On Perception and Appearance

Framing

You see an apple. You know you see an apple. But what have you actually perceived?

Not the apple itself, in any simple sense. You have perceived light reflected off the apple. Your eye has received an image. Your brain has processed that image. Your mind has interpreted the visual data and recognized it as an apple.

At each stage, something has been added, something has been lost, something has been transformed. By the time you experience yourself seeing an apple, you have already moved so far from the raw sensory data that what you are experiencing is as much a construction as a perception.

This is not a problem with perception. It is the very nature of perception. We do not perceive the world directly. We perceive the world as it appears to us, filtered through the structures of the nervous system, shaped by past experience, organized by attention, interpreted through concepts.

The question is: what is the relationship between what we perceive and what is actually there? If our perception is always mediated, always constructed, then in what sense are we perceiving reality at all?

And perhaps more fundamentally: what does it mean to perceive? What is the structure of perception such that we can say we are perceiving something?

I. The Layers of Perception

Consider what happens when you see the apple. The process is instantaneous from your perspective, but it involves multiple stages.

First, there is the light. Photons reflecting off the apple enter your eye. These photons are not themselves visible. They are not colored. They are simply electromagnetic radiation at certain wavelengths.

Second, there is the reception. The photons strike the retina at the back of your eye. Specialized cells in the retina, called photoreceptors, respond to this light. They convert the electromagnetic energy into electrical signals. But at this stage, there is still no image. There is only a pattern of electrical activity.

Third, there is the transmission. The electrical signals travel along the optic nerve to the back of the brain, to the visual cortex. The signals are processed, enhanced, interpreted. Cells in the visual cortex respond to features like color, shape, movement.

Fourth, there is the integration. The brain combines the information from the visual cortex with information from memory, from expectations, from the other senses. It constructs a unified image. This is the first moment at which something like an image emerges.

Fifth, there is the interpretation. The brain recognizes the unified image as something—in this case, an apple. It accesses memories of previous apples. It activates associations with the word "apple." It places the perceived object within a conceptual framework.

Only at this final stage do you experience yourself seeing an apple. Only here does perception become conscious, becomes something you are aware of.

But notice: at each stage, something original in the sensory data has been lost. The brain does not simply receive information. It actively processes it, filters it, transforms it.

The raw sensory data—the pattern of photons on the retina—is vastly more complex than what reaches consciousness. Most of the information is discarded. The brain selects certain features and ignores others. It sees what it expects to see.

II. The Role of Expectation

Your perception is not determined solely by what is actually there. It is shaped by what you expect to be there.

This can be demonstrated experimentally. If you are shown an image very briefly, you often see what you expect to see rather than what is actually there. If the context suggests that you should see a certain word, you may read that word even if different letters are actually present. If a face is shown upside down, you may fail to notice distortions that would be obvious if the face were right-side up.

These are not failures of perception. They are features of how perception works. The brain uses expectations to guide perception. It uses past patterns to predict what should be present. It then matches the incoming sensory data to these predictions.

This is called predictive processing. The brain is constantly making predictions about what it should perceive, and then updating those predictions based on sensory input. Perception is not a passive reception of data. It is an active process of hypothesis and revision.

This means that your perception is shaped by your history. What you have experienced shapes what you expect to experience. Your past, encoded in the structure of your brain, shapes what you perceive in the present.

In one sense, this makes perception very fragile. It makes perception vulnerable to all the limitations, biases, and distortions that shape expectation. We see what we expect to see, which means we miss what we do not expect to see.

In another sense, this makes perception robust. It makes perception possible in the first place. Without expectations, without the ability to predict and anticipate, we would be overwhelmed by the raw chaos of sensory data. We would have no way to organize it into meaningful patterns.

The brain's use of expectations is not a bug. It is a feature. It is what makes perception work.

III. The Ambiguity of Perception

Many perceptual situations are fundamentally ambiguous. The sensory data can be interpreted in more than one way.

The classic example is the figure-ground reversal. Look at an image that can be seen as either a white vase on a black background or two black faces on a white background. You will see one interpretation, then the other, then the first again. But you cannot see both simultaneously. The sensory data is the same in each case. What changes is your interpretation of it.

Or consider the Necker cube, a wireframe cube drawn in two dimensions. You can see it as oriented one way, or oriented another way. Again, the sensory data is fixed. Your interpretation fluctuates.

These examples show that perception is not simply a matter of reading off what is there. The same sensory data can support multiple interpretations. Your perception depends on which interpretation your brain settles on.

In real-world perception, this ambiguity is usually resolved quickly. Your expectations guide you toward one interpretation. The context makes one interpretation more plausible. But the ambiguity is still there, lurking beneath the surface.

Moreover, there are cases in which the ambiguity is not resolved. There are perceptions that remain genuinely equivocal, that can be understood in multiple ways, and in which there is no fact of the matter about which interpretation is correct.

Consider a gesture. Someone waves their hand. Is it a wave hello or a wave goodbye? The same physical movement can mean two different things. The interpretation depends on context, on what you expect, on what the person intends.

Or consider a facial expression. Someone's mouth is turned upward slightly. Are they smiling or smirking? Genuinely happy or sarcastically amused? The sensory data underdetermines the interpretation.

In these cases, perception is not straightforward. It is a matter of judgment, of interpretation, of reading between the lines.

This suggests that perception is not simply a process of passive reception. It is an act of interpretation, and like all acts of interpretation, it can be done well or poorly, correctly or incorrectly, in multiple ways.

IV. Perception as Co-Creation

If perception involves expectations, interpretations, and construction of meaning, then perception is not simply a discovery of what is already there. Perception is a kind of co-creation.

The object being perceived contributes something. It has properties that constrain what interpretations are possible. An object cannot appear as whatever we want it to appear as. There is a constraint from the object's side.

But the perceiver also contributes something. The perceiver brings expectations, past experience, attentional focus, interpretive frameworks. The perceiver brings the structure of the nervous system, which processes sensory data in a particular way.

The perception that emerges is a result of both contributions. It is neither purely objective (determined entirely by the object) nor purely subjective (determined entirely by the perceiver). It is something that arises in the interaction between the perceiver and the perceived.

This is why the same object can be perceived differently by different perceivers. Not because the object is different, but because different perceivers bring different expectations, different frameworks, different ways of paying attention.

A biologist perceives an apple as a reproductive strategy. A merchant perceives it as a commodity with a certain market value. A painter perceives it as a form and color. A child perceives it as a toy or a source of food. The apple remains the same, but what is perceived is different.

This is also why perception can change over time. As you learn more, as your expectations change, as your attention shifts, the same object can come to appear differently to you.

You might see a face as cold and unfriendly. Then you learn more about the person behind the face. You learn about their struggles, their kindness, their vulnerabilities. And suddenly, the face appears differently. It is warmer, more open. The face itself has not changed. But your perception of it has.

This suggests that perception is always somewhat plastic, always somewhat malleable. It can be shaped by learning, by attention, by intention.

V. The Relationship Between Perception and Reality

Given that perception is constructed, interpreted, shaped by expectations, the question becomes: what is the relationship between perception and reality?

One possibility is that perception reveals reality. The world is as it appears to us. Our perceptions are accurate representations of how things are.

But this is difficult to maintain. We know that our perceptions are often wrong. We know that we are subject to illusions. We know that different species perceive the world in radically different ways.

Another possibility is that perception distorts reality. The world is how it actually is, and our perceptions are inaccurate representations of that underlying reality.

But this too is problematic. It assumes that there is a way the world is in itself, independent of all perception. But we have no access to such a world. All we have access to is the world as it appears to us.

A third possibility is that the distinction between perception and reality is not as clean as these first two options assume. Perhaps the world as it is in itself is not fully independent of perception. Perhaps the properties we perceive as belonging to objects are actually relational properties—properties that objects have in relation to perceiving systems.

The color red, for instance, is not a property of the object in isolation. It is a relational property—it is a property that the object has relative to a perceiving system with a certain kind of color vision. The same object that appears red to a human appears differently to a creature with different color vision.

Similarly, the solidity of an object is a relational property—a property the object has relative to perceiving systems like us that interact with it in a certain way. To a creature that could pass through matter, the object would not be solid.

If most of the properties we perceive are relational in this way, then the distinction between perception and reality becomes blurred. The properties we perceive are not invented. They are real. But they are real only in relation to a perceiving system.

VI. The Limits of Perception

Our perceptual systems are specialized for certain tasks. We perceive the range of light wavelengths that are useful for navigating our environment. We perceive the range of sounds that carries important information. We perceive textures, temperatures, tastes—all the qualities that matter for our survival and functioning.

But there is much that we cannot perceive. We cannot see ultraviolet light, though many insects can. We cannot hear ultrasound, though many animals can. We cannot perceive magnetic fields, though some animals navigate by them.

Moreover, our perception has blind spots. There are patterns and processes that are happening constantly around us that we do not perceive. The immune system working inside our bodies. The bacteria living in our digestive systems. The electromagnetic fields generated by electrical appliances. The ultraviolet radiation hitting our skin.

These things are not less real because we cannot perceive them. They are just as real as the things we can perceive. But they are invisible to us.

This means that our perception gives us access to only a thin slice of reality. A slice that is tailored to our evolutionary history and our survival needs. But there is much more to reality than what we can perceive.

We can extend our perception through instruments. A telescope lets us see distant galaxies. A microscope lets us see cells and microorganisms. Instruments that detect infrared radiation let us see heat. But these extended perceptions are still limited. There will always be aspects of reality that remain beyond our perceptual reach.

This suggests a kind of epistemic humility. Our perception is real. It gives us genuine access to the world. But it is not comprehensive. There is more to reality than what appears to us through perception.

Closing: The Constructed Appearance

Perception is constructed. It is shaped by the structure of the nervous system, by past experience, by expectations, by attention, by interpretation. It is not a simple reading-off of what is there.

But construction does not mean distortion. The world being perceived contributes to the perception. There is a constraint from the object's side. The construction is not arbitrary.

What we perceive is the world as it appears to us, given our particular embodied perspective. It is not the world in itself, independent of perception. But it is a genuine appearance, a genuine way that the world reveals itself to perceiving beings like us.

To understand perception in this way is to recognize both the reality and the limitation of our perceptions. Our perceptions are real, but they are not the whole story. They reveal something true about the world, but they also conceal something. They make certain aspects of reality visible while rendering other aspects invisible.

The work is not to escape perception, to somehow get access to the world as it is in itself. That is impossible. The work is to become more aware of how perception works, more attentive to the ways it shapes what we see, more humble about the limits of what we can perceive.

It is also to recognize that others perceive differently. That different embodied perspectives reveal different aspects of the world. That what is invisible to us might be visible to someone else. That the world is larger and stranger than what appears to any single perceiver.

This recognition does not lead to despair about the possibility of knowledge. It leads instead to a different understanding of what knowledge is. Knowledge is not access to the world as it is in itself. Knowledge is the achievement of ever more adequate perception, ever more refined understanding of how the world appears from various perspectives.