Monday, 7 July 2014

Neurosurgeons find small brain region that turns consciousness on and off, like the key in a car's ignition

The 54-year-old epilepsy patient - her name remains concealed to protect her privacy - was lying on the operating table while surgeons explored inside her brain with electrodes. They were looking for the source of her epileptic seizures. Suddenly, after they applied electricity to a small region, buried deep, near the front of the brain, the woman froze and her eyes went blank. She was awake, but entirely unresponsive.

The precise area the surgeons had zapped included a sliver of tissue known as the claustrum, which is part of a network that supports awareness. Mohamad Koubeissi and his colleagues state that nobody has ever examined the effects of stimulating this specific brain region before, despite this kind of surgical procedure having been performed for decades. Just as geographers still surprise us with reports of having discovered previously unchartered parts of the earth, it takes one aback to hear of unexplored areas of neural terrain.

Intrigued by the woman's response to the stimulation of this specific brain region, the surgeons investigated further. Ten further stimulations, and on every occasion zapping the claustrum had the same effect. By contrast, zapping an area just 2.7mm away did not.

Perhaps the woman was simply paralysed by the electrical stimulation? The effects are more intriguing than that. If given an instruction prior to the stimulation, such as words to utter or movements to make, she continued this for a few seconds after the stimulation began, but then descended into still, unresponsive stupor. It was also striking to observe that as soon as the stimulation ended, the woman regained consciousness. However, she had no memory of the preceding moments during the stimulation period.

The researchers also examined the synchronisation of activity across the brain during the stimulation of the claustrum. They found that it increased synchronisation across the brain, possibly to a debilitating level. If so, this would match the situation observed in epileptic seizures that trigger loss of consciousness.

Caution is required - after all, this is a single case study, and the patient in question was missing part of one hippocampus, removed during earlier treatment for epilepsy. Nonetheless this is an intriguing finding. "... [T]he disruption of consciousness that we herein describe has never been precipitated by electrical stimulation of any other site in the human brain," the researchers said.

Speaking to New Scientist magazine, lead author Koubeissi likened the claustrum to a car's ignition. While both the brain and the car are made up of many functioning parts, "...there's only one spot where you turn the key and it all switches on and works together," he told them. "So while consciousness is a complicated process created by many structures and networks - we may have found the key." If these results can be replicated, the hope is that stimulation of the claustrum may offer a way to treat disorders of consciousness associated with epileptic seizures.

_________________________________ ResearchBlogging.org

Mohamad Z. Koubeissia, Fabrice Bartolomei, Abdelrahman Beltagy, Fabienne Picard. (2014). Electrical stimulation of a small brain area reversibly disrupts consciousness.  Epilepsy & Behavior Volume 37, August 2014, Pages 32–35

Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.

23 comments:

Research Digest said...

CLAUSTRUM NOSTRUM

This center cuts off awakeness, not (just) consciousness. Inactivating the claustrum seems to put the subject into an immobile trance that is not sleep (which is an active dynamical state) but a kind of “suspended animation”).

But consciousness means feeling — feeling anything at all. It is not (just) awakeness,

If something could "cut off" feeling while leaving “doing” intact (moving, talking, etc.), then it would make us into the Zombies that we would have been if we were not conscious. (Now that would be a real “on-off” switch!)

But there is no such center, or switch. Because consciousness is much more fundamental and pervasive than mere awakeness.

And for some reason that no one can understand or explain, there (probably) cannot be Zombies — at least not with human-scale (or probably even any biological-scale) doing-capacity. To be able to explain how and why that is the case would require solving the mind/body problem (the “hard” problem).

By the way, general anaesthesis also cuts of awakeness, as this claustral inhibition does, but it induces a lot of other accompanying changes in state along with it. (Maybe, if it is not harmful, claustrum inhibition could be used for surgery instead of pharmacologically inducing sleep or coma?)

And local anaesthesia merely cuts off sensation (which also happens to be felt): It makes the stimulation of the anesthesized location unfelt (but of course it leaves all other feeling intact).

http://bit.ly/hardproblem

Research Digest said...

So when ur dad said; "Don't marry that meathead." He probably knew what he was talking about. :D

Research Digest said...

This is consistent with Carrier and Morgan's "Facial Buttressing Hypothesis" http://onlinelibrary.wiley.com/doi/10.1111/brv.12112/abstract

SCIENCE!!!

Research Digest said...

Wanna have fun with me Liza. I'd fxxk you so hard that you'd scream for more.

Research Digest said...

Sounds like you just want more cock.

Research Digest said...

Spoken like a small penis.

Research Digest said...

Spoken like a true slut.

Research Digest said...

Astoundingly stupid comments here, there's no hope for humanity. Very few people have a basic grasp of basic statistics. Outliers do not invalidate a trend, and interesting robust correlations are worthy of further research and speculation. People just durrhh out the expression "correlation isn't causation" thinking it makes them sound smart.

Research Digest said...

More research in this area could provide us with more answers - definite answers!

Research Digest said...

Accually you do. And very much, in context with your comment.

Research Digest said...

2/10 can`t award higher points to easy targets you pick my entertaining friend. my just average size dick would have you grunting moaning anyways and I know it. confidence ftw dear. oh yeah I can also fight but you wanted to talk about dicks so, dicks to you madam. Ps I love you

Research Digest said...

@Liza Mack I`m still partial to you dick size theory!

Research Digest said...

@Liza Mack I mean not "whoever"

Research Digest said...

I think women don't really have penises, contrary to what your mother may have told you.

Research Digest said...

The next comment was directed towards the "spoken like a small penis" comment.

Research Digest said...

Penises don't speak.

Research Digest said...

I just think that a wider face like A correspond to more shoulder-neck-arm muscles. Men with that built are generally stronger.

Research Digest said...

Well, but they do jump to conclusions here about what a wider face implies. Interestingly, they did use the word "experienced" when describing the better fighters, and to me, THAT would seem to be the key--not "higher testosterone." Men try to reinforce certain things they like to believe about themselves, so they love "evolutionary" hooey that bolsters their favorite myths. But in this case, know what? Plain old AGE makes heads wider. I'm not talking about receding hairlines. We watch enough movies and TV in concentrated bursts to notice that actors' heads widen over time--including those of many women. People could well be responding to an innate sense that wider head = older = more experienced. How about some GOOD science for a change instead of silly, sensationalized guesswork?

Research Digest said...

From what I am aware steroids (PED's) can increase the thickness of the face.

Research Digest said...

At least in the figure illustrated in this article, fighter A has a larger degree of cauliflower ear and a wider nose, both factors which result from environmental factors (i.e. lot's of grappling and getting punched in the face) which likely correlate with fighting experience and thus formidability. When I walk into a gym or meet a new persom these are the features I key on to determine how likely that person is gonna kick my *ss.

Research Digest said...

This is very flawed since it doesn't take into account PED's and HGH's effects on performance, muscularity in the face and neck, and recovery to compete for many fights.

"support the idea that humans have evolved..." There is nothing in this study that proves those men were born that way.

Research Digest said...

Jon Jones is 6'4, how tiny are the faces of men his size?

Research Digest said...

I agree.
"Samuele Zilioli and his collaborators believe their findings support the idea that humans have evolved..."
This is completely left field, there isn't anything in the study that reflects their facial muscularity and structure are due to genetics rather than PED, diet, and training.

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