Category: Inside the Brain

Hanging is a frighteningly efficient way of ending a life, as executioners can attest and suicides cannot, but surprisingly, we’re still not sure how it causes death.

An intriguing study just published in the Journal of Forensic Sciences ponders current theories in light of historical research which has attempted to answer the question.

In fact, we know so little about the exact mechanism of death from hanging that studies from the 1800s are still some of our best sources of information.

To remedy this, a research group now been formed with the grim task of studying videos of hanging to try and see determine which of the traditional theories might be correct: death by asphyxiation, by stopping blood to the brain, or by the heart stopping after stimulation of the nerves running through the spinal cord.

From the article:

In cases of hanging, the exact mechanism leading to death has yet to be elucidated. Most of our contemporary knowledge is still based on writings from the end of the 19th and the beginning of the 20th century. This article reviews the historic experiments that shaped our current theories. Medico-legal textbooks written in English and French from 1870 to 1930 were reviewed. Various animals, such as rabbits, mice, and dogs, have been used to develop animal models of hanging.

Limited human studies on cadavers and judicial hangings have provided some additional insight into the pathophysiology of death by hanging. The main pathophysiological theories described were respiratory asphyxia, interruption to cerebral blood flow because of occlusion of vessels in the neck, and cardiac inhibition secondary to nerve stimulation. The relative contributions of each of these theories to death in cases of hanging is still debated today.

Recently, filmed hangings have been used as a powerful tool in understanding the pathophysiology of human asphyxia. The Working Group on Human Asphyxia (WGHA) was formed in 2006, and since its creation, 8 filmed hangings have been analyzed. Observing the videos reveals that loss of consciousness occurs quickly, followed by convulsions and a complex pattern of alternating phases of decerebrate and decorticate rigidity. The videos also demonstrate some auditory evidence of persistent air passage through the airways during the hanging process.

The study of the WGHA has provided interesting new insight into the pathophysiology of asphyxia by hanging. Before these new developments, most of our contemporary knowledge was based on writings from the end of the 19th and the beginning of the 20th century.

Tempted to join the Working Group on Human Asphyxia? Fear not, membership criteria are given in the scientific paper:

“It is known, however, that some hanging victims film their hangings, mainly in an autoerotic context…. Each scientist who has such a video or who has access to such a video is welcome to join this group and the video will be added to the ongoing study.”
 

Link to PubMed entry for study on history of hanging.
Link to PubMed entry for video study of hangings (via @sarcastic_f).

A few weeks before they are born most babies show a bias for turning their head to the right, rather than to the left. This bias continues for the first six months after birth.

Behavioural biases to one side are interesting to psychologists. They are an example of exceptions to the general rule of symmetry in biological development. The placement of language-related brain areas is another exception. Babies’ head turning bias is the first behavioural bias to occur in humans, and may be related to handedness bias, which in turn is related to the language-area asymmetry in the brain.

Mindhacks.com readers will remmeber our report of Paul Rozin’s call for more observational reports in psychology. Perhaps he’d approve of this 2003 paper in Nature: Adult persistence of head-turning asymmetry.

Onur Güntürkün observed adult head turning behaviour among kissing couples in the U.S, Germany and Turkey. Sure enough, his observational research, in ‘international airports, large railway stations, beaches and parks’ discovered that during most kisses (64% of the sample) couples turned their heads to the right rather than the left. A statistically significant difference and, according to Güntürkün, ‘a surprising romantic reappearance’ in later life of the neonatal head turning bias.

So, next time you hold a child in your arms and they turn their head to the right, you are seeing an echo of a bias that may be directly linked to our species’ most remarkable evolutionary achievement, language, and a bias that stays with us throughout our lives.

Reference: Gunturkun, O. (2003). Human behaviour: Adult persistence of head-turning asymmetry. Nature, 421(6924), 711. doi:10.1038/421711a which contains the line ‘It takes two people to kiss (Fig. 2)’!

We recently discussed how the term ‘neuroplasticity’ is widely used as if it were a precise scientific concept, when, in fact, it is virtually meaningless on its own. Several commenters suggested that while not scientifically meaningful, it serves as a useful reminder that we no longer think the brain is ‘fixed’ as we did ‘about 20 years ago’. This is also part of the neuroplasticity hype, and, as I’ll demonstrate, discussions of neuroplasticity go back as far as the 1800s.

This is not to say that we haven’t discovered new ways in which the brain changes and adapts. But this hasn’t been a sudden discovery, and it hasn’t solely happened in the last few decades. On the contrary, these discoveries have peppered the last century and this knowledge has been slowly accumulating.

So here’s a hastily gathered list of scientific papers from before 1970 in which neuroplasticity was discussed, found with nothing more than Google Scholar and 30 minutes of time:

A 1896 paper from the Journal of Mental Science that discusses cortical plasticity as the basis of insanity, as well as tackling neural regeneration and recovery of function.

A 1897 paper from The American Journal of Psychology that discusses how “intelligence… enables the organism to make better adaptations. Its neural pre-requisite is plasticity”.

A 1932 study from Brain on recovery of function after brain injury.

A recent paper that reviews neuroplasticity in the work of neuroscientist Ramón y Cajal (1852-1934) who argued for fixed circuits but extensive local plasticity both in structure and function.

A 1943 review article from Brain on recovery from three types of nerve injury that discusses regeneration of nerve fibres.

The transcript of the 1950 Royal Society Ferrier Lecture on “Growth and Plasticity in the Nervous System”.

A 1967 paper from Acta Neurologica Scandinavica reviewing findings in sensory plasticity.

I’m sure there are many more examples that you could find for yourselves.

I suspect the neuroplasticity hype was fuelled by two main things: the 1998 discovery that adults humans have a limited ability to regenerate neurons and the growth of functional brain imaging in both science and the media.

In fact, neuron regeneration accounts for very little of our ability to learn and adapt, but after decades of thinking that ‘we are born with all the brain cells we’re ever going to get before we slowly decline’, it perhaps seems very significant to many and is certainly used in that way in popular discourse.

Functional brain imaging scans are often used as ‘visual proof’ that the brain changes. In reality, neuroimaging, almost by definition, relies on mechanisms that we must at least broadly understand already. But as a tool in popular discourse, it has increasingly come to stand for the brain’s flexibility.

I’m also interested by the fact that ‘neuroplasticity’ is often used in two seemingly contradictory ways.

The first is that it highlights ‘hidden potential’, the second that it highlights ‘hidden vulnerability’. These in themselves are not contradictory but often the message is that ‘we now know that your behaviour is now more susceptible to change than before’ but with an implicit message that once the change has taken place it is more permanent than before. Hence the additional risk or benefit. After all, your brain has changed, right?

To be clear, I am not suggesting that the brain is not flexible or that the discoveries about how the brain changes are not important. It’s simply that neuroplasticity has become a rhetorical device that, in itself, tells us nothing without further explanation.

All neuroscience is the science of how the brain changes and if you’re not being told exactly how this change is taking place, someone is likely wasting your time or trying to pull the wool over your eyes.

Link to previous Mind Hacks piece on neuroplasticity hype.

Neuroscientist Bradley Voytek discusses how brain damage and neurosurgery can be windows into the functioning of the mind in an engaging TEDxBerkeley talk.

As well as being remarkably well-explained, the talk has a personal current running through it as Voytek reflects on his own motivations for becoming involved in brain research after experiencing his grandfather suffering the effects of Parkinson’s disease.

Understanding brain damage is still one of the most powerful tools in cognitive science and this is a great introduction to how researchers go about making the leap from damaged tissue to psychology.

If you’ve got 20 minutes to spare and are interested in the links between neuropsychology and human nature, you’d do well to spend them here. Great stuff.

Link to Bradley Voytek TEDxBerkeley talk.

Frontiers in Neuroscience has an amazing scientific article that has collected all the studies that have recorded what happens when the brain is electrically stimulated in living patients. It’s like a travel guide to the unnaturally active brain.

As you might expect, science generally takes a dim view of researchers cracking open people’s skulls just to see what happens when bits of their brain are stimulated, hence, almost all of these studies have been done on patients who are undergoing brain surgery but have agreed to spend a few minutes during the operation to report their experiences for the benefit of neuroscience.

This procedure is also essential in some forms of brain surgery to make sure the surgeons avoid essential areas. For example, in some cases of otherwise untreatable epilepsy the surgeons track down the ‘foci’ or trigger area, and can often stop seizures completely just by removing it.

However, if an area is heavily involved in speech production, you wouldn’t necessarily want to give up being able to talk for the sake of being seizure free, so surgeons will open the skull, wake you up, and then ask you to speak while stimulating the areas they are considering removing. They can map your speech areas by seeing when you can’t speak as the areas are stimulated, and hence, know what areas to avoid.

So through years of experimental and clinical studies we now have what amounts to a travelogue of what happens when brain areas are stimulated. Neuroscientists Aslihan Selimbeyoglu and Josef Parvizi have compiled these reports into something like a cortical guidebook.

Here’s the entry for the temporal lobe:

Stimulations in the anterior medial temporal structures were associated with complex feelings and illusions such as feeling of unreality or familiarity (déjà vu) or illusion of dream-like state; emotional feelings such as feeling of loneliness, fear, urge to cry, anger, anxiety, levitation, or lightness; and recall of past experiences.

Stimulations in the superior temporal structures were associated with hallucinations in the auditory domain such as hearing “water dripping”, “hammer and nail”, music, or human voices, or changes in the quality of auditory stimuli such as muffling of environment. If stimulations of the superior temporal region were in the depth of the sylvian fissure, and toward the insula, stimulations induced pain or automatisms such as sudden movement, staring, unresponsiveness, plucking, or chewing.

Stimulations in the inferior and middle temporal and temporooccipital structures were associated with hallucinations in the visual domain such as seeing a face, geometric shapes, and color or blurring of vision, macropsia, visual movement, things looking sideways, and lines seeming out of kilter. In addition, disruption in reading, or reading comprehension, picture naming and or identification were also reported with left inferior temporal lobe stimulations. Laughter with a sensation of mirth was associated with stimulation of the left inferior temporal region in the vicinity of the parahippocampal gyrus.

The article is open-access so you can read the full details online.

Link to ‘Electrical stimulation of the human brain’.
Link to so-so Wikipedia page on ‘When Prophecy Fails’.

The latest edition of Neurosurgical Focus has an interesting article on the use of brain-computer interfaces in the military.

One part talks about funded US military brain-computer interface projects and it seems someone in the rank and file has seen Avatar one too many times.

Alongside therapeutic interventions, rapid advances in BCI technologies will also create opportunities for neurosurgeons to participate in improving military training and operations, particularly through combat performance modification and optimization. In fact, the use of neuroscientific approaches for achieving these goals is already an evolving area of research.

During the last decade, the Pentagon’s DARPA launched the ‚ÄúAdvanced Speech Encoding Program‚Äù to develop nonacoustic sensors for speech encoding in acoustically hostile environments, such as inside of a military vehicle or an urban environment. The DARPA division is currently involved in a program called ‚ÄúSilent Talk‚Äù that aims to develop user-to-user communication on the battlefield through EEG signals of ‚Äúintended speech,‚Äù thereby eliminating the need for any vocalization or body gestures.

Such capabilities will be of particular benefit in reconnaissance and special operations settings, and successful applications of silent speech interfaces have already been reported.

The whole article is worth a read and luckily for us it seems to have been made open access.

Now, must get me some of those “”high-resolution BCI binoculars that can quickly respond to a subconsciously detected target or a threat”.

Actually, maybe it was Rogue Trooper the military have been overdosing on?

Link to article on neurosurgery and military BCI interfaces.

Taken from the Wikipedia entry on ‘brain sand’:

Corpora arenacea (or brain sand) are calcified structures in the pineal gland and other areas of the brain such as the choroid plexus. Older organisms have numerous corpora arenacea, whose function, if any, is unknown. Concentrations of “brain sand” increase with age, so the pineal gland becomes increasingly visible on X-rays over time, usually by the third or fourth decade. They are sometimes used as anatomical landmarks in radiological examinations.

Chemical analysis shows that they are composed of calcium phosphate, calcium carbonate, magnesium phosphate, and ammonium phosphate. Recently, calcite deposits have been described as well.

French philosopher René Descartes famously concluded that the mind and the brain existed as entirely separate entities (a position now known as Cartesian dualism) and believed that pineal gland was the point at which the two interacted.

This was due to the fact that that, unlike most other structures in the brain, there is only one pineal gland and it is located exactly along the midline.

As Descartes largely thought of the mind and soul as the same thing, I’d like to think he would have called these calcified particles ‘soul sand’ had he known about them.

If you want some more details on ‘brain sand’, of which we know very little, this large abstract of a scientific study has a wealth of information.

Link to Wikipedia page on ‘brain sand’.
Link to abstract of scientific study.

The New York Times has a gripping article and video report about how a family in Colombia may be the key to unlocking the neuroscience of early-onset Alzheimer’s disease, one of the most devastating forms of degenerative brain disease that can strike as early as the 30s or 40s.

Alzheimer’s disease is a form of dementia, meaning that the mind and brain decline quicker than would be expected through normal ageing, but usually it is a condition of the old.

Most dementias are not thought to have one specific cause and are put down to a lifetime’s ‘wear and tear’ combined with different levels of risk from a number of genes.

In contrast, there are some forms of dementias, known as early onset dementias, that typically strike in middle-age and are much more likely to be due to mutations in single genes or mutations in only a handful of genes.

While we understand the genetics of these conditions quite well these days, it is still not understood why they cause the terminal and rapid decline of the brain.

The New York Times article discusses research from my own university, the Universidad de Antioquia, because one family in the Antioquia region of Colombia has the highest known rate of early-onset dementia in the world.

Genetically, the Antioquia region is very interesting and is known as a ‘population isolate’ because there has been very little influence on the gene pool from outside the region for about two centuries, largely due to the imposing mountains for which the area is famous.

The population originates with settlers from the Basque region of Spain who intermarried with native people (interestingly, almost entirely Spanish men with native women) while subsequent generations largely intermarried with each other. A recent study of the region shows very little change in genetic variation across the region and little change in common surnames for 200 years.

In effect, the region is like a giant ‘petri dish’ for population genetics and this means it is a lot easier to link genetic influences to specific disorders of the mind and brain. The New York Times piece features the work from the neuroscience department while my department, psychiatry, have completed much work on the genetics of bipolar disorder for the same reason.

The article describes both the potential of the research and the challenges of working in the region and is a fantastic account both for its scientific content and its humane approach to the issue. If you do nothing else, however, watch the short video report which is a powerful piece of scientific film-making.

Link to NYT piece ‘Alzheimer‚Äôs Stalks a Colombian Family’.

Inkling Magazine has a fantastic article detailing unusual objects which have accidentally ended up in the brain and have subsequently made the pages of medical journals as surprising case reports.

It covers everything from fairly lights to stiletto heels to human teeth and is cheekily titled ‘Not Right in the Head’. The article also mentions that the Neurophilosophy blog published a similar article two years ago, but rather surprisingly there was only one case that overlapped between the two.

The moral of the story is that if you can imagine it ending up in the brain, it probably has at some stage.

However, neither article mentions my all time favourite case, which involved a miniature fencing foil being lodged in the brain after being accidentally shoved through the nostrils (see a previous Mind Hacks post on things that have become stuck in the brain through the nose).

It was first reported in a 1968 article for the journal Neuropsychologia and just gives the following details:

N.A. (born July 9, 1938), a young American airman, was injured on December 15, 1960, while stationed at the Azores. The injury resulted from a mock duel with another serviceman, when a miniature fencing foil entered the patient’s right nostril and punctured the base of the brain, after taking an obliquely upward course, slightly to the left.

The case is not only notable for its strangeness, however, it is also one of the most important cases in the neuropsychology of memory.

NA suffered a dense amnesia, not unlike the famous Patient HM, without experiencing any other cognitive problems and while retaining his exceptional intelligence.

A major difference with HM was that HM had his hippocampi and surrounding tissue surgically removed on both sides while NA had a much smaller penetrating injury that largely affected his thalamus and a nearby pathway called the mammillothalamic tract – deep brain structures known to be widely connected to the brain’s outer cortical areas.

This was some of the first evidence that amnesia could be caused by damage to a ‘memory circuit’ and hence this type of conscious ‘declarative’ memory did not solely rely on the hippocampi, as was thought by some after the studies on HM.

We now know that damage to a circuit involving the hippocampus, fornix, mammillary bodies, the dorsalmedial nucleus of the thalamus and to a lesser extent, the septal nuclei, can cause strikingly similar amnesic problems and, hence, have been identified as key memory areas.

NA subsequently became one of the most studied patients in neuropsychology but because ‘NA’ is such a nondescript search term, in the age of the internet it has become easier to find studies on him by searching for “miniature fencing foil”.

A curious epitaph for such an important figure in our understanding of the brain.

Link to Inkling Magazine on unusual objects in the brain.
Link to Neurophilosophy on unusual penetrating brain injuries.

The Neuroskeptic blog has done a fantastic analysis of the popularity of different areas of the brain among neuroscientists by looking at how many scientific papers have been published on them since 1985. It’s like Vogue magazine’s hot styles, but for neurobiology.

I’ll leave you to check out the wonderful graphs, but here’s the punchline.

“The orbitofrontal cortex and cingulate cortex are both undergoing massive growth at the moment. The amygdala and parietal cortex are pretty hot too. By contrast, the cerebellum and the caudate are stuck in the scientific doldrums.”

The cerebellum has more neurons than the whole of the rest of the brain put together but we still don’t understand it very well. Not least because damage to the area doesn’t seem to produce some of the striking selective impairments in our abilities as does damage to other brain areas.

Consequently, the traditional way to annoy anyone doing a talk on their brain scanning experiment is to ask what the activity in the cerebellum means.

Link to Neuroskeptic on ‘This Season’s Hottest Brain Regions’.

This is an amazing summary of a study just published in the latest edition of Magnetic Resonance in Medicine. I have no idea what it’s about but it helps if you read it in the voice of Dr Spock.

Susceptibility mapping in the human brain using threshold-based k-space division.

Magn Reson Med. 2010 May;63(5):1292-304.

Wharton S, Schäfer A, Bowtell R.

[Captain] A method for calculating quantitative three-dimensional susceptibility maps from field measurements acquired using gradient echo imaging at high field is presented. This method is based on division of the three-dimensional Fourier transforms of high-pass-filtered field maps by a simple function that is the Fourier transform of the convolution kernel linking field and susceptibility, and uses k-space masking to avoid noise enhancement in regions where this function is small. Simulations were used to show that the method can be applied to data acquired from objects that are oriented at one angle or multiple angles with respect to the applied field and that the use of multiple orientations improves the quality of the calculated susceptibility maps. As part of this work, we developed an improved approach for high-pass filtering of field maps, based on using an arrangement of dipoles to model the fields generated by external structures. This approach was tested on simulated field maps from the substantia nigra and red nuclei. Susceptibility mapping was successfully applied to experimental measurements on a structured phantom and then used to make measurements of the susceptibility of the red nuclei and substantia nigra in healthy subjects at 3 and 7 T.

When I grow up, I want to be in k-space division just like my father, so I can avenge his death at the hands of the structured phantom.

Link to abstract on PubMed.

This is an fMRI study on how Christian faith healers influence the brains of believers and non-believers. It is an absolutely remarkable experiment when you think about it but I still don’t know quite what to make of it.

The power of charisma–perceived charisma inhibits the frontal executive network of believers in intercessory prayer.

Soc Cogn Affect Neurosci. 2010 Mar 12. [Epub ahead of print]

Schjoedt U, St√∏dkilde-J√∏rgensen H, Geertz AW, Lund TE, Roepstorff A.

This study used functional magnetic resonance imaging to investigate how assumptions about speakers’ abilities changed the evoked BOLD response [changes in blood oxygenation indicating neural activity] in secular and Christian participants who received intercessory prayer. We find that recipients’ assumptions about senders’ charismatic abilities have important effects on their executive network. Most notably, the Christian participants deactivated the frontal network consisting of the medial and the dorsolateral prefrontal cortex bilaterally in response to speakers who they believed had healing abilities. An independent analysis across subjects revealed that this deactivation predicted the Christian participants’ subsequent ratings of the speakers’ charisma and experience of God’s presence during prayer. These observations point to an important mechanism of authority that may facilitate charismatic influence, a mechanism which is likely to be present in other interpersonal interactions as well.

There’s a write-up over at the excellent Inkling Magazine if you want more.

Link to PubMed entry for study (via @anibalmastobiza)
Link to write-up on Inkling.

The Charlie Rose discussion show has an ongoing series on the brain and all of the episodes are available online where some of world’s leading neuroscientists extensively tackle the big questions of the field.

I’m just watching the programmes at the moment and while they can seem a little stiff at times, it lovely to see neuroscience being discussed without being dumbed down but while key concepts are explained and explored.

The discussions are co-hosted by Charlie Rose and Nobel prize winning neuroscientist Eric Kandel and the seven shows so far have tackled The Great Mysteries of the Human Brain, The Perceiving Brain, The Acting Brain, The Social Brain, The Developing Brain, The Ageing Brain and The Emotional Brain.

Future shows include The Anxious Brain, The Mentally Ill Brain, The Disordered Brain, The Deciding Brain, The Artistic Brain and The New Science of the Mind, all of which will appear online just after they are broadcast on US TV.

A great introductory guide to contemporary cognitive neuroscience.

Link to Charlie Rose Brain Series.

Frontier Nerds has an excellent guide to toy EEGs (the commercially available ‘mind control’ games) and detailed instructions on how to hack the MindFlex to use it as a brain-computer interface.

In the last year or so, numerous ‘mind control’ games have appeared that are essentially cheap consumer EEG devices with a dull as ditch-water games attached. For example, the ‘Force Trainer‘ reads off EEG signals and levitates a ball. Yes, that’s it.

There are developer’s kits available for some of the products but they tend to be quite expensive. Frontier Nerds realised you can buy a cheaper model and with a little messing around can pull the data right off the electronics.

Even if you’ve no intention of hacking any of these devices, the piece is an interesting look inside the construction of these toy EEGs.

As we’ve mentioned before, it should be possible to do some serious science of sorts with these devices.

Because the data is so noisy, almost all EEG experiments, even in the best equipped labs, get people to do the same thing over and over and then average the signals to filter out the noise. This is why EEG experiments can be a bit dull to take part in as there tends to be lots of repetition. In a second stage each person’s EEG signals are averaged together to get an overall effect.

You could potentially have an internet-based experiment that uses these devices which people can try at home, and with a large enough data set, get a reliable result.

It won’t have the precision of a lab-based set-up, but it could still be useful.

Link to Frontier Nerds guide to hacking toy EEGs.

Those tenacious chaps over at Language Log have followed up Louann Brizendine’s claims that men have a ‘defend your turf area’ by chasing up the references in her ominous new book The Male Brain which is showing all the signs of being as scientifically shaky as the last one.

Like a couple of people who commented on our post, they picked up on my previous and erroneous remark that the dorsal premammilliary nuclei had not been identified in humans – it has, but its function, as far as I know, has never been studied in humans (the previous post has now been updated).

Language Log also note that many of the Brizendine’s claims seem to be drawn from directly from rat studies and just assumed to apply to humans even when they specifically refer to, er, cat odor.

In other words, the DPN is involved in rats’ (passive) defensive responses to the presence of a cat, or even just to cat odor, but not to other sorts of threats such as the open arms of a maze, or an electric shock to the foot, where odor is not involved. Thus the DPN is more (and also less) than “the defend-your-turf area” in rats ‚Äî it responds to predator threats as well as threats from dominant conspecifics, but it’s apparently not involved in more active or aggressive forms of defense. Who knows what its homologue’s functions are in humans ‚Äì but presumably the mediation of instinctive “freezing, avoidance, and stretch” responses to cat odor are not among them.

The book was just reviewed in The New York Times which also wasn’t impressed by its scientific basis, noting “Brizendine‚Äôs trick, after all, is to give a scientific veneer to ‚ÄúMen Are From Mars, Women Are From Venus.‚Äù”, although you can bet it will still be all over the glossy magazines.

To be fair, I’ve not read Brizendine’s new book, although I read the last one and her ‘male brain’ articles I’ve read so far just seem equally dodgy.

Link to Language Log on ‘The defend-your-turf area?’.
Link to NYT review.

Author Roald Dahl was particularly well known for darkly humorous children’s books that form a riotous part of almost every childhood in Britain. Less well known is that he also made some significant contributions to neurology, as detailed in a brief article for Advances in Clinical Neuroscience and Rehabilitation.

The article is available online as a pdf and starts by noting that several of his books contain possible nods to neurological syndromes or fantastical fictional experiments.

These descriptions may hardly be termed “contributions” but two personal tragedies certainly did lead to developments of clinical import. Whilst living in New York in 1960, Dahl’s son Theo, aged 3-4 months, was involved in a road traffic accident which caused some brain damage and secondary hydrocephalus [a dangerous problem preventing cerebrospinal fluid drainage in the brain], the latter requiring shunting. Problems with blocked shunts occurred. The family returned to England and Theo came under the care of Kenneth Till, a neurosurgeon at Great Ormond Street Hospital (1956-80). Prompted by Dahl, and in collaboration with Stanley Wade, an hydraulic engineer, a new type of shunt valve was designed. Reported in the Lancet by Kenneth Till, under the rubric of “New Inventions”, the special characteristics were reported to be “low resistance, ease of sterilisation, no reflux, robust construction, and negligible risk of blockage”. The author acknowledged that the valve was “designed by Mr Stanley C.Wade… with the assistance of Mr Roald Dahl and myself”. The Wade-Dahl-Till (or WDT) valve became widely used.

Kenneth Till subsequently wrote a preface for a new edition of Valerie Eaton Griffith’s book entitled A stroke in the family, a manual of home therapy, wherein lies another Dahl connection. In 1965, Dahl’s first wife, the American actress Patricia Neal, suffered a stroke due to a ruptured intracranial aneurysm, one of the consequences of which was marked aphasia, a potential career-ending misfortune for an actress (her illness and recovery are recorded in a book by Barry Farrell). Dahl appealed to Valerie Eaton Griffith, who lived in the same village, for help. With Dahl, she devised a rota of volunteer carers to engage the patient in conversation and hence to stimulate language recovery. This approach, different from formal speech therapy, was documented in Griffith‚Äôs book (initially published in 1970, with an introduction by Roald Dahl). It earned the approbation, as “treatment of a surreptitious character” of no less a neurological figure than Macdonald Critchley, and still has advocates today. It has been suggested that Patricia Neal’s aphasia may have influenced Dahl’s creative processes, for example in the neologisms of The BFG (1982).

The EEG unit at Liverpool’s Alder Hey Children’s Hospital is called the Roald Dahl EEG Unit but I’d never made the connection before.

Dahl was not the first father to be motivated to create a shunt to treat his child. As we discussed previously, engineer John Holter found himself in a very similar position and invented the Holter shunt to treat hydrocephalus in his daughter.

 

pdf of article on Roald Dahl’s neurological contributions.