Perception of the Outside World Is a Construction from Within

When I look at the mountain that exists outside of me, I know that its existence is not a construction of my mind. Our scientific model tells us that the mountain was created by the shifting of tectonic plates. Even without me, those plates keep shifting under and above each other, as they have done for millions of years.

The world changes incessantly through the entangled exchange of the fundamental forces of nature. My mind does not construct the existence of the mountain. The mountain does not disappear when I am gone.

Different Bodies, Different Worlds

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The classical view of perception told us that the world inside is a representation of the world outside, as if my eyes detect images that exist outside my body and represent them inside. The new psychology of predictive processing teaches us the opposite. Every moment, outside my consciousness, my brain actively builds a model of the world (Feldman Barrett & Quigley, 2021).

During the cellular conversations of my brain, inside my body, a model of the world is incessantly being built. My senses bring moving light waves, air pressure changes, and molecules from outside my skin into my body. The networks in my brain add memories, anticipate, predict and control. My perception of the world is an exchange process between what I already know and what my senses bring in.

The external world is created during a cellular conversation within. The experience of the external world is an internal creation. These creations of the mind's models happen largely hidden from consciousness. Consciousness can inspect these images. We call this hidden construction process of the senses exteroception.

The mountain I see outside me is built inside me. There is no way to know anything about that mountain as sliding plates outside the cellular conversations inside. Predictive processing is a theory of how the brain works that suggests that the brain is constantly creating and updating a mental model of the environment. The brain uses this model to predict what it will next see, hear, feel and do, and then compares these predictions with actual sensory input.

The brain tries to minimize the difference between its predictions and reality, either by changing its model or by changing its actions. The concept of predictive processing is based on ideas from neuroscience, psychology, and computer science, and it attempts to explain many aspects of perception, cognition, and action. Our brain does not detect an outside world; our brain constructs a world from within. (Seth, 2021)

Perception of Our Body Is a Construction from Within

Similarly, experience of the world exists in our body as a cellular story. The events in our body are abundant. They build our life energy: the supply of oxygen through the respiratory system, the supply of sugars and fats through the digestive system, transport through the blood stream, the production of ATP in all cells. The possible sensations of these are cellular conversations processed by our brain. The construction of these sensations, known as interoception, happens outside our consciousness.

“Interoception is a secret ingredient in some of the most important and intimate parts of your life.” (Lisa Feldman Barrett & Karen Quigley, 2021)

The quality of the interoceptive processes influences the construction of the exteroceptive processes. The emotional feelings we have affect the way we see the external world. When you are sad, it is difficult to see the beauty of the mountain.

On the other hand, if you manage to see the wonder of the mountain, it will have emotional effects that change your body. Your senses open up, your curiosity increases. Your eyes become absorbed in the shape of the mountain, you see the green carpet of trees, you see the colors.

Exteroception and Interoception Are Not Separated

Interoception and exteroception do not exist as separate processes. The exchange between the two constructs the perception of ourselves and the world. This fundamentally embodied exchange determines who we are and how we perceive ourselves and the world.

It is impossible to directly experience the embodied exchange of another person. How we think the other person feels is a creation from our own bodies. A world exists outside my body. The existence of the world is not a construction of my mind, only the knowing of it.

My knowing of the world is always embodied. Our body always participates in our knowing. Consciousness never manifests separately from an embodied context. The world and my experience of it are embodied psychological processes. This entanglement of intero- and exteroception has enriching implications for our understanding of illness and health. A participatory reality requires a coherent perspective on well-being. How we feel is reflected in our construction of the world.

If all of our knowing seems to be a construction from a living body, if our body seems to create our experience of the world, what could we know about the mountain without our bodies? Our psychology is deeply embodied: What you see depends on how your heart beats. How you know depends on what you feel.