Seeing a Red Apple
Given that psychiatry considers the mind to be the brain, I would like to discuss a rather philosophical topic.
I want to think about "seeing a red apple."
If we think about it naively, it goes like this: my retinas capture the apple that objectively exists in front of me, that light data is sent to the visual cortex in my brain and processed, and thus I subjectively see the apple.
Philosophically speaking, this model seems to be problematic.
In this model, the subject performing the information processing of "seeing" leads to an infinite regress, and "what it means to see" never becomes clear. We cannot say that a little person, or homunculus, is doing the seeing inside the brain (see diagram below).
According to "A Spiritual History of Generation and Extinction" (by Kazumi Shimonishi), the direction for resolving this "homunculus paradox" can be found in Francisco Varela's embodied cognitive science.
When considering human visual cognition, light data entering through the eyeballs is first received by retinal cells, and that information is sent to the lateral geniculate nucleus (LGN), a nerve nucleus in the posterior thalamus. It is then explained by a visual pathway where vision is realized by that information being sent to the primary visual cortex in the back of the brain. However, Varela explains that in reality, information from retinal cells accounts for only about 20% of the information the LGN receives. Approximately 80% of the visual information the LGN receives is recursive information passed through complex and dense networks within the brain. In other words, in vision, the cognitive system does not achieve sight by simply reconstructing light data from the outside world; rather, it realizes vision by incorporating external data as stimuli into the organizational structure of data self-generated by the networks within its own system.
In short, the amount of light data from the apple that enters the eyes directly accounts for only about 20% of the total information that realizes the visual image of the apple I am perceiving.
What kind of information is the remaining 80% (recursive information through complex and dense networks within the brain / the organizational structure of data self-generated by the networks within its own system)?
The author does not explicitly state it, but if we grasp the meaning, it is likely as follows.
Information processing the discrepancy in light data between the right and left eyes (depth)
Information on the sensation of weight received by the hand holding the apple
Information processing the changes in light data when moving the apple up, down, left, and right, as well as changes in bodily sensations when moving the hand
Memory information from when I went to an apple orchard and picked apples two years ago
And so on.
Merleau-Ponty's phenomenology once proposed that our cognition, not limited to vision, is structured and established by such active bodily behaviors. Referring to this, Varela thought that the mind is something generated by engaging with the world through bodily actions.
The red hue of an apple is not an objective piece of information called 'red' existing on the side of the world that the brain represents; rather, it is a texture perceived from unique information quantities and relationships, historically formed based on the coupling of the cognitive system and the environment, as a sequence of processes where I pick up the apple, move it in front of me, learn the patterns of change in light reflection, and repeat this over and over.
In other words, "seeing a red apple" means mobilizing all past bodily memories and current bodily information to experience the apple with my entire body.
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About this essay
Author's intent
The assigned book was my own work. Therefore, I thought I would write about content that I couldn't fully cover when I wrote the book. Mr. Shiromura, who sent the publication proposal for this book to the publisher, once said to me, "Why don't you write your thoughts on what is happening inside the brain?" and that has stayed with me ever since. I wrote an essay on this theme in June of this year, but I wanted to brush it up further.
In psychiatry, drug therapy is conducted on the premise that the mind is a function of the brain. On the other hand, there is also psychotherapy that is as effective as medication, and recently, a treatment method called Open Dialogue, which does not use drugs, has been attracting attention. We tend to think of drug therapy and psychotherapy as opposing forces, but both are used in clinical practice. Why are materialistic drug therapy and idealistic psychotherapy compatible? The best philosophy provides the basis that makes this possible. I have written about that philosophy using "seeing a red apple" as the subject matter.
Process to completion
This work is the first draft. On Thursday, November 13th, I looked back at the reference book "A Spiritual History of Generation and Extinction," which I had finished reading by then, and brainstormed ideas. I considered which parts of the book would be good to quote. I got the feeling that I could use "seeing a red apple" as the subject matter (60 minutes). The next day, I started writing the first draft (85 minutes). I took a day off and completed the first draft on Sunday, November 16th (190 minutes). I finished it the following day, Monday, November 17th. I clarified the connection with my own book and further adjusted the expressions (65 minutes).
This time, since the quoted parts inevitably became long, I decided that for the 800-character limit, I would make the body text, excluding the quoted parts, around 800 characters. Please forgive me.