The physiology of perception and imagination

Posted by
This entry is part 2 of 4 in the series Doctrinal Insights from Embodied Cognition


Part 1. We briefly explored how the Restored Gospel emphasizes the importance of divine embodiment and what that might mean for us in an eternal perspective. We argued that our divine destiny has always been to become embodied beings of flesh and bone in the eternities. We also stated that, even with this restored understanding of divine embodiment, members of the Church of Jesus Christ of Latter-day Saints often don’t fully understand the importance of physical embodiment

Part 2. We introduced the idea of mind-body dualism, the idea that the mind is wholly separate and distinct from the body. Many have questioned mind-body dualism, but some have done so in a way that reduces human thought and activity to mere biological processes, which eliminates the possibility of agency and morality. Instead, we suggest we talk about human action holistically as something that requires and is informed by physiology, but can never be reduced to mere biology.

Mind-body dualism and Plot holes

It is uncontroversial among Latter-day Saints — a matter of doctrine, in fact — that our mortal bodies expand our capacities and that taking up flesh and bone is part of our eternal progression. To be physiologically embodied is to become more like our Heavenly Father, who is Himself a being of flesh and bone. Very rarely, however, do we talk about exactly why and how it is that physiological embodiment expands our capacities.

Sometimes we might talk about how our physicality allows us to experience things like climbing a mountain, smelling flowers, or feeling a cool summer’s breeze. We typically assume (rightly, we think) that spirits cannot do these sorts of things. However, our ordinary understanding of spiritual embodiment tends to reflect the assumption of mind-body dualism (see Part 2). That is, we assume (typically without giving the matter much serious thought) that all (or, at least, most) of the functions of the mind (and perception) are housed in our spirits, and only the more tactile senses depend on our physiological embodiment.

It is easy to take this way of thinking for granted because we see it not only reflected in conventional religious thought, but also in popular media. In most fictional depictions of ghosts, for example, the only thing that “ghosts” are unable to do as ghosts is touch, taste, or feel (the more tactile senses). Beyond that, they act, think, look, and even sound like their former selves.

In the aptly-titled Marvel superhero movie Doctor Strange, the titular character sometimes leaves his physical body behind and moves his “soul” through the astral plane. The film visually represents his incorporeality by showing him existing as a translucent version of himself, moving through physical objects with ease. In his astral form, he is no longer bound by the physical constraints of his body, or forces of the material world such as gravity. However, some obvious questions arise:  When in astral form, how is it that Dr. Strange can see or hear anything at all? How does light interact with his eyes (since his eyes are back in his physical body)? How exactly do sound waves interact with his ears? (As we will soon see, this is just the beginning of the questions that arise when we take a moment to consider what is going on here.)

The fact that all non-tactile physical and cognitive capacities remain intact is, in fact, a major plot hole in almost every ghost story (or any story in which a character’s “mind” or “spirit” is separated from their body). Many of us take these sorts of plot holes as a given, without serious question and in no need of justification or explanation. These sorts of plot holes are almost always overlooked by writers, readers, and viewers as a matter of convention and for the sake of story-telling convenience. Of course, there are always necessities of story and plot; we wouldn’t be able to write or tell ghost stories without taking some liberties like this.

The point here is that “ghost stories” like these illustrate how we tend to overlook similar questions in the way that mind-body dualism plays out in our religious worldviews. Even in its most subtle and nuanced forms, mind-body dualism presents tremendous “plot holes” that we usually ignore. And, we tend to ignore them because the chore of patching them up seems too intellectually taxing. After all, the “mind-body” problem has been around for centuries and some truly brilliant thinkers have been unable to patch up holes and bridge the gaps, why would we think we could do any better? Our central argument here, however, is that there is an alternative approach available:  instead of patching these plot holes — something that might well just be impossible anyway — maybe we can challenge the assumption of mind-body dualism right from the start.

We take it as uncontroversial that our physiology expands the horizon of possibilities available to us. It allows us to do things like play hockey, swim, go camping, embrace a friend. These sorts of possibilities are obvious. But what if our physiology also allows us to do so much more than we realize? What if there are skills that we typically take to be matters of the “mind” that depend just as much on functioning physiology as they do the seemingly intangible dimensions of thought, memory, and imagination? Consider simple tasks such as reading (pictured in the cover image) — could the capacity to detect meaning in graphical symbols on a page (or even picture those words in our be just as physiological as anything else we do?

Perception and cognition as an embodied activities

Many psychologists, physicians, and neuroscientists have explored how injuries and differences in birth can damage a person’s ability to perceive the world in certain ways. Most of the following examples are pulled from various works written by the neurologist and author Oliver Sacks, who specialized in documenting cases where brain injuries (like strokes) produce idiosyncracies in perception and cognition. Let’s delve into a few examples.

Color vision

Most of us readily accept that the full perception of color depends on the proper functioning a special light-sensitive photoreceptor cells called “cones” located in the retina of the eye. A sizable percentage of the human population experience one or another form of color-blindness in part because they are missing some crucial types of these receptor cells. While most daily activities are wholly unaffected, those who are blue-yellow colorblind, for example, are less able to detect a ripe banana from an unripe one, an ability that many of us might take for granted. They may be less apt to appreciate some works of art (in the same ways as someone who is non-colorblind, at least). We could say of these individuals that the horizon of possibilities is different for them (thought not tremendously so in most cases).

However, for some, their horizon of possibilities is dramatically altered. This is particularly the case for those who develop color blindness not through any condition of their eye, but due to injury to their brain. Dr. Sacks shared a case study of a painter (referred to as Jonathan I.) who, after a car accident, found that he could no longer see in color. This was not due to any defect in his eyes, but rather to damage that was done to his brain, particularly in that area of his brain demonstrated to be vital to distinguishing colors. For Jonathan I., a once color-filled world now presented itself in black, white, and shades of grey.

This was more than a mere nuisance to Jonathan I. He described most things as having taken on a leaden grey, something which made most foods appear unappetizing. Tomato juice or a red apple would appear completely black to him, and people looked like animated lead statues. Sacks explained, “He saw people’s flesh, his wife’s flesh, his own flesh, as an abhorrent grey; ‘fleshed-colored’ now appeared ‘rat-colored’ to him.”((Sacks, An Anthropologist on Mars, p. 7.)) And, interestingly, memory was no reprieve for him — things took on the same leaden tones even in his imagination and recollections. “His vivid visual memory was preserved,” explained Sacks, “but was now without color as well . . . . Jonathan I. did not lose just his perception of color, but imagery, and even dreaming in color.”

This suggests that the same part of our brain that is involved in imagining color is also involved in perceiving and interpreting it in the first place. Visualizing in color, perceiving color, distinguishing colors, and certainly making art with color as seem as though they are not simply “mental” activities but also physiological activities as well, and at the same time. Because of certain physiological deficits, Joanathan I. lived in what Dr. Sacks refers to as an “impoverished world.” Because the rest of us have functioning physiology, we live in a world of expanded possibilities.


The term “aphasia” refers to the loss of the ability to form or generate verbal speech, or other types of language. Dr. Sacks describes the experiences of a number of aphasic patients who, because of brain damage, were unable to communicate with others (in the ways they were used to, at least). For example, Dr. Sacks describes the story of a French physiologist named Jacques Lordat who, in the early 1800s, suffered a stroke. Lordat described his experiences:

Within twenty-four hours all but a few words eluded my grasp. Those that did remain proved to be nearly useless, for I could no longer recall the way in which they had to be coordinated for the communication of ideas . . . I was no longer able to grasp the ideas of others, for the very amnesia that prevented me from speaking made me incapable of understanding the sounds I heard quickly enough to grasp their meaning . . . Inwardly, I felt the same as ever. This mental isolation which I mention, my sadness, my impediment and the appearance of stupidity which it gave rise to, led many to believe that my intellectual faculties were weakened . . . I used to discuss within myself my life work and the studies I loved. Thinking caused me no difficulty whatever . . . My memory for facts, principles, dogmas, abstract ideas, was the same as when I enjoyed good health . . . I had to realize that the inner workings of the mind could dispense with words.((See Sacks, The Mind’s Eye, p. 37))

Lordat, of course, eventually recovered his ability to process language, since we have his story today. Another story is that of Dr. Samuel Johnson, the famous poet, playwright, and essayist, who suffered a stroke in 1783 and woke up without any ability to speak, although he could still understand speech and form words in his mind. (His was only a case of expressive aphasia.) He could also write just fine — he just was unable to form words with his voice. There are many kinds of aphasia. For example, it is possible for a deaf person fluent in sign language to be able to see with perfect clarity, but due to a stroke find themselves unable to find meaning in sign language anymore. To use a metaphor from our previous post, the capacity to process visual cues into meaning depends in part on having a properly functioning brain, in the same way that playing hockey requires properly functioning knees.

Alexia and agraphia

Another illustration of this idea can be found in the experiences of those with alexia and agraphia. Alexia refers to the inability to read, and agraphia refers to the inability to write. Alexia and agraphia can manifest separately from one another. When we write, we are enwrapping our world in semantic meaning through motor action (e.g., scribbling marks on a page with a pencil as we confess our feelings for a loved one). When we read, we are making meaning from visual stimuli (those same scribbles on a page). These are two things are — surprisingly enough — very different skill sets. Dr. Sacks describes the story of a writer named Howard Engle who, through a stroke, lost his ability to read. One morning he grabbed the newspaper and thought he was the victim of a practical joke:

The July 31, 2001, Globe and Mail looked the way it always did in its make-up, pictures, assorted headlines and smaller captions. The only difference was that I could no longer read what they said. The letters, I could tell, were the familiar twenty-six I had grown up with. Only now, when I brought them into focus, they looked like Cyrillic one moment and Korean the next.((Sacks, The Mind’s Eye, p. 54.))

Sacks recounts a similar story of a man who, “following a head injury, found himself unable to read the police accident report — he saw print of different sizes and types but could make nothing of it, and said that it looked ‘like Greek or Hebrew.’”((Sacks, The Mind’s Eye, p. 54.)) In Howard’s story, however, it was significant that he could still write just fine — he just could not read what he had written once it was on the page. He later wrote whole books, relying on the assistance of editors and other inventive strategies for revising his work.

Most notably, Howard slowly learned a way to read again — not by recognizing words on a page, but by tracing the letters he saw with his finger, and then later with his tongue. He could look at a word, trace it, and by tracing it, learn its meaning. He was, essentially, reading by writing — reading with his tongue. He was detecting meaning from scribbles on a page not directly through visual means (i.e., eyesight), but through motor action. This should highlight the physicalness of this skill — it involved physiological activity just as much as hockey, soccer, or painting. By reading through motor action, Howard simply made this more obvious.


Howard’s story is similar to the story of Lilian Kallir, who over a lengthy period of time lost her ability to read. Although she was able to identify individual letters, individual words just stopped making sense to her, despite the fact that she could see them quite plainly. Indeed, Lilian retained perfect competence in all other areas of her life — at least she did for quite some time, until she also started developing agnosia (the inability to recognize objects using sight) as well. Interestingly, Howard Engle experienced the same during his own recovery.

Agnosia refers to the ability to correctly identify things that we see. Because this is a skill that we learn in infancy, we hardly think of it as a skill at all. But evidence has shown that those who regain their sight later in life — particularly if they were blind from birth — often have to learn how to recognize the things that they see. Sacks explains, “When we open our eyes each morning, it is upon a world we have spent a lifetime learning to see.”((Sacks, An Anthropologist on Mars, p. 114.)) Not only is being able to recognize objects it a skill, it is (in part) a physiological skill. And, because it is a physiological skill it is something that can be lost through injury.

Both Howard Engle and Lilian Kallir experienced a form of agnosia. Howard described his experience this way:

Familiar objects like apples and oranges suddenly look[ed] strange, as unfamiliar as an exotic piece of Asian fruit. A rambutan. I would surprise myself with not knowing whether I was hold an orange or a grapefruit, a tomato or an apple. Usually, I could sort them out by sniffing or squeezing.((Oliver Sacks, A Mind’s Eye, p. 55))

Both Lilian and Howard were still able to identify objects by touch. Lilian found ways to organize her life, so that she knew where everything in her home was. However, the moment something was misplaced, she could not find it again — despite being able to “see” just fine. She could recognize colors all around her, but recognizing objects in her visual field was a skill she slowly lost altogether.


Whether it is due to environmental toxins or genetics, there is mounting evidence that autism is at least partly a consequence of abnormalities in brain development. Among other things, one symptom of autism is a diminished capacity to recognize and internalize norms for social behavior, or to pick up subtle nuances in communication with others. Sometimes autistic individuals are less able to correctly detect emotions in the faces of others, or infer appropriate subtexts in verbal conversation, or to intuit the norms that govern the activities of their friends and associates.

Dr. Sacks recounts the experiences of Temple Grandin, a professor at Colorado State University with autism. He explains that part of what make Grandin’s experiences different from others is that most people have:

implicit knowledge of social conventions and codes, of cultural presuppositions of every sort. This implicit knowledge, which every normal person accumulates and generates throughout life on the basis of experience and encounters with others, Temple seems to be largely devoid of. Lacking it, she has instead to ‘compute’ others’ intentions and states of mind, to try to make algorithmic, explicit, what for the rest of us is second nature.((Sacks, An Anthropologist on Mars, p. 270.))

We can compare this to recognizing objects through visual means. The ability to understand others’ intentions, navigate social norms and expectations, and detect subtle emotional nuance is a skill most of us have learned so well that we hardly recognize it as a skill at all. Indeed, we would find it quite difficult, if not given sufficient time for reflection and deliberation, to adequately articulate just how it is that we are able to do such things with such ease and naturalness. Noticing the patterns and norms in human activity that help us anticipate what others expect of us in a social context is something that many of us do intuitively — that is, skillfully. In contrast, Sacks describes Grandin’s experience in her youth:

Something was going on  between the other kids, something swift, subtle, constantly changing — an exchange of meanings, a negotiation, a swiftness of understanding so remarkable that sometimes she wondered if they were all telepathic. She is now aware of the existence of these social signals. She can infer them, she says, but she herself cannot perceive them, cannot participate in this magical communication directly, or conceive the many-leveled kaleidoscopic states of mind behind it.((Sacks, An Anthropologist on Mars, p. 272.))

What we would like to suggest is that social and interpersonal activities such as these require properly functioning physiology of the brain just as much as recognizing objects visually, or making meaning from words on a page. In a similar way that our brain allows the creation and revealing of meaning in scribbles on a page, it allows us to disclose patterns in our social encounters, and from those patterns intuit what others expect of us in social contexts. And, just as our capacity for detecting meaning in scribbles can be imperiled through damage to the brain, so too can our capacity for intuiting social norms (and the feelings of others) be imperiled by abnormal brain development or damage.

Entertaining a Possibility

The above are just a few of the many possible examples we could consider that hint at ways in which our physiological embodiment plays a far larger role in our mental world and everyday life than we realize  — even when we are doing nothing but daydreaming in our beds. Much of what we might think of as “mental” experience, and thus purely psychological or internal, even spiritual, is in fact deeply physiological in ways most of us rarely consider. In our next post, we will explore further dimensions of this idea, going well beyond what we have discussed here. Of course, even at this point, this discussion raises a startling question:  What could spirits do prior to physiological embodiment?

We admit at the outset suggest that we don’t know the answer to this question. There are competing narratives within the Church, and opinions seem to have varied widely. On one end of the spectrum, premortal experience is fully analogous to physical experience, and we were perhaps even more powerful as spirits than we are now (e.g., we helped create the world, had immense powers of foresight, intelligence, and creative capacity). Others have disagreed with this view, however, arguing that premortal spiritual life is severely impoverished when compared with our current, physiological life experiences.

The remainder of this series will flesh out a perspective squarely in the latter camp. Our central assumption is that the expanded capacities of mortal physiology are additive; that is, we did not lose what we could do as a spirit when we stepped into mortality, but rather were “added unto.” Thus, in our view, our physiological embodiment does not hamper our spirit, it expands our possibilities. Now, this assumption may be completely true, largely true, or only partly true. (We are fairly certain that it is not completely false.) Moving forward, we will assume that it is at least largely true:  most of what we could do as spirits, we can still do now, plus so much more. And, conversely, most of what requires functioning physiology to do now, we could not do at all as spirits (or, at least, much less so).

We suspect many of our readers may have both questions and objections, and we hope that they will be patient with us as we set forth our argument, answer questions, and respond to potential rebuttals over the course of many future posts. We have a lot of ground to cover ahead! Our argument here will contradict the particulars of what might be considered “conventional” Latter-day Saint thought, and for that reason, we do not expect our readers to accept it as doctrinal in the slightest. Our project is purely speculative, and may perhaps stake out a new position to explore, a new corner in the topography of Latter-day Saint thought on the subject.

Series Navigation<< Embodied cognition and the content of our mindsMind-body dualism and reductive materialism >>


  1. While it’s interesting to consider the physiological benefits, described here, as being distinct, it might be worth considering that those capabilities may instead (or also) be inherent in the spirit–and merely inaccessible because of injury or improper physical development.

  2. The problem with trying to place the idea that cognition relies on the physical brain within the LDS tradition is that pretty much every instance in modern-day scripture of interaction with spirits explicitly rejects the idea.

    According to D&C, we’re not even necessarily able to tell whether a messenger is resurrected or not without explicitly testing their corporeality. Jesus governed all creation as a spirit before His birth, and his form (as the brother of Jared was told) was as he was when embodied. Lucifer is feverishly working on master-planning his way to world domination, and doing a pretty good job of it. Accounts of the spirit world suggest an *increase* in mental intensity, not a decrease. Indeed, while it’s explicitly stated that the lack of a body after death is a loss, it’s never made particularly clear why.

    On the other hand, though, in the LDS tradition, being a spirit is, itself, an embodiment. There is such a thing as spiritual matter. We were not orignally spirits, but intelligences, and becoming spirits is our ‘first estate’. I think if there a synthesis to be made of these ideas, I think it will more likely be there.

    1. Here, I’ll repeat what we wrote at the end of the post:

      “We suspect many of our readers may have both questions and objections, and we hope that they will be patient with us as we set forth our argument, answer questions, and respond to potential rebuttals over the course of many future posts. We have a lot of ground to cover ahead! Our argument here will contradict the particulars of what might be considered ‘conventional’ Latter-day Saint thought, and for that reason, we do not expect our readers to accept it as doctrinal in the slightest.”

      We’re going to suggest that there’s some more flexibility than we assume on this matter, and we will discuss most of your examples directly. More to come.

  3. While embodiment is additive as you say, perhaps in a fallen world and for mortal bodies composed of fallen elements, there may be capabilities that a pure spirit being and a resurrected being may have that ordinary mortal beings do not. As an example, consider Alma’s three days of torment. Ordinary mortals do not feel the intensity of pain or joy that Alma felt during the time he lost the ability to move his body. This suggests to me an out-of-body experience which in turn suggests that in this mortal state our capability to feel pain and joy is dulled. Unembodied spirits and immortal beings seem to have a greater capacity to feel than mortals do. Maybe other capabilities are attenuated as well in mortality.

    I enjoy reading this series and the insights you bring to this subject! I’ve often wondered about the statement in Doctrine and Covenants 138 that the spirits of the dead viewed separation from their bodies as a bondage. By reading this series, I hope to understand why.

Leave a Reply

Your email address will not be published. Required fields are marked *