Bence Nanay is Professor of Philosophy and BOF Research Professor at the University of Antwerp. He is the author of Between Perception and Action (Oxford University Press, 2013), Aesthetics as Philosophy of Perception (Oxford University Press, 2016), Mental Imagery: Philosophy, Psychology, Neuroscience (Oxford University Press, 2023), all open access, and Perception: The Basics (Routledge, 2024) as well as six other books published or forthcoming and more than 160 articles on various topics in philosophy of mind.
This week at The Junkyard, we’re hosting a symposium on Bence Nanay’s recent book Mental Imagery: Philosophy, Psychology, Neuroscience (Oxford University Press, 2023). Today we begin with an introduction from Bence. Commentaries and replies will follow Tuesday through Thursday.
* * *
When I give a talk about mental imagery, I usually illustrate what mental imagery is by asking the audience to close their eyes and visualize an apple. That is without doubt one form of mental imagery, but it may give the wrong impression about how rife mental imagery is.
So I will go with a different way of introducing the phenomenon here: I’m writing this during a flight. And much of what I’m doing involves mental imagery of one kind or another.
(a) I’m having a flashback to my delusional and ultimately fruitless attempt to get upgraded before boarding. That is mental imagery, but very different from visualizing an apple inasmuch as it is not voluntary: I am not counting to three and having a flashback, it comes unbidden.
(b) The drinks trolley shows up. I feel like having a tomato juice. This brings about gustatory and olfactory imagery of tomato juice.
(c) I’ve nodded off and I dreamt that I am in a fancy hotel room, sleeping in a soft bed, with many pillows around me.
(d) I am half-watching the movie the passenger in front of me put on, but I only see a fairly small portion of her screen. It’s the Big Lebowski, a film I know fairly well. My visual system fills in the rest.
(e) My headphone slid down at the side of my seat and it’s now under my seat. I’m trying to fish it out from there while still sitting (the seatbelt sign is on), reaching down and try to feel my way to where it must have fallen.
(f) The passenger next to me is asleep and snoring, fairly regularly. Each time a new snore is due, I have the (unpleasant) expectation of what’s coming.
(g) I have 20 minutes between landing and the time the next train departs the airport. I’m imagining the route from the gate to the train station at the airport, trying to decide whether I should run for it.
(h) We’re landing. I can see the cityscape of a familiar city through the windows, but I only see the vista through those little oval-shaped windows, But I am also somehow very much conscious of the rest of the cityscape (between the ovals), which I don’t actually see.
All these are (very different) forms of mental imagery. They are all perceptual representations that are not directly triggered by the sensory input. While they are very different in some ways, what they have in common is that our perceptual system is at work, but it’s running on empty. It is not processing the sensory input, turning it into a perceptual representation, but produces perceptual representations in the absence of sensory input.
The examples (a)-(h) are very different in many ways. Some are voluntary, some are involuntary. Some are visual, some are auditory, some are about some other sense modalities. Some are accompanied by some form of a ‘feeling of presence’, some are not. But they are all perceptual representations that are not directly triggered by the sensory input.
I hope that these examples make the big picture point that the whole book is devoted to, namely, that mental imagery is everywhere: it is part of the vast majority of our mental functioning. It plays a crucial role in memory, decision-making, planning, desires, some actions, amodal completion, dreams, expectations.
And more. Besides the examples (a)-(h) that I talked about, mental imagery also plays a very important role in pain processing, in implicit bias, in cognitive dissonance, in psychiatric practice, and much more. So much so that in the past decade, I engaged in what could probably be best described as somewhat juvenile trolling, publishing papers with the title ‘X as mental imagery’ for as many possible Xs as I could (just some examples: amodal completion, boundary extension, implicit bias, pain, hallucination and the Stroop Effect).
But there is a serious point behind all the trolling. There is a common denominator in all these seemingly extremely diverse mental phenomena, and it is the kind of representations involved in them: perceptual representations that are not directly triggered by the sensory input. And it is these kinds of representations that I call mental imagery.
The book is structured in a way that makes it possible to pick and choose what mental phenomena you are interested in. There are 30 (relatively) short chapters, grouped in five parts: Mental Imagery, Perception, Multimodal Perception, Cognition, Action, covering much of what is going on in the human mind.
There is a fair amount of neuroscience and psychology in the book, but I do not assume any prior knowledge of these disciplines, so even if you have no empirical background, you should be able to follow. But I find it really important to combine philosophy, psychology, and neuroscience when tackling the problems about mental imagery.
Take the role of imagery in everyday perception. Philosophers have been thinking about this issue for centuries – including a certain Immanuel Kant. Psychologists did many experiments on this, going back to the birth of this discipline at the end of the 19th century. And neuroscience has a lot of much more recent findings on this. If we want to understand a complex mental phenomenon like this, we need to use everything we have and that involves combining philosophy, psychology, and neuroscience.
This blog is about imagination, not mental imagery. Mental imagery is a kind of representation (perceptual representations that are not directly triggered by the sensory input). Imagination is a mental action. So they are very different. One take on the relation between them is that imagination is one way, but by no means the only way, of using mental imagery. In any case, we should not confuse the two.
To make things more confusing, the term ‘imagination’ was often used throughout the history of philosophy to refer to exactly what I mean by mental imagery (especially in the early modern period, for example by Hobbes). It would be a super-interesting project to wade through the history of philosophy with an eye on this issue. But that is not my project. My project is less historical, and throughout the book, I am making a sharp distinction between imagination on the one hand and mental imagery on the other (and devote a chapter to the relation between the two).
Imagination may be the junkyard of the mind. As the readers of this blog know full well, this does not need to mean something bad: junkyards can be great fun. You can find amazing things at a junkyard. In one of the best episodes of It’s Always Sunny, the gang finds an almost fully functional police car. The same goes for the junkyard of the mind: some amazing things there.
To push the junkyard metaphor just a bit further, if imagination is the junkyard of the mind, then mental imagery is what all the junk is made of. But not just all the junk. Mental imagery is also what much of the entire city around the junkyard is also made of. Not just the discarded police car, but also all the police cars in the city and also the police station and the policemen.
I’m not saying that everything in the human mind is mental imagery. But there are very few mental phenomena where mental imagery doesn’t play a substantial role. We can’t understand the human mind if we don’t understand the role mental imagery plays in these diverse mental phenomena.
Oh, and the book is fully open access, the pdf can be freely downloaded from the Oxford University website.