Consciousness Signature: Awareness Warnings during surgery

Anaesthesia wearing off mid-operation is not just the stuff of nightmares – it occurs in around 0.2 per cent of surgeries globally. Keeping tabs on the brain during surgery could stop this.

Indirect signs of consciousness such as changes in heart rate, blood pressure and muscle tone can be tracked during surgery but more reliable indicators are not currently available.

"It's slightly frightening that millions are given anaesthesia every year and the anaesthetist has no way of knowing with certainty that the patient is unconscious," says Tony Absalom at the University of Groningen in the Netherlands.

To look for a more concrete signature that could be monitored during surgery, Emery Brown at the Massachusetts Institute of Technology and his team attached an EEG cap with 64 electrodes to the heads of 10 adults.

They used this to measure changes in brain activity across multiple brain regions as unconsciousness was induced using a general anaesthetic.

As the volunteers lost and regained consciousness they were asked to press a button whenever they heard a click or a spoken word, allowing brain activity to be matched to different stages of wakefulness.

By constructing a montage of the activity from different parts of the brain, the team identified recognisable patterns that corresponded to different levels of consciousness, allowing them to tell when someone was waking up.

Mysterious sleep
EEG monitoring during surgery is carried out in about 2 per cent of hospitals in the UK, but only three or four electrodes are used, in a strip across the forehead.

This looks at just one brain region, however, and so can only give you a probability of unconsciousness, not a conclusive answer, says Absalom.

"You don't want something that says a patient is probably asleep. You want to know 'Are they or aren't they?'"

Using more electrodes, as Brown has done, should shore this up. Although applying more electrodes means the patient's head must be shaved and a conductive gel applied.

"The mechanisms underlying anaesthesia remain a mystery," says Ram Adapa at the University of Cambridge. But these results support the idea that anaesthesia affects the communication and synchronisation between brain regions, he says. "It is yet another piece of the jigsaw puzzle."

However, Adapa notes that it may be a while before the technique can be used in a clinical setting. EEG measurements are very sensitive to mechanical and electrical interference, he says, "and the operating room environment is unfortunately burdened by both."

Journal reference: 
Electroencephalogram signatures of loss and recovery of consciousness from propofol PNAS, 10.1073/pnas.1221180110

Global Consciousness - Edgar Mitchell: Apollo 14 Astronaut - Cartoon

 

 

All credit for the cartoon goes to Zen Pencils

EEG finds consciousness in people in vegetative state

Signs of consciousness have been detected in three people previously thought to be in a vegetative state, with the help of a cheap, portable device that can be used at the bedside.

"There's a man here who technically meets all the internationally agreed criteria for being in a vegetative state, yet he can generate 200 responses [to direct commands] with his brain," says Adrian Owen of the University of Western Ontario.

"Clearly this guy is not in a true vegetative state. He's probably as conscious as you or I are."

In 2005, Owen's team, used functional MRI to show consciousness in a person who was in a persistent vegetative state (PVS), for the first time.

PVS is also known as 'wakeful unconsciousness', whereby the body still functions but the mind is unresponsive.

However, fMRI is costly and time-consuming, so his team set about searching for simple and cost-effective solutions for making bedside diagnoses of PVS.

Now, they have devised a test that uses the relatively inexpensive and widely available electroencephalogram (EEG).

An EEG uses electrodes attached to the scalp to record electrical activity in the brain.

Imagine wiggling your toes
Owen and his team used an EEG on 16 people thought to be in a PVS and compared the results with 12 healthy controls while they were asked to imagine performing a series of tasks.

Each person was asked to imagine at least four separate actions – either clenching their right fist or wiggling their toes.

In three of the people with PVS, brain regions known to be associated with those tasks lit up with activity, despite physical unresponsiveness.

This suggested to the researchers that the subjects were carrying out a complex set of cognitive functions including hearing the command, understanding language, sustaining attention and tapping into working memory.

"It isn't the case that just because somebody doesn't respond they're not conscious," Owen says. "There's a growing body of data now demonstrating that many of these patients aren't what they appear."

Criteria of Vegetative State (PVS)
"The diagnostic criteria for vegetative state have to change," he adds. The official diagnosis for PVS was formulated in the 1970s, before neuro-imaging was widely used, says Owen.

The last update was made in 1995, but the criteria for declaring someone conscious is still based on whether an outside observer believes the patient is trying to communicate.

Morten Overgaard, a cognitive neuroscientist at Aalborg and Aarhus University in Denmark, says that determining whether Owen's patients are actually responding consciously or whether they are unconsciously reacting to suggestions from the command is difficult to know without further study.

"If this is suggested as a standalone test to decide whether a person is conscious or not, then we need [signs] that are very strong and not just an indication of consciousness," he says.


Absence of Awareness
The test cannot prove the absence of awareness, but it can identify people who weren't thought to be conscious, says Damian Cruse, a collaborator on the study.

This was particularly apparent when 25 per cent of the healthy controls returned EEG readings that were below expected levels of conscious thought.

Communicating with carers
However, for those people previously considered to be unaware of their surroundings, communicating with their caretakers through EEG tests could change their life. "We're trying to work out how to use this technique to find out more about somebody's internal mental state," says Owen. "It opens up the possibilities for potentially facilitating recovery. If you have a channel of communication with a patient, you can have that patient play a role in therapeutic intervention."

New Brain Structure Explains Willful Blindness

The article in today's NYT by Nancy Koehn titled “Why Red Flags Can Go Unnoticed” was chiefly concerned with the effects of willful blindness in humans. It did not answer the primary question: WHY do people ignore clear warnings of impending problems.

Bruce Nappi, in his new novel LIARS! provides a profound explanation: two human species coexist on earth today, and one of them is not able to broadly understand or apply logical reasoning, and no, it's not males and females!

The new discovery came when he first determined what creates consciousness in the human brain. Step one was recognising a new physiological brain model that revises Sigmund Freud's Id, ego and super-ego brain structure.

The second was sorting out what makes humans different from animals. In fact, contrary to common belief, that difference does not occur at the homo sapiens level but further back down the evolutionary tree. Differences in awareness for humans and animals are described and labeled A2 and A1 respectively, but, the characteristics listed for humans (A2) raised a big problem: they didn’t describe all known human abilities.

He categorised the additional abilities with a new label A3. The implication was both amazing and unsettling! Both A3 and A2 had human traits, but they were as distinct as A2 (humans) and A1 (animals). The solution required that each be considered a different species - amazing for sure.

However, if the discovery was true, it would have huge ramifications for human social structures. He tested the theory against more and more of the great social questions. The new A3 model produced so many logical answers that he is convinced he has stumbled onto a profound discovery.

New Brain Structure Explains Willful Blindness In Humans And Why Red Flags Go Unnoticed

Quantum gods: Creation and everything beyond

Quantum Gods: Creation, chaos and the search for cosmic consciousness by Victor J. Stenger

Maharishi Mahesh Yogi, founder of transcendental meditation, claimed his techniques gave practitioners access to the "quantum field of cosmic consciousness" (Image: CSU Archives / Everett Collection / Rex)

QUANTUM mechanics is remarkably weird: even though it is well understood mathematically and can produce accurate, ultra-precise predictions, nobody really knows what it means. This leaves lots of room for people in search of the spiritual - and who are not burdened by any knowledge of mathematics - to impose on it whatever quasi-religious beliefs or interpretations they like.

In this much-needed book, physicist Victor Stenger isolates and then debunks the claims of two kinds of "quantum belief". One he calls "quantum theology" because it offers quantum physics as a way for God to act in the world without violating natural laws. The second is "quantum spirituality", which is rooted in the even vaguer notion that quantum physics connects the human mind to the universe, allowing us to create our own reality.

If I could choose my own reality, would I be wearing these shoes?