When he was nineteen, Ireneo Funes had a terrible accident: he fell from his horse and was knocked unconscious. Upon waking, he soon realized that something very weird had happened to his senses and memory.
Funes found he could perceive far more than he used to: every single leaf of a tree, every single word of a conversation, and every single detail of his neighbors’ houses. Also, he could remember all of this. Vividly and effortlessly.
“His perception and his memory were infallible”, says the narrator of Jorge Luis Borges’ fictional story Funes the Memorious.
Sounds cool, right?
Yet, Funes’ superpowers came at a high price.
His nights were sleepless. He was endlessly haunted by memories he could not help but recall, conversations played over and over in his head until they became meaningless. Everything was so detailed. Way too detailed. Abstract thinking became impossible.
Luckily, our perception and memory are not much like Funes’.
When we go hiking, we usually see paths surrounded by trees, flowers, mountains in the background, and maybe some waterfalls. We do not see − or at least we do not immediately and often see − small insects hanging out on the surface of a pond, a tiny mark on the petal of a flower, or the shape of a particular wave in a river.
And when we recall our hikes, we do not seem to remember every tiny detail. Either because we have not perceived these details and they did not make it into our memory. Or, if we have perceived them, because they got lost over time. For example, because they were not interesting or because there is nothing in our environment that reminds us of them.
Much of what we experience seems to be forgotten in the very act of experiencing. Or it seems to be forgotten later on, in all that happens in our memory between the original experience and when we try to remember it.
It’s good news that we forget more and perceive less than Funes. We sleep more and suffer less. And the way we approach the world is better. More flexible, more dynamic.
Still, isn’t there a way that we see ourselves in Funes? Of course we are different. But how different? Asking these questions helps us reflect on the significance of episodic memory − memory for events of our personal past.
Cognitive scientists and clinical psychologists have shown that, up to a certain point, forgetting is functional. Forgetting some information from our past helps us regulate our emotions, facilitates learning, and it even makes us more forgiving.
One thing that forgetting teaches us about us is that, in order to be good and to feel good, we should not hold too much onto our past.
Forgetting can also teach us things about episodic memory and its function.
Consider this idea:
If we don’t retain much of what we perceive, then it doesn’t seem that episodic memory is for the past − for full and perfect retention of our experiences. It could then be for something else: for the future and for the possible.
It could be for imagining future scenarios in which we have to make decisions about ourselves and about others. Or for imagining a way the past could have gone instead.
Suppose that you are trying to choose a school for your child, deciding between schools X, Y, and Z. To make this decision, you may check the websites of these schools, gather information about the teachers from other parents, read reviews on the web, etc. And you may also go check the schools in person and participate in orientation events.
When it is time to decide, you need to combine what you learned from all these sources. As you activate and integrate these memories, having too many extraneous details around will get in the way. When thinking back on the orientation meeting, for example, it isn’t helpful to include the weirdly shaped moustache of the guy sitting next you.
Such details would distract you from what is important: your overall impression of these schools. And they might make it difficult to combine relevant information you gathered during these events with relevant information from other sources.
Memory clutter could lead to bad choices.
All of that sounds plausible. And it seems to support the idea that episodic memory is not for the past, but for the future and the possible.
But plausible and true are two different things. That idea is valid only if the fact that we forget a lot is true. And − against our intuitions − we have evidence that we forget way less than we might think, even at the stage of perception.
In a recent study, Pacozzi and colleagues asked participants to watch cartoon clips in which some animals entered a hiding place and then either stayed hidden or came back out. The stimuli were presented subliminally. Participants were made to focus on another activity and were not told that they would be asked about these cartoon clips later.
Then, participants were asked to rewatch these clips and decide whether two animals would linger together in a shelter and rate how easy it was to give these answers.
Their performance showed that they retained information about which animals hid from the original experience. Even though they didn’t attend to it, even though they expressed little confidence in their guesses about it.
And they could recall these details up to 10 hours after the first clip presentation.
Fair.
But 10 hours is not that long. And it could be that the participants − unlike Funes would have done − forgot these details later on.
Yet, other studies show similar results over longer periods of time − from days to years. A cool one is a study conducted by Diamond and colleagues at the Baycrest Hospital in Toronto.
One group took an audio-guided tour of the hospital. Participants were instructed to inspect things like paintings and exhibits and to complete different tasks, like locating items in a gift shop. While another group participated in a training session in which people had to learn how to use respiratory masks.
Participants were recruited to the study after touring the hospital and after undergoing the mask fit training: knowledge of being in the study did not influence memory encoding.
Later on, both groups were asked to recall as many details as possible, without receiving prompts from the experimenters. Participants were tested over the course of 2 years.
Diamond and colleagues observed that, although many details got lost over time, participants could recall dozens and dozens of them. Some could recall even more than 1oo details! And they could do so accurately.
These studies cast doubt on the idea that, since we perceive only a small portion of our surroundings and then we forget much of that, episodic memory is not for the past but for the future and the possible. Of course, we are not exactly like Funes: we perceive way less than him and we forget way more than him. Still, we perceive and later recall way more than what we think.
These observations about perception and memory teach us important things about how we ought to study the function of memory for our personal past.
We should be cautious about the inferences we make from the amount of forgetting to the function of episodic memory. Making an inference from the supposedly huge amount of forgetting to the idea that episodic memory is not for the past is not the right way to go. And also making an inference from the supposedly huge amount of forgetting to the idea that episodic memory is for the future or the possible is not the right way to go.
If this cautionary tale should lead us to say that episodic memory is for retaining our personal past is another issue. The fact that our lives are better than Funes’ because we perceive less and forget more than him makes me think that the idea that episodic memory is for the full and perfect retention of our own past experiences is misleading.
But this does not mean that episodic memory is not for the past at all…
I have thoughts about this idea. I will think about these thoughts in the future. Provided that I will be able to retain them in my memory for long enough.[1]
[1] This post is partly based on my comments on Felipe De Brigard’s book Memory and Remembering, which I presented at a book symposium at IPM4 at the University of Geneva. I thank Felipe for his feedback on my comments, and Sarah Robins for her feedback on this post.