Subliminal

psychologists in the 1920s had noted in studies of people’s memory for geometric shapes: if you show someone a shape that is irregular and jagged, and quiz them about it later, they’ll recall the shape as being far more regular and symmetrical than it actually was.²² In 1932, after nineteen years of research, Bartlett published his results. The process of fitting memories into a comfortable form “is an active process,” he wrote, and depends on the subject’s own prior knowledge and beliefs about the world, the “preformed tendencies and bias which the subject brings to the task” of remembering.²³

For many years Bartlett’s work on memory was forgotten, though he went on to an illustrious career in which he helped train a generation of British researchers to work in experimental psychology. Today Bartlett’s memory research has been rediscovered, and replicated in a modern setting. For example, the morning after the explosion of the space shuttle Challenger, Ulric Neisser, the man who did the John Dean study, asked a group of Emory University students how they’d first heard the news. The students all wrote clear accounts of their experiences. Then, about three years later, he asked the forty-four students who were still on campus to again recall that experience.²⁴ Not one of the accounts was entirely correct, and about one-quarter of them were entirely wrong. The act of hearing the news became less random and more like the dramatic stories or cliches you might expect someone to tell, just as Bartlett might have predicted. For example, one subject, who’d heard the news while chatting with friends at the cafeteria, later reported how “some girl came running down the hall screaming ‘the space shuttle just blew up.’” Another, who’d heard it from various classmates in her religion class, later remembered, “I was sitting in my freshman dorm room with my roommate and we were watching TV. It came on a news flash and we were both totally shocked.” Even more striking than the distortions were the students’ reactions to their original accounts. Many insisted that their later memories were more accurate. They were reluctant to accept their earlier description of the scene, even though it was in their own handwriting. Said one, “Yes, that’s my handwriting—but I still remember it the other way!” Unless all these examples and studies are just strange statistical flukes, they ought to give us pause regarding our own memories, especially when they conflict with someone else’s. Are we “often wrong but never in doubt”? We might all benefit from being less certain, even when a memory seems clear and vivid.

HOW GOOD AN eyewitness are you? The psychologists Raymond Nickerson and Marilyn Adams invented a neat challenge. Just think of—but don’t look at—an American penny. It’s an object you might have viewed thousands of times, but how well do you really know it? Can you draw one? Take a moment to try, or at least try to imagine one. What are the main features on each side? When you are done, have a look at the graphic on the following page and try this easier task: pick out the correct penny from among the beautiful sketches Nickerson and Adams kindly provided.²⁵

If you picked A, you would have been in the minority of subjects who chose the correct coin in Nickerson and Adams’s experiment. And if your drawings or imaginings have all eight features of the penny—features such as the profile of Abraham Lincoln on one side, and phrases like IN GOD WE TRUST and E PLURIBUS UNUM—then you are in the top 5 percent in memory for detail. If you did poorly on this test, it doesn’t mean you have a bad memory. Your memory for general features might be excellent. In fact, most people can remember previously viewed photographs surprisingly well, even after a long interval. But they are remembering only general content, not precise form.²⁶ To not store in memory the details of a penny is for most of us an advantage; unless we have to answer a question on a game show with a lot of money at stake, we have no need to remember what’s on a penny, and to do so could get in the way of our remembering more important things.

^{Reprinted from R. S. Nickerson and M. J. Adams, “Long-Term Memory for a Common Object,” Cognitive Psychology 11, 287–307, copyright 1979, with permission from Elsevier}

One reason we don’t retain details of the images that our eyes pick up is that in order for us to remember them, the details first have to have captured our conscious attention. But while the eye delivers a multitude of details, our conscious mind doesn’t register most of them. The disparity between what we see and what we register and, therefore, remember, can be dramatic.

The key to one experiment investigating that disparity was the fact that when you study an image with many objects in it, your eye will shift among the different objects displayed. For example, if an image shows two people seated at a table with a vase on it, you might look at one person’s face, then the vase, then the other person’s face, then perhaps the vase again, then the tabletop, and so on, all in rapid succession. But remember the experiment in the last chapter, in which you stood facing a mirror and noted that there were blanks in your perception during the time your eyes were moving? The researchers who performed this study cleverly realized that if, during the split second their subjects’ eyes were in motion, the image the subjects were looking at changed subtly, the subjects might not notice. Here is how it worked: Each subject started by looking at some initial image on a computer screen. The subject’s eyes would move from object to object, bringing different aspects of the scene into focus. After a while, during one of the subject’s numerous eye shifts, the experimenters would replace the image with one that was slightly altered. As a result, once the subject’s eyes settled on the new target object, certain details of the image were different—for example, the hats the two men in the scene had been wearing were exchanged. The great majority of subjects didn’t notice. In fact, only half the subjects noticed when the two people exchanged heads!²⁷

It’s interesting to speculate how important a detail has to be to register with us. To test if memory gaps like this also happen when the objects that change from shot to shot are the focus of attention, Dan Simons and his fellow psychologist Daniel Levin created videos depicting simple events in which the actor playing a particular character changed from scene to scene.²⁸ Then they recruited sixty Cornell University students, who agreed to watch the videos in exchange for candy. In a typical video, as depicted by the sample frames below, a person sitting at a desk hears a phone ring, gets up, and walks toward the door. The video then cuts to a view of the hallway, where a different actor walks to the telephone and answers it. The change is not as drastic as, say, replacing Brad Pitt with Meryl Streep. But neither were the two actors hard to tell apart. Would the students notice the switch?

^{Figure provided by Daniel Simons}

After viewing the film, the students were asked to write a brief description of it. If they didn’t mention the actors’ change, they were asked directly, “Did you notice that the person who was sitting at the desk was a different person than the one who answered the phone?” About two-thirds of them admitted that they hadn’t noticed. Surely during each shot they were aware of the actor and her actions. But they didn’t retain in their memory the details of her identity. Emboldened by that startling find, the researchers decided to go a step further. They examined whether this phenomenon, called change blindness, also occurred in real-world interactions. This time they took their experiment outdoors, onto the Cornell University campus.²⁹ There, a researcher carrying a campus map approached unsuspecting pedestrians to ask for directions to a nearby building. After the researcher and pedestrian had spoken for ten or fifteen seconds, two other men, each holding one end of a large door, rudely passed between them. As the door passed, it blocked the pedestrian’s view of the experimenter for about one second. During that time, a new researcher with an identical map stepped in to continue the direction- asking interaction while the original researcher walked off behind the door. The substitute researcher was two inches shorter, wore different clothing, and had a noticeably different voice than the original. The pedestrian’s conversational partner had suddenly morphed into someone else. Still, most of the pedestrians didn’t notice, and were quite surprised when told of the switch.

^{Figure provided by Daniel Simons}

IF WE’RE NOT very good at noticing or remembering the details of scenes that occurred, an even more serious issue is recalling something that never happened at all. Remember the people in my audiences who reported seeing in their mind’s eye a vivid picture of the word “sweet” on the list I had presented to them? Those people were having a “false memory,” a memory that seemed real but wasn’t. False memories feel no different than memories that are based in reality. For example, in the many variations of the word list experiment researchers have performed over the years, people who “remembered” phantom words rarely felt they were taking a shot in the dark. They reported recalling them vividly, and with great confidence. In one of the more revealing experiments, two word lists were read to volunteers by two different readers, a man and a woman.³⁰ After the readings, the volunteers were presented with another list, this one containing