JD's Guide to Imposition
dedicated to cheesebread
(if you have not yet, read my visualization guide first)
For many people, complete visual imposition of their tulpa is the end-goal of development. An imposed tulpa can be considered a voluntary, but unconscious, visual hallucination, allowing the host to see and believe their tulpa has a space in the physical world just as any other physical object. The imposition process can be considered complete when the host can no longer immediately see through their tulpa. The most important prerequisites to imposition is that you are able to visualize your tulpa flawlessly and consistently for extended periods of time, and that you have no doubts about your tulpa's existence or "realness."
Bottom-Up and Top-Down Processing
Before we begin imposing, we must discuss a few things about how we see, and how we visualize. Human vision starts with light traveling into your retina, containing tons of rod cells and cone cells responsible for vision in low light and color/detail respectively. The retina contains rhodopsin, which is a chemical that converts light into electrical signals conducted through the optic nerve that the brain interprets as vision. Your brains interpretation from visual data is considered a bottom-up process by brain theorists, because low-level details are turned into high-level models. Perception is largely data-driven because it must accurately reflect events in the outside world. Naturally, the interpretation is determined mostly by information from the senses, not by your expectations. In imagination, the process works in reverse. The brain starts with high-level goals and generates mid-level and low-level details that are consistent with them -- a process that is responsible for things such as spontaneous unconscious generation of details in your wonderland. Visualization of your tulpa is a top-down process.
Most people are born with the ability to differentiate between self-generated and external sources of information, as bottom-up and top-down processes must occur without much interference. However, this skill may break down to cause hallucinatory experiences; a hypothesis from cognitive and neuroscientist Stephen Grossberg suggests that overactive top-down processing, or strong perceptual expectations, can generate hallucinations. By exercising influence over our own systems of belief and expectations (as we do in many other areas of tulpa development), we can create an unconscious need for our brain to accept top-down visualizations in the place of bottom-up interpretations of physical perception.
In psychology, a set is a group of expectations that shape experience by making people especially sensitive to specific kinds of information. A perceptual set is a predisposition to perceive things in a certain way, leading us to see what we expect to see. Perceptual sets can be created by motivation and suggestion; with mental discipline, we can create a perceptual set that our tulpas are physical and allow it to become an unconscious expectation, hence imposing our tulpas. It is fortunate that imposition is usually considered one of the final steps of creating a tulpa, since it requires expectation-building techniques that are used in much earlier developmental processes such as reaching sentience, sapience, and hearing your tulpa's voice.
You can use any expectation-creating technique you like, whether it be meditation, hypnosis, forcing, and so on (although take note, you cannot use these to improve your visualization ability alone.) You must convince yourself that there is literally no difference between what you can see with your eyes, and what you can visualize, as the end result either way is an entirely interpreted construction in your brain. Your mental image of the world is entirely subject to your conscious will. Every physical object you see with your eyes is constructed in your mind by the bottom-up process of your eyes reacting to photons emitted by those objects, and your brain translating them into colors and forms. Mental objects you see with your mind's eye, including your tulpa, are constructed by the top-down process of visualization, with details being filled in as needed. A perceptual set must be created to enforce an overactive role for your brain's inherent ability to use top-down processing. You must commit yourself to constantly visualizing your tulpa, ensuring that all details are consistent throughout the day, and accept your tulpa as "real." As time goes on, this constant visualization will become an unconscious routine -- a passive ability. The more your visualization remains consistent not only with itself, but with its surroundings, the sooner you will begin to confuse this as actual perception. Top-down visualization will begin to take priority, dulling your bottom-up perceptions, creating the illusion that you cannot see past your tulpa.
Realistic Visualizations: Basics of Compositing
In order to accelerate the confusion of visualization with perception, you will want to practice the basics of compositing your visualizations into reality in much the same way that a graphic designer or visual effects artist composites computer-generated images into a scene. This is a step by step process that can be replicated through visualization to integrate your tulpa's image into your surroundings as realistically as possible.
In this picture, we can see the tulpa with weak visualization skills. Attempting imposition too early will be unconvincing, as visuals will not be vivid enough.
This will be the base of our imposed visual. Take note that the tulpa looks pasted in and unnatural, as if it was just a picture made by an unskilled nerd with Photoshop. The process of compositing will allow us to make this visualization look more natural given the setting. Rather than using computer graphics though, you will be doing it with your mind.
In graphics, color correction is often done through manipulation of the red, green, and blue channels. By fine-tuning each channel for the tulpa layer, the visualization ends up looking more like it belongs in its setting. This will be easier in your mind, since you don't have to worry about individual color channels. Just use common sense, if you're in a very green forest, there's more green light bouncing around. If you're in a volcano, things will have a fiery color palette.
You will also want to focus on visualizing proper shadows and highlights onto your tulpa, taking into account light-sources in your environment.
Finally you will want to make sure you can visualize any shadows cast by your tulpa (or lights, if your tulpa glows or something).
And voila, you have a more natural looking tulpa. Practice compositing your visualizations so they maintain a realistic look, and in time it will become something you don't even have to think about. After a month or more, depending on how often you practice, you may find you no longer need to put effort into imposition. When you realize your tulpa looks real, and you can no longer immediately see through it, then you have accomplished hallucination.