FYI, that is super hand-wavey and covers over a lot about how the path of the information from the cones/rods gets into V1. The chain of neurons that pass infomation from your eyes to V1 is well studied . Interruptions in that path cause a lot of sightedness issues and are not fun diseases to have. The musician, Stevie Wonder, among others, aledgedly has a form of blindness known as blindsight  where relfexes to motion are perserved, but information is not passed into the conscious mind.
In the end, though neuroscience is a facinating subject, we're just in the beginning of our understanding of the brain. More research is needed.
 https://en.wikipedia.org/wiki/Optic_chiasm a good place to start learning about the chain of information transfer.
EDIT: Additionally, if you want to learn more about neuroscience, the best place to look is at Kandel's Principals of Neural Science . It is a tome of a book, but is the best place to get a deep dive into the brain and our understanding of it. I've not yet seen anything else that is somewhat accessible to the general public but also gets into all the issues with any particular experiment. Most pop-sci book brush over a lot of the very important and thorny issues that each experiment has. I'd also love to know of a good book that is more accessible than Kandel.
Principles of Neural Science, Fifth Edition (Principles of Neural Science (Kandel)) 5th Edition
This has never been a good proxy for truth. It is also completely irrelevant given that the majority of the world has never studied neuroscience.
>science has no idea what consciousness is
Not true. Neuroscience has discovered a lot about consciousness. I recommend Principles of Neural Science if you're interested: https://www.amazon.com/Principles-Neural-Science-Fifth-Kande...
>Plus, there are all kinds of problems and contradictions if the mind reduces to matter.
This is a good text, at an upper-div/grad level, of fundamental neuroscience with all sources cited.
That particular connection is straightforward to do in humans. A Golgi stain to the rector muscles/ON and dissection in cadavers would be sufficient to trace the reflex to the SC and then another Golgi stain to that area to get back to the optic nerve. I'm unfamiliar with the toxicity of Golgi stains, but it may be able to be done alive.
Also, the visual systems to the brain-stem are remarkably conserved through evolution. I would not be surprised to see this connection in lampreys. That any significant percent of humans lack it would be a hell of paper.
Blind individuals usually have these reflexes too (like Stevie Wonder): https://en.wikipedia.org/wiki/Blindsight
For more information on the sensation of taste and all it's myriad complexities, you may want to check out these resources:
http://www.ucdenver.edu/academics/colleges/medicalschool/dep... Sue is a world expert on taste, along with Tom Finger, and her work is excellent in every way.
https://www.amazon.com/Principles-Neural-Science-Fifth-Kande... The bible of neural sciences, though thick and dense, the sections on gustation and olfaction may prove useful to your endeavors.
Edit: Here are some other resources on how to modify your taste sensation to better understand how your taste buds work:
There is also a supplement that you can take that will elliminate your sensation of sweet for a few hours, but I forget the name
Lastly, to understand umami, try getting a few bags of chips of similar salt content and hold your nose the entire time. One of just regular Lays potato chips, one of something like Doritos, and one of those baked Parmesan cheese ships from whole foods. While eating them with your nose held close, try to recognize the changes in the umami taste.
Much of what you say is correct on the first pass, and is better than that of the typical citizen, however, some important details are missing. It seems like you are actually interested in the subject and would benefit from learning in depth about the subjects.
The mind does indeed work in parallel, but you cannot focus on 2 things at once. I think you are referring to reflexes, which are subtlety different than cerebellar functioning and 'automatic' movements. You are very much in control of your own mind, how else would you define what a mind is? However, you are correct in thinking that certain neural processes are outside of our control and that our mind is conditioned by experience to perceive things in a schema.
Really though, the book I linked is great for you, as it seems you have an interest in the subject and want to learn more.
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