Author: vaughanbell

Terry Wallis, a man who was in a coma-like minimally conscious state for 19 years after a car crash, seems to have shown brain re-growth since he recovered consciousness.

A research team led by Henning Voss scanned Wallis’ brain using a technique called diffusion tensor imaging or DTI that can pick out the white matter pathways in the brain.

An image from Wallis’ DTI scan is shown on the left, and shows the connections in the rear section of the brain.

The image is shown as if we’re looking down and from the side into the brain. Note how the structures do not match on either side – often a good indicator of brain injury.

Crucially, the researchers re-scanned Wallis’ brain after 18 months and found that the density of the white matter seemed to increase over time, suggesting that his axons were regenerating. These are the long insulated fibres that connect the brain’s neurons.

When scanned using a PET scanner, the increase in white matter also seemed to match an increase in the use of glucose, suggesting greater levels of brain activity in these areas.

In the last decade it was discovered that adults can grow limited numbers of new neurons, but the regeneration of the brain’s connections is still largely unknown, and especially not in people who have suffered such severe brain injury.

Wallis was the subject of a 2005 Bodyshock documentary called The Man Who Slept For 19 Years.

Contrary to depictions in many films (where people tend to gently open their eyes and return to normality), Wallis is still markedly disabled by his brain injury and is not able to care for himself.

Wallis’ recovery is no less remarkable, however, and highlights shortcomings in the scientific understanding of both coma-like states and the neuroscience of consciousness.

UPDATE: Pure Pedantry has a great article looking at some of the background issues to do with this case, such as the exact definitions of different coma-like states. Well worth checking out.

Link to ‘Rewired brain’ revives patient after 19 years from New Scientist.
Link to write-up from The Age (thanks Kate!)
Link to full-text of scientific study.
Link to previous Mind Hacks story on minimally conscious state.

The New York Times has an excellent article on people who experience chronic déjà vu, or, more accurately déjà vécu Рthe feeling of already having lived through something.

The article discusses work by Leeds-based neuropsychologist (and blogger) Chris Moulin who was asked to investigate a recurring feeling of familiarity in Susan Shapiro’s 77 year-old mother.

He was countacted because he is one of the only people to have investigated a similar case, that of a person known as ‘A.K.P.’:

His d√©j√† vu episodes seemed to be “practically constant,” as Moulin and colleagues outlined in a 2005 paper [abstract|pdf] in the journal Neuropsychologia:

He refused to read the newspaper or watch television because he said he had seen it before. However, A.K.P. remained insightful about his difficulties: when he said he had seen a program before and his wife asked him what happened next, he replied, “How should I know, I have a memory problem!” The sensation… was extremely prominent when he went for a walk ‚Äî A.K.P. complained that it was the same bird in the same tree singing the same song… When shopping, A.K.P. would say that it was unnecessary to purchase certain items, because he had bought the item the day before.

A little ironically, the New York Times published another excellent article on déjà vu last February.

Link to article ‘Deja Vu, Again and Again’ from the New York Times.

One I missed the other week – a fantastic edition of the Australian All in the Mind on Early Childhood and the Developing Brain.

Child neuropsychology is now becoming an increasingly important area as the once neglected field is seen as increasingly important both to understand children themselves, and how adult abilities and disorders develop.

This edition of All in the Mind looks at how neuroscientists are uncovering the neurobiological changes that take place during parental care, and how the brain can be markedly altered by abuse or neglect during the early years.

The programme takes a particularly in-depth look at research on children who were largely abandoned in Romanian orphanages during the communist era and had virtually no human contact for the first four years of their life.

Both their social and cognitive development was markedly impaired, suggested that love and attention is needed both for healthy emotional and intellectual development.

Link to transcript and audio of ‘Early Childhood and the Developing Brain’.

The New Yorker magazine has an article on hemispherectomies – surgical procedures which remove half of the cortex, usually in an attempt to cure otherwise life-threating epilepsy.

These operations are usually carried out on children, as remarkably, those in their early years can often develop normal adult skills and abilities if surgery is carried out early enough.

For example, a 2001 book by Antonio Battro (sample chapter: pdf) describes a three year old boy named ‘Nico’ who had the whole of his right hemisphere removed to control life-threatening epilepsy.

Nevertheless, he has developed with very little impairment and has turned out to be a bright and engaging child, despite the fact that a similar operation in adults would be profoundly disabling.

The New Yorker article charts the development of this procedure from the first operation on a human in 1923, to the latest in neurosurgical technology and practice.

Two of the pioneers of the procedure, Dr John Freeman and Dr Ben Carson are also featured, who explain how the team at John Hopkins first tackled a left hemispherectomy. Potentially hazardous, because the left side of the cortex has the majority of the language function in most people.

The article also introduces us to some of the patients who have had the procedure. Christina now drives, graduated from high-school and is studying at university, despite on having only one hemisphere of her brain left.

Link to New Yorker article ‘The Deepest Cut’.
pdf of sample chapter from ‘Half a brain is enough’.
Link to ‘Half a brain is enough’ book details.

The American Civil Liberties Union has filed a Freedom of Information Act request to try and find out whether the US goverment is using brain scan lie detection technology on suspected terrorists.

The most likely technology to be used for anti-terrorism purposes is Functional Magnetic Resonance Imaging (fMRI), which can produce live, real-time images of people’s brains as they answer questions, view images, listen to sounds, and respond to other stimuli. Two private companies have announced that they will begin to offer “lie detection” services using fMRI as early as this summer. These companies are marketing their services to federal government agencies, including the Department of Defense, Department of Justice, the National Security Agency and the CIA, and to state and local police departments.

While fMRI is certainly a hot-topic at the moment, EEG-based lie detection technology based on the same principle has been around for almost two decades now, and has the advantage of being more portable and considerably cheaper.

It’s interesting that it’s still not clear (publically at least) whether fMRI has any advantages over the existing EEG method, so it will be interesting to see if anything comes out of these enquiries.

Link to ACLU press release (via /.)
Link to actual Freedom of Information Act request.