Month: April 2007

John Holter, brain engineer

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.

Bongo-bongoism

A curious term from anthropology describing the tendency for someone to come up with a counter-example from some usually obscure and remote tribe when anyone makes a general claim about human culture.

Bongo-bongoism: the venerable but ultimately sterile anthropological practice of countering every generalization with an exception located somewhere at some time.

Apparently, it was first used by anthropologist Mary Douglas in her book Natural Symbols.

Link to the culture evolves! blog (where I found the definition).

Interfacing consciousness, action and vision

Consciousness research journal Psyche has just released a new issue that tackles the limits of vision and visual cognition.

The issue starts with an article summarising the main arguments in the book Ways of Seeing by philosopher Pierre Jacob and neuroscientist Marc Jeannerod.

The book tackles the interface between vision and our other psychological abililties and particularly focuses on the visual pathways.

These are the two main pathways that run from the visual cortex at the back of the brain either through the dorsal stream to the parietal lobes, or the ventral stream to the temporal lobes.

The dorsal stream is sometimes called the ‘where’ stream as it seems to process the location of objects, whereas the ventral stream is sometimes called the ‘what’ stream as it seems to process the identification and meaning of objects.

After brain injury, one stream could be damaged and the other left intact, so a patient, when shown an object, might be able to tell you what it’s for, but would not be able to point to its location.

This distinction is particularly important when considering how we act based on visual information, as it is known that we don’t always access both these streams of information to the same degree for different types of action, and we aren’t always conscious of all the visual information we use during action.

Exactly how the interaction between conscious and unconscious information occurs, and the exact function of the streams, is still a mystery and this exactly what Jacob and Jeannerod tackle in their Psyche article:

Visually guided actions raise a different (almost complementary) puzzle: how can actions directed towards a target be so accurate in the absence of the agent’s awareness of many of the target’s visual attributes? Ways of Seeing (WoS) has three related goals, the first of which is to make the case for a broadly representational approach to the above set of puzzles.

The second goal of WoS is to argue that the version of the ‘two-visual systems’ model of human vision best supported by the current empirical evidence has the resources to solve the puzzle of visually guided actions, which has been at the center of much recent work in the cognitive neuroscience of vision and action.

The third goal of WoS is to draw attention to some of the tensions between acceptance of the two-visual systems model of human vision and some influential views about the nature and function of the content of visual experience espoused by philosophers in response to the puzzles raised by visual experience.

The remaining articles in the issue are debate from philosophers and cognitive scientists who question whether these two visual systems really create distinct forms of mental content, and whether the object-based actions and social actions are handled differently by the brain.

The journal is open-access, so all articles are freely available online.

Link to Psyche.

All the taste, none of the calories

Why does this leave a bad taste in my mouth? Numerous news sources are reporting that chocolate has a stronger effect on the heart and brain than kissing.

Alarm bells started ringing when it became obvious that the story is a promotion for a sweet company trying to advertise a new line of chocolate bars.

The ‘research’ was conducted by a company called The Mind Lab who offer to do psychology studies for a number of purposes, including “PR oriented research” to get a “route into the media”.

Their founder, Dr David Lewis, can even be hired to “provide independent, third party, endorsement”, demonstrating that contradiction is no barrier to good marketing.

Apparently, the study used EEG and heart rate measures to compare response during kissing, to response during a bizarre condition where a lump of chocolate was put on the tongue and was left until it melted.

I say apparently, because the research itself seems not to be available.

It doesn’t seem to have been published anywhere (although I can’t say there are many neuropsychology journals crying out for EEG studies comparing melted chocolate and kissing) and so far, the company has not responded to my request for the details of the study.

What is slightly disappointing is that the company seems also to do ‘serious’ research and the founder is an established researcher.

A well-written, elegantly designed, surprisingly creative research paper may yet turn up in my inbox, but until that time, I’d avoid the junk.

Anyway, we know from published neuroscience research that too much chocolate makes you feel sick (and just how the brain might generate the feeling).

UPDATE: Four days later and no reply to my requests. This one’s junk.

UPDATE 2: I finally did get details of the study from The Mind Lab. I posted about it here.

Link to a genuinely interesting chocolate study.

The uncanny, fantasy and imagination in Irish art

Dublin’s National Gallery of Ireland has a free exhibition looking at how the uncanny, fantasy and imagination have been represented in Irish art.

Although only three rooms, there are some wonderful pieces, many of which explicitly touch on psychological themes.

This is an extract from the programme:

The Fantastic has manifested itself in various ways, some subtle and some more dramatic and outrageous. The most obvious manner in which the concept was presented in both literary and visual terms was by drawing the viewer’s attention to the ambiguity of everyday experience. This effect can be considered in terms of the idea of the uncanny, where the familiar is made to appear strange and disturbing.

Sigmund Freud, writing on this phenomenon in 1919, expressed his fascination with the way in which an artwork could affect a strong psychological response in the viewer or reader by creating something that was both familiar and alien at the same time. He believed that the uncanny triggered repressed memories from childhood and it is notable that many of the artworks in this exhibition which evoke the uncanny, refer to childlike forms or activities.

There’s also various free talks associated with the exhibition, the best of which looks to be ‘The Fantastic in Art: The Inner World of the Imagination’ which unfortunately happens at the inconvenient time of 10.30am on Tuesday 17th April.

The exhibitions runs until the 12th August.

Link to exhibition information.

Battery powered brain scanner

BBC News has an interesting video report on a hand-held device that uses near-infrared light to penetrate the skull and test the cortex for haematomas – a type of potentially dangerous blood clot caused by head injury.

The device is called the InfraScanner and doesn’t create the sort of brain scans you might be used to seeing, but instead is a hand-held device specifically designed to diagnose this specific type of injury.

It uses technology called ‘near infrared spectroscopy‘ that involves rays of near infrared light being beamed into the head.

This light can penetrate through the skull and a few centimetres into the brain.

Some of this light is reflected back and some is absorbed, depending on what the light encounters on its path.

By measuring the light that get reflected back, it’s possible to determine the structure of the underlying material.

The device uses these principles to work out whether the area under the scanner is normal brain tissue or has a bleed in it.

This can be life-saving information and being able to do this on the spot, rather than needing to give someone a full brain scan, would obviously be incredibly useful.

The technology is also being used in a more complex form called Functional Near Infrared Spectroscopy (fNIRS) to look at brain activation during mental tasks, in a similar way to other types of brain imaging.

The advantage with fNIRS, however, is that it doesn’t involve being put into a big tube (like fMRI), injected with radiation (like PET), doesn’t need a shielded room (like MEG) and has better spatial resolution than EEG.

The technology is still relatively new though and it can only look at surface brain structures, but looks like a promising technology, particularly when it can be modified into hand-held diagnostic devices.

There’s a excellent review of its use in brain imaging in a recent scientific paper (if you have access to the journal) and in a freely available article (pdf) from an IEEE engineering magazine.

Link to video report from BBC News.
Link to PubMed abstract of scientific review.
pdf of magazine article on fNIRS.

Back to the Future Brain

It’s a timeless romantic tale. Boy meets girl. Boy accidentally puts girl into a coma in a car accident. Boy tries to revive girl in his neuroscience lab while singing an 80s pop song.

The video for the 1985 song Future Brain by Italian pop artist Den Harrow is on YouTube if you want to satisfy your morbid curiosity.

According to Den Harrow’s Wikipedia entry he didn’t even sing his own songs. Presumably the lab was all his own work though.

Neuroscience made simple

If you think the neuroscience of mental illness is just too complicated to understand, there’s no need to worry your pretty little head about it.

Dr Bonkers has kindly collected explanations of these otherwise poorly understood disorders, simplified for you, by those ever helpful drug industry marketing departments.

Why waste time following those baffling scientific debates about how the most complex organ in the known universe experiences distressing and disabling mental states when the following explanation will suffice:

Although [insert name of mental disorder here] is not fully understood, there is growing evidence that it is caused by an imbalance of chemicals in the brain.

What ‘growing evidence’ can mean is everything from virtually none (in the case of serotonin and depression) to the evidence points to some role for an excess of neurotransmitter action in a particular brain circuit but there is still some contradictory evidence and isn’t a complete explanation of the whole disorder (in the case of dopamine and psychosis).

But who would want to worry patients who already have a lot on their minds with complicated brain science, let alone trouble them with mixed evidence from the results of clinical trials that tested the medication for its usefulness.

It’s interesting to note that the information on Dr Bonkers’ site is all from direct-to-consumer marketing, at a time when psychiatrists themselves are being specifically trained to communicate the complexities of the science to patients.

An excellent Royal College of Psychiatrists podcast tackles how to communicate the results of randomised controlled trials (RCTs) to a patient wanting to know how a drug might affect them.

It’s well worth listening to if you want some insider knowledge that will help you make sense of the marketing claims.

And if you want a simple explanation of the neuroscience of mental disorder and how drugs affect the brain, well, there isn’t one.

Don’t let anyone tell you otherwise.

Link to Dr Bonkers’ Science Made Simple (thanks Ben!).
Link to RCP podcast on interpreting drug trials.

Central catacomb

“But when the self speaks to the self, who is speaking? ‚Äî the entombed soul, the spirit driven in, in, in to the central catacomb; the self that took the veil and left the world ‚Äî a coward perhaps, yet somehow beautiful, as it flits with its lantern restlessly up and down the dark corridors.”

A quote from Virginia Woolf’s short story An Unwritten Novel.

Woolf suffered from debilitating depression throughout her life and eventually committed suicide at the age of 58, but not before revolutionising modernist literature and leaving a huge legacy of both fiction and non-fiction works.

Zimbardo on heroism

Edge has a video of Philip Zimbardo talking about what his investigations into the psychology of conformity and abuse have told him about the psychology of non-conformity in the face of evil.

He starts his talk with the following:

One of the questions I’ve been asking myself is, is there a counter point to Hannah Arendt’s classical analysis of evil in terms of her phrase ‘the banality of evil’.

Zimbardo largely describes how his previous work pointed him towards studying heroism and non-conformity, but also gives a nice outline of some of the historical and political background to his work.

Link to page with embedded Quicktime video.

2007-04-13 Spike activity

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

More from Cardiff’s Violence and Society Research Group: Wins, not defeats make fans more aggressive.

The New York Magazine has an in-depth article on research that has looked at the psychology of the boss in the workplace.

Retrospectacle examines new evidence that lactate may be a key in understanding how the brain responds to traumatic injury.

American Scientist reviews a series of books on morality, moral evolution and decision making.

A new blog called ‘On the Brain‘ launches, written by a professor of neuroscience.

The genetic contribution to sexual orientation and sexuality is considered by an article in The New York Times.

The Neurophilosopher investigates recent research into alien abduction, reincarnation and memory errors.

Salon has an interview with Cathryn Jakobson Ramin, author of a new book on midlife memory loss.

Gun ownership linked to suicide

A study just published in the Journal of Trauma found that across 50 US States, home gun ownership was linked to an increase in the risk of gun-related suicide.

The man-in-the-street wisdom on suicide goes something like this: ‘If someone wants to kill themselves, they’ll always find a way to do it’.

In actual fact, we now know that availability of an easy method of suicide makes it more likely.

Many drugs are no longer provided in pill bottles, but instead, in blister packs and this is linked to a reduced severity of overdose.

You would think that if someone wanted to die by overdose, pushing pills out a blister pack would be no less of an obstacle than emptying them out of a bottle, but simple measures such as this can be an effective form of self-harm prevention.

Why is this? Well, it’s not really clear, but possibly because every action someone takes on the path to suicide has to be contemplated and thought about.

Perhaps each contemplation makes people reflect and less likely to act impulsively. Certainly, in some people (but not all it seems) impulsivity is linked to a history of suicide attempts.

Pushing 100 pills out of a blister pack is 99 more actions than emptying a bottle of pills, so maybe this gives more time for people to halt any impulsive actions.

Guns are an instant way of killing yourself and this is one explanation of why they might be linked to a higher rate of suicide.

One objection to the gun-suicide association might be that this is just a correlation and suicidal people might be more likely to have guns in their house because they have acquired a method to kill themselves, or otherwise lead lifestyles that would make both owning a gun and killing themselves more likely.

The finding in the Journal of Trauma study is indeed a correlation, but an experimental approach that would find a true causal link – e.g. putting guns in randomly selected households and seeing if more people kill themselves in these homes – would be highly unethical.

However, the study controlled for a number of factors that are typically given as reasons other than just gun ownership for the link, such as poverty, urbanisation, unemployment, mental illness, and drug and alcohol dependence and abuse.

Still the link remained, and remained only for death by firearm, not suicide by any other method.

Link to summary of study (via Furious Seasons).
Link to abstract of scientific study.

Kurt Vonnegut has left the building

This is a novel somewhat in the telegraphic schizophrenic manner of tales of the planet Tralfamadore, where the flying saucers come from. Peace.

A quote from Slaughterhouse-Five, a novel by American writer Kurt Vonnegut, who died yesterday.

Slaughterhouse-Five is a novel about World War II, the bombing of Dresden, alien abduction, youthful foolishness, time travel, brain injury and forgiveness.

It is a truly remarkable book that gives a profound and sensitive portrait of a person with brain injury, and the chaotic, hallucinatory, terrifying and sometimes wonderful experiences that can come with it.

The unique construction of the blind brain

ABC Radio National’s All in the Mind recently had a two programme special (part 1, part 2) on the neuroscience of blindness, focusing on how blindness affects the development of the brain and how electronic neural implants and being developed to restore lost vision.

One of the most remarkable parts is the interview with psychologist Zoltan Torey, who became blind as a student in an industrial accident.

He has written The Crucible of Consciousness (ISBN 0195508726), a remarkable and highly regarded book on the conscious mind.

In the 1st part of the series, he describes how he constructs a a ‘visual’ representation of the world and how his blindness has informed his study of consciousness:

But what is new of course is just the way in which I am able to combine things in my brain without the interference of vision. Normally when people want to think they close their eyes because the flood of visual impressions that comes at you is a distraction. I have the privilege of not having to cope with that, of thinking without…I’m a sort of ‘thinkaholic’, if I might use this expression. This is the way I did my research work about psychology and the consciousness. Not being troubled with vision itself, it was possible for me to imagine complex internal systems, and so I have this marvellous opportunity to run an internal show like a movie director.

Researchers studying neuroplasticity (how the brain changes its structure and function) are now focusing on the brains of blind people, as it has become clear that, for example, the area of the brain normally functioning as the visual cortex in sighted people seems to be active during touch-based reading, which is something that doesn’t occur in sighted people.

The second programme looks at the latest research on ‘bionic’ retina implants, that aim to process light and, through implanted electrodes, stimulate the optic nerve to act as an artificial retina replacement.

Link to The Blind Brain: Part 1 of 2.
Link to The Blind Brain: Part 2 of 2 – The bionic eye.

Sex, love and SSRIs

Psychology Today has an interesting article on anthropologist Helen Fisher’s theory that SSRI drugs (commonly used as antidepressants) interfere with love and attraction.

SSRI stands for ‘Selective Serotonin Reuptake Inhibitor’ and the group includes drugs such as Prozac (fluoxetine), Seroxat (paroxetine) and Zoloft (sertraline) which all increase the availability of the neurotransmitter serotonin in the synapse – the chemical junction between neurons.

Despite the (somewhat misleading) use of the word ‘selective’ in the title, these drugs also affect many other types of neurotransmitters to varying degrees – of which dopamine is one.

Fisher maintains that as attraction, desire and sexual pleasure are known to involve dopamine circuits in the brain, these drugs interfere with relationship formation.

This dopamine deficit affects people in a variety of ways, according to Fisher and her research partner, Virginia-based psychiatrist J. Andrew Thomson, Jr. Singles using antidepressants may have a harder time meeting people, because their natural sexual response is dampened. Some researchers believe desire was designed to help people select mates who are genetically suited to them. The spark that ignites on meeting someone new is telling you something: This might be your match. When you miss those signals, your odds of finding an appropriate mate decrease.

Fisher outlines her theory in a paper published with psychiatrist J. Anderson Thomson in the recent book Evolutionary Cognitive Neuroscience.

Luckily, the paper is also available online as a pdf file if you want to see their argument in full.

As an aside, the Psychology Today article is by science writer Orli Van Mourik, who you may know from Neurontic blog.

Link to Psychology Today article ‘Sex, love and SSRIs’.
pdf of scientific paper (warning: big download!).

The dramatic history of anaesthetics

BBC Radio 4’s In Our Time had a recent programme on the history of anaesthetics, covering their discovery and their application from the first pain killers to their use in modern day surgery.

It starts with Humphrey Davy testing a wide selection of seemingly randomly chosen gases on himself and discovering ‘laughing gas’ or nitrous oxide.

The programme continues to cover the development of other important Victorian anaesthetics such as ether, chloroform and cocaine, including dramatic demonstrations, usually involving public operations or tests on unwary research assistants.

Link to In Our Time on anaesthetics (with audio).