The first book by Oliver Sacks that I read was The Man Who Mistook His Wife for a Hat. That was a long time ago, and I was young enough that the stories, while fascinating, were abstractions to me. But now, older if not necessarily wiser, when reading The Mind’s Eye I was thinking, “Oh great, more things that can go wrong, including parts of our brains starting to atrophy, progressively and incurably. What else is the universe going to throw at us?”
This book is about people who lose one of their senses, how it affects them, and the sometimes remarkable compensatory abilities they develop. After suffering a devastating loss it would be understandable if they were to sink into deep depression, but these people are fighters, inspirational in their determination to carry on. Also inspiring is the hard work of their therapists, including a woman who is herself quadriplegic, but developed an ingenious method for people who have lost the ability to read and write to communicate with those around them.
To those on Goodreads reading is a large part of who we are, and not being able to read would be like not being able to see. We learned to read at such a young age that to us it seems like the most natural thing in the world: we look at words and meaning floods into our minds. It is never actually that simple. Evolution may have wired our brains for speech, but reading and writing (which are two different skills) are too recent for natural selection to have adapted them. Brain scans show that reading is a distributed process in our brains, taking place in a number of different areas which were originally used for other things but have been repurposed for literacy. As Sacks says, “We think of reading as a seamless and indivisible act, and as we read we attend to the meaning and perhaps the beauty of written language, unconscious of the many processes that make this possible. One has to encounter a condition [resulting in its loss] to realize that reading is, in fact, dependent on a whole hierarchy or cascade of processes, which can break down at any point.” (p. 50)
The key word here is aphasia, an inability to comprehend language, and it is not an extremely rare condition. “Aphasia is not uncommon: it has been estimated that one person in three hundred may have a lasting aphasia from brain damage, whether as the consequence of a stroke, a head injury, a tumor, or a degenerative brain disease.” (p. 32)
One of the case studies in this book involves a writer who woke up one morning and found that a stroke had left him aphastic. Initially he could look at letters and know they were letters, but they appeared to be in some incomprehensible alphabet. Later, through hard work and therapy he regained the ability to recognize individual letters and then, with great difficulty, to piece them together into words. He even managed to work around his loss and write more books, a tribute to his determination.
Not all of the chapters in this book are about Sacks’ patients. He also discusses his own limitations in perceiving the world, one of them neurological, and the other physical. He had a lifelong case of severe prosopagnosia, which is the inability to recognize faces. His own assistant, who worked for him for years and whom he saw almost every day, would have been unrecognizable if he were to pass her on the street. There are certainly worse conditions to have, but how odd it must be to exist in a world where everyone is a stranger, always living among a sea of anonymous faces.
His other disability resulted from melanoma in his right eye. Surgery to correct it left him with only peripheral vision, and then later, bleeding from the surgery caused him to lose sight entirely in that eye. He gives a cautionary reminder to his readers that he had skipped his annual eye exams for almost three years, and had thus missed the opportunity to find the tumor when it was smaller and might have been treatable with less severe consequences.
His loss of vision in one eye left him without the ability to see in three dimensions. People like him see the world as flat, and he uses a good example when he describes seeing himself in the mirror; his image did not appear to be behind the glass, but on it, with no depth of field. As I read about this, I found myself looking around the room, noting how normal everything looked: the clock, the windows, the lamp, all in their proper places, all automatically placed in my mind’s eye at their respective distances, and then I noted that this was all just a representation of reality that my brain had constructed, and which could be interrupted or lost at any time.
I would have liked for Sacks to have spent more time exploring what we know of healthy brains based on damaged ones. He occasionally makes remarks about how we interpret the world around us that made me want to learn more, such as, “The recognition of representations may require a sort of learning, the grasping of a code or convention, beyond that needed for the recognition of objects. Thus, it is said, people from primitive cultures who have never been exposed to photographs may fail to recognize that they are representations of something else.” (p. 18) That is a fascinating idea, and made me want to look for a book that expands on the idea of how the mind constructs coherent models of reality.