How many times have we found ourselves recanting a story of a past event we remember well when somebody suddenly butts in and corrects you? Don’t you just hate it when that happens?
So who’s right and who’s wrong? As far as you are concerned, it’s your memory of the event that is the accurate one, not the person who’s just about to ruin your story. And yet there’s always that nagging doubt the other person might just be right – it was a while ago after all, and you don’t remember the woman with the red shoes, and so you bow to social pressure and go along with the new version, if only not to appear argumentative. Maybe the other guy was right. Before you know it, you’ve done a bit of self-correction and a new memory has been formed.
I hate it when that happens and I always make a mental note to stick to the original story in future… but that’s not as easy as it might seem.
The truth is, your memory (or the other guy’s memory) is unlikely to be accurate in the first place and people regularly replace their stored memory with a memory that is recounted by a friend or colleague, especially if it’s someone you trust.
Too bizarre to be believed? In an effort to prove the point, researchers from University College London arranged for volunteers to watch a short documentary film. The volunteers were split into two groups. Three days later, they returned to the lab one at a time to take a memory test and answer questions about the film. They were also asked how confident they were in their answers. They were then invited back to retake the test while the researchers scanned their brain activity.
The second time the volunteers were tested, they were given some help – they were given the answers of the other people in their group, along with a selection of photographs. Planted amongst the supplied answers were some deliberately incorrect answers to questions the volunteers had answered correctly and confidently first time around.
At this point, the experiment turns into an object lesson in social conformity as each volunteer gave answers that were incorrect nearly 70% of the time.
But were the volunteers simply conforming to social demands, or had their memory of the film actually undergone a modification? To find out, the researchers invited the subjects back to the lab to take the memory test yet again, telling them that the answers they had previously been fed were not those of their fellow film watchers, but random answers generated by a computer. Some of the responses reverted back to the original, correct ones, but close to 50% remained erroneous, implying that the subjects were relying on false memories implanted in the earlier session.
Of course there is going to be some inaccuracy in any event because participants in tests such as these sometimes perform in accordance with what they perceive to be the demands of the experiment. In other words, they say what they think the experimenter wants to hear. This is especially so when the whole process is obviously an experiment and an experiment to do with memory to boot and takes place in a laboratory. This is why researchers often disguise the purpose of experiments – Milgram for example told volunteers his experiments were about memory when in fact he was in reality measuring social compliance and obedience.
However, an analysis of the brain scan data showed differences in brain activity between the persistent false memories and the temporary errors of social compliance.
The most outstanding feature of the false memories was strong simultaneous activation and connectivity between two areas – the hippocampus and the amygdala.
The hippocampus is known to play a role in long-term memory formation, while the amygdala, usually thought of as the part of the brain which creates and regulates emotions, plays a role in social interaction.
The researchers at UCL believe that the amygdala may act as a gateway which connects the social and memory processing parts of our brain. The amygdala might be required to approve some types of memories, giving the OK for them to become part of the long-term memory. It could be that social reinforcement could influence the amygdala to persuade our brains to replace an accurate memory with a false one.
This study was reported in the respected journal Science and is a masterpiece of detective work. But it does raise some serious questions concerning the validity of witness statements and testimonies in courts of law. If nothing else, the study demonstrated how incredibly easy it would be to fool innocent people into believing they have carried out a crime that never took place.
Derren Brown succeeded in doing this to an unsuspecting volunteer in one of his TV specials. The confused and distraught chap found himself in a mock police station admitting to a murder he had not committed.
In a series of experiments, psychologists found that during just three hours of interviews, normally sane adults could be convinced they had perpetrated a theft, an assault, or even attacked somebody with a weapon when they were teenagers. Using suggestive memory retrieval techniques, the researchers were able to trick 70% of the participants into believing they had committed an offence. In fact the effect was so strong that the participants ended up providing detailed descriptions of things that had never actually taken place.
This ‘magic’ figure of 70% keeps cropping up during these experiments and coincidentally, 70% is also the percentage of people who are suggestible enough to be hypnotised on a stage to believe a variety of nonsense, so I’m inclined to believe there is a connection here between the ability to implant a false memory and suggestibility. In addition, speaking with many of my hypnotherapist friends and colleagues, 70% is also the benchmark success rate in changing client’s beliefs and attitudes sufficiently for them to be considered ‘cured.’
I can also attest to the fact that there have been many, many cases worldwide where hypnotherapists have inadvertently (and occasionally deliberately) implanted a false memory in the minds of their subjects. This sort of thing used to happen a lot more than is generally recognised or admitted and has, in extreme circumstances, led to false memories of childhood sexual abuse, alien abduction and belief in past lives.
Dr. Julia Shaw, a researcher from the University of Bedfordshire is particularly concerned about the effect these sorts of interviews may have on false memories.
“Our findings show that false memories of committing crime with police contact can be surprisingly easy to generate, and can have all the same kinds of complex details as real memories. All participants need to generate a richly detailed false memory is three hours in a friendly interview environment, where the interviewer introduces a few wrong details and uses poor memory-retrieval techniques.”
After hearing a false account of their teenage crime, peppered with true details of their life at that time, the participants appeared to ‘internalise’ the fabricated story.
The researchers told a participant about two events they had experienced as a teenager – one was true and the other false. By adding true details taken from interviews with the student’s parents to the false events, the researchers were able to implant a series of false memories.
For the study, 60 students who had not been involved in any crimes were interviewed. The researchers contacted their parents and asked them to fill out a questionnaire about their child’s teenage years. The students then took part in three 40-minute interviews that took place about a week apart.
In the first interview, the researchers told the student about two events they had experienced as a teenager even though only one of these events actually happened. For half of the students, the false event related to a crime that resulted in contact with police – an assault, assault with a weapon, or theft. For the other half, the false event was emotional in nature, including an attack by a dog or the loss of a large sum of money.
When describing the false event to the student, the researchers included details about that time in the person’s life that were actually true, details which had been taken from the parent’s questionnaire. The participants were asked to explain what happened in each of the two events. If they had difficulty explaining the false event, the interviewer encouraged them to try anyway.
In the second and third interviews, the researchers again asked the students to recall as much as they could about both events. The students also described certain features of each memory, such as how vivid it was and how confident they were about it.
Dr. Shaw says this highlights the fundamental malleability of memory:
“This research speaks to the distinct possibility that most of us are likely able to generate rich false memories of emotional and criminal events. The findings have clear implications for criminal interrogation and other aspects of legal procedure, affecting suspects, witnesses, and law-enforcers, as well as for interviews that take place as part of therapy. Understanding that these complex false memories exist, and that ‘normal’ individuals can be led to generate them quite easily, is the first step in preventing them from happening. By empirically demonstrating the harm that ‘bad’ interview techniques – those which are known to cause false memories – can cause, we can more readily convince interviewers to avoid them and use ‘good’ techniques instead.”
Of the 30 participants who were told they had committed a crime as a teenager, 21 (70%) were classified as having developed a false memory of the crime. Of those who were told a story about an emotional event that had never taken place, 23 (nearly 77%) formed false memories.
“Memory researchers have long speculated that certain tactics may lead people to recall crimes that never occurred, and thus could potentially lead to false confessions. This is the first study to provide evidence suggesting that full episodic false memories of committing crime can be generated in a controlled experimental setting.”
This research should make us all think twice! If the innocent can be bamboozled into believing they had committed an offence, then what effect could these tactics have on witnesses and jurors? It should also give rise to concern about what happens in jury deliberations. If the figure of 70% is anywhere near accurate, it follows that 70% of jurors would be suggestible enough to have their memories of vital pieces of evidence modified. This would be especially true if the jury included one or two strong personalities with their own ideas about guilt and innocence. [I have long argued that juries are unreliable and that justice would be better served by two or more professional assessors sitting alongside a judge. The theory that a defendant’s fate will be decided by twelve good men and true is ludicrously outdated; for instance jurors are often prejudiced simply by a defendants looks or appearance.]
Greater care needs to be exercised by police and prosecutors, particularly if dealing with vulnerable and easily swayed or suggestible suspects. One step would be to teach awareness of the problem to interrogators. Another would be to remind courts and their officers – barristers and judges – that memory is a delicate state of mind and it is all too often fallible. This research could be the first step.
Copyright Andrew Newton 2015. All rights reserved.