Category: Inside the Brain

These completely passed me by last year but are well worth checking out: BBC Radio 4 broadcast a couple of excellent radio programmes – one on the effects and treatment of mild brain injury and other other on the doomed historical attempt to link intelligence to skull size.

Mild traumatic brain injury doesn’t necessarily mean that effects are minor.

For some people, fatigue, poor concentration, memory difficulties and irritability may continue when the immediate affects of the injury have subsided.

These symptoms can be quite dramatic, even after simple concussion, and there is now significant interest in this post-concussional syndrome as it is quite disabling for some people.

What is interesting, is that there is evidence that these symptoms can arise out of a combination of the original brain damage plus psychological distress and poor coping strategies.

In other words, it’s not just the brain injury that causes the problems but also how people make sense of and deal with their experience.

The programme on skull size and intelligence looks at how early 20th century researchers tried to link intelligence to skull size in the futile attempt to prove that various races where biologically inferior.

A dodgy aim but an important chapter in the history of science gone wrong.

Link to documentary on mild brain injury.
Link to documentary on intelligence and skull size.

If you roll your eyes every time you hear more media hype surrounding the pseudoscientific ‘think your way to victory’ film The Secret, Scientific American has a short, sharp, shock of a reply to its dodgy claims about the mind and brain.

A pantheon of shiny, happy people assures viewers that The Secret is grounded in science: “It has been proven scientifically that a positive thought is hundreds of times more powerful than a negative thought.” No, it hasn’t. “Our physiology creates disease to give us feedback, to let us know we have an imbalanced perspective, and we’re not loving and we’re not grateful.” Those ungrateful cancer patients. “You’ve got enough power in your body to illuminate a whole city for nearly a week.” Sure, if you convert your body’s hydrogen into energy through nuclear fission. “Thoughts are sending out that magnetic signal that is drawing the parallel back to you.” But in magnets, opposites attract–positive is attracted to negative. “Every thought has a frequency…. If you are thinking that thought over and over again you are emitting that frequency.”

The brain does produce electrical activity from the ion currents flowing among neurons during synaptic transmission, and in accordance with Maxwell’s equations any electric current produces a magnetic field. But as neuroscientist Russell A. Poldrack of the University of California, Los Angeles, explained to me, these fields are minuscule and can be measured only by using an extremely sensitive superconducting quantum interference device (SQUID) in a room heavily shielded against outside magnetic sources.

Actually, I’m all for anything that helps people to think more positively, but basing your advice on misinformation and empty promises is a recipe for disaster.

Link to SciAm article ‘The (Other) Secret’.

BBC Radio 4’s weekly medical programme Case Notes just had a special on multiple sclerosis. The programme looks at what we know about the brain disorder and investigates the controversial use of cannabis as a treatment.

Some neurons in the brain have extended sections called axons that allow the neuron to transmit signals over distance.

The signals travel down the axon as electrical pulses, and as with electrical wires in the house, the signalling is more efficient when it is insulated from the outside world.

Axons are insulated by a layer of fatty covering called myelin.

In MS, the myelin starts to degrade and the neurons are eventually unable to send signals, becoming useless and withering.

It is not clear why this happens, but it might be because a problem with the immune system means the body starts attacking and destroying the myelin.

The destruction of myelin in the brain is not evenly spread out and doesn’t continue at a steady rate, meaning that people with the disorder may have difficulties with a whole variety of different brain functions.

This pattern might differ from person to person, and might progress at a different rate.

Movement, memory, attention, mood, perception and speech can all be affected (to name but a few), and the person is at a much higher risk for mental illness as a result.

Currently, there is no cure for MS but several treatments are known to slow the disorder or help with the symptoms.

These can include drugs that regulate the immune system and steroids to limit the damage.

However, many patients report that cannabis significantly helps with the symptoms.

While cannabis treatment is illegal in most countries, researchers are trying to understand what is it about cannabis that helps, and are working on developing medications based on cannabinoids.

The programme looks at these treatments, as well as looking at the science of MS, and how is it managed by the clinical team.

Link to Case Notes special on MS.

Prozac is twenty and The Observer celebrates with an article noting 20 things you may not know about the drug that was supposed to make us ‘better than well’.

Prozac is the brand name for the drug fluoxetine and was so successful that it has become a by-word for antidepressants and psychiatric drug treatment.

Its popularity was partly due to it being a safer alternative to the older tricyclic antidepressants, such as amitriptyline, and the addictive benzodiazepine drugs used to treat anxiety, such as Vallium.

Also, it came at a time when depression was becoming destigmatised and more widely recognised. Helped in no small part, of course, by Eli Lilly heavily funding a number ‘public education’ campaigns and depression support groups.

During the 1990s Prozac was truly considered a wonder drug.

Psychiatrist Peter Kramer’s 1994 book Listening to Prozac (ISBN 0140266712) had case studies of people who’s marriages were saved, porn addiction was cured (!) and generally became better, more thoughtful people after taking the drug.

Notably, several of the case studies were not people who were clinically depressed. Kramer wondered whether we would take such drugs to improve on normality rather than to treat pathology, and coined the term ‘cosmetic pharmacology’ for the former.

As the 90s drew to a close, clouds started to form and the sunshine started to fade.

The storm broke in 1998 as court cases focused on the negative effects of Prozac and related drugs and an influential paper was published suggesting the drug wasn’t as effective as it was thought.

Drug company Smithkline was sued by the family of a man who killed himself and his family after taking the related drug paroxetine, also known as Paxil or Seroxat.

The court case involve psychiatrist Dr David Healy who had been investigating the possible role of Prozac in stirring up suicidal thoughts in some depressed patients.

Healy discovered that Eli Lilly had obscured the adverse effects of Prozac from their pre-release drug trials and was subsequently subjected to a dirty tricks campaign by the company.

This became a legal case in itself and he eventually settled for what are thought to be significant out-of-court damages.

Furthermore, an influential paper published by Irving Kirsh and Guy Sapirstein (wittily titled ‘Listening to Prozac but hearing placebo’), analysed a series of antidepressant drug trials and reported that only 25% of the improvement in the patients was due to the drug, the rest, the data suggested, was placebo effect.

Researchers started to challenge the virtually evidence free message that ‘low serotonin causes depression’ on which the marketing campaigns for SSRI drugs relied.

More recently, worries have emerged about Prozac and related drugs increasing suicidal thoughts in some children (again with allegations about drug companies burying negative findings), with antidepressants now carrying a warning on the box to alert doctors and clinicians.

The pendulum has swung back a little since then, with recent studies indicating that while some children will have an increase in suicidal thinking, they are a small minority and, generally, the benefits outweigh the risks in most children.

Current evidence suggests that Prozac is an effective treatment for depression, although it’s not without side-effects and, on balance, is about as effective as most other antidepressants.

Prozac is a useful treatment for depression and anxiety, but is no longer the ‘wonder drug’ it once was – and we’re probably all better off for having a more balanced view.

The Observer article is a guide to the drug and its wide-ranging impact on society, covering everything from its neurochenical effects to its influence on the music scene.

Link to Observer article ‘Eternal sunshine’ (via Furious Seasons).

ABC Radio National’s All in the Mind has a compelling discussion about the development and dangers of weapons designed to target the brain and nervous system.

The guests on the programme are Prof Malcom Dando and Dr Mark Wheelis, who have recently written a paper for the International Red Cross entitled ‘Neurobiology: A Case Study of the Imminent Militarization of Biology’ [pdf].

The programme largely focuses on what we known about the secret development of nerve agents, based on the glimpses we see of them in action – for example, during the Moscow theatre siege of 2002, where Russian special forces used an opiate-based ‘knock out gas’ that resulted in the death of 129 hostages.

Interestingly, one of the guests notes that although these sorts of compounds are banned for use in war under international treaties, these regulations can have specific exemptions that allow them to be used in civilian ‘crowd control’ operations.

So while it would be illegal to use some drugs as weapons against soldiers, governments are, in some cases, allowed to use them on their own population.

It’s fascinating and somewhat troubling coverage of a too-rarely discussed topic.

Link to AITM on ‘Bioterrorism and Your Brain’.
Link to full-text of ‘Neurobiology: A case study of the imminent militarization of biology’.

The Scientist has an article on the latest developments in the world of fMRI lie detection, looking at how accurate and reliable the technology really is.

This is a particularly hot topic because a commercial company, No Lie MRI, are marketing a brain scan lie detection service.

This is despite the fact that neuroscientists and the legal system are still unconvinced that it is accurate enough to be useful.

Interestingly, the company was partly funded by the US Government, and you can bet that they’ll be trying the system, even with the low accuracy rates, in case it proves useful for the secret services.

Probably the main advantage for most buyers is that is looks intimidating and high-tech.

Like with the polygraph test, many people put through the system will undoubtedly be more truthful because they believe that they will be caught if they lie.

In terms of its ability to catch genuine lies made by an individual, it’s still fairly limited though.

Not least because most brain imaging research is done as group studies. The results are usually based on average brain activity across all participants, rather than on any one individual.

Also, the studies don’t really resemble real-world conditions:

And in the real world, lying is verbal and carried out in defiance of instruction, and the stakes are incomparably higher. Rather than missing out on a $20 study reward, being caught in a lie could mean life in prison. Lying under these circumstances comes with an emotional component that is poorly elicited by a playing card, she argues.

“Applied fMRI studies of the kinds done so far have similar limitations to those of typical laboratory polygraph research,” according to a 2003 National Academy of Sciences report. “Real deception in real life circumstances is almost impossible to explore experimentally. You can’t randomly assign people to go do crimes. I do think that’s an inherent limit,” says Gabrieli, a professor of cognitive neuroscience. Others worry about the level of nuance that fMRI-posed questions can accommodate.

Still, researchers are hoping further studies will help improve the system, until, maybe, it will be the most accurate lie detection system in existence.

Until then, it’s an interesting field, but I wouldn’t bet your life on it.

Link to Scientist article ‘Watching the Brain Lie’.

There’s been a wonderful series of posts at neuroscience blog Neuroevolution which have charted the history of cognitive neuroscience from ancient Greece to the age of the brain scanner.

There’s been 26 posts in all, each of them a beautifully illustrated snapshot of a groundbreaking discovery.

The series tells the story of how we’ve come to understand more and more about the workings of the mind and brain, with each discovery building on the lessons of history.

Highly recommended.

Link to “History‚Äôs Top Insights Into Brain Computation”.

Open-access science journal PLoS Biology has another fantastic article that investigates what neuroscience tells about about the causes of antisocial behaviour and how damage to the brain can, in rare cases, lead someone to become violent.

The article looks at research on the neuropsychology of violent criminals, as well as ‘forensic neurology’ – the science of understanding how brain injury can remove the normal inhibitions for aggression.

Some striking case studies are covered as well as possible ways of understanding and managing criminality.

Criminality and violence is a difficult area, as personal motivations and influences are complex. The paper notes that:

To be clear, there is at present no reason to believe that all criminal behaviours, or indeed even all violent criminal behaviours, are the result of organically dysfunctional brains. However, there is ample evidence to suggest that some kinds of dysfunction are likely to increase the probability of some kinds of behaviours that society labels as criminal.

The discussion also covers how the legal system might make sense of these new brain discoveries, in light of neuroscience evidence being increasingly used in court cases as a way of determining if someone is telling the truth, and as a way of arguing for reduced responsibility for a criminal act.

Link to PLoS Biology article ‘Law, Responsibility, and the Brain’.

Author Bruce Stutz writes about his experience of depression, stopping antidepressants and the science of SSRI withdrawal in an article for the New York Times.

Withdrawal from SSRI medication, a group which includes drugs such as Prozac, Seroxat and Zoloft, is known to cause considerable discomfort in about 1 in 5 people.

It’s been spun as a ‘discontinuation syndrome‘ by the drug companies, as ‘withdrawal symptoms’ sounds a bit too much like what drug addicts have.

Although SSRIs are not addictive in the sense that they don’t cause a strong desire to take more, the brain does go through a significant period of readjustment when the drug leaves the body.

The NYT article examines Stutz’s experience of treatment for depression, and how he coped with the withdrawal symptoms that he was unlucky enough to experience.

The piece also takes a look at the neuroscience of serotonin and mood, with a more critical analysis than is often found in some mainstream science articles.

Link to NYT article ‘Self-Nonmedication’.

Huge numbers of news sources are reporting on recent neuroscience studies that have linked the effect of cannabis on the brain to the development of psychosis.

The excitement is because the 2nd International Cannabis and Mental Health Conference is currently under way in London where scientists from around the world are presenting the latest research on the effects of cannabis.

Luckily, the conference programme and summaries for all the research presented are available online as a pdf file, so you can get a more accurate idea of what the studies have found.

It is now clear that cannabis increases the risk of psychosis in some people who have a family history of psychosis and / or certain versions of the COMT gene.

However, the main thrust of the news stories is that even a single dose of THC, the main ingredient in cannabis that causes the ‘high’, can trigger psychotic symptoms.

A study by Dr Cyril D’Souza noted that:

Δ-9-THC produced schizophrenia-like positive and negative symptoms, altered perception, increased anxiety, produced euphoria, disrupted immediate and delayed word recall, impaired performance on tests of attention and working memory without impairing orientation.

The difficulty is that just because something seems to cause similar effects to psychosis, it doesn’t necessarily mean it is strongly linked to it.

For example, a dose of alcohol can ‘produce’ similar symptoms to Alzheimer’s disease – loss of memory, disorientation, mood swings, aggression and so on – but that isn’t a good basis to say that the alcohol is doing the same thing in the short-term as the degenerative brain disorder does in the long-term.

More convincing are the results from the cognitive tests: impairment in immediate and delayed recall, attention and working memory without impairing orientation.

This is because the subjective effects of both cannabis and psychosis are, well subjective, but the cognitive effects are measurable with controlled neuropsychological tests.

One particularly interesting study from Dr Cecile Henquet found that when compared to controls, patients experienced a greater increase in psychotic experience after taking THC, but also had a greater improvement in their mood.

This might explain why people with psychosis will often continue smoking cannabis even when they know it causes their mental state to deteriorate.

Another fascinating finding, is that as well as containing the possibly psychosis increasing THC, cannabis also seems to contain an antipsychotic called cannabidiol or CBD.

One study presented by Prof Markus Leweke found that purified CBD had a beneficial effect equal to amisulpride, a widely used pharmaceutical antipsychotic medication.

If you’re interested in finding out more about the cutting-edge of cannabis research the surprisingly readable conference programme is well worth checking out.

Link to conference programme and research summaries.

Online psychedelic drug archive Erowid has scanned in a copy of a classic guide to hallucinogenic plants of the world and how they are used by native peoples.

The Golden Guide to Hallucinogenic Plants is by pioneering ethnobotanist, Richard E. Schultes.

Ethnobotany is the study of how people make use of plants, and hallucinogenic plants are obviously of keen interest owing to their important place in ritual and religion throughout the world.

The book is sadly out of print and and second hand copies are now collectors items. However, the full version has been scanned in full colour, so you can read it online or download it as one single zip file.

Link to Golden Guide to Hallucinogenic Plants (via BB).

ABC Radio National’s All in the Mind just broadcast some essential listening with a programme that takes a critical look at the reporting of brain scanning studies and discusses what brain scans actually tell us about human nature.

The panel discussion also covers how cognitive and neuroscience discoveries get translated from lab work to public awareness, and how the core messages might get warped along the way.

The panel members are researchers and science journalists Deborah Blum and Jonica Newby, as well as neuroscientist Fred Mendelsohn.

It’s a rare but important discussion that actually takes a look at how brain scans are used in the media compared to what they actually tell us.

Link to All in the Mind brain scan programme webpage with transcript.
mp3 of programme audio.

ABC Radio National’s All in the Mind recently broadcast an incredibly moving account of a young woman’s fight with a life threatening brain tumour that eventually resulted in her death.

The woman in question was the Australian writer Julie Deakin (pictured left), who wrote the most touching and elegant prose about her experiences of diagnosis and treatment, and the impact of her declining health on her loved ones.

The programme weaves Deakin’s writing with her mother’s recollection of the time, making for a powerful programme.

I was listening to it while walking to work this morning and it stopped me in my tracks on a couple of occasions.

Link to information and transcript.
mp3 of programme audio.

Independent artificial intelligence researcher Jeff Hawkins has an article in this month’s IEEE Spectrum magazine asking the question ‘why can’t a computer be more like a brain?’.

Hawkins argues that while we hope that machines will be able to simulate human intelligence, we ignore the thing that makes us so – the brain.

He suggests that we need to create artificial intelligence systems that closely match the architecture of the brain to achieve this task.

Hawkins has outlined his arguments, and his own theories of simulated brain architecture, in his book On Intelligence, but if you want a whistle-stop tour of his theories, this article is a great summary.

Link to Hawkin’s article ‘Learn Like a Human’.

Researchers from the University of Calgary have released the first version of NeuroArm – a surgeon-controlled robot for conducting brain surgery.

The key feature of the robot is that it is designed to work inside an MRI brain scanner.

MRI scans currently provide the most accurate structural image of the brain and therefore provide important information for planning operations.

Neurosurgeons also use MRI scans completed before surgery to guide the operation while it’s happening, using a method called stereotactic neurosurgery.

This allows surgical instruments to be guided to an exact spot in the brain by tracking their position in real time, in relation to the 3D scan completed earlier.

One disadvantage is that the brain scan can’t be updated as the brain is altered during the operation.

Being able to scan people while they’re having surgery might sound a simple idea, but MRI scans involve the patient being inside a tube surrounded by hugely powerful magnets, meaning the environment isn’t accommodating to surgeons who need free space and surgical steel.

NeuroArm has been designed to fit inside the tube, and crucially, is not made of any magnetic materials that will affect and be affected by the MRI machine.

This means the surgeon can update the brain scan and complete the operation by controlling the robot remotely.

He or she can do this by using a specially designed surgical workstation that provides a virtual interface to the robot arms, including force feedback on the tools, so the surgeon does not have to give up his ‘surgical touch’.

While the current set-up seems to involve the surgeon being located in the same building as the patient, it is interesting to speculate that, in the future, operations could be directed from hundreds or even thousands of miles away.

The combination of the accurate brain scan and the robot controlled tools also means that the surgeon should be able to attempt microsurgery on very fine brain structures.

You may be surprised to learn that robot-assisted neurosurgery isn’t particularly new and was introduced in the 1980s.

Brown University has a fantastic history of the technology and procedures if you want some background.

Link to Project neuroArm page.
Link to more info on Project neuroArm.
Link to write-up from New Scientist.
Link to history of robotic neurosurgery page.

In 1955, after seven years of trying, John and Mary’s first child was born. The birth of Casey Holter turned John Holter’s life upside-down and changed the course of medical history.

Agonisingly, Casey had spina bifida, a condition where the spine doesn’t fully form and may be dangerously misshapen.

The condition was also causing hydrocephalus, a life-threatening build-up of fluid in the brain.

The fluid that surrounds the brain is called cerebrospinal fluid or CSF and acts as a fluid ‘bath’ which cushions and protects the delicate organ.

It is produced by a structure in the brain stem called the choroid plexus and circulates around the brain before being drained into the blood supply.

If the drainage system is blocked, however, it can lead to a dangerous build-up that can pressure, distort and eventually damage the brain beyond repair. If left untreated, it can be deadly.

In 1955, the only thing keeping Casey Holter alive was a twice daily procedure where a needle was inserted into the fontanelle, the soft spot on a baby’s head, and the excess fluid was removed with a syringe to reduce the pressure.

Eventually, Casey was given an operation by the neurosurgeon Eugene Spitz to insert a ball and spring valve that would, in principle, allow the fluid to drain into the blood supply, without letting anything dangerous from the blood wash back into the CSF.

Unfortunately, the valve was clumsy technology, and when inserted, it irritated Casey’s heart to the point where the young child had a heart attack and suffered permanent brain damage.

John Holter, then working as a technician in a hydraulics factory, asked Eugene Spitz about the details of the procedure. He was surprised that the problem, which seemed to him like a simple hydraulics issue, had not been solved.

He had noticed that when nurses inserted needles into certain types of medical tubing, leaks didn’t occur because the gap was water-tight under low pressure conditions.

But, like a teat on a baby’s bottle, when the pressure was high enough the gap opened and the fluid forced its way through. A perfect valve for releasing built-up CSF and preventing backwash.

Holter went home, sat in his workshop, and constructed the first version that very evening. It was a rough-and-ready rubber-tubing and condom prototype, but it worked.

While the principle was sound, Spitz noted that that the valve must made of a material that wouldn’t irritate the body, as this might cause the same problem that had brain-damaged his son.

Holter contacted Dow Chemical and was advised to use silicone, at the time, a newly developed material.

Holter had created a usable version within months. So quickly, in fact, that his son was still too weak from the last operation to have it installed.

It was first and successfully installed in another child, and then in March 1956, Eugene Spitz installed John Holter’s valve into Casey, successfully treating his hydrocephalus.

Sadly, Casey never fully recovered from his brain damage from the initial operation, and died during an epileptic seizure five years later.

Fittingly, Casey’s legacy is that Holter’s invention, now called the Spitz-Holter shunt, is still in use today.

Holter spent the rest of his life developing valves for medical use and passed away in 2003, having saved the lives of thousands children affected by the same condition as his son.

It is estimated that 15,000 valves based on Holter’s design are installed every year in the United States alone.

John Holter’s remarkable story was retold in a 2001 paper published in the Journal of the American College of Surgeons upon which this article was based.

Link to PubMed entry for Journal of the American College of Surgeons paper.