The Shape of Things Unseen (Review)

Part I: for readers with "normal-ish" visual imagination

Millions of people have learned in the past ten years that their inability to form visual images is a recognized, if atypical, condition. I am one of these people. While most humans have a vivid visual imagination – that is, can actually see sheep when told to “count sheep” – for many of us, the term “mind’s eye” has always been a metaphor.

The world owes a debt to Adam Zeman, Professor of Neurology at the University of Exeter Medical School, for identifying and naming two important conditions, aphantasia (the lack of internal visual imagination) and hyperphantasia (an especially vivid visual imagination) and showing how profoundly we differ internally. (About 3-5% of the population are estimated to have aphantasia and another 5% have hyperphantasia.) If humans are still thinking in terms of “checking boxes” a decade from now, many may prefer to identify in terms of imaginative abilities. The astonishing variations inside our heads are infinitely more interesting than those on the outside.

The imaginative system generally and the crucial predictive role it plays is the subject of Zeman’s momentous new book, The Shape of Things Unseen: A New Science of Imagination (Bloomsbury 2025). Zeman uses his discovery of aphantasia to launch a more ambitious project that he was surely working on previously: an exploration of why imagination is so central to human survival and flourishing. In the AI era, these questions are more pressing than ever.

Some backstory if you aren’t familiar with aphantasia: in 2003, Zeman had a patient who had lost his ability to visualize after a heart operation. Zeman published a paper about the case in Neuropsychologia in 2010. Science writer Carl Zimmer then brought the case to public attention in Discover magazine. Suddenly Zeman’s inbox began receiving a “steady trickle of emails” (290) from people who had read the article and realized, with a “click of realization” (291), that they had never had a mind’s eye in the first place.

Zeman’s subsequent research culminated in the landmark 2015 Cortex paper where he and his colleagues defined and named “aphantasia” (13). The public reaction was explosive. Zeman describes going on “breakfast TV discussing the work,” after which emails were “dropping into my inbox many times every second” (13).¹

In codifying aphantasia, Zeman learned he was reviving a field of inquiry that had lain dormant for over a century. Francis Galton, the Victorian scientist, polymath, and eugenicist, was the first to systematically measure mental imagery, in the 1880s. Galton reported that many of his fellow “men of science” insisted that “mental imagery was unknown to them,” while it was abundant in the general population (78). Yet, as Zeman notes, this “intriguing lead” was largely abandoned by the field of psychology, as prominent behaviorists dismissed subjective experience as unscientific (80).

Zeman offers a modern tool, the “Vividness of Visual Imagery Questionnaire” (VVIQ), which provides a concrete framework for understanding the vast spectrum of imaginative experience (79). It is a helpful tool for gauging cognitive diversity. Zeman, for example, notes his own score is “close to the average of 59/80” (78). For those of us at the very bottom, it is startling to learn how different our internal worlds are.

Aphantasia is only a small part of The Shape of Things Unseen, however. Those with more “normal” visual imagination will get just as much if not more out of reading it. But because so many of my responses to the book are so personal, I will post about them separately in Part II. The book helped me better understand my own condition and my distance from what evidently goes on in other people’s heads.

Imagination as production and prediction tool

Zeman’s central argument is that imagination isn’t a peripheral and fun human feature but the very core of how our brains operate:

imagination is a cardinal hallmark of human thought. We may not all be constantly engaged in creative work, but we are all incessant visitors to imaginative worlds – as we contemplate future possibilities, recollect vanished experiences, enjoy vicarious lives, travel into the imagined territories of science. Deeply absorbed by these pursuits, we spend so much of our time in our heads that we often need to be reminded to return to the here and now (2).

In short, we are what we imagine. Imagination is what makes us human. Or perhaps imaginor, ergo sum.

Zeman’s second “big idea” is that what we perceive as the “real world” is to a large part “a product of our creative minds,” and a “process of ‘controlled hallucination,’ massively dependent on our vast accumulated knowledge and the elaborate predictions that it makes possible” (2).

That is, our imaginations help us both construct and predict the world we live in and the world we’d like (or fear) to live in.

Zeman defines his theoretical territory in Part I, “The Scope of Imagination,” exploring everything from mind-wandering to sublime flights of creativity. He sprinkles his analysis with lines from poets (Donne, Coleridge) suggesting that they have long had the best grasp of the mind’s generative power. This attention to poets makes sense, considering they claim property rights in the imagination space. He quotes William Blake, for whom the world was “all one continued vision of fancy or imagination” (9), and Shakespeare, whose poet gives “to airy nothing / A local habitation and a name” (27). This very lively first section defines the human experience that the rest of the book sets out to explain scientifically

Zeman builds on the work of thinkers such as Hermann von Helmholtz (25) and the neuroscientist Anil Seth (2, 26) to argue that we don’t passively perceive reality. Instead, our brain actively constructs our world from the inside out (26). He offers side trips through abstract categories such as history, cults, lies, fake news, racism, to suggest how our imagination reacts to what we take in and produces predictions from assumptions real or unreal.

The various terms we use – such as “cognition,” which refers to the processing of gaining, interpreting, and storing knowledge – are broken down in the process. Zeman notes that our cognitive capacities are largely independent of each other. A typical list of cognitive capacities, he writes, looks like this:

i) consciousness, in the sense of wakefulness, alertness;
ii) attention, our ability to focus our mental resources;
iii) perception, our ability to gain knowledge by using our senses;
iv) memory, the capacity of our experience and behav­iour to change over time as a result of what we have experienced and done in the past;
v) language, our ability to communicate using symbols, typically words;
vi) praxis, our ability to perform skilled actions;
vii) executive function, our ability to organise our own thought and behaviour. (88)

He notes that “visualization” and “imagination” don’t generally appear on these lists, and have been (wrongly) thought of as means to an end but not important part of cognition itself. Yet it is via imagination (with or without visualization) that we generate ideas; it is via imagination that we maintain these ideas, inspect them, transform them, re-enact them, ruminate on them.

The work of imagination, that is, seems to be at the heart of what an artificial intelligence, with its impressive cognitive capacity (from a kind of “consciousness” down the list to “executive function”) is not quite doing. Humans imagine future worlds. The way Zeman describes imagination, AI will never even get close.

How we got here and how it works

In the book’s second part, Zeman shows us how the brain is an active model-builder, not a passive receiver of information. Drawing on contemporary neuroscience, Zeman explains that our brains develop internal, ‘generative’ models of the world and the self, using them to constantly issue predictions about what will happen next and to minimize surprise (248). These are the systems that allow us to create, in his words, “a world” within our heads (192).

Zeman argues that our imaginative capacity co-evolved over millions of years with our ‘hyper-cooperative’ social minds, our development of language, and our sophisticated use of tools (163, 179). He points to the discovery of the brain’s “default mode network,” a web of regions that becomes active when we are not focused on the outside world, as the primary hub for the mind-wandering, reminiscence, and future planning that defines so much of our inner lives (130). There is sufficient scientific and evolutionary plausibility for why a human brain is, by its very nature, an imaginative one.

Having established his scientific and evolutionary framework, Zeman tests his theory in Part III, “The Besieged Imagination.” What happens when the brain’s predictive and imaginative systems are pushed to their limits? Drawing on a series of case studies, Zeman shows us what happens when imagination breaks down, is never allowed to develop, or is put under extreme pressure.

We are reminded of the awful, awful story of the hundred thousand-plus Romanian orphans under Ceauşescu, who were raised in state-run institutions with devastatingly little human interaction or affection. Severe neglect is an understatement. While their basic physical needs were often (but not always) met, they often suffered cruel emotional neglect: no speaking, caressing, no love (202). The result was a measurable stunting of brain development, particularly in the white matter that connects different brain regions, which led to profound and lasting cognitive and social deficits (203-204). Zeman contrasts this story with the case of a seemingly unresponsive 23-year-old woman in a vegetative state who was able to prove she was conscious by willfully generating distinct patterns of brain activity on an fMRI scanner when asked by researchers to imagine playing tennis versus imagining walking through the rooms of her house (281-282). Her well developed system (in contrast to many of the neglected orphans) is a tool that can be directed. An act of imagination can be separated from physical movement.

Zeman shows what happens when the predictive brain is starved of expected input, causing it to generate hallucinations that feel wholly real. He gives us the story of “Irma,” a 73-year-old widow who, weeks after her husband’s death, had a comforting and fully formed vision: “I heard him say, as so often before, ‘why don’t we go to bed now …?’ And when I turned to him and saw him sitting in his chair beside me as he used to... he was gone” (211). He gives us the story of “Jean-Luc,” a patient with Parkinson’s disease who is besieged by complex hallucinations of “devils” with blurred faces and changing sizes (225). Jean-Luc has partial insight into his condition; he knows he can “scatter” the devils by turning on a light, but also speaks to them because they “look so real,” describing his life as being “like living in a fantasy novel” (225).

Zeman’s point is that hallucination makes sense: the brain, trying to make meaning, over-relies on its internal models to generate sensory experience. It fills in the blanks when external data is missing (from grief) or corrupt (from neurological disease).

Trauma can also affect the imaginative system, as can disease. Zeman gives us the story of Viktoria, a Ukrainian mother haunted by intrusive images after her husband and then her daughter were killed after the family was fired upon. “When I looked her head was gone” (233). Viktoria’s predictive system is locked by trauma into a painful sensory simulation. We are also given an account of “Graham,” a patient with Cotard’s Delusion who becomes unshakably convinced that he is brain dead. (242). Graham’s brain, trying to account for the feeling of emptiness from his depression, generates a radical, delusional belief. In both cases, Zeman argues, the imagination has been taken over by external and internal phenomenon.

Finally, Zeman argues that chemically induced hallucinations are a matter of drugs acting on the 5HT2a serotonin receptor, disrupting the brain’s normal hierarchical networks and creating a “hyperplastic state” of increased connectivity. He notes that when Albert Hofmann accidentally discovered LSD he experienced an “uninterrupted stream of fantastic pictures, extraordinary shapes with an intense kaleidoscopic play of colors” (236). Aldous Huxley, under the influence of mescaline, described flowers shining “with their own inner light” (237).

Here again, my own aphantasia shaped my reading. A reader with typical imagery might see all these cases as cautionary tales about the fragility of their own perception. For a reader with aphantasia, the analysis is more complicated. Without a mind’s eye, I understand Viktoria’s trauma intellectually and as a mother. But I wonder if it may be “easier” for those with aphantasia to get the worst possible image out of our minds. I can’t imagine the trauma of not being able to get an image out of my mind.

The System Re-Imagined: Creativity Without a Mind’s Eye

Zeman ends the book with non-visual imagination, with his profile of Ed Catmull, the co-founder of Pixar. Zeman quotes at length from an email Catmull sent him, where Catmull, who also has aphantasia, describes his creative process. Catmull adds that his colleagues, the legendary animator Glen Keane, also has this “lack”:

I had some kind of mental model and I would interact with paper to figure out how to do the math... I was then surprised to hear him [Keane] say that he also could never see images, and that he never has... Glen says that he has something in his head, and he has to interact with the paper in order to get it out, but whatever is in his head, it isn’t an image. Likewise I have something in my head, but I see no images. (295-296)

For reader with typical imagery, this must have seemed surprising. For me – and I have previously written about Catmull’s revelation – reading it after the many case studies of visual systems going awry, aphantasia seems a kind of gift. After hundreds of pages analyzing the breakdown of the visual imagination, cases of aphantasia prove that the system’s core function – the generation of novel, complex models – is not dependent on a sensory screen. “Imagination” is the underlying conceptual model, not visual images or pictures, though visualizing is what people generally mean by imagining. As Zeman writes in his epilogue:

Perception, for all that it seems effortless, provides a hard-won, creative ‘presentation’ of reality: imagination uses the knowledge and models engaged in perception to represent and reconfigure reality off-line. We, uniquely on earth, have developed an ability to represent these representations using symbols, from everyday language through specialised notations, like algebra or computer code, to each of the arts. With their help, human imagination is as much a social as a personal achievement – we share what we imagine; sharing helps us to imagine. (301)

However, the use of “we” and returning to aphantasia only at the end to qualify that “imagination does not always require imagery” (302) gives the book a kind of structural imbalance. Zeman’s main point is the essential crucial nature of the imaginative system (for all humans) and his argument is supported by cases where it breaks down. I see the utility of describing the neurology of other people’s ghosts by showing the “normal” visual faculty in its most extreme state. And Zeman is careful to remind the reader (occasionally) that there are those of us without a mind’s eye. But it often seems as though he recognizes that it is simply easier to make his larger point about the imagination by assuming universal visual imagination, which it probably is.

The great strength of Zeman’s case study method is also its recurring limitation. Once the stories serve their purpose as evidence, they’re abandoned, but not forgotten. We never return to the Romanian orphans (though there is a lot on the web to find, all of it sad) or Viktoria, though it is good to know Graham is doing well. It leaves a bit of a void.

There are some practical questions unanswered as well, particularly about childhood development. Reading about the role of social nurturing in building imagination, I wondered about the best way to support a child with aphantasia or hyperphantasia. When should you explore whether a child does or does not have a mind’s eye, or an especially vivid one? How might knowing about my own lack of an ability to call up visual images have changed my career choices or my understanding of myself? Are there educators working on pedagogical strategies for children who cannot picture their mother’s face, an historical event, or characters in a story? Or who cannot get awful images out of their minds? I found myself often putting Zeman’s book down and pondering these questions.

Because of my personal interest, I probably spent more time reading (and looking up full poetry context) than most readers will. But it was worth it. My debt is immense.

For the general reader, The Shape of Things Unseen is an important book that should make people rethink how we think about human imagination, particularly in the AI era. It provides the vocabulary and framework that allows people to understand their own imaginative capacity and why it matters. I look forward to reading Adam Zeman’s future work and the work of researchers new to the field exploring variations in how we imagine and how we might understand better those around us who process the world very very differently.

1. There is a paper to be written on how aphantasiacs like myself are so quick to email Adam Zeman – perhaps without the capacity to visualize we leap to do rather than sit and ponder.