Most of us have had moments, if not days or even weeks during this pandemic we'd rather forget. And the good news is we will, says neuroscientist Dr Scott Small.
He studies memory and says forgetting is not only normal, it's also good for you. He tells Jesse Mulligan new neurological insights point to it benefiting us creatively and cognitively.
Photo: 123RF
It's when we can't forget that we run into problems, he says.
“Both memory and forgetting work in balance to allow our minds to be healthy mentally and even to be creative and smarter,” he says.
If we were not able to forget traumatic things that happened during the pandemic it could potentially burn our brains so hot it would lead to a form of post-traumatic stress disorder (PTSD), a condition of 'too-little forgetting'.
Our brains are designed to allow us to remember the important things that happened during these periods, he says.
“I emphasis that it’s so important to remember the facts, the details, the loved ones lost and the incredible mobilisation of society - New Zealand in particular was an exemplar as a society who responded well. We should learn from that to do better next time.
“But the best way we learn and remember those details is having our forgetting mechanisms prune away at some of the information that is not helpful, that is often detrimental."
Small says it had been conventionally believed remembering was always the hero, while forgetting was the villain who should be fought tooth and nail.
But he makes an important distinction, as does modern neuroscience. There is pathological forgetting that worsens over time, and normal forgetting, which is functional and healthy.
“The reason I wrote the book is there’s an emerging new science of normal forgetting that is showing our brains actually have separate mechanisms, one is dedicated to memory, the other to forgetting and then the studies that show you have to have both working in unison to live a happier, smarter and more successful life,” he says.
When the normal forgetting mechanisms break down through emotional trauma our bodies run into problems.
“It’s easiest to explain it most intuitively to understand that we need emotional forgetting," Small says.
"After all we often say we have to forget to forgive. Even in society the term amnesty for forgiving comes from the Latin, meaning to forget… PTSD is a disorder of our emotional forgetting gone awry.
“But what was really interesting to me was there are other disorders in which forgetting might go awry and that really teaches us that we need forgetting to think better, to be more creative.”
Fear memories are formed and stored in one part of the brain, the amygdala, he says.
“We know that those memories of the brain are hyperactive in disorders like PTSD, which illustrates what happens when your normal fear forgetting doesn’t work normally.”
The mechanics of our brain's capacity for memory involves the work of ‘nano machines’. These strengthen connections across neurons, they build up the synopsis which is the way neurons connect, he says. These also dissemble memories from the neurons in cells.
"That is a cellular definition of memory and for the longest time people thought that normal forgetting was just a breakdown of those memory nano machines," he says.
“But the most exciting part of the new science of forgetting is that scientists have discovered that there’s a completely different set of nano machines that are dedicated to the opposite, to the careful disassembly of connections. So, you have two separate mechanisms.”
The way we encode, store, retrieve and delete memory in a computer is analogous to how the brain does the same, he says.
“When anyone types something on their computer that’s a short-term memory. If you turn your computer off, you’ll lose that information forever.
“If you want to store that information for later, to memorise that information you need to use your save function, all computers have a version of that and when you do that what you’re basically doing is moving that information from your short-term memory to your hard drives.
Dr Scott Small Photo: supplied
“The other part of a memory machine particularly in a world where you have a lot of memories, you would need retrieval mechanisms but because most of our computers have hundreds of documents you also need tomorrow to have an ability to click ‘open’ to open up your files and find the right ones.
“So, you need an ability to store information, to retrieve information and now when it comes to the brain and this is simplification, but it’s one I used to teach neurologists and medical students. We have a region of the brain called the hippocampus, there are two of them, tiny structures deep in our temporal lobes and what they do simply stated is the click-save function.”
When you engage the hippocampus you can remember what you were talking about by moving into your ‘hard drive’. There’s another part of the brain located in the prefrontal cortex that we need to retrieve information on demand, Small says.
Sleep plays a vital role in this process. One of the insights of the new neuro-science is that we sleep in order to ‘smart forget’, a state of being that allows us to prune sensory information that would otherwise overwhelm us.
“Our brains are very eager to remember and ‘sticky’ with its desire to remember," he says.
"Over the course of eight to 12 hours each day you are exposed to a lot of information, even information you’re not conscious of…
“Your brain is always recording it and so you’d quickly run out of capacity and in fact if you examine people who are formally sleep deprived two or three days what they have is a brain exploding with two many memories.
“They can’t think straight, they’re inattentive and have hallucinations. We now know that one of the key purposes of sleep is to disassemble all that extraneous information that we don’t need.”
There are ways to speed up the process of functional 'good' forgetting, including the clinical use of the drug MDMA. But there are other more conventional ways of doing so, namely being connected to others and having meaningful connections to the external world.
“One of the most natural ways to accelerate ‘fear forgetting’ is to socialise," he says.
One of the worries about the pandemic period was those suffering emotional trauma had been asked to socially isolate, severely limiting the opportunities to connect with others.
Neurological insights point to a simple effective way to lose emotional trauma memories - to simply “live a life littered with friends, laughter and love," Small says.
It remains the most effective way of avoidance of 'looping' in fear memories, while causing the beneficial release of oxytocin, the brain's key chemical messenger of good tidings.
