Research shows we can’t trust our own memories.
Many of us probably think our individual experiences (sights, sounds, and feelings) are saved intact in our brains. A loose analogy might be a video camera recording everything it sees to a flash drive. When the time comes to remember something, we just play it back from the recording so we can know exactly what happened. This analogy is completely wrong.
A better analogy might be how an archaeologist operates. By surveying, excavating, and performing some analysis, an archaeologist reconstructs a likely theory of what might have happened in the past. The result is illuminating, instructive and possibly even correct – but it shouldn’t be considered complete.
In his book ‘Think: Why You Should Question Everything,’ Guy P. Harrison makes the case that memory is fallible. Your memory is not an exact recording of what happened and, no matter how well or how vividly you remember something, it may not be accurate. Here’s what Harrison writes about the reliability of your memories:
They [your memories] may come to you in great detail and feel 100 percent accurate, but it doesn’t matter. They easily could be partial or total lies that your brain is telling you. Really, the personal past that your brain is supposed to be keeping safe for you is not what you think it is. Your memories are pieces and batches of information that your brain cobbles together and serves up to you, not to present the past as accurately as possible, but to provide you with information that you will likely find to be useful in the present. Functional value, not accuracy, is the priority.
Harrison’s book references the work of Elizabeth Loftus, a cognitive psychologist and a leading expert on memory. Loftus has been an expert consultant in hundreds of legal cases and has raised awareness that eye witness testimony may not be reliable. In fact, she has shown memory is so malleable that someone can convince you that you remember an event which never happened.
In a famous experiment, Loftus was able to implant the specific memory of being lost in a shopping mall or a large department store at about the age of five. She asked participants about three actual childhood events and one false one. After a series of suggestions and some period of time, three out of the four respondents remembered being lost – even though the event never really took place. In a very real sense, Loftus changed their minds.
It’s worth watching Loftus’ TED talk:
Given my own digital-ness, I’ve decided the best analogy for your memory is a Wikipedia page. It’s an incomplete collection of historical tidbits created by multiple people with their assumptions and biases – and it’s constantly being updated as new information arrives.
No, my memory isn’t infallible but I don’t think I’ll resort to recording events on my own body like the lead character in the movie Memento.
Apparently the brain, when retrieving a memory, recreates and potentially alters/edits the memory itself from external stimulus about the incident. For example, witnesses recollect seeing a yellow cab on recalling an incidence when there was none after it was casually suggested in an interrogation! Most pristine memory is one never accessed, buried, forgotten. What irony!
Déjà vu may well be related to the two hemispheres storing the same information at marginally different times. A 60 – 100 millisecond or so difference may mean that a second transfer of a certain memory to the slower hemisphere means when it is passed to the designated storage location it matches an existing memory, and the mind interprets this existing memory as a prior occurrence