“We Should Form in Us the Shadows of Ideas…”

by Joseph Shieber

When I think back on when I realized that I think differently than most people, what surprises me most is that I didn’t realize it sooner.

The earliest indication that I can explicitly recall would have occurred to me some time in the 1990’s. It was around then that I’d learned about the “method of places” technique for memorization — also known as the “memory palace” technique.

The technique works like this. Choose a location that you know very well from memory — say, the street where you grew up. Visualize yourself walking down the street, observing landmarks along your walk. Now, when you want to memorize items in a list in order, simply visualize those items at locations along the familiar path in your mind.

I could pretend that I first learned about the method of places from Jonathan Spence’s 1984 book The Memory Palace of Matteo Ricci, but it’s likely that I actually encountered it first in Thomas Harris’s 1999 novel Hannibal. Harris would have led me to Spence’s book — as well as to Frances Yates’s 1966 book The Art of Memory.

The technique is one of the most widely used strategies by mnemonists — like the journalist Joshua Foer, who wrote about how he employed the technique to win the 2006 U.S. Memory Championship in his 2011 book Moonwalking With Einstein.

Now, the technique is not easy. It took Foer a year of concentrated effort to prepare for the Memory Championship, for example. But when I set out to try it for myself, I found that I was unable even to get started.

The problem was that first step: visualization. I can’t do that. I’ve never been able to.

When I say that I can’t visualize, I don’t mean that I actually can do it but am just bad at it, in the way that I might claim that I can’t play tennis. I mean that I can’t do it at all, in the same way that I mean that I can’t breathe underwater or that I can’t lift a diesel locomotive.

Does that seem unbelievable to you? Try this. Close your eyes and picture to yourself a single red rose about six inches in front of you.

Okay, now open your eyes again.

What did you see while your eyes were closed? I’m guessing you saw a rose, or less vividly, with more or less detail.

What I see is nothing — gray to black, depending on the ambient light around me, plus some lazily moving lighter flecks, like floaters.

Around the same time that I had my unsuccessful attempts with the “method of places”, I must have been participating in a graduate philosophy seminar in which we read Christine Korsgaard’s The Sources of Normativity, where Korsgaard writes the following:

If I say to you, “Picture a yellow spot!” you will. What exactly is happening? Are you simply cooperating with me? No, because at least without a certain active resistance you will not be able to help it.

Korsgaard uses this example as an illustration of the way that language can be both normative — because if you were to picture a pink spot you’d be in error — and compulsive. A little further on, she writes: “All I have to do is talk to you in the words of a language you know, and in this way I can force you to think.” (If only it were that easy to get someone to think!)

I don’t need to quibble with Korsgaard here. The point of mentioning that passage is that, when we discussed that passage in the seminar, I mentioned that, Korsgaard is mistaken. If she said to ME, “Picture a yellow spot!” I won’t — I CAN’T!

The professor and my classmates treated my claim as if I had asserted that I wasn’t in fact human, but rather a cleverly constructed android. Basically, they ignored the comment. I guess they thought I was trolling — never a completely unreasonable assumption in the context of a philosophy seminar.

I’ve never forgotten that passage from Korsgaard, however, nor the incomprehension that met my denial that I possessed any conscious mental imagery.

One result of my inability, however, is that in some sense I don’t actually remember the event itself. Oh, clearly I remember THAT it occurred. After all, I just described it. But I don’t have any recollection of the experience of the event. The technical jargon is that I have a semantic memory about the event, but I lack an episodic memory.

In fact, as best as I can tell I have no episodic memories at all. I remember THAT all sorts of events occurred, but I can’t recall the events themselves, or picture them “in my mind’s eye”.

Despite my having been aware of all of this, it never occurred to me that I was unusual. If anything, I thought that other people were speaking metaphorically when they referred to “the mind’s eye” or appealed to examples involving mental visualization.

It wasn’t until I came across the work of Adam Zeman in 2015 that I was able to put a name — aphantasia — to my experience.

Actually, there are TWO names corresponding to two different aspects of the experience that I’ve described. “Aphantasia” refers to the inability voluntarily to engage in mental visualization.

But I also described my virtually complete lack of episodic memories. That too has a name: “Severely Deficient Autobiographical Memory”. It was first investigated by Brian Levine and his colleagues at the University of Toronto, around the same time as Zeman’s discovery of aphantasia.

Interestingly, there hasn’t yet been an attempt to link the two conditions — although researchers are certainly aware that they can co-occur (as described, for example, in this 2018 article from the BBC).

What got me thinking more about aphantasia — and severely deficient autobiographical memory — was a recent paper entitled “The transition of object to mental manipulation: beyond a species-specific view of intelligence”, by Bar-Hen-Schweiger and Henik. As they state in the abstract, in their paper they “suggest that intelligence, or g/G, is reflected in a biological capacity that evolved from object manipulation in animals, into mental manipulation in humans, in response to various environmental conditions”.

The fact that they tie the sort of human ability for mental manipulation to an ability that evolved from object manipulation in non-human animals suggests to me that they should be open to an understanding of mental manipulation that does not involve a capacity for voluntary, conscious mental imagery.

If that’s right, then Bar-Hen-Schweiger and Henik’s suggestion would be compatible with attributing to people with aphantasia whatever abilities for mental manipulation that are tied to g/G. (In fact, there is some evidence that people with aphantasia actually score better on mental rotation tasks.)

One of the other questions that remains open — with respect to both aphantasia and severely deficient autobiographical memory — is what specific implications these phenomena might have for philosophical debates.

For one, from my own experience it seems quite plausible that the someone who has severely deficient autobiographical memory would have virtually no episodic memories — and thus no knowledge based on episodic memory

However, I suppose that it would be open for a philosopher to hypothesize that severely deficient autobiographical memory affects only conscious episodic memories, and that there is still the possibility that someone suffering from severely deficient autobiographical memory could have knowledge based on unconscious episodic memories. (I’m most definitely NOT endorsing this maneuver; I’m only recognizing that it’s a move that some philosophers might be tempted to make.)

For another, the phenomenon of severely deficient autobiographical memory would seem to pose a challenge to philosophers who are tempted to tie episodic memory (and the related notion of “mental time-travel”) to self-consciousness and personal identity.

For a final example, consider philosophical positions that tie cognition very closely to the ability voluntarily to create and manipulate mental imagery. The phenomenon of aphantasia suggests that such positions should be careful about how closely they tie cognition to phenomenological imagination. Again, it is open to philosophers to suggest that those with aphantasia do in fact have unconscious mental imagery — although, again, this is most definitely NOT a maneuver I would endorse.