Alicia Head came from a wealthy Spanish background but something must have been missing in her life that money could not buy. She needed the attention and sympathy from others, and saw herself as the victim in a romantic tragedy set against the backdrop of the world’s worst terrorist attack. As Tania, Alicia would have lived out this lie if she had not been exposed. We will probably never know exactly why she created this charade but we must assume that this was the story she wanted to live. She may have come to even believe her own false memories, locked in her own fantasy world where she recast herself as a survivor against the odds.
We Are Our Memories
What is a memory? Can you hold one? Can you make one? Can you copy a memory? If we are our memories, can we be re-created? Memory is information stored as a pattern of electrical activity that ‘re-presents’ the original pattern at the time it was formed. This representation is what memories are – although human memories are not rigid but dynamic and continually changing as new information is encountered. If we are our brains and our brains are a network of physical cells connected together in a pattern of weighted electrical activity, then it really should be possible to copy a memory in the same way we can copy any information. We should be able to copy our selves.
The possibility of copying memory is at the heart of what it is to be unique. Imagine a machine that can copy any physical object right down to its basic atomic structure. It can perfectly duplicate any material thing irrespective of what it is made of or how complicated it is. Remarkably, engineers are working on precisely this type of machine known as a 3D printer. They typically work using a laser to scan a target object to calculate its dimensions and then relay that information to a jet-moulding device where liquid plastic is squirted to gradually build up a reproduction of the object. It’s the sort of technology that would make constructing colonies on distant planets more feasible without having physically to transport every object. At the moment the technology is fairly crude and solving how to build the internal structures of complicated objects made of different substances presents considerable challenges. However, just like the wooden block printing press of Johannes Gutenberg was considered a technological marvel of the fifteenth century and yet seems so primitive by today’s standards, it may simply be a matter of time before we can reliably manipulate matter to create accurate duplicates.
Whatever way we achieve it, let us assume that we have the technology to reliably duplicate anything. Imagine now that you step into the machine and an identical physical copy of you is created. What would this new you be like? Let’s also assume that you accept that there is no immaterial spirit or soul that cannot be reproduced. Would this identical copy be you? It’s the sort of question that has entertained philosophers and writers8 in one form or another for centuries though in recent years it has enjoyed a resurgence of interest because of rapid developments in technology such as gene sequencing and 3D printers. In all of these different scenarios, the same fundamental question of identity is raised: what makes us unique?
John Locke thought about this issue in the context of reincarnation9 – something that was of interest in the seventeenth century when it came to the notion of the immortal soul. Locke was of the opinion that conscious awareness of one’s own history was important when it came to unique personal identity. In short, he was thinking about the role of autobiographical memories in defining the self. Even if one does not believe in the immortal soul, modern adults also regard personal memory as the most important thing that defines who we are. In one study, adults were told about the unfortunate Jim who was in a serious accident where his body was irreparably damaged so that he needed a transplant.10 Only this was a science fiction story where the transplantation was very advanced. In one version of the story, Jim had lost all his memories but they could transplant his amnesic brain into either a robot or genetically engineered biological body. In another version of the story, doctors had managed to download all of Jim’s life memories before his brain died and could transfer them to the replacement body. After the transplantation, Jim’s original body was cremated. Adults were then asked if each operation was a success – was the patient still Jim?
The most important thing that determined whether adults considered the patient to be Jim was whether his memories had been saved irrespective of whether they were now stored in a mechanical body or a biologically engineered one. In fact, the biologically engineered body that contained Jim’s original brain was considered less Jim than the robot with his memories. In the absence of his memories, Jim was gone.
The relationship between memory and identity is an intuition that starts to emerge in children from around four to five years of age. We used duplication machine studies11 to see if children would think that a live hamster could be copied exactly and whether its doppelganger would have the same memories.12 To achieve the illusion of duplication we used two identical-looking Russian hamsters that were indistinguishable to the untrained eye. Once children had been convinced by the power of the machine to faithfully duplicate any toy, we introduced our pet hamster and proceeded to tell children about some of the unique physical properties the hamster had that could not be directly seen. We said it had swallowed a marble in its tummy, had a broken back tooth and had a blue heart. We then created some memories that were unique to the hamster. Of course, memories are also invisible but they are not physical like marbles and blue hearts. We showed the hamster a drawing by each child, whispered the child’s name into the hamster’s ear and got the child to tickle the hamster. These are all episodes that can be stored in memory. We then placed the hamster in the duplicating machine and after the buzzer sounded, we opened both boxes to reveal that there were now two identical hamsters. What would the children think? Would the invisible physical properties and the memories be the same or different for each animal? So we asked the child whether each hamster had a blue heart, a broken tooth and a marble in its tummy. We also asked about the memories. Did each hamster know the child’s name and what picture the child drew, and remember being tickled?
What’s your intuition? If you walked into the machine would the duplicate of you have the same memories? We conducted a straw poll online with sixty adults to get a sense of their intuition about duplicating hamsters and themselves in our machine. We asked whether the identical copy created by the machine would have the same body and memory? Around four out of five adults agreed that both the copied animal (84 per cent) and human (80 per cent) would have the same body. About half (46 per cent) thought the hamster would have the same memories compared to just over a third when it came to the human (35 per cent). So overall, adults thought that bodies were more likely to be copied compared to memories and this belief was stronger when related to humans compared to hamsters.
Back in the lab, we repeated the hamster study a number of times with variations to check the results and found the same basic pattern. About one third of children from four to six years thought that the second hamster was completely different on both mental and physical properties. Maybe they did not believe that the machine could copy something alive. Another third thought that the second hamster was identical on all properties. However, the interesting group was the remaining third of children who thought that the physical properties but not the memories were copied. In other words, they believed that the machine worked but could not copy the mind, just as the adults did.