What is the true range of mental imagery?
Schwarzkopf, D. S. (2024). What is the true range of mental imagery?. Cortex, 170, 21–25. doi:10.1016/j.cortex.2023.09.013
Abstract
This research paper highlights the subjectivity of mental imagery, noting that it's challenging to determine if different people experience imagery similarly. While most studies view imagery as a one-dimensional spectrum of vividness, anecdotal evidence suggests a vast diversity in how people experience their mental images. The article introduces the idea of "projectors" and "associators" in the context of mental imagery. Projectors experience mental images directly within their visual field, while associators process mental images separately from their visual input. Interestingly, the diverse descriptions of mental imagery mirror findings about synaesthesia. Some synaesthetes are "projectors" who experience sensations of color, while "associators" internally link colors in their mind without any actual sensation. Unlike synaesthesia, mental imagery is under some voluntary control. The paper suggests that understanding these distinctions is crucial for scientific studies on mental imagery. Current methods, like the Vividness of Visual Imagery Questionnaire (VVIQ), are deemed ambiguous. The paper emphasizes the need for improved methodologies to study and quantify the subjective experience of mental imagery. Understanding the neural and cognitive processes of mental imagery can help in addressing various mental health issues.
Authors
- D. Samuel Schwarzkopf5
Understanding Mental Imagery: Why Your Mind's Eye Might Work Differently Than Everyone Else's
When you close your eyes and picture your best friend's face, what exactly are you experiencing? For most people, this seems like a straightforward question. But according to cognitive neuroscientist Dietrich Schwarzkopf, we've been asking it all wrong—and our misunderstanding could explain why decades of brain research on mental imagery may have reached misleading conclusions.
Here's the problem: Scientists have long assumed that mental imagery exists on a single spectrum, from vivid and crystal-clear to completely absent. They measure this using questionnaires that ask people to rate how "real" their mental images seem, ranging from as clear as actual vision to not seeing anything at all. This approach made sense on the surface. But Schwarzkopf argues it's like trying to describe human visual experiences using only a brightness dial—you're missing something fundamental.
His central insight comes from carefully examining how people actually describe their mental imagery in everyday conversation. Some people say they can literally place a mental image in front of them, as if projecting it onto the world. Others insist their mental images exist only in their mind's eye, somewhere "off-screen" or "behind their head." Still others can conjure detailed mental images but only when their eyes are closed. These aren't small differences in degree; they sound like different types of experiences altogether.
Schwarzkopf proposes a bold redefinition: Mental imagery might vary not just in intensity, but in what he calls phenomenological mode—essentially, the fundamental way your brain creates and experiences mental images. He borrows terminology from synaesthesia research (a condition where senses cross-wire, like seeing colors when hearing sounds) and distinguishes two main types of imagers. "Projectors" experience mental images as somehow superimposed onto their visual field, as if their imagination and perception overlap directly. "Associators," by contrast, don't experience mental images projecting outward; instead, their mental visual representations exist separately, processed in a kind of internal buffer disconnected from their immediate visual perception.
The implications are striking. If Schwarzkopf is correct, current research might be comparing apples to oranges without realizing it. A study that measures "imagery vividness" might be mixing together projectors with very intense experiences and associators with very weak ones, incorrectly concluding they're the same type of phenomenon. Even more intriguingly, some recent neuroscience research hints that brain activity in the visual cortex—the region traditionally thought to be the seat of mental imagery—might not actually cause the experience of imagery at all. Perhaps it's just a byproduct, and the real action happens in other brain networks involved in memory and attention.
What makes this research particularly relevant is that it exposes a fundamental challenge in studying consciousness: we can never directly access someone else's subjective experience. You can't see through another person's eyes. Researchers typically rely on people's descriptions of what they experience, which makes studying something as intimate and private as mental imagery enormously difficult. This is why the distinction between projectors and associators matters so much. If different people literally experience mental imagery in different ways—not just in intensity but in kind—then our current measurement tools are fundamentally inadequate.
Schwarzkopf's prescription is methodological reform. Rather than continuing to use vague questionnaires asking people to rate "vividness," researchers should design tasks that probe the actual characteristics of mental imagery more directly. They should ask concrete questions: Do your mental images feel like they're in front of you or inside your mind? Can you manipulate them while they're "projected," or do you need to work with them separately? What is the relationship between mental imagery and working memory, that system your brain uses to hold information temporarily?
The beauty of this proposal is that it might finally explain why mental imagery research has been so messy and contradictory. Different studies might have inadvertently recruited different types of imagers, then been surprised when they couldn't replicate findings. It could also provide new insight into aphantasia, the condition where people report having no visual imagery at all. Perhaps some people with aphantasia are actually strong "associators" rather than having broken imagery systems—they process visual information differently, not less.
Whether Schwarzkopf's specific "projector versus associator" framework ultimately holds up to rigorous testing remains to be seen. But his larger argument is hard to dismiss: we've been studying mental imagery with tools too blunt for the job. The real value of this research might not be proving he's right about projectors and associators, but in catalyzing a broader rethinking of how we approach one of the mind's most intimate and elusive phenomena. By taking seriously the idea that people might experience their imagination in fundamentally different ways, we move closer to actually understanding what's happening inside our heads when we close our eyes and think.
This summary was generated by AI and may contain errors. Always refer to the original paper for accuracy.