In the film “Eternal Shine of the Mind”, the characters became part of a scientific experiment which would let them erase their memory. But what if, instead of erasing memory, you would be able to restore it? One prominent neuroscientist is working on making this possible.
Theodore Berger from the University of Southern California has been working on developing an implant, which will be able to restore memory, replacing a section of the hippocampus in the human brain. Berger described his research findings at the International Congress “Global Future 2045”, which took place in New York on June 15 and 16 of this year. This device has already been successfully tested in rats and monkeys, and is currently being tested in humans.
Hippocampus is a structure located deep inside the temporal lobe of the brain, responsible for transforming short-term memories into long-term recollections. Epilepsy and other neurological disorders can damage hippocampus, preventing individuals from generating new memories.
The device developed by Berger and his colleagues can replace damaged parts of hippocampus and even improve functioning of a healthy hippocampus. A microchip with electrodes is implanted into hippocampus and records signals representing short-term memories, then these signals are sent to a computer where they are mathematically converted into long-term memory, and then sent back to a second set of electrodes, which stimulates another part of hippocampus.
The purpose of this device is not to identify discrete memories, but to learn how they are converted into long-term recollections. “It’s like rules used for translation,” explains Berger, adding that memories are equivalent to words, and their mathematical conversion is similar to the process of translation.
Berger’s team has tested this device on rats trained to perform a simple memorization task. Each rat with an implant was placed in a chamber with two levers. At first, the rat was shown one lever on one side of the chamber, and the rat was trained to push on it. After a while, two levers on both sides appeared, and if the rat pressed the second lever, it would get some water. Successful completion of this task required the rat to memorize which lever to push first.
To test memory implants, the researchers injected rats with a chemical disrupting the natural functioning of memory, and the experiment with lever was repeated. The rats were still able to use the levers correctly, and this meant that they were still capable of generating new memories. In other words, the implants help rats to remember required information.
Interestingly, the researchers have also found that the implants were able to improve memory function even in rats which had not been treated with chemical injections.
Berger’s team has found that the device perform just as effectively in monkeys. Presently, they are conducting studies in patients with epilepsy. According to Berger, so far they did not collect enough data, but, in his opinion, the results of this experiment will be remarkable.
He adds that the main problem is to determine how to mathematically convert short-term memories into long-term recollections, because you only have one chance to do it correctly.
According to Berger, an important factor for the efficiency of this device in patients is the ability of patient’s brain to adapt, or its plasticity. “A person has more impact on the device than the device has on a person,” he says.
The ultimate goal of the researchers is to create a device that can restore lost or improve normal human memory. But the philosophical aspect of the manipulation of the memory is immense: if people can control their memories, will they also be able to alter them?
What are the consequences of such transformation for people themselves? Can memories be decoded and used as evidence in court? Or will people be able to erase their memories and replace them with completely different ones? At present time, these questions still remain unanswered.