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Models of Perception

Sometimes a random note in a pile of paper opens up the most delicious rabbit hole. I offer you the fruit of an evening’s fall in to, and subsequent scramble out of, said hole. You’re welcome!

Apparently in October of 2020 I was looking at the Wikipedia definitions of Perception and Viññāṇa. I found the notes while tidying up around the apartment.

And since these concepts both apply to the upcoming Dharma PhD Podcast episode (where we’ll talk about Paṭiccasamuppāda and the twelve-link model of Dependent Origination as a Buddhist Model of Cognition) I figured, why not explore these a bit?
Here’s what I’d saved from the entry on Perception:

The process of Perception begins with an object in the real world, known as the distal stimulus or distal object.[3] By means of light, sound, or another physical process, the object stimulates the body’s sensory organs. These sensory organs transform the input energy into neural activity—a process called transduction.[3][9] This raw pattern of neural activity is called the proximal stimulus.[3] These neural signals are then transmitted to the brain and processed.[3] The resulting mental re-creation of the distal stimulus is the percept.

To explain the process of perception, an example could be an ordinary shoe. The shoe itself is the distal stimulus. When light from the shoe enters a person’s eye and stimulates the retina, that stimulation is the proximal stimulus.[10] The image of the shoe reconstructed by the brain of the person is the percept.

And this about Viññāṇa:

In Buddhism, the six sense bases (Pali: saḷāyatana; Skt.: ṣaḍāyatana) refer to the five physical sense organs (cf. receptive field) (belonging to the eye, ear, nose, tongue, body), the mind (referred to as the sixth sense base) and their associated objects (visual forms, sounds, odors, flavors, touch and mental objects). Based on the six sense bases, a number of mental factors arise including six “types” or “classes” of consciousness (viññāṇa-kāyā). More specifically, according to this analysis, the six types of consciousness are eye-consciousness (that is, consciousness based on the eye), ear-consciousness, nose-consciousness, tongue-consciousness, body-consciousness and mind-consciousness.[12]

In this context, for instance, when an ear’s receptive field (the proximal stimulus, more commonly known by Buddhists as a sense base, or sense organ) and sound (the distal stimulus, or sense object) are present, the associated (ear-related) consciousness arises. The arising of these three elements (dhātu) – e.g. ear, sound and ear-consciousness – lead to the percept, known as “contact” and in turn causes a pleasant, unpleasant or neutral “feeling” to arise. It is from such feeling that “craving” arises. (See Fig. 1.)

It’s obvious there are correlations here. The Viññāṇa article plays a bit loose with the scientific vocabulary, but it’s close enough for our exploration.

Here’s the first table I put together of the correlation with the addition of Hedonic Tone/Vedanā:

Distal stimulus (actual shoe)
Physical process (light waves)
Sense object (eye-object)
Sense organ (eyeball)Sense organ (eye-base)
Transduction
Proximal stimulus (raw patterns of nueral activity)
Percept (mental re-creation of the distal stimulus)Sense-consciousness (eye-consciousness)
Phassa
Hedonic toneVedanā

You’re welcome!

I was quite pleased with myself and this little table for just under one minute. The trouble with tables is they make it much easier to compare information. They also show very clearly when things are mis-aligned.

The biggest problem for me was around the term “consciousness”.
Does the percept arise in consciousness? Of course it does. But it doesn’t have to. “I” am aware of all kinds of things that “I” am not necessarily conscious of.

But if the percept arises in unconsciousness, is it still “sense consciousness”?

And if it arises in unconsciousness, does it create hedonic tone (Vedanā)? Surely. That’s a huge chunk of that “neither-pleasant-nor-unpleasant” category, I think. Stuff that doesn’t actually make it through to consciousness. I have a percept, I cognize the thing, the conscious “I” just doesn’t know it’s happening. If the hedonic tone (Vedanā) that subsequently arises is neutral, it’s not determined by the system to be worth pursuing or avoiding, and “I” never experience it.

It was in that final bit, the “I never experience it” that I understood the difference of these two maps. Maybe it was obvious to you all along, but it took me some wrangling to see the disconnect.

My understanding of Gotama is that he was primarily interested in experience. And by that I mean conscious experience. (Can we technically have unconscious experience?) Cognitive Science is concerned with a much wider swath of processes that includes both unconscious and conscious.

So the maps don’t overlap precisely. But as John Peacock says in Buddhism Before the Theravada Part 6 (which I’ll post a transcript for soon), the Buddhist Model of Cognition presented in the twelve-item list of Dependent Origination is not the entire process of cognition. It is, however, good enough to get you exploring your subjective, embodied experience.

I think, similarly, this correlation is good enough to help us in that exploration.

So here’s a little diagram showing my present-moment understanding of the overlap and the looser correlation. Sense consciousness in this model is more directly related to conscious percepts. But because unconscious percepts also generate hedonic tone which can then arise into conscious, it is not unrelated…

And you’re still welcome!

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