Asa neuropsychologist I feel like I’m supposed to start this article with an attitude of deep respect for the brain. I might highlight the staggering number of neuronal connections (comparable in size to the number of stars in the Milky Way), or draw your attention to our increasingly sophisticated neuroimaging tools that are moving us closer to a complete picture of how the brain works, or signals simply to the deep-seated mystery of matter that gives rise to experience.
But while I often experience something of that reverence, I think it can be a distraction in our efforts to understand thought. I know from clinical experience that if the brain is damaged, so is our cognition, often in fairly regular and predictable ways. If you suffer damage to your frontal lobe, you will likely be less able to control your behavior. If you have a stroke in the affected part of your occipital lobe, your ability to make sense of visual information will be reduced. This brain-cognition link is an increasingly central tenet of our scientific culture, but with it comes a sense that we must understand ourselves as analogous to machines. Remove part of the hardware and the software is damaged.
However, the more time I spend with patients, the clearer it becomes that this is only part of the picture. One of my clinical tasks is to make unusual demands on people to erase cognitive symptoms that would otherwise go unnoticed. I once interviewed a man with severe memory loss after an injury caused by a lack of oxygen to his brain. His wife, also present at the interview, then took me aside. She was shocked. She didn’t realize how bad he was because just by talking to him, it wasn’t obvious that he had trouble making new memories. But when I asked him straight up why he was in the hospital, he didn’t have a clue. But to what extent have I manifested a problem and to what extent have I created one? Doesn’t our ability to think depend significantly on the demands our life makes on us?
Clinical work and life experience have revealed the ways in which, to a surprising extent, cognition is also something that goes on within our relationships with other people. It seems counterintuitive in the age of neuroscience, but I increasingly think that how cognitively impaired you are is a function of the social context in which you find yourself.
When I first moved into our current home with my young family, one of our elderly neighbors, Emily, came out to introduce herself. She was warm and friendly and silly with our kids in a sweet, over-the-top way. She would also repeat herself in conversation. Regularly. I wondered if she might have dementia and in time my impression was confirmed. She saw me almost daily when I walked the kids home from school, but every time we ran into her, she introduced herself as if we had never met before. It never mattered. She adored the children and they adored her. She laughed and sang with them, sometimes in the middle of the road. I was worried about her, but she always looked good and I knew her son lived nearby and took care of her basic needs.
In a sense, Emily was disadvantaged. She couldn’t remember who we were and she was socially uninhibited. But in another important way, the social context greatly enhanced her disability. Not only were her memory problems masked, but she found a space in which it was not important and where her joyful personality and infectious exuberance could flourish. This aligns with the views of some disability activists – the social model of disability suggests that people are disabled by barriers in society rather than by their physical or mental difference.
This is especially true for thinking. Think of those times when the presence of others reminded you of an appointment, a name, or simply encouraged you to refocus your attention. Our relationships provide a context in which to think, and a reason to think. We confer with each other to come to important decisions, talk through ideas to test them out. These processes are embedded in our political institutions. Democracies assume that meaningful moral and political decisions are best made through interpersonal processes of debate, rather than being left to individuals.
Developmental psychology has long recognized the social element in thinking. Almost a hundred years ago, the Soviet psychologist Lev Vygotsky noted that the emergence of individual thought can be understood as the internalization of interpersonal dialogue. Young children playing alone often talk to themselves and echo what sound like the instructions of adults. It clearly resembles the kind of verbal structure they were given by caregivers. Learning to think for yourself is a process of imagining the contributions of others.
The people around us can also impair us cognitively. A conversation partner who seems to want to avoid a topic can make it surprisingly difficult for you to think about it properly.
So while my brain is important, cognition exists outside my head. I make important decisions by consulting with those close to me. I use reminders and rely on family and colleagues to discuss plans. This kind of social process not only supports my cognition – it is my cognition. By extension, the degree to which a person is cognitively impaired is a function of the social supports they have around them. This is not to say that we can wish away the ill effects of brain injury and dementia. Damage to the brain will tend to lead to problems with thinking. But to talk about cognitive disability is to talk about something that could not exist in the same way without the other people who populate our lives.
Huw Green is a clinical psychologist and neuropsychologist at Addenbrooke’s Hospital in Cambridge. He is working on a book on neuropsychology and personality.
Further reading
Talking heads: The New Science of How Conversation Shapes Our Worlds by Shane O’Mara (Bodley Head, £22)
The Complete Guide to Memory: The Science of Strengthening Your Mind, Richard Restak (Penguin Life, £10.99)
Social: Why Our Brains are Wired to Connect, by Matthew Lieberman (Oxford, £12.99)
