Quantifying Consciousness

Device to measure how conscious we really are…
Consciousness is one of the most profound concepts of our human existence. What is it that makes a mass of brain cells “aware”? How are our brains able to perceive sensations, memories, moods and thoughts throughout our lives? On an even deeper level, how are we aware of ourselves?
Professor Tim Crane, from the Philosophy department of Cambridge University, expresses his views on consciousness: “It’s sometimes assumed that it’s obvious what consciousness is, and the only question is how it is embodied in the brain,” says Professor Crane. “But many people now recognize that it’s not clear what it means to say that something has a mind, or is capable of thought or conscious experience. My view is that there are lots of assumptions that are being made in order to get to that conclusion and not all of the assumptions are correct.”
Crane’s research moves beyond the concept of mere brain activity to question the “essence of mind”. In effect, he is researching that extra factor which can influence the path from sensory experience to receptor.
There is new research from a team at Cambridge University on understanding consciousness. The neuroscientist Srivas Chennu claims that “In 10 minutes, he (Srivas Chennu) can work out what’s going on inside your head.”
The method, developed by Chennu, places a hairnet filled with electrodes on a person’s head, which is connected to a device measuring the patterns of electrical activity in the brain. From these patterns Chennu can calculate a brain’s signature “which represents the ways in which neurons, and neural networks, are firing.” He does this using classic EEGs with graph theory. In essence, graph theory studies the “pairwise relation between objects”.
Chennu states: “Being conscious not only means being awake, but also being able to notice and experience. When someone is conscious, there are patterns of synchronized neural activity arcing across the brain that can be detected using EEG and quantified with our software.”
While the measuring technique itself is not new, analyzing the output using graph theory is. This analysis gives Chennu the level of a person’s consciousness. The immense use of this “quantification” of consciousness is to determine how self aware a person in a coma or vegetative state after a stroke or injury is. For example, Chennu’s aim is to create a “bedside device” so that doctors can use it to measure the consciousness level of their patients. This can then be used to make the best possible choices for the patient and their family.
Chennu highlights the aspect of how important the level of consciousness relates to quality of life: “Understanding how consciousness arises from neural interactions is an elusive and fascinating question. But for patients diagnosed as vegetative and minimally conscious, and their families, this is far more than just an academic question – it takes on a very real significance. The patient might be awake, but to what extent are they aware? Can they hear, see, feel? And if they are aware, does their level of awareness equate to their long-term prognosis?”
A healthy, conscious brain has a signature which looks like a periodically raging ocean of waves, stemming from the neutron activity of understanding, integrating and storing. During sleep the waves become a calm sea with the occasional dream bump. Chennu shows examples of the brain signatures of two patients, both in a vegetative state. One patient’s signature showed only a few lines, whereas the other had a whole set of the raging ocean waves going on, very similar to that of a healthy awake person’s signature. This patient woke up one year after measuring his signature. The other one did not.
The Evelyn Trust is funding Chennu to carry out a study on 50 rehabilitating patients over three years. Simultaneously with the National Institute for Health Research Healthcare Technology Co-operative for Brain Injury he is developing his device.
The potential to develop his device further offers an intriguing possibility: what if one day we could communicate through a device with patients in a vegetative state? The communication might be basic at first but it would provide a channel to the space in which these patients are trapped. Wouldn’t that be just simply amazing?