practical issues involved, drawing on the writers own experience of his brother’s suicide.

Link to Boston Globe article ‘On the Edge’ (via The Situationist).

Waterfalls, adaptation and light

Firstly, you’ll have to excuse the somewhat ‘in house’ nature of this post, as it’s me writing about Christian writing about Tom. It’s an account of Tom giving an address to the Association for the Teaching of Psychology where he conducted a fantastic demonstration of how you can test out whether your brain adapts to certain visual conditions ‘locally’ on an eye-by-eye basis, or ‘centrally’ in eye independent perceptual brain areas.

Moments into the keynote talk, the teachers and I found ourselves blinded by darkness. As our eyes adjusted, we were told to cover one eye with our hands before the lights were raised again. A little wait for our open eyes to become light-adjusted and then the lights re-dimmed. What would happen to our vision this time? The answer depends on whether adaptation to light levels occurs centrally, in the brain, or locally in each eye. The audience tested this, looking through each eye one at a time and discovering the strange experience of having one eye adapted to the light and one to the dark, thus showing that light adaptation occurs locally. Both eyes open led to a strange, grey, grainy, effect. ‚ÄúWhoever said psychology isn’t useful is wrong,‚Äù Stafford said. ‚ÄúYou now have the perfect strategy for visiting the toilet in the night and finding your way back to your bed in the dark.‚Äù

Light adaptation may well occur locally, but what about adaptation to motion? A huge video of a waterfall filled the screen. After a minute staring at the cascading water, the video was stopped and the audience experienced the well-known illusion of the water appearing to flow upwards. But what if the flowing water was watched with just one eye (with the other covered), with the paused video then observed through the previously covered eye? The illusion was still experienced, thus showing that in this case, adaptation to motion had occurred centrally, in the brain.

If you don’t have a waterfall handy, you may be interested to know it’s a form of ‘motion after effect‘ illusion and there’s a similar demonstration online that you can try. If you go to that link, click ‘detach’ and resize the window to get a bigger version.

You’ll need to supply the room and light yourself though. The hall full of teachers is optional.

Link to BPSRD on visual adaptation.
Link to motion after effect example.

Silence, but for the clouds moving across the sky

Lee Tracy is an artist who creates poems out of brain scans.

The image is from a 2006 exhibition called Negative to Positive that was shown in the International Museum of Surgical Science in Chicago.

Each image is an CT scan of the artist’s brain, mounted in a light box and etched with a statement of the profound to the whimsical.

If you’re a neuroscientist and your lab needs more poetry or you’re an artist and your studio needs more neuroscience, you can purchase the pieces from the artist through Etsy.

Link to Lee Tracy’s poetic CT scans on Etsy (thanks Sandra!).
Link to Time Out review of ‘Negative to Positive’.

Whatever happened to symptom substitution?

Symptom substitution is at the core of Freudian psychology but according to a new article in Clinical Psychology Review there is virtually no evidence for its existence and the concept should be abandoned.

The idea is that if you treat a symptom, say a phobia of social situations, without addressing the underlying conflict, another symptom will just appear because the core problem is unchanged. It is based on the Freudian theory that all symptoms of mental illness are simply a reflection of an underlying unconscious conflict.

Freud was inspired by the first law of thermodynamics that says that energy cannot be created or destroyed just turned into another form. His psychology, and much Freudian-inspired psychodynamic psychotherapy that follows, applies a similar idea to emotions.

In this model, a conflict is caused by a forbidden unconscious impulse being held back by our conscious ego. Supposedly, we want to banish them from our conscious mind to maintain a positive self-image, so we repress them into our unconscious. But because they can’t just disappear they are expressed in other ways – i.e. as neurotic symptoms.

However, this model also plays an important symbolic role in the politics of mental health. It suggests that psychoanalysis is the only truly effective treatment, because it supposedly deals with the ‘root cause’, while drugs, behaviour therapy and CBT just alleviate symptoms and leave the patient open to further suffering.

Rather unusually for a Freudian idea, it leads to a directly testable hypothesis. Psychoanalytic treatment should lead to a better long-term prognosis, whereas we should see other other symptoms appear after treatment with other approaches.

Psychologist Warren Tryon decided to look at the medical literature to see whether other approaches were more likely to result in the appearance of other symptoms, and found no evidence from relevant empirical studies.

In fact, Tryon found only two cases studies that claimed to provide direct evidence for symptom substitution and one of them didn’t even fulfil the definition, it just reported that the same symptoms came back – therefore describing a relapse rather than a substitution.

Despite their being a lack of evidence so far, he does note that not many studies have directly addressed the issue, but proposes a direct test:

The following experimental design could identify genuine psychoanalytic symptoms. Form two groups of demographically matched patients displaying a hypothesized symptom. Provide psychoanalytic treatment to one group and symptomatic treatment to the other group. The hypothesized symptom can be considered to be a bone fide psychoanalytic symptom if patients receiving psychoanalytic therapy get better and symptom substitution occurs in patients receiving symptom oriented therapy. Helping these patients to get better by providing psychoanalytic therapy would provide additional supportive evidence and be ethically responsible. The literature review reported above indicates that the presence of bona fide psychoanalytic symptoms has yet to be demonstrated.

Link to ‘Whatever happened to symptom substitution?’ (thanks Karel!).
Link to PubMed entry for article.

Strippers for taxation reform

Frontal Cortex has an excellent post on the near futility of election coverage and why people tend to vote with what they feel, rather than what they know.

The piece reviews a whole range of studies that have highlighted possible non-issue influences on people’s voting preferences, from the weather to the facial expressions of news presenters.

One other line of research has found that facial structure can predict leadership, allowing people to reliably pick out business leaders or political winners just from a photo of their face.

Advertisers have long known that marketing products on the basis of facts is a lot less effective than marketing on the basis of appeals to emotion, desire and self-image.

While this is often labelled ‘sex sells’, ‘you-can-be-sexy sells’ is just as widely used.

Traditionally, this avenue has not been open to political candidates since it leaves the candidate open to the emotional counter-attack of accusations of impropriety.

After seeing the popularity of the ‘Obama Girl’ video, it struck me that the internet opens up this avenue, as supporters not officially associated with a candidate can now make their own wide-coverage sex sells promotions without ‘sullying’ the name of the official party machine.

As Frontal Cortex notes:

The problem, as political scientist Larry Bartels notes, is that people aren’t rational: we’re rationalizers. Our brain prefers a certain candidate or party for a really complicated set of subterranean reasons and then, after the preference has been unconsciously established, we invent rational sounding reasons to justify our preferences.

Link to Frontal Cortex on ‘Rational Voters?’.

Is banking on neuroscience a false economy?

The Economist has a great article taking a wide-angle view of neuroeconomics, asking whether it actually contributes anything useful to our understanding of economic systems or whether its just a personal psychology of gains and losses that won’t actually scale.

The fiercest attack on neuroeconomics, and indeed behavioural economics, has come from two economists at Princeton University, Faruk Gul and Wolfgang Pesendorfer. In an article in 2005, “The Case for Mindless Economics” [pdf], they argued that neuroscience could not transform economics because what goes on inside the brain is irrelevant to the discipline. What matters are the decisions people take—in the jargon, their “revealed preferences”—not the process by which they reach them. For the purposes of understanding how society copes with the consequences of those decisions, the assumption of rational utility-maximisation works just fine.

But today’s neuroeconomists are not the first dismal scientists to dream of peering inside the human brain. In 1881, a few years after William Jevons argued that the functioning of the brain’s black box would not be known, Francis Edgeworth proposed the creation of a “hedonimeter”, which would measure the utility that each individual gained from his decisions. “From moment to moment the hedonimeter varies; the delicate index now flickering with the flutter of the passions, now steadied by intellectual activity, low sunk whole hours in the neighbourhood of zero, or momentarily springing up towards infinity,” he wrote, poetically for an economist.

Part of the scepticism seems to originate from more general reservations about the results of brain scanning studies being over-interpreted, echoing wider concerns in cognitive neuroscience.

What’s interesting though is that the article mentions that neuroeconomics researchers are turning to transcranial magnetic stimulation (TMS) – a technique that alters brain function for a few hundred milliseconds while people are actively completing tasks.

Because TMS alters brain function, it’s not just showing you a correlation like brain scans do. If task performance changes when you’ve altered that brain area you can infer that the particularly part of the cortex you’ve targeted is causally involved in the psychology of the task.

Along these lines, one recent high-profile study [pdf] managed to alter participants’ fairness behaviour in the Ultimatum Game (a common experimental task) when the function of the upper outside surface of the right frontal lobe was disrupted.

Link to The Economist article ‘Do economists need brains?’.
pdf of ‘The Case for Mindless Economics’.
pdf of TMS study on fairness in the Ultimatum Game.