Science is making great inroads into understanding our minds, and much insight has emerged from understanding the workings of our brains. Perhaps in time evidence will emerge that will show that being able to move in response to an event that an organism senses in the outside world requires the ability to experience, and this underpins consciousness, but science is not quite there yet. I suspect that not only will we fail to find zombies, we will also fail to find zombie chickens, zombie shrimp and zombie dogs. There are lots of publications on zombie insects, but these are animals whose brains have been infected by the fungus Ophiocordyceps unilateralis, the pathogen that created human zombies in the fictional TV series The Last of Us. In real life, the fungus kills infected ants, flies and spiders, and before they die it alters their brains in such a way they seek out a final resting place that maximizes the chances of the fungus infecting other insects. Whether such an infection alters the consciousness of insects, if indeed they have any, is unknown. Consciousness is an evitable feature of the brains of some animals, including us, and it emerges because of the way the brains work. How conscious an organism is is thought to vary with the degree of complexity of parts of the brain. There is still a lot to learn about consciousness across the corner of the tree of life where animals are found.
Nagel’s question about what it is like to be a bat made me think about what it is like to be me. It is a surprisingly difficult question to answer, in part because I don’t have any comparison about what it is like to be anything else other than my younger self. Nonetheless, on balance I think being me is OK. The senses I use to experience the world – sight, hearing, touch, taste and smell – all work. My eyesight has never been particularly good and, as I’ve got older, I’ve had to buy reading glasses, but my poor vision hasn’t stopped me from experiencing many remarkable things. Similarly, my hearing isn’t as good as it used to be, but overall, I am still able to experience the world, and I get enjoyment from seeing nature, from listening to music, from human contact, and from good food and drink. The organs I have to experience the world are functioning.
My memory, something that is a key part of consciousness, is also functioning adequately. I have a good memory for facts, particularly about biology, and when I reminisce with friends and family I can recall past events as well as they can, even if sometimes I wish I could forget daft things I have done. My memory for faces is less good, but it has always been thus. When acquaintances used to greet me on the street, and we would have a conversation for a few minutes, Sonya used to ask me why I didn’t introduce her. The answer was always the same: I had no idea with whom I was chatting. She no longer asks the question, simply observing that I had no clue who they were. It is the same with famous faces. Much to my children’s chagrin, I had no idea I had been at a drinks event also attended by the singer Katy Perry until someone told me who she was. On the plus side, she didn’t know she was at a drinks party with me either.
Deciding how to act in a situation is also part of consciousness, and in pondering what it is like to be me, I thought about how I make decisions. I am good at making decisions, even if they end up being bad ones. I try to base all my decisions on information available to me and, having made them, I don’t worry about the decisions being less than perfect. If further down the line I wonder if I could have made a better choice, I try to learn from my mistake, thinking through where I made an error, but I do not get anxious about it. I tend not to panic, and I rarely get stressed by situations. Shortly after my brush with malaria in my youth, I got quite anxious about my mortality, but eventually realized there was little point worrying about it. I developed a strategy where I divide situations into those that I can control (my choices), those that I may be able to influence (other people’s decisions), and those that I have no impact on. I don’t stress about the latter two as what’s the point, and I am in control of the first. I do think carefully how I might influence other people’s decisions by working out what they will want from a situation, where our interests align, what leverage I might have, and what might appeal to them. This is part of being human, and something that all of us do.
As well as being me, I have also spent time trying to work out what it is like being Woofler. It is clearly quite different to being me. He is well equipped to experience the world, with excellent vision, hearing and smell. He also has an active memory, particularly of places where he has had success hunting squirrels and rabbits, but he also remembers other dogs and people, and some of these memories are long-lasting. His decision-making often fails to meet with my approval, but I do believe that not all his actions are pure instinct. He will not take food from a plate when someone is in the room, but as soon as they leave, he will. Woofler does not have the wherewithal to understand that by a process of elimination we can work out that it is he who stole the Manchego. He is also not allowed on our bed, and will not jump on it when we are in the house, but if we go out he makes a nest among the pillows and we hear the thump as he jumps down when we return home. The dog will also often look at me, perhaps trying to assess my likely response, before deciding on whether to do something that he knows will lead to me telling him off. This is usually having a go at other dogs that are normally sufficiently large they can beat him up, or rolling in fox poo. On some occasions he will walk on by, but often he appears to decide that getting in trouble is worth it. I am, of course, anthropomorphizing Woofler’s behaviour, but if we could measure consciousness, I am confident we would conclude he has a degree of it.
It turns out we can measure consciousness. Doctors do this by using brain scanners that detect patterns of electrical activity within the brain. Brain scans can detect electrical fields produced by large groups of brain cells in different parts of brains. Scientists have come up with ways of describing these electrical patterns by placing them on a scale from purely random through to highly structured and entirely predictable. The electrical activity of a waking, conscious brain when you are thinking about the challenges of daily life lies between these two extremes. If you could scan my brain as I write this paragraph, you would see electrical waves beginning in one part of the brain that go on to move to other areas, before fading out. The electrical activity in my brain is not random, with cells flashing on and off in an unpredictable way. The electrical patterns are also not highly predictable. It is not possible to say with confidence which cells will next become active because nearby neighbours are active now. Signals instead propagate in a particular location before moving as a wave, but not in a way we can always accurately predict. The waking brainwaves of a normal person that the hospital scanner detects are organized, but not rigidly so.
Our brain’s electrical activity changes when we do different things. When you initially go to sleep your level of consciousness changes and your brainwaves become more predictable and more localized. They slow down even further when you fall into a deeper sleep, before speeding up again later when a type of sleep called rapid eye movement, or REM, begins. Mind-altering drugs such as LSD also change the state of consciousness, with the electrical pattern in the brain becoming more random. The brain scans of anaesthetized people show even greater randomness than those on mind-altering drugs, with consciousness disappearing completely. Being anaesthetized is very different from being asleep, in that after you have slept you are aware that time has passed. If you are anaesthetized, being put under and waking up are experienced as instantaneous, and during that period your brain’s electrical activity is disorganized and random for much of the time. It is like being in a trauma-induced coma.