We are a story our brain tells itself. And our brains are habitual liars.
Take a moment to think of a cherished childhood memory. Try to recall it in detail. Think of where you were, who you were with, the sights, the smells, the tastes. Recall the sounds, like the wind in the trees, and how you felt. Were you happy? Anxious? Laughing? Crying?
We would all like to think that our memory is like a camera that records a scene, tucks it away in a corner of our brain, and retrieves it for playback when we want to relive that birthday ice cream or feel a long lost summer breeze on our cheeks. In a large sense we are what we remember, so memories are an integral part of who we are.
Unfortunately memory isn’t even remotely like a record/playback device. As neurologist and renowned skeptic Dr. Steven Novella puts it,
When someone looks at me and earnestly says, “I know what I saw,” I am fond of replying, “No you don’t.” You have a distorted and constructed memory of a distorted and constructed perception, both of which are subservient to whatever narrative your brain is operating under.
As I like to say, we are a story our brain tells itself, and our brains are motivated, skilled, pathological liars.
Lets take a look at memory, get a rough idea of how it works, and learn when and why we need to be cautious about trusting it. Functionally, the three parts of memory are encoding, storage, and retrieval.
As Dr. Novella points out, the problems begin with encoding, even before a memory has been stored. Our brain is constantly filtering information, and constructing its own reality. We are surrounded by detail. Take a moment right now to be aware of every distant sound around you, of all the leaves on the trees, fibers in the carpet, your breathing, and the sensations on your skin — all of it. Imagine dealing with all of that all of the time! Our brains evolved to construct a narrative of what’s going on, lending attention to what matters most. That thing over there that might be a predator is a more pressing matter than the sensation of every individual blade of grass you’re standing on. But just as things get lost, distorted, or added when your favorite book becomes a movie, the running story your brain puts together isn’t a faithful rendition. In fact, sometimes the circuitry in your brain that distinguishes what’s currently happening from a memory gets confused. This is the most likely explanation for déja vu. It’s a glitch in your own brain’s matrix.
And the first thing your brain does with most information is forget it.
By Marc Lallanilla, Assistant Editor LiveScience
Most people have experienced it at one point or another: déjà vu, the haunting sense that you’ve experienced something before.
French for “already seen,” déjà vu has been under investigation for years by scientists, who have yet to offer a complete explanation for the phenomenon, though it’s reportedly experienced by more than 70 percent of people at some point.
Recent research, however, has yielded some clues into what causes déjà vu. It seems to occur equally among men and women and across races, according to a 2003 study from the Journal of Nervous and Mental Disease, but déjà vu happens more often in people ages 15 to 25.
That fact has led some experts to believe déjà vu may be linked to neurotransmitters like dopamine, which are found in higher levels in teenagers and young adults — a hypothesis that gained traction after the peculiar case of a healthy 39-year-old man came to light.
The man — a doctor by profession — was fighting the flu by taking amantadine and phenylpropanolamine, two drugs known to increase dopamine activity in the brain. Within 24 hours of starting the drugs, he reported intense, recurrent episodes of déjà vu.
This case study, published in 2001 in the Journal of Clinical Neuroscience, reported that once the doctor stopped taking the drugs, his déjà vu also disappeared.
Déjà vu and epilepsy
Another insight into the causes of déjà vu comes from studies of epilepsy. There is a strong and consistent link between déjà vu and the seizures that occur in people with medial temporal lobe epilepsy, a type of epilepsy that affects the brain’s hippocampus.
The hippocampus plays a key role in . . .
- What Is Déjà Vu? (livescience.com)
- Wait, Have I Been Here Before? The Curious Case of Déjà Vu (blogs.smithsonianmag.com)
- Deja Vu (spiritualanalog.wordpress.com)