Memory and imagination
I’ve been thinking about things like this lately, so it interests me a lot. Though it probably would even if I hadn’t been thinking about it – it probably would have started me thinking about it.
Humans are born time travelers. We may not be able to send our bodies into the past or the future, at least not yet, but we can send our minds. We can relive events that happened long ago or envision ourselves in the future. New studies suggest that the two directions of temporal travel are intimately entwined in the human brain. A number of psychologists argue that re-experiencing the past evolved in our ancestors as a way to plan for the future and that the rise of mental time travel was crucial to our species’ success. But some experts on animal behavior do not think we are unique in this respect. They point to several recent experiments suggesting that animals can visit the past and future as well.
They have to go by themselves though. That’s what I was thinking about recently – the fact that they can’t discuss the past with anyone, or inform anyone about it, or be informed about it.
Endel Tulving, a Canadian psychologist, defined episodic memory as the ability to recall the details of personal experiences: what happened, where it happened, when it happened and so on…Episodic memory was also unique to our species, Dr. Tulving maintained. For one thing, he argued that episodic memory required self-awareness. You can’t remember yourself if you don’t know you exist. He also argued that there was no evidence animals could recollect experiences, even if those experiences left an impression on them.
Some researchers are skeptical, and have done experiments that they take to indicate something like episodic memory; other researchers are skeptical.
“Information is not really what characterizes mental time travel,” Dr. Suddendorf said…Episodic memory also depends on many other faculties that have only been clearly documented in the human mind, Dr. Suddendorf argues. He said he believes it evolved after our ancestors branched off from other apes. The advantage lay not in knowing the past, however, but in providing “an advantage for predicting the future,” he said…Daniel Schacter, a psychologist, and his colleagues at Harvard University recently studied how brains function as people think about past experiences and imagine future ones.
That interests me because I’ve long been interested in the fact that there is no real difference between remembering something and imagining it – no phenomenological difference. It’s interesting if remembering past experiences and imagining future ones are essentially the same adaptation.
Constructing an episodic memory causes a distinctive network of brain regions to become active. As a person then adds details to the memory, the network changes, as some regions quiet down and others fire up. The researchers then had their subjects think about themselves in the future. Many parts of the episodic memory network became active again.
There you go. And that’s why memory is so unreliable – it gets mixed up with imagining, and we not only don’t know how to disentangle them, we don’t even know when they’re tangled.
“Voyaging through strange seas of thought, alone” ?
I was similarly struck by the article, but I think that your remark that “there is no real difference between remembering something and imagining it – no phenomenological difference” may be misleading. I think there is, must be, a real difference, and I think that the difference is phenomenological, but not in the sense of an extra-corporeal phenomenon. I don’t doubt that episodic memory and imagination might largely occur in the same clumps of neurons, but I think there is reason to expect that, at least in some of us, there are additional bits of grey matter or different elecro-chemical impulses that are analogous to a faculty of discriminating between episodic memory and imagination.
It is my hypothesis that some of us, most of us or perhaps all of us, have some kind of intermittent, but frequent, mechanism for checking our most recent beliefs against some kind of background weltanschauung, and that this mechanism is remarkably reliable – but nevertheless fallible. I was once involved in a discussion thread on the blog ‘Fake Barn Country’ concerning the possibility of imagining something and simultaneously disbelieving it. It strikes me that there are similarities with episodic memory. Could one remember something whilst disbelieving it? I think not, but in the case of an imagined episode I would expect our cognitive ‘reality checking circuit’ to kick in sooner or later and let us know whether our recent train of thought had been running along the tracks of our general expectation or had jumped the rails and veered into the fields of imagination. Does anyone think this is either blindingly obvious or wildly wide of the mark?
“I’ve long been interested in the fact that there is no real difference between remembering something and imagining it”
Interesting. Very occasionally, I faintly seem to “remember” something that actually was part of last night’s dream – which can be quite confusing. Of course, here the remembering is really remembering – it’s just a memory of an imagined experience rather than a “real” one.
More to the point, there’s the way in which people with dementia will supplant lost memory with imagined memory – in a way constructing enough of one to get by on. Probably it doesn’t necessarily take dementia for something like that to happen.
So I’d tend to agree that there is no phenomenological difference – we usually tend to be able to distinguish between imagination and memory, but there are areas where it becomes problematic. Agreed on the problematic consequences which you apply as well. If memories are basically imaginary (and they are: we focus on some details, neglect others, slant the whole experience in some way) then the whole idea that we have this tape recorder in our head which can be played off under therapy or hypnosis becomes madness.