As reported last week in Science, a team of researchers in Cambridge have demonstrated that a patient in vegetative state preserved conscious awareness. Using a fMRI scanner the patient showed same activation patterns as healthy volunteers when she was asked to imagine playing tennis. Dr. Adrian Owen, the leader of this research, claim that the vegetative diagnosed brain was able to understand the meaning of sentences and respond consciously. For a detailed description of the research visit the Medical Research Council website. This specific research work is published in Science, 8th September 2006 under the title Detecting Awareness in the Vegetative State.

If these research conclusions are confirmed, it means that current techniques to assess the level of consciousness of humans are not fully valid. One might be unable to move or speak, however that does not neccesarily means that the subject is unable to experience some level of consciousness.

Taking this idea about consciousness level assesment to the field of machine consciousness, one could think about the best way to determine the level of awareness of a robot. Obviously, the first reference is always the Turing test. However, as demonstrated in humans, a purely external evaluation could not be valid in terms of assessing the real level of consciousness of an artificial entity. Anyway, from a strictly engineering point of view this question is irrelevant.

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As published in the last issue of JAMA (The Journal of the American Medical Association) by Irene Tracey (Oxford University) emotions and motivations play an important role in the mechanisms of the perception of pain in the human brain. Using brain imaging techniques with patients suffering chronic pain neuroscientists have discovered that pain perception areas are activated at the same time as expectation areas. In one hand, anxiety and anticipation can worsen a pain experience. On the other hand, positive experiences can relieve the pain perception.

Cognition and consciousness mechanisms obviously greatly affect the amount of perceived pain. As Tracey argues, pain requires much attention. She has demonstrated that inattentive or amused subjects feel less discomfort when applying heat in the hand. In fact, distraction techniques are being evaluated as painkillers.

Other conscious pain inhibitors are motivations. When a harmful stimulus appears, the perception of the pain can be reduced if there is a reason to ignore the pain. For instance, during the search for food, endogenous opioids are released to eliminate the pain feeling, Tracey explains in her paper.

• Link to University of Oxford PAIN Group. 
  

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