Take “false memories.” False memories can be very dangerous, especially if they’re a false memory of something awful. There have been reports of arguably well-intentioned psychologists and psychiatrists trying to uncover repressed memories in patients who have seemingly ended up creating (supposedly by accident) the terrible memories they’re trying to “uncover” in the first place. This is the psychological equivalent of poisoning the water supply.
The most worrying thing is that you don’t need to be suffering from psychological issues to have false memories created in your head; it can happen to virtually anyone. It might seem a bit ridiculous that someone can implant false memories in our brains by just talking to us, but neurologically it’s not that far-fetched. Language is seemingly fundamental to our way of thinking, and we base much of our world view on what other people think of and tell us (see Chapter 7).
Much of the research on false memories is focused on eyewitness testimonies.31 In important legal cases, innocent lives could be altered forever by witnesses misremembering a single detail, or remembering something that didn’t happen.
Eyewitness accounts are valuable in court but that’s one of the worst places to obtain them. It’s often a very tense and intimidating atmosphere and the people testifying are made fully aware of the seriousness of the situation, promising to “tell the truth, the whole truth and nothing but the truth, so help me God.” Promising a judge you won’t lie and invoking the supreme creator of the universe to back you up? These aren’t exactly casual circumstances, and probably will cause considerable stress and distraction.
People tend to be very suggestive to those they recognize as authority figures, and one persistent finding is that when people are being questioned about their memory, the nature of the question can have a major influence on what is remembered. The best-known name connected to this phenomenon is Professor Elizabeth Loftus, who has done extensive research into the subject.32 She herself regularly cites the worrying cases of individuals who have had extremely traumatic memories “implanted” (presumably accidentally) by questionable and untested therapeutic methods. A particularly famous case involves Nadine Cool, a woman who sought therapy for a traumatic experience in the 1980s and ended up with detailed memories of being part of a murderous satanic cult. This never happened though, and she ended up successfully suing the therapist for millions of dollars.33
Professor Loftus’s research details several studies where people are shown videos of car accidents or similar occurrences and then asked questions about what was observed. It’s been persistently found (in these and other studies) that the structure of the questions asked directly influences what an individual can remember.34 Such an occurrence is especially relevant for eyewitness testimonies.
In particular conditions, such as the individual being anxious and the question coming from someone with authority (say, the lawyer in a court room), specific wording can “create” a memory. For example, if the lawyer asks, “Was the defendant in the vicinity of the cheese store at the time of the great cheddar robbery?,” then the witness can answer yes or no, according to what he or she remembers. But if the lawyer asks, “Where in the cheese store was the defendant at the time of the great cheddar robbery?,” this question asserts that the defendant was definitely there. The witness may not remember seeing the defendant, but the question, stated as a fact from a higher-status person, causes the brain to doubt its own records, and actually adjust them to conform to the new “facts” presented by this “reliable” source. The witness can end up saying something like, “I think he was standing next to the gorgonzola,” and mean it, even though he or she witnessed no such thing at the time. That something so fundamental to our society should have such a glaring vulnerability is disconcerting. I was once asked to testify in a court that all the witnesses for the prosecution could just be demonstrating false memories. I didn’t do it, as I was worried I could inadvertently destroy the whole justice system.
We can see just how easy it is disrupt the memory when it’s functioning normally. But what if something actually goes wrong with the brain mechanisms responsible for memory? There are a number of ways this can happen, none of which are particularly nice.
At the extreme end of the scale, there’s serious brain damage, such as that caused by aggressive neurodegenerative conditions such as Alzheimer’s disease. Alzheimer’s (and other forms of dementia) is the result of widespread cell death throughout the brain, causing many symptoms, but the best known is unpredictable memory loss and disruption. The exact reason this occurs is uncertain, but one main theory at present is that it’s caused by neurofibrillary tangles.35
Neurons are long, branching cells, and they have what are basically “skeletons” (called cytoskeletons) made of long protein chains. These long chains are called neurofilaments, and several neurofilaments combined into one “stronger” structure, like the strands making up a rope, is a neurofibril. These provide structural support for the cell and help transport important substances along it. But, for some reason, in some people, these neurofibrils are no longer arranged in neat sequences, but end up tangled like a garden hose left unattended for five minutes. It could be a small but crucial mutation in a relevant gene causing the proteins to unfold in unpredictable ways; it could be some other currently unknown cellular process that gets more common as we age. Whatever the cause, this tangling seriously disrupts the workings of the neuron, choking off its essential processes, eventually causing it to die. And this happens throughout the brain, affecting almost all the areas involved in memory.
However, damage to memory doesn’t have to be caused by a problem that occurs at the cellular level. Stroke, a disturbance in the blood supply to the brain, is also particularly bad for memory; the hippocampus, responsible for encoding and processing all our memories at all times, is an incredibly resource-intensive neurological region, requiring an uninterrupted supply of nutrients and metabolites. Fuel, essentially. A stroke can cut off this supply, even briefly, which is a bit like pulling the battery out of a laptop. Brevity is irrelevant; the damage is done. The memory system won’t be working so well from now on. Although there is some hope, in that it has to be a powerful or particularly precise stroke (blood has many ways of getting to the brain) to cause serious memory problems.36