The deadly South American arrow poison

I’ve just found a fantastic article on the history of curare, the powerful Amazonian arrow poison that causes paralysis and death. It’s from a 2005 edition of the Journal of the Royal College of Physicians Edinburgh and is available online as a pdf.

The article tells the story of how the New World poison came to be known to the West, and how explorers, researchers and ‘gentleman scientists’ attempted to work out how it had its deadly effect.

Curare can be extracted from several plants but the active ingredient is d-tubocurarine.

It has its effect by blocking the effect of the neurotransmitter acetylcholine at the neuromuscular junction. In other words, it blocks the chemical signals that allow nerve signals to activate the muscle.

You may be interested to know that Botox works in an almost identical fashion. It is used in in very small doses in plastic surgery to supposedly ‘smooth’ wrinkles.

Actually, the main ‘smoothing’ effect is due to the fact that the underlying muscles are paralysed and so cannot move to cause creases in the skin.

In larger doses it is also very dangerous. The name is a clue – Botox is short for ‘botulinum toxin’.

The article on curare also has some fascinating asides about the myths associated with the compound, and some curious historical incidents associated with it – such as its role in a plot to assassinate the British Prime Minister during World War One.

pdf of article ‘Curare: the South American arrow poison’.

Faces, genetics and addiction

BBC Radio 4’s science programme Material World just had an interesting edition on the links between face structure, psychological attributes and genetics, as well as a discussion on the science of addiction.

It is well known that certain genetic disorders that affect brain development can also lead to differences in facial structure (the most well-known example being Down Syndrome) owing to the fact that the brain and face develop from closely related groups of cells during embryogenesis.

One interesting example mentioned by medical geneticist Dian Donnai is the link between having a single incisor (‘front tooth) and possible problems with brain development.

It’s now being found that differences in the face, even in people without genetic disorders, reflect aspects of growth and development that can be linked to psychological attributes (or just as interestingly, are reliably linked to perceived psychological traits).

Psychologist Anthony Little is one of the guests on the programme and, with a number of colleagues, has done some fascinating work in this area (often using morphed or averaged faces like the one on the left) with many of the research articles available online.

The second part of the programme discusses the science of addiction in terms of both its psychology and neurobiology, but also in terms of its place in our culture as a concept that is applied to patterns of excessive behaviour.

Both are engaging discussions and are well-worth a listen.

Link to Material World with permanent audio archive.
realaudio of programme.

Neurology in the UK

I’ve just found this on the announcements for the Wellcome Trust’s Small Arts Awards grant scheme. It’s a proposed art / science project that combines neurology, computational modelling, robots and punk rock!

“Neurotic” by Fiddian Warman

Neurotic questions the neurology associated with the essential human experience of pleasure, learning, taste and aging in the context of the instinct to dance. The project, which involves a collaboration between a neurologist, a computational biologist, punk musicians and a robotics artist, culminates in a live performance at the ICA. Punk band Neurotic will play to an audience of both humans and a group of robots whose cognition is modelled on brain function. The human-sized robots will ‘pogo’ alongside the human audience when their neural networks, modelled on real neural pathways, are appropriately stimulated by the music. The event will be accompanied by discussions on the role of memory, emotion and cultural context in the development of taste in humans and a website which explores neuroscientific issues raised by the research and performance.

Rock on! I can’t wait to see it completed. The full list includes many more innovative art / science collaborations.

Link to full list of Wellcome Trust Small Arts Awards funded projects list.

Full disclosure: I’ve been involved in Wellcome funded art / science projects and am an occasional grant reviewer for the scheme.

My brain made me do it

Gerontologist and all-round skeptic Raymond Tallis has written an article for The Times where he laments the rise of ‘neurolaw’ where brain scan evidence is used in court in an attempt to show that the accused was not responsible for their actions.

Tallis cites the example of the trial of Bobby Joe Long where his lawyers tried to argue (unsuccessfully as it turned out) that he wasn’t responsible for his crimes because brain scan evidence showed that he had an overactive amygdala (supposedly suggesting increased aggression) and underactive frontal lobes (supposedly suggesting reduced ability to inhibit aggression).

This, Tallis argues, is hardly evidence for diminished responsibility because it assumes that our brain is some sort of separate ‘alien force’ that is somehow not ‘us’, when we generally think of the brain as being synonymous with the self.

However, he goes on to cite the example of an epileptic seizure and argues that this is an example where we definitely can’t say the person is responsible for twitching or losing consciousness.

Tallis aims to make a clear cut distinction between these different sorts of action and how we attribute responsibility for them, but he is perhaps relying on the extremes when reality can be full of grey areas.

Each of us has a propensity or threshold for violence, so some people will have aggressive urges more easily than others.

One way of looking at the question is ‘how responsible is the person for their actions’, but another is ‘what strength of urge do we think it is reasonable for a person to inhibit’.

Life experience, genetic factors, brain injury or any forms of neurological disturbance may make urges stronger or reduce our ability to inhibit them.

Some epileptic seizures may be ‘irresistible’ in this way of thinking (although interestingly, some seizures may cause thoughts or urges that are resistible to varying degrees), whereas other patterns of brain activity will produce desires or intentions that can be more easily suppressed.

A serial killer may genuinely have reduced ability to inhibit violence urges, but at what point do we say that the effort they would have to make to stop them reacting violently is beyond what is considered reasonable or possible.

Link to Times article ‘Why blame me? It was all my brain’s fault’.

All in the Mind blog launches

ABC Radio National’s ever-excellent radio programme All in the Mind has just launched a blog.

It has the latest on issues arising from the programme as well as other interesting snippets from the world of psychology and neuroscience.

The blog will also clue us into forthcoming editions, and there’s also a chance for you to comment, discuss and suggest ideas on anything that comes to mind.

And there’s even a scan of Natasha Mitchell’s brain. What more could you ask for?

As for the programme itself, tomorrow’s edition will feature Steven Pinker discussing ideas from his latest book.

Link to ABC Radio National’s All in the Mind blog.

2007-10-26 Spike activity

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

BPS Research Digest has an article on the secret to remembering material long-term.

Dennis Brain has a posse, sorry, orchestra.

Mixing Memory discusses the psychology of women in maths, science, and engineering.

A transcript of R.D. Laing interviewing Van Morrison in 1986. Personally, I’m still waiting for Thomas Szasz to interview the Spice Girls.

Why do some babies talk sooner than others? The mighty Cognitive Daily investigates.

The Washington Post reports on a US Government committee who have concluded that only exposure therapy is known to be effective in treating PTSD. Presumably the Cochrane report on psychological treatments for PTSD escaped them at the time.

Newsweek has a report and video on a case of ‘multiple personality disorder’ which is remarkable largely for the fact that it tells us our concepts about the condition have barely moved on since the famous cases in the 70s.

The ‘source of optimism’ has not been found in the brain, but two brain areas have been identified which are relatively more active when positive events are imagined.

Furious Seasons notes the curios yoga-themed advertising campaign for antipsychotic ziprasidone (aka Geodon).

Lack of sleep makes it more difficult to manage negative emotions. This story got mangled by much of the press. BBC News did the best job, but it’s probably best to read the original abstract.

PsyBlog reviews The Most Dangerous Animal, a book on war and human behaviour.

Lovely Francis Crick quote: “Any theory that fits all the facts is bound to be wrong since some of the facts will be misleading”. James Watson is probably wishing he remembered this before putting his foot in his mouth about race and intelligence and subsequently losing his job.

The Phineas Gage Fan Club discusses a wonderfully clear schematic map of the visual cortex.

Just beautiful, if not slightly surreal. Neurophilosophy finds an online exhibition of photos from an abandoned soviet brain research lab.

Who’s afraid of Kanye West?

Jonah Lehrer is a neuroscientist, blogger, editor and now author of a new book on what neuroscience can learn from art and literature. Wired has a brief Q&A with him, where he discusses Virginia Woolf, cognitive science and Kanye West.

Actually, this just serves as a brief introduction to some of Lehrer’s thoughts, as he’s promised to talk to Mind Hacks in more detail about art, the cutting edge of brain research and his new book Proust was a Neuroscientist.

We’ll post the interview shortly, but in the meantime Wired has a brief introduction to some of the key ideas.

Link to Wired Q&A with Jonah Lehrer.