The Memory Illusion

by Dr Julia Shaw

  The particular island of genius a savant displays is clearly incongruous when we consider their mental capacities in general. For example, according to his mother Francis Peek, and author Lisa Hanson,19 Kim Peek (the real Rain Man) had impairments in his ability to communicate socially, but had islands of genius expressed as an encyclopedic knowledge of music, geography, literature, history, and a number of other areas. The question, much like with HSAMs, becomes why and how individuals like Peek have such amazing memories.

  This phenomenon of unusually enhanced memory is still referred to hyperthymesia when it occurs in conjunction with abnormal conditions such as brain damage or developmental difficulties. It is essentially the opposite of amnesia.

  Autism has long been clearly linked to amnesia as well as hyperthymesia. In 1985 an autopsy on an autistic man by medical doctors at Massachusetts General Hospital, Margaret Bauman and Thomas Kemper,20 revealed the first glimpse that autism may be linked to abnormalities in the hippocampus, a part of the brain we have already mentioned as being associated with memory. Many researchers today continue to argue that this is the case; a team including medical researcher Simon Maier at the University of Freiburg, for example, found support for increased hippocampal size in individuals with autism spectrum disorders.21 In a review of the science on this topic, neuroscientist Dorit Shalom from Ben Gurion University in Israel proposed in 200922 that in autism there is damage to part of the brain most often associated with episodic remembering of personal events, the limbic-prefrontal system, but other types of memory remain spared. This means that people with autism are going to more generally have worse memories of their own lives. This is different from what we would usually classify as amnesia, as it is not a complete lack of ability to form these memories, just a deficit.

  Dorit also claims that high-functioning autistic individuals, who only have minor social disabilities but otherwise function normally, appear to rely particularly heavily on their semantic memories, while those with low-functioning autism rely mostly on their basic perceptual systems. What this means in practice is that those with high-functioning autism may tend to have a proclivity for remembering facts, while those who are low on the spectrum have difficulty remembering much of anything, leading to restricted and inflexible cognitive abilities.

  It seems that the memories of savants are essentially the reverse of the memories of HSAMs. While HSAMs have incredibly enhanced memory of their own lives, but do not display any particular excellence in other kinds of memory, savants appear to lack autobiographical memory, but have an incredible memory for non-autobiographical things – facts and information. The memories of HSAMs are almost exclusively personal, while the memories of savants are almost exclusively impersonal. They are the yin and yang of incredible memory. Maybe to have one type of extraordinary memory we cannot have interference from another type of exceptional memory? Or, perhaps due to limited cognitive resources, our brains simply cannot excel at remembering everything.

  Further, what the autistic deficit in autobiographical memory means for the notion of the self and personal identify is also still a mystery. It seems intuitively likely that lacking autobiographical memory capacity may leave an individual perceiving themselves – and indeed other people – differently than the rest of us do. In support of this, individuals with autism are thought to have an underdeveloped theory of mind, or as Simon Baron-Cohen, Professor of Developmental Psychopathology at the University of Cambridge, has called it, mindblindness,23 meaning the inability to understand the mental states of others and to appreciate that other people may have different emotions and desires from your own. Perhaps without the wealth of information from our own autobiographical memories to draw on it is harder to figure out not only our own selves, but also the selves of others.

  Poison from the past

  Because HSAMs and other amazing rememberers are such a newly identified group, we truthfully do not know yet why their memories work the way they do – we can only theorise. Savants are also extremely rare, and so the same is true of them. But one thing is clear: while you and I may see HSAMs as having an enviable superpower, for most people who actually possess it, having an exceptional memory appears to be more of a curse than a blessing. Just ask HSAM Alexandra Wolff, who said in an interview with NPR,24 ‘It seems like you hold onto everything, and it seems like you’re just stuck in the past all the time.’

  Or HSAM Joey DeGrandis, who told New York Magazine,25 ‘I don’t even know what it means when someone says, “I’ve let that go – it’s out of sight, out of mind …”. The other HSAMers I have met seem to share similar traits: the need for approval, seeking attention, putting themselves out there a little bit, maybe being a little sensitive to criticism and having issues with depression and closure. They are all contributing members of society and it doesn’t seem like any of us are so hindered that we’ve ceased to function like a normal person, but there is a commonality in that we seem to be a little more sensitive and we sometimes have trouble with our emotions and we can be more prone to depression and it must be related to the fact that we remember in the way we do.’

  Some researchers argue that the abilities of HSAMs are so rare because evolution has selected this feature out as it is actually an evolutionary disadvantage to remember everything.

  You see, forgetting is generally considered to be important. According to neuroscientist Dr André Fenton at New York University, ‘forgetting is probably one of the most important things that brains will do’.26 Much like we need to be able to suppress distractors in our environment all the time – filtering out the conversations around us, the sights and sounds, other browser windows we have open, and so on – in order to focus on whatever task we may need to perform, we also need to avoid getting distracted by memories that are irrelevant to our current situation.

  In a neuroimaging study led by Brice Kuhl at Stanford University, published in 2007,27 researchers looked at the importance of the suppression of irrelevant memories. They had their participants study pairs of words that didn’t naturally link, such as tomato–chips, bike–chair, water–night. Next, they showed participants one word and asked them what word it had been paired with. So if presented with tomato, the participants would ideally say chips; if presented with bike, ideally they would say chair. Crucially, the researchers would leave some word pairs out. Then, after this retrieval practice, the participants were tested on all the word pairs, while having their brains imaged by an fMRI machine.

  The researchers found that the rehearsed pairs, those pairs that had come up during the practice session, corresponded with reductions in activity in the parts of the brain responsible for detecting and dealing with memory competition. In other words, the participants in their study needed to filter out less distracting information to find the word they needed. This is evidence that the more information we forget related to a concept, the stronger links between the remaining relevant information become.

  As the researchers put it, ‘These findings indicate that, although forgetting can be frustrating, memory might be adaptive because forgetting confers neural processing benefits.’ We become more efficient rememberers if we filter out the less relevant information. It allows us to become better at remembering the important stuff in life. So, if we cannot filter out memories that are less important, as HSAMs seem to be, we may be at a disadvantage.

  Another situation in which we can see the downside of a memory that is difficult to forget is in PTSD, post-traumatic stress disorder. One of the major symptoms of PTSD, according to the DSM-V (Diagnostic and Statistical Manual of Mental Disorders), the leading handbook for clinical psychologists, is intrusion: ‘Recurrent and intrusive distressing recollections of the event, including images, thoughts, or perceptions.’ Most people would agree that if something terrible has happened, we may not wish to have an exceptional memory of it, especially one that is hard to suppress.

  According to a team of researchers led by psychiatrist Olivier Cottoncin from the U
niversity of Lille, France, people suffering from PTSD often experience a disturbance in the working of their autobiographical memory. They become overly fixed on a particular event. In a paper they published in 2006,28 they supported this claim with an experiment involving 30 patients with PTSD, using another word-list paradigm. However, instead of using pairs like the Stanford fMRI study, they used what is known as a directed forgetting task. This is an experiment where participants are shown a series of words, and after each one is presented, are instructed to either remember or forget that particular word. Afterwards they are immediately asked to report as many of the words they were instructed to remember as possible, while omitting all those they were asked to forget.

  In Cottoncin’s study, those suffering from PTSD ended up remembering significantly fewer words overall, and fewer of the words they were instructed to remember, than individuals who did not have PTSD. They also remembered more of the irrelevant words. What the team inferred from these results was that those with PTSD were less able to forget irrelevant information, leading to problems remembering the items they were actually supposed to. PTSD sufferers showed an increased deficit in the inhibitory processes associated with memory compared to the rest of us; that is, they were less efficient rememberers because their brains were bogged down with parts of their past they were unable to forget. Causally, it is difficult to say whether these individuals had PTSD in the first place because they were already worse at forgetting things, or whether experiencing a trauma rewired their brains.

  Overall, from looking at all the various cases of exceptional memory, one thing is certain: no one has an absolutely perfect memory. Indeed no one can have a perfect memory. But we should be grateful for that. We may not all have powerful recall for particular kinds of information, like HSAMs or savants, but when our memories are working at their best we remember most things pretty well. Functionally our memories turn out to be well rounded, able to deal with the many different kinds of information that are launched at us on a daily basis.

  What is more, our memories are built to forget. Forgetting is a beautiful mechanism that trims down our neuronal connections to make our brains more efficient at storing only the information that is most important to us. When we realise the beauty of forgetting, we also see that perhaps the ability to remember everything would be a super-burden rather than a superpower.

  5. SUBLIMINAL MEMORIES

  Baby learning, psycho-phones,

  and brainwashing

  Why we need to pay attention in order to form memories

  IMAGINE A WORLD where we could flick our smartphones to ‘learn Spanish’, go to sleep, and – bam! – wake up with a whole vocabulary course completed. Or, perhaps next time we want to completely forget an unpleasant event, just walk over to our local hypnotist and ask for the memory manipulation special to have the offending engrams removed. How about giving up smoking or achieving sustainable weight loss? No problem – just some music with backward messages stealthily embedded within it that says smoking and sweets are bad.

  There are a lot of products on the market touting the effectiveness of hypnosis for helping us change bad habits, or of audiotapes that can ‘reprogram’ us while we sleep. However, in order to understand the very notion of such claims we must first understand the role of attention for memory.

  On my first day in the first memory class I ever took at university I remember the professor picking up a piece of paper. He waited for the eager class of 150 students to settle down, then held up the unfolded sheet of paper and proclaimed: ‘This is what happens in the world around us.’ He then folded the paper in half. ‘This is what you perceive.’ He folded the paper in half again. ‘This is what you pay attention to.’ He folded the paper in half again. ‘This is what you are interested in.’ Another fold. ‘This is what the brain makes into engrams. And this …’ (he folded the paper one final time; it was now a fraction of its original size) ‘is what you are able to access and recall later on.’

  The confused class looked around at each other. What was his point? He broke the silence by saying ‘Let’s make sure this piece of paper is as big as possible when we are done with this class.’ It was a clever opener. He had used the piece of paper as a memory aid to help the class remember some of the core components of the memory process itself. And right after the very fundamental principle that we need to perceive things in order to encode them – in other words, we need to see, hear, feel, smell or taste things – he had placed the importance of attention. Why did he do this? Because attention is a prerequisite for memory formation. Put simply, attention is the glue between reality and memory. If we do not pay attention to a stimulus in our environment, we cannot remember it. It’s as simple as that. Attention and memory cannot operate without each other.

  This basic principle is even true for things that we are actually looking at, or otherwise perceiving, but are not actually paying attention to. Think of those times in school when you were looking at the teacher but were thinking about something completely different and were unable to process – never mind later recall – what the teacher had actually said.

  The importance of attention for memory even helps to explain why we are often bad at remembering people’s names when we are first told them – because in the process of meeting someone new we are often dealing with so many new pieces of information at once that we do not pay sufficient attention when they say their name. We are busy attending to other things: Nice tie. Where is his accent from? He seems nervous. I wonder if he is single. What is that cologne? Everything but his name.

  Okay, I just boldly declared that memory needs attention, and as a general rule of thumb that’s true. However, if I’m being completely honest, there is a research study that appears to threaten this view. In 2012 a team of researchers led by neurobiologist Anat Arzi at the Weizmann Institute of Science in Israel1 looked at memory during an inherently inattentive state – sleep. The results of their study, when published in the journal Nature Neuroscience, were given a straightforward title: ‘Humans can learn new information during sleep’. The team found that participants who were exposed to certain smells accompanied by sounds during sleep formed associations between them, so that when exposed to the same tones during waking hours, they started to sniff as if searching non-consciously for smells. The participants did not have memories that they could intentionally recall of ever having been exposed to the smells, so when a particular tone was played they could not correctly specify the smell with which they associated it. The researchers argued that they had made very simple memories, as evidenced by the sniffing behaviour they displayed.

  Somehow this basic association formation seemed to have overstepped the usual attention requirement for memory creation. Many researchers, in fields as diverse as child psychology, medicine, psychotherapy and cognitive science, have tried to achieve similar results. Some of these have found ways of understanding our attentional process that can help us to maximise our ability to remember information, and many have found themselves debunking common memory myths. So, what do scientists today understand the precise nature of the link between attention and memory to be? Let’s start at the very beginning, by looking at attention in babies.

  Baby Einstein

  Everybody loves babies. At least it seems that way, as photos of friends and family with their tiny self-replicas certainly seem to pop up often enough. People share their babies’ accomplishments as if it is the first time humanity has ever witnessed the development of an infant. Look at his first smile! His first drawing! His first word! Sometimes it seems that in this constant chatter of tiny baby updates, both in real life and online, everyone is trying to convey just one simple thing: ‘Look at what a wonderful, astounding, unique creature my baby is!’ And while it’s easy to roll your eyes at it all, the truth is that babies are pretty amazing, already well on their way to utilising the intelligence we pride ourselves on as a species. But in order to do that they need to learn, and learning is inherently
a memory process – to gain lasting effects from exposure to things in our environment we need to be able to remember them.

  And if you’re one of those parents who are anxious that their child should be brainier than its peers then you may be tempted to turn to products marketed specifically at the so-called diaper demographic, touting brain development and memory skills for children under two. People hear from a study published in 19932 that listening to Mozart improves college students’ test scores, so they play Mozart to their babies to help them develop their problem-solving abilities. They find videos that claim to train their babies’ intelligence, teaching them how to understand the world and equipping them with ways of thinking. They invest in sign language skills for babies. There’s a whole world of baby learning, supposedly all based on solid science.

  The companies that market baby media of this sort often provide testimonials from parents that show just how much their little Jim or Janet benefited from the experience. In these, the parents often mention the exceptional amount of attention that their infants pay to the videos. If attention equals memory, then this may be the key to their effectiveness, right?

  Wrong. While attention is (apart from in exceptional circumstances) a prerequisite for memory formation, at the same time attention does not necessarily mean a memory will form. And when talking about attention in babies we often refer to just one thing – how long a baby looks at something, known by researchers as attentional gaze. As we know from our own lives, simply looking at something for a period of time by no means guarantees that we are giving it our full attention; we also need to be internally focused on the information that we want to encode and remember, we need to recognise patterns, and we need to be able to filter out all the other unimportant information that we may be taking in at the same time.