In one sense the reliability of behaviour as a measure of consciousness is unknowable, since we have no way of confirming whether or not there is consciousness other than here, now for 'me'. We do not even know how many 'me's there are in our own head or whether they are conscious in the same way.

Having said that, in the medical sphere behaviour can be a reasonable basis for inferring the presence of conscious thoughts similar to 'mine' if the behaviour is of a sort that we never find ourselves engaging in without being aware of it. 

The problem is that although behaviour may be a guide to the presence of consciousness, absence of such behaviour is not a good guide to the absence of consciousness. That is because these behaviours arise from a combination of two factors - conscious thought and the context in which those thoughts occur - what one might call mindset perhaps. As an example, if you tell people to press a button when they are conscious of a number of a screen you can be confident if they press that they were conscious of a number. If they did not press there might have been no number, or a number flashed so fast that it only activated areas of brain that do not on there own trigger thoughts of the sort we report as conscious, or there might have been a letter. The person might have been very conscious of the letter, but because they had been told to press for a number they would not press. But they were conscious of something. Experiments like this have recently shown that assumptions about what sort of brain activity is needed for consciousness may be completely wrong, simply because studies have not been designed to take into account the importance of context.

Other contextual factors include defects in motor pathways in people with brain injury or psychiatric disease. The thoughts may be there but not lead to any revealing behaviour. So we get back to the fact that we can never really tell if there is absence of conscious thought.

In my opinion behaviour is a derivative of consciousness and therefore studying behaviour can determine the level of awareness which drives a particular behaviour. Behaviour does not give rise to consciousness but it is consciousness that gives rise to behaviour. In non human research this is one of the best methods for determining consciousness, which has been challenged based on a few unrealistic tests e.g. mirror test. Human behaviour cannot be compared to non human or animal behaviour which are unique in their own way and therefore behavioural observations should not be compared rather they should be studied independently to determine the level of consciousness. In my opinion looking for unique behavioural characteristics in species  is one of the best methods to measure consciousness.

I think it's an imperfect method at best. But it depends in part on your definitions. Is consciousness simply "awareness" or is it a fuller measure of "inner life." My own experience as a clinical psychologist is that the trend to focus on behavior  treated as insignificant a rich literature on what was going on inside the mind of a person. As the DSM became more behaviorally focused, more clinicians practiced "parallel diagnoses" using one to satisfy the insurance companies and another for actual psychotherapeutic work. They constructed their own Psychodynamic Diagnostic Manual: (PDM  [2006, by Alliance of Psychoanalytic Organizations] and continue to rely on clinical texts that honor the inner world which cannot be captured by external behavior. I think for example of what happened to schizoid and schizotypal disorders in the DSM versus the "thick" descriptions in books such as R. D. Laing's The Divided Self, Peter Giovacchini's The Treatment of Primitive Mental States, Harry Guntrip's Schizoid Phenomena, Object-Relations and the Self, or Frank Lake's Clinical Theology.

We naturally interpret each other through our body expressions or language expressions or other artistic expressions.  We do not measure other people consciousness, we self-enact it through our interpretation process of their behaviors.  We do not need course to do that our human cortex is wired to do that. It is why we really can understand each other.  

We are connected but with a barrier to transfer our thoughts, which someday we may overcome. We perceive one's consciousness from a third person perspective and compare it to our own behaviour to bring in an assumption but from a first person experience it may not be what we see. E.g. once while walking down a street I seen a man stand by the roadside staring at me, suddenly he fell to the ground. From a third person perspective I considered him a drunkard but actually he had just suffered from a massive attack and when I went to pick him up he was dead. From a first person standpoint, he knew that something was wrong with him but he could not communicate  and from a third person perspective I thought he was drunk because he kept staring at me. 

Contzen,

You mentioned one situation where you wrongly interpreted the situation.  But in most situations where both human can speak (the same language) they manage to understand each other.  Languages have evolved for that and our mind reading capacities are not perfect but damn good in general.

Gentlemen,

A baby does not speak yet is able to communicate all its needs and its joy to its mother - and the mother can understand her baby!!! This is not done through words - it is through the “feeling heart” - an aspect that science as yet knows little about. This is in fact the subject of my PhD. 

Tina, this for sure is a wonderful topic for Ph.D and I wish you all the very best. A baby is very well connected to the mother through the “feeling heart” but would this be possible in cases where the two are not connected ?

To what extent behavior is a reliable measure of consciousness is in fact impossible to answer. In fact, I think you put it well in asking "to what extent" is it reliable? Measuring for instance an interrater-reliability on you will get a measure on the reliability in the case you are studying. This is, I would say, as close as you will come. More theoretically, I would say that there is no one good answer to your question given the complexity of the two concepts behavior and consciousness, let alone the relation between them. Behavior can certainly reflect consciousness but need not to. The more conscious a thought or emotion gets, the weaker relation to behavior gets. This I would think is a proper way to think of it, yet it won''t do you any good in your research, I guess. Better stick with the reliability measures if it is possible. See attached

Article Consciousness and the Varieties of Emotion Experience: A The...

Article Intentional avoidance and social understanding in repressors...

You ask a good, and very important, question.  I recommend Daniel Dennett's "Consciousness Explained" as a good starting point.    I believe that experimental behavioral paradigms can allow inferences about conscious and unconscious processes, but these processes are quite difficult to infer.   I wrote the attached paper on the topic several years ago.  It may be helpful as well.   

Article Electroencephalographic Registration of Low Concentrations o...

Thanks Contzen -regarding your question to me,  I am going to keep you in suspense until my Phd is finished ...... when it is finished you are most welcome to read it! 

Best regards - tina

All the best Tina....I would love to read it :-)

I read Machio Kaku's Future of the Mind, it is a great model. 

 In one sense the reliability of behaviour as a measure of consciousness is unknowable, since we have no way of confirming whether or not there is consciousness other than here, now for 'me'. We do not even know how many 'me's there are in our own head or whether they are conscious in the same way.

Having said that, in the medical sphere behaviour can be a reasonable basis for inferring the presence of conscious thoughts similar to 'mine' if the behaviour is of a sort that we never find ourselves engaging in without being aware of it. 

The problem is that although behaviour may be a guide to the presence of consciousness, absence of such behaviour is not a good guide to the absence of consciousness. That is because these behaviours arise from a combination of two factors - conscious thought and the context in which those thoughts occur - what one might call mindset perhaps. As an example, if you tell people to press a button when they are conscious of a number of a screen you can be confident if they press that they were conscious of a number. If they did not press there might have been no number, or a number flashed so fast that it only activated areas of brain that do not on there own trigger thoughts of the sort we report as conscious, or there might have been a letter. The person might have been very conscious of the letter, but because they had been told to press for a number they would not press. But they were conscious of something. Experiments like this have recently shown that assumptions about what sort of brain activity is needed for consciousness may be completely wrong, simply because studies have not been designed to take into account the importance of context.

Other contextual factors include defects in motor pathways in people with brain injury or psychiatric disease. The thoughts may be there but not lead to any revealing behaviour. So we get back to the fact that we can never really tell if there is absence of conscious thought.

Maybe Tetsuro Matsuzawa 's work on chimp's is a good  example to read in the context of cognition, where these chimps apparently perform better than humans but unfortunately humans don't call it conscious because their science cannot prove it. Cogntion like the brain is a derivative of consciousness and the reason that we cannot measure it is because its all around us and it is that which drives us from the outside as well as the inside. 

Hydranencephaly is an interesting, exceptional situation regarding consciousness. There is one Scandinavian researcher who amazingly reports conscious behaviour  for all of the children in the study.

Consciousness cannot be measured.  It is not an object but, rather, the medium of experience and is, therefore, always consciousness-of something.  

I would say : " to the extent of our understanding what consciounsness really is,and our capability of measuring it" . "To my knowledge consciousness would be linked to awareness, and awareness doesn't seem to be restricted to the  animal lifeform" . I 'd say :"ask the shaman, don't limit your search to the academic world alone". Best of luck on your journey , Carol

It's a great question. One way of tackling it is to ask people to self-report states or conditions or contents of consciousness and to correlate these reports with behaviour on cognitive or motor performance tasks and/or with brain states. I have found that the correlations are quite strong one when one assesses imagery vividness on a scale like the VVIQ or VMIQ (e.g. see Marks, 1973).

If we do not know what consciousness is we are not able measuring IT. 

''Measuring Consciousness''!  This is a very funny notion.  It is like having a mechanistic way to assess what is supposed to be the opposite of what is mechanistic: consciousness.  It is a reverse Turing Test where we have a machine evaluating consciousness.  While in Turing approach to evaluate intelligence, he uses humans to assess intelligence of machines as they do to assess the intelligence of other humans.  Turing did accept that the concept of intelligence is a subjective one.  Here we have a pretention to assess what is intrinsically subjective: consciousness  through an objective measure!!!!  Lets call this funny notion: the reverse turing test approach!!!!!

Behavior is nothing but the action of entire human beings .It is an attitude of mind & brain  relate to our action which create a foaming of our behavior  for our attitude reflected with our associated members & our working environment .

With this our behavior is whatever we are as we remain with other human beings .Behavior may be positive & negative depending on our outlook for us for this we have to control our mind & temperament & if we have control our negative traits thru our conscious mind our behavior always speak for positive action .

If it is otherwise we can certainly be an object of ridicule & in directly critical remarks from our group .

This is my personal opinion