On May 26, 2011, then-Ph.D. student Steve Ramirez, a neuroscientist, and his colleague at MIT, the late Xu Liu, placed a rat in a box in which it had never had a negative experience, then turned on a laser to deliver pulses of light through optical fibers surgically implanted into its neural tissue, awakening its memory of the shock it received in a completely different box. Just as the researchers had hoped, the rats froze in fear. The successful experiment was a major advance in the field of optogenetics, or the use of pulses of light to control neural activity, in this case to activate memory.
Ramirez currently serves as a professor of psychology and brain sciences at Boston University, and says in his new book: how to change your memory, He details how this research could lead to advances in psychotherapy and treatments for conditions such as depression and Alzheimer’s disease.
What is memory?
It is what connects and unifies our identity and sense of being. What we can live and reproduce is an autobiographical account of the world. Memories can also make our happiness and future livelihood possible. This is the brain’s way of accessing previous experiences so we can learn from them to take the next steps.
You call positive memories the most powerful biological tool the brain can use. What can memories give us?
If you think about the worst day of your life (loss, grief, or adversity of any kind), you can burst into tears within seconds. Or you might think about the best day you’ve ever had and become borderline euphoric. You feel dizzy, your pupils dilate, and your heart rate goes up for the whole nine yards. It’s amazing how something as seemingly simple as recalling going to soccer with my dad can change my biology. Could we harness the magic that positive memories can do in a neuroscientifically tractable way to provide an antidote to the brain? Could positive memories be another thing that can be used beyond the counter in a way to enable well-being? Your positive memories don’t have to be similar to mine, but we share the biological ability to have them. That’s what we want to leverage.
What role does your work play in that development?
We know from my lab and other research that we can artificially activate memory in rodents. This means that they can access and manipulate cells that are thought to contain memory, turning them on or off. The goal is to see whether it can be therapeutic or protective. There is a lot of untapped potential there.
Is that possible with optogenetics?
In 10 years or so we won’t be shooting lasers into the brain. But we will try to give you an idea of how memory works in a therapeutic setting. Is it possible to artificially trigger positive memories in rodents in a way that can guide humans, who cannot remember specific positive experiences or feel the benefits of those experiences, on how to do so? We will try to find ways to activate processes that may be impaired in people suffering from certain types of depression. Perhaps by adding recall of positive memories to our toolkit in a very guided way, or by identifying the conditions that must be met for positive memories to be accessed or have beneficial effects.
Many people find the effects on humans of turning positive and negative memories on and off to be quite scary.
That scary future is what I think about. We want to learn from history and from examples where new technologies are accessible to prevent misuse. We want to learn from the ways in which our culture was built to be reactive rather than actually prevent substance abuse or addiction. We know that memory manipulation is as easy to access as street drugs, and that you can walk into an alley and total recall Memories of separation. Ideally, skills should be kept in hospitals with the goal of restoring health, not recreation. Because there are red flags that we as a society are not equipped to manage.
Does that fear stop you?
The consequences of memory manipulation are just as great. But because we know how malleable memory is, we have continued to manipulate our own memories, and so far the fabric of our personal identity has not collapsed. So, as long as we have an ethically bounded goal, such as restoring health, I think we’re in business. If you do it for fun, you may run into problems because you are dealing with Pandora’s box.
Is there anything you would like to say to people who think memories should not be changed or erased?
I think that’s what I’m saying from a place where I’m not living with a mental illness tied to memories. When someone finds reminiscing debilitating, the idea of suppressing or deleting that aspect of the past becomes part of the conversation. Especially when it is something that is preventing a person from living the life they want to live.
Do you hope this research could lead to treatments that help prevent memory loss in conditions like Alzheimer’s disease?
I hope that this work will give us a much more concrete understanding of how something as seemingly transitory as memory has a physical and measurable basis. This allows us to tailor treatments that are much more effective. For example, it is hoped that reflecting on positive experiences for 10 minutes once a day could lower the likelihood of developing Alzheimer’s disease or some aspect of cognitive decline by 10%. I don’t know if Alzheimer’s patients will ever be able to remember one specific memory. But now that we’ve figured out how to protect the brain from the runaway train that Alzheimer’s disease can inflict, there may be treatments that generally make memories more accessible or make it a little less likely to get worse. If we can do that, I think we will have made progress in understanding how we can regain access to our memories and thus reconnect with who we are.
Shall we go there?
If you’re lucky. This stage of ignorance is where science exists. What led me to this work was the recognition that memory can be a form of guidance for how we live our lives. And if we could play the tape forward and imagine the end of our species and wonder what we wish we had done more of, I think science and research would be one of those things. Because they would have pushed back the time of death indefinitely.
