It is the only major question in the sciences that we don’t even know how to ask.
What is it to be conscious?
To be conscious is to be aware. This means awareness of one’s self as well as one’s surroundings. It includes the fundamental experience of what it is to be a person.
What does that mean?
Imagine for a moment that you are perfectly relaxed without a single care in the world. I put you in a concert hall. You relax and take your shoes off and listen to some of your favorite pieces of music. You feel nice and peaceful.
Now, the question is what is it to feel nice and peaceful? This is an experience. The fact that you have this experience implies you are conscious and feeling. In contrast, if you were asleep or unconscious, it would not matter to you where you were or what audio waves were impinging on your ears.
That was obvious. Now here’s the tricky part, why did you feel what you felt?
Well, a neurologist might take an MRI scan of your head and point out that while the music played, certain regions of your brain showed a lot of activity and say that this kind of phenomenon is linked to feelings of pleasure. He may further (in principle though not presently in practice) be able to trace out the path taken by neural signals from your ear to different part of your brain and also model how the brain reacts to music. He may draw the conclusion that stimulation of these parts of the brain with this intensity and frequency of pulses leads to a pattern of brain activity characteristic of happiness.
All these things describe peace and happiness, they don’t explain it. It no more explains the feeling of happiness than the banal statement that if you smile you must be happy or that if you are tickled you will laugh. It is actually very difficult to explain scientifically what is meant by experiencing peace and happiness.
This brings us to the easy and the hard problems of consciousness. First the easy. The term “easy” is something of a misnomer. From a practical point of view even these are extremely complex. These are basically those areas of study, where we know “kind of” what the “right questions” are and what needs to be done. You may have been impressed with the stunning progress made in artificial intelligence, machine learning, deep learning and artificial neural networks. All these are examples of the progress made in solving some of these so-called “easy” problems. Easy problems include:
- Ability to categorize, discriminate and react to environmental stimuli (think of object recognition or pretty much most machine learning research)
- Deliberate control of behavior (think of robotics)
- Difference between wakefulness and sleep
- Reportability of mental states
While achieving these in practice is very difficult, in principle, our current avenues of research seem promising enough. We should eventually be able to get some answers without fundamentally questioning our assumptions or research methods.
In contrast, the “hard” problems are mostly those that involve subjective experience where it is often unclear how to approach the problem using tools and modes of thinking we currently have. For instance, it is not at all clear to what extent the principle of reduction can be used when describing subjective feelings without distorting them fundamentally.
“The sensation of color cannot be accounted for by the physicist’s objective picture of light-waves. Could the physiologist account for it, if he had fuller knowledge than he has of the processes in the retina and the nervous processes set up by them in the optical nerve bundles and in the brain? I do not think so”
Hard problems include:
- How can we explain why there is something it is like to entertain a mental image, or experience an emotion?
- When we think and perceive, there is a lot of information processing but there is also a subjective aspect, how does that arise?
- How are physical processes linked with conscious experience?
- How do emotions emerge? What gives rise to bodily sensations like pain?
- What gives rise to the stream of conscious thought
For each of these, we aren’t even sure where to begin our research.
Scientists have certainly made many attempts. In 1990, famed biologists Francis Crick and Christof Koch proposed a neurobiological theory of consciousness. In 1991, Daniel Dennet proposed his Multiple Drafts Model. Hameroff and Penrose proposed a quantum mechanical model of computation in the brain which results in quantum computation within neuron structures. Many other models have also come forward.
To date, the endeavor to evolve a scientific theory of consciousness remains a work in progress.
[Note: This post is based on material from a presentation I had the pleasure to attend given by a friend from IISc, Bangalore]