What we Overlooked by David Eagleman
Intuition suggests that you open your eyes and voilà: there’s the world, in all its beautiful reds and golds, dogs and taxicabs, bustling pedestrians and blinking traffic lights. Vision appears effortless and, with occasional exceptions, faithful to what’s out there.
But intuition is wrong. The act of ‘seeing’ feels so natural that it is difficult to appreciate the vastly sophisticated machinery underlying the process. One third of the human brain is devoted to vision. Those neural resources perform an enormous amount of work to interpret the billions of light signals (photons) streaming into the eyes. Your brain disambiguates raw visual information by taking context into account, making assumptions, and aggressively filtering.
All this doesn’t happen effortlessly, as we can learn from patients who surgically recover eyesight after decades of blindness: they do not suddenly see the world; instead, they must learn to see again. At first the world is a buzzing, jangling barrage of shapes and colors, and even when the optics of their eyes are perfectly clear, their brain must learn how to interpret the data coming in.
So vision is not effortless. Nor is it faithful: if you ever believed that your brain gives an accurate representation of what is “out there” in the same way that a movie camera would, then David Brown’s untouched photographs should quickly disabuse you of that notion. Instead, your attentional machinery slowly crawls the scene, analyzing interesting landmarks until it detects what is useful for the next step. In the case of one of Brown’s visual moments in time, you might be in the middle of looking for the door to the shop, or where to step, or whether the traffic light is ready to let you cross. All the other details are unconsciously and nimbly filtered out.
The psychologist William James once pointed out that the art of being wise is the art of knowing what to overlook. And indeed, the brain overlooks most of the data hitting the eyes. It sieves the world. It reduces clutter. It uses a portion of the information that reaches it and blocks the rest.
Neuroscientists weren’t the first to discover that placing your eyes on something is no guarantee of seeing it. Magicians figured this out long ago, and perfected ways of leveraging it. Knowing where your attention is, magicians perform sleight of hand in full view. They aren’t worried that their actions will give away the game: they know your brain will only process the small part of the scene that they navigate you toward.
The discovery that you don’t see most of what’s out there helps to explain the colossal number of traffic accidents in which drivers hit pedestrians in plain view, collide with cars directly in front of them, and even intersect with trains. In many of these cases, the eyes are in the right place, but the brain isn’t seeing the stimuli. Vision is more than looking. This also explains why you probably missed the fact that the word “of” is printed twice in the triangle above.
Upon seeing David Brown’s photographs, most people express surprise that there is no manipulation of the scene. Brown has pointed the camera and shot and printed. He has frozen a moment of the world exactly as it hits our senses, capturing the great raw flood of data that normally undergoes unconscious winnowing and discarding.
To understand what his photos mean, consider their auditory equivalent: a conversation in a crowded coffee shop. All the sounds are converging on your eardrums: the voices, cup-clinks, laughter, honking, whirr of the coffee grinder. From the cacophony you extract the words of your conversation partner. The couple right next to you is pulling off the same feat with their own conversation. Out of the shared airwaves we each download our own conversation.
We believe we’re experiencing the world in all of its detail until it’s called to our attention that we’re not. Brown’s photographs, aside from being beautiful, ask us to slow down and take a closer look.