by itself is not the important factor. It also matters to whom, what, when, where, why, how it was said. Researchers have studied this by showing test participants various videos. In one video, a person speaks directly to the participants, and indirectly in the other video, by looking off to the side of the camera lens. This has an apparent effect on participants’ memories—not of the contents of the words spoken (which they are able to recall well under both circumstances)—but of the conversational situation. Most participants falsely recall having been directly addressed in the video, even when they were shown the video with the person speaking indirectly.7 While the hippocampus (if you recall, the memory center of the brain) was busy saving the contents correctly, a neighboring region of the brain, the anterior cingulate cortex (ACC), was responsible for the incorrect memories of the conversation and was excessively active in creating the false memories. We seem to take in information subjectively which we also do not save objectively.
To add insult to injury, emotions can lead to memory distortions as well, even in a simple DRM test. For example, if study participants are placed under emotional stress, such as giving a speech in front of an audience or having to take a terrible math test before they are instructed to memorize a list of words, they end up generating a large number of false memories.8
However, not all emotions have the effect of misleading our memories. Those types of emotions particularly predisposed to distort our memories tend to have two traits in common: the emotions are intense, and they also appear to match the information that we are supposed to remember. So, if we are in a good mood, we are more prone to falsely remember words from positive vocabulary lists. If we are in a bad mood and stressed out, it’s more likely that we will confuse lists of negative words.9 The best option would be to always be in a good mood when driving a car because this would enable us to be the perfect witness to traffic accidents. Although . . . research has pretty clearly shown that no one makes for a very good witness to an accident. This is due to another memory-related weakness of the brain.
The perfect memory crime
NOT ONLY DOES our brain have problems saving information, it also struggles to consolidate and retrieve the information from memory since it is susceptible to all kinds of misinformation, which it gladly accepts and adds to the previously existing memory. Our memory is thereby no longer true, though it may seem more coherent.
Just imagine, for example, that you are sauntering down the street when you suddenly hear the sound of squealing tires! You can only guess where the noise is coming from and you turn to look just in time to see two cars crashing into each other. Naturally, you voluntarily offer yourself as a witness to the scene, and this is where the problems start. You only really “half” experienced the crash. You believe you saw how the cars drove into one another, but you aren’t quite certain. It all happened so quickly. The brain really dislikes being in a condition of uncertainty (experts call this “cognitive dissonance”), and it is always trying to create a coherent overall picture. If what you perceived is fragmented, the brain will substitute in the rest of the information without you even noticing. Incidentally, this is the same brain that both generates a seamless consciousness and recalls false memories, so you also won’t be able to trace the origins of the false memories. In other words, it is the perfect memory crime story—in which the perpetrator (your brain) and the detective (your brain) are one and the same. Both players have very little interest in an explanation, meaning you won’t even think twice about the false memory.
Imagination is learning too
OKAY. SO, IF this is true, how should our brain be able to figure out which memories are true? Because the brain does not have any “criteria for truth,” it uses a trick in which it only classifies information as real if it activates a large portion of the brain. In other words, if something really did happen, it must have left large tracks of activity across the network. This is true in principle since authentic experiences trigger particularly intensive brain activity. If we merely imagine a photograph, the image processing areas of our brain are not as strongly active as they would be if we had the physical photo in our hands and were looking at it. The only problem is that these tracks of imagined memory activity are enlarged retrospectively until they artificially grow to be as big in our memory as real-life stories.
This phenomenon has been studied by showing test participants a series of different photographs from daily life situations.10 On the following day, the participants were reminded about the photos from the previous day by being told brief descriptions. What they didn’t realize, however, was that some of the descriptions were deceptive and falsely described the photos. Misled in this way, some of the participants formed false memories of the original photos and were no longer able to select the correct (original) images from a selection of photos. Some of the participants even claimed to have seen a manipulated version of an earlier photo. At this point, the level of brain activity triggered was very similar for true and false memories, with one decisive difference: the image processing area became more active with the correct memories (since the participants had, after all, really seen these photos). On the other hand, if a participant incorrectly recalled an image, the audio area of the brain was more active (because they mixed up the new deceptive information that they had been given verbally with their actual memory). In other words, if the total amount of activity covers enough area and is integrated into the brain, the memory is accepted as true, even if it is not.
This study significantly illustrates that memories are by no means static but, on the contrary, may be altered retroactively—and that this takes place every single time you bring them out and dust them off. Whenever a memory is in this state (of being hauled out and dusted off), it is particularly vulnerable to external influences. One elegant experiment was able to demonstrate this effect. Participants were first asked to memorize a list of words and then received a new list the next day. Before being given the new list on the second day, half of the participants were asked to try to remember the first list. On the third day, all of the participants were tested on their memories. Some participants who were once again asked to try to remember the very first list got it mixed up with the second list—but only if they had also been asked to remember the first list on the second day. Those who only concentrated on the second list on the second day (and were not asked about the first list) were able to separately recall both the first and second lists.11 The conclusion: a memory that is in the process of being recalled is in a fragile state and susceptible to corruption by new information.
Peer pressure memory falsification
AS IF IT wasn’t enough that we can make mistakes when saving information, as well as altering our memories each time we pull them out, we are also hardly able to defend our memories from being actively manipulated by external factors. Even if we are aware of this, we are powerless and continue to indulge in memory falsification. Peer pressure—the obligation to adapt our memories to those of other people—actively influences our memories.
In order to demonstrate this concretely, participants were shown a two minute documentary film and then asked a series of questions about the video.12 Directly after viewing the videos, participants made few errors in their responses and were correctly able to recall the details. Four days later, they could still remember the details and didn’t allow their memories to be swayed by any false information about the film. This changed, however, when participants were shown fake responses about the film made by other participants. Upon seeing the incorrect answers of others, participants were also drawn toward the wrong answers themselves. Even after they found out that the other answers had been contrived and didn’t have anything to do with the documentary, it was too late. The participants were no longer able to distinguish between truth and fiction. They had already modified their memories to fit the group. Interestingly, this peer pressure effect is conveyed through a brain region that neighbors the hippocampus, called the amygdala. This almond-shaped, dice-sized region showed a flurry of activity, particularly whenever the fake responses were shown along with a photograph of the other participants and not merely
