On believing you died during the operation

I just found this interesting paper in the medical journal Anesthesiology on fear of imminent death or the delusion that death has actually occurred, both linked to anaesthetic intoxication.

Despite our repeated explanations that she had suffered a local anesthetic-induced complication, the patient remained convinced that she had died and come back to life. This patient had been a non-practicing Christian who believed in an afterlife. She had not had any previous experience of this kind or know of others who had had. She had had no fear of death in the preoperative period.

The article notes that the delusional belief that one has died has been linked to complications with the use of lidocaine, procainamide, and procaine.

As with the drugs used in the Anesthesiology case study, all of these are local anaesthetics. They are just intended to numb a specific area, so the patient is not ‘put under’ with globally conscious altering substances.

It’s also interesting because the delusion that one has died is also known in the psychiatric literature, usually in the context of diagnoses such as schizophrenia or after brain injury.

In these cases it is known as the Cotard delusion which is usually explained, rather unsatisfactorily, as being caused by a general emotional disconnection from the world, interpreted by the patient’s faulty reasoning system as being convincing evidence that they are dead.

The case studies from the anaesthesiology literature suggest that these beliefs can be triggered in other ways, although the exact process still remains a mystery.

If you’re put off by academic journals, give this article a try. It’s well written, short and fascinating.

Link to Anesthesiology article on death delusions.

Sir Humphrey teaches questionnaire design

Classic British TV comedy Yes Prime Minister has important lessons for those who want to interpret questionnaire data. This clip shows two civil servants discussing a policy suggestion. Bernard Woolley, who we see first, thinks the public are in favour of the policy – the minister has had an opinion poll done. Luckily senior civil servant, Sir Humphrey Appleby is there to set him straight:

Fans of cognitive biases, note that Sir Humphrey uses at least three in his illustration of a biased questionnaire: framing, priming, and acquiescence bias.

This example exaggerated, but the moral still holds : questionnaires can be designed to encourage the answers you want. People’s opinions are not objective facts like their height and weight, they change depending on the context and on how they are asked.

2009-02-27 Spike activity

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

BBC Radio 4’s science programme Leading Edge covers memory in the dock, and memory and ageing.

New Scientist discusses virtual autopsies and looks inside the skull of a suicide victim with a medical scanner.

One for Spanish language readers: El Pais discusses the neuroscience of religion and spiritual experience with an article entitled ‘Dios habita en el cerebro‘.

Seed Magazine discusses the role of the internet in the recent voodoo fMRI controversy with a mention of Mind Hacks.

Beauty affects men’s and women’s brains differently, reports Wired.

The Times discusses the increasing trend for children with behavioural problems to be given numerous psychiatric diagnoses.

Neuroscientists develop ‘wireless‘ activation of brain circuits, reports press release on EurekaAlert.

Petra Boynton covers the ‘Facebook causes cancer’ debacle and the subsequent unhelpful and misleading contribution from neuroscientist Baroness Greenfield who should know better.

A study on the social benefits of social networking is covered by The Washington Times. Does this mean Facebook cures cancer too?

New Scientist discusses the psychology and neuroscience of suicide.

BBC’s science programme Horizon recently had a programme on the neuroscience of dreaming which is available to view online for another month or so. UK residents only though unfortunately.

The Neurocritic has an excellent critique of a recent imaging study that was rather widely and poorly reported as ‘men think of women in bikinis as objects’.

Does mentioning sex help students learn about other stuff too, asks Cognitive Daily with coverage of an interesting study on exactly this.

Science News reports that people who hold negative attitudes toward the elderly have an increased risk of heart-related ailments later in life.

An interesting study on the role of the 5-HTTLPR gene in attention to fearful or positive images is appallingly spun by New Scientist with nonsense about ‘happiness genes’ and genetic basis for optimism.

The Daily Mash has a <a href="Daily Mash
http://www.thedailymash.co.uk/news/society/facebook-gives-you-short-attention-span%2c-says…–ooh-what%92s-that?-200902251602/”>satirical take on the ‘Facebook causes cancer / rots your brain’ nonsense.

Research suggesting a possible genetic flag for brain cancer is covered by Science News.

The New York Times reports on a recent small sample size but interesting study on structural brain changes found in childhood abuse victims.

Brain scans replace job interviews within five years, reports gullible Digital Journal.

Neuroanthropology reviews a bunch of great brain books for kids. Yay!

New kind of epilepsy shakes up memory, reports New Scientist who seem to have no idea that transient epileptic amnesia is not new.

Furious Seasons is essential reading at the moment – e.g. catching AstraZeneca ordering it’s Seroquel sales reps to lie about the the drug causing diabetes. In case you didn’t know journalist Phil Dawdy is entirely funded by reader donations and he’s having a fundraiser at the moment.

First gene discovered for most common form of epilepsy, reports Science Daily.

BBC News reports that Alzheimer’s plaques may have a bigger impact on the brain than previously thought.

An interesting study on the interplay between reason and emotion in buying decisions is covered by Frontal Cortex.

Warning of ghosts in the machine

Today’s issue of Science has a letter from neuroscientist Martha Farah and theologian Nancey Murphy warning against ‘non-materialist neuroscience’ becoming the new front-line in the religion wars.

Most religions endorse the idea of a soul (or spirit) that is distinct from the physical body. Yet as neuroscience advances, it increasingly seems that all aspects of a person can be explained by the functioning of a material system. This first became clear in the realms of motor control and perception. Yet, models of perceptual and motor capacities such as color vision and gait do not directly threaten the idea of the soul. You can still believe in what Gilbert Ryle called “the ghost in the machine” and simply conclude that color vision and gait are features of the machine rather than the ghost.

However, as neuroscience begins to reveal the mechanisms underlying personality, love, morality, and spirituality, the idea of a ghost in the machine becomes strained. Brain imaging indicates that all of these traits have physical correlates in brain function. Furthermore, pharmacologic influences on these traits, as well as the effects of localized stimulation or damage, demonstrate that the brain processes in question are not mere correlates but are the physical bases of these central aspects of our personhood. If these aspects of the person are all features of the machine, why have a ghost at all?

By raising questions like this, it seems likely that neuroscience will pose a far more fundamental challenge than evolutionary biology to many religions. Predictably, then, some theologians and even neuroscientists are resisting the implications of modern cognitive and affective neuroscience. “Nonmaterialist neuroscience” has joined “intelligent design” as an alternative interpretation of scientific data. This work is counterproductive, however, in that it ignores what most scholars of the Hebrew and Christian scriptures now understand about biblical views of human nature. These views were physicalist, and body-soul dualism entered Christian thought around a century after Jesus’ day.

As I’ve noted before, I remain sceptical that this will pose much of a threat, largely due to the fact that non-materialist neuroscience is not particularly new – many famous neuroscientists (including the Nobel prize-winning John Eccles) have been explicitly non-materialist with few contemporary ripples.

Unlike evolution, which bluntly contradicts what many religious texts claim, very few holy books describe any concepts of the soul that can be directly contradicted by neuroscience.

However, there is certainly some interest in the neuroscience bashing among Christian fundamentalists, who recently held their first conference on the issue. We shall have to see how successfully they manage to enthuse their flock.

Link to letter ‘Neuroscience and the Soul’.
Link to DOI entry for same.

Brain implants and cognitive side-effect trading

This week’s Nature has an interesting article on the ethics of electronic brain enhancements. It does something quite unusual for an article on technological brain enhancements – it talks about the side effects.

Brain implants and ‘neuroprosthetics’ have been widely covered by the science media in recent years owing to a number of impressive advances but very little discussion has focused on the adverse effects.

In considering the ethics of using brain implants to enhance both the damaged and healthy brain, this article actually touches on some of the research on unwanted effects of deep brain stimulation.

Many patients with Parkinson’s disease who have motor complications that are no longer manageable through medication report significant benefits from DBS. Nevertheless, compared with the best drug therapy, DBS for Parkinson’s disease has shown a greater incidence of serious adverse effects such as nervous system and psychiatric disorders and a higher suicide rate. Case studies revealed hypomania and personality changes of which the patients were unaware, and which disrupted family relationships before the stimulation parameters were readjusted.

Such examples illustrate the possible dramatic side effects of DBS, but subtler effects are also possible. Even without stimulation, mere recording devices such as brain-controlled motor prostheses may alter the patient’s personality. Patients will need to be trained in generating the appropriate neural signals to direct the prosthetic limb. Doing so might have slight effects on mood or memory function or impair speech control.

The author of the piece argues that this does not raise any new ethical questions, as many psychiatric drugs also have side effects.

However, it’s probably true to say that ethical difficulties often arise with regard to specific side effects – talking about unwanted effects in general is a bit too vague to be useful.

Risk-benefit analyses are only useful when you know both the extent and quality of the risks and benefits and this is where it truly gets interesting.

The neuropsychology literature is full of surprising findings about what sort of functions the brain performs, suggesting that specific effects, wanted and unwanted, may have to be traded off against each other.

For example, is the loss of the ability to have an unconscious emotional reaction to a loved one worth a change in pathological gambling behaviour?

This is a hypothetical example based on the role of the ventromedial cortex in both situations, but who knows what sort of effects might need to be weighed up against each other.

Nature Network has an online discussion about the issues the piece raises which also links to the weekly podcast which has an interview with the author.

Link to Nature article ‘Man, machine and in between’.

The life and times of the truth serum

I just found this fascinating photo in a 1932 book on forensic psychology in the Universidad de Antioquia’s history of medicine section. It pictures the inventor of the truth serum, Dr House, administering the drug to an arrested man in a Texas jail.

The book is called Manual de Psicolog√≠a Jur√≠dica (literally ‘manual of legal psychology’) by the pioneering forensic psychiatrist Emilio Mira y L√≥pez and is a curious mixture of psychological theory, mental tests and descriptions of what seem like strange lie-detecting contraptions.

The history of the ‘truth serum’ is recounted in a fantastic article by medical historian Alice Winter from Bulletin of the History of Medicine which describes the Dr House’s invention and the influence it had on society of the time.

Truth serum was the creation of a rural Texas physician, Robert House. House claimed that the drug scopolamine hydrobromide, which was known for erasing the knowledge of painful events, could actually be used to extract intact information. His announcement was seized upon by journalists, police, and forensic scientists as heralding a potentially transformative new technology, and was just as robustly rejected by the legal community.

Scopolamine’s identity as an extractor of “truth” was indebted to certain earlier conventions‚Äînotably, research into altered psychic states such as mesmerism and hypnotism, which sometimes were said to create a confessional state. Scopolamine, in turn, created the shoes that other chemical agents would come to fill when, later in the decade and in the 1930s, the new barbiturates sodium amytal and sodium pentothal were said to have the potential to extract “truthful” memories.

These drugs largely act by reducing inhibition, with the hope that the person will speak more freely, but they have never been found to reliably make anyone more truthful.

Alice Winter was also recently interviewed on SciAm’s Mind Matters blog, in light of rumours that one of the men involved in the Mumbai attacks had been subjected to interrogation under ‘truth serum’.

Link to Winter’s article The Making of ‘Truth Serum’.
Link to ‘What is truth serum?’ from SciAm.

The future of experimental philosophy

March’s Prospect magazine has an excellent article on ‘experimental philosophy’ that gives a good overview of an exciting new branch of philosophy as well as picking up on some of the growing criticisms and detractors.

The first half of the article covers the current methods and strands of thought in the field, discussing brain scans, trolley problems and intentionality. If you’re familiar with the ‘x-phi’ movement this is really just a well-written recap.

However, the second half tackles criticisms of the field by more established philosophers and is a useful counter-point to much of the unfettered enthusiasm which has gripped the recent media reports.

Points of disagreement include relying on the fuzzy data of brain scans, the fact that the field aims to find out about what people think in general rather than building the soundest conceptual solutions, and the accusation that it’s “a cynical step by researchers to appear cutting edge and to tap into scientists‚Äô funding”.

Ouch. If you’re not wincing already, it’s probably worth noting that this is the philosophical equivalent of saying your girlfriend looks fat in her new dress.

The piece finishes on the interesting idea that perhaps one of the field’s main contributions is to develop a context dependent philosophy that isn’t so swayed by the world view of academic thinkers.

Link to Prospect article ‘Philosophy‚Äôs great experiment’.