Italian research that measures invisible consciousness
The neuroscientist from the University of Milan explains the method that can distinguish those who, in the silence of coma, are still present to themselves
When the body is silent and the brain does not respond, how do we know if there is still someone inside? This is the question that guides the research of Marcello Massimini, Professor of Physiology at the University of Milan and Senior fellow at the Canadian Institute for advanced research, among the protagonists, on 10 November, of "Development and evolution: thinking about the future", a series of meetings promoted by the Milan Academy of Sciences and Letters. His group has been working for years on a method that makes it possible to measure consciousness even when behaviour cannot reveal it: the Perturbational complexity index (Pci).
Professor, what do we mean when we talk about conscience in medicine?
Consciousness is everything that disappears when we fall asleep in a dreamless sleep or during general anaesthesia: that inner presence that makes us say 'I am there'. We all know what it means to be there or not to be there, but everything changes when we have to evaluate it in others. The consciousness of others is not directly observable: we have to infer it from indirect signals, such as behaviour. It is the principle of coma scales: if the patient reacts, we consider him conscious; if he does not, we consider him unconscious. But this method can fail.
How often does behaviour deceive?
Research shows that about one in five patients classified as non-responsive actually has some form of residual consciousness. These are people who are awake but unable to move or communicate, as in cases of 'locked-in syndrome' or a state of minimally consciousness. In these cases, consciousness is there but does not manifest itself. What is needed then is an approach that measures it for what it is, not for what it does.
