Consciousness
If you were to encounter an intelligent alien, they might ask you what it is like to be human. I suspect they are much more likely to ask such a question than undertake the type of orifice examination reported by many who claim to have been abducted by little green men. Would the first thing you do on encountering a sentient species from another planet be to poke your finger into any openings it may have? Probably not. So how might you answer questions on what it is like to be human? You might talk about your body inhabited by your mind, where your mind is the part of you that reasons and thinks. You might say that your mind is what makes you you. That would be a sensible response given our minds feel special and unique, and for some people too good to be temporary as they believe their minds live on after death. Observation forces us to accept that when we die our bodies serve no function, and decay, but it can be harder to accept that our minds die too. We might fight the inevitable ravages of age on our bodies by eating healthily, exercising daily and avoiding guilty pleasures that doctors tell us are bad for us, but it can sometimes seem inconceivable that our minds will wear out and die. Alzheimer’s disease and dementia demonstrate that our minds can, and sometimes sadly do, fall apart like the rest of our disposable soma, but these illnesses do not stop many people believing their minds will live on post death. Our minds feel special and a little bit different from our bodies.
One reason that makes the mind seem special is we have been unable to locate it in the way we have the heart or spleen. Unlike a kidney, liver or lung, there is no organ called the mind that we can dissect out of the body and study. There is no mind transplant procedure, and even though science fiction writers describe futures where minds can be downloaded on to a USB stick and uploaded into a computer, this is not going to happen any time soon. Given we can’t locate the mind, how could it decay along with our brains, skin and muscles? However carefully we dissect the human corpse, no mind has been found, so perhaps it moves on after death. Personally, I don’t subscribe to this view. My mind resides in my brain, the organ (or more accurately the set of organs) found in my skull, and upon my death it will no longer exist. My brain, and therefore my mind, is part of my disposable soma and none of it has life after death. I die and the lights go out. Of course, this makes me sad, but it does raise another question: why do we have minds, why are we aware of our thoughts and existence? Is it simply the universe’s way of marvelling at its own magnificence, or just an accident of nature? Can we study the evolution of the mind in the same way we can study the evolution of any other phenotypic trait?
The hard problem of consciousness, a term coined by David Chalmers in 1995, is concerned with why we experience anything at all, and it has been central to consciousness research for the last few decades. The problem is wryly named, because all aspects of studying the brain and consciousness are hard; there are no easy bits. But the hard problem was seen as particularly difficult. Put another way, it asks, would it not be possible for a conscious-less zombie to behave just like us, doing everything we do but experiencing nothing? The hard problem is hard because it assumes that even if we get to a point where we understand everything about how the human brain works and are able to build an accurate computer model of it, the question of why we experience life would still remain.
What it feels like to be human is important, and perhaps the most important part of our existence. Given this, it is no surprise that researchers have been keen to understand why being human feels like it does. An obvious follow-up question is what does it feel like to be a bat, cat, or rat? We know the structure of the brain of each species holds the key to answering this question, and we also know that being conscious is the process that gives us the sense of self. Understanding how our brain works, and how our brain differs from those of other animals, has helped scientists begin to understand consciousness and why we have minds.
An influential scientific paper on consciousness by the philosopher Thomas Nagel has the great title, ‘What Is It Like to Be a Bat?’ The paper starts by assuming that most animals have some degree of consciousness, takes the position that we can’t understand consciousness by breaking it down into physical processes such as interactions between cells in the brain or the workings of genes, and concludes that it is impossible to know what it is like to be a bat, but, because bats are conscious, it must be like something. The paper was published in 1974, and much has been discovered since. Psychologists are now confident that bats do have a degree of consciousness, and these researchers also have a reasonable understanding of how a bat’s brain works. But we still do not know what it feels like to be a bat. There are probably ups and downs, good times and bad, with bats experiencing a sense of pleasure and of pain. I doubt they feel anxiety about the fate of the insects they eat while pondering the pros and cons of vegetarianism (I’m assuming they’re not fruit-eating or vampire bats), they are probably unaware that death awaits them, but they take actions to avoid predators, and although they communicate with one another up to a point, they do not lecture one another on the wondrous achievements of bats past.
Understanding consciousness is one of science’s hardest challenges. Conducting experiments on consciousness is difficult, and most experiments conducted to date do not provide much insight into the hard problem of consciousness. Nonetheless, there are a range of views on why consciousness exists, often discussed by philosophers rather than consciousness researchers conducting experiments. When reading this literature, I had to use my mind to try to understand why it exists, trying to balance evidence against speculation. I have concluded that there is evidence that most animals have a degree of consciousness. A fly or a shrimp does not experience the world in the same degree of complexity as you and I, but they still do have experiences, and these experiences are a form of consciousness. Their form of consciousness may be very different from ours. Octopuses, for example, ‘see’ the world through their skin, and many octopus species can change colour and pattern in response to a change in light or background colour and texture. Working out what consciousness is like in other species is extremely challenging and perhaps impossible, and genetics does not help us much here. There is no evidence that there is a single gene that turns consciousness on or off either in octopuses, shrimps, flies or humans. Despite the horror film industry’s love of mindless, murderous zombies, a mutant who lives their life just like you and me but without experiencing any of it has never been observed. There is no simple, single cause of consciousness, although we can use drugs to turn it on and off.
I am not persuaded the hard problem is an issue, but this will be seen as contentious by some researchers. Consciousness inevitably arises from the workings of brains, and I suspect it would be impossible for a brain to receive and process signals from the eyes, ears, nose and skin, combine this information with memories and decide how to act without experiencing something. Given we are conscious, and we have been unable to find what makes us conscious, the logical conclusion is it must arise from the way that brains work. We do some things subconsciously, of course, but this does not mean that everything we do can be done without us knowing about it. The starting assumption of the hard problem that everything could be done subconsciously is wrong. Zombies that behave just like conscious people don’t exist because they can’t. A growing number of psychologists are coming to the conclusion that conscious minds are an inevitable consequence of a complex brain, and if we can understand how the brain works, that could reveal why we are conscious.