The measurement has always been key to science. That's how we collect data. Most of the time we don't even think too much of it. But at the quantum level, the measurement is mysterious. The wave nature of the particle suddenly "collapses." An example of this is the classic double-slit experiment. There's a wave-like interference when the fired electrons are unobserved, but when they are "observed" as they pass through the slits, the electrons demonstrate particle-like interference patterns. The reason for this is very debated, and for that I recommend looking up the interpretations of quantum mechanics. So, while we are not sure why particles' wave nature collapses into one, definite value, we at least know that it does.
These constant measurements that collapse into particles cause decoherence, which is why a table doesn't just collapse suddenly, because the particles in the table constantly interact with each other to cause a nonstop particle nature. But, what our are thoughts? From my research, it appears that no one knows the answer to this yet. Well regardless, is it something metaphysical or physical? I don't think it is metaphysical, because it wouldn't make sense how can we physically utilize something metaphysical. If physical, is it a "process" or "part"? For a more in-depth discussion of thoughts, definetly read https://mcgovern.mit.edu/2019/07/29/ask-the-brain-do-thoughts-have-mass/. But regardless, if it is something in the neurons of our brain to make us think, there has to be some "collapse" of the particle/wave to convey and express a particular thought. But then what makes us think a thought if it's a collapse? Is it other particles in our brain? Is it the wiring of our brains? God? Do these answers suggest pure randomness? Something already deterministic that solves all this? Even if a thought isn't a physical part, the process that makes it still is fundamentally a result of quantum mechanic measurement collapsing. And with that collapsing, what does that entail for the correct interpretation of quantum mechanics for our universe? What does that entail for the nature of our free will, randomness, or deterministcy? And what in our brain is preventing our brain from being a static object like a table? Wouldn't constant measurements in our brain cause a quantum Zeno effect where nothing ever really happens due to constant measurement? But then again, nothing is ever completely static, quantum uncertainty prohibits that. But wouldn't that resulting fuzziness still imply randomness? But then how does randomness lead to competent thoughts? Are we really diving too much into the idea of conscienceness? Is it something that even particles have, and we humans just make a bigger deal about it than it should be? Where do these questions even end?
MY PERSONAL RESPONSE TO ALL THIS (not required to read, but I hope you do): I think this is all some pretty crazy stuff. I think we have definteley some randomness, but our universe, compared to so many other likely possibilities of a universe full of "nothingness," is just unlikely. I couldn't fathom how our universe could even be. To me, this personally suggests a many-worlds interpretation. However, I think that through God, one can control their "path" in the splitting of the universes. I hope a discussion of the quantum measurement as it applies to our brain supports my view. My view makes the universe that we are presently in so special, so unique, and so perfect. Ok, granted it is not perfectly perfect, because not everyone may be taking the "right" path, and our universe has sin in it, but it is for sure much better than a universe of straight up nothingness. And it makes our universe, and every universe, unique, only one of it's kind for every desiscion and event that is made.
Wow, this is really a crazy topic. I hope this might shine more light into the really, really odd nature of our brain, thinking, and quantum physics+interpreations. I sincerely hope there is more discussion on this, like in this (https://www.newscientist.com/article/mg22830500-300-is-quantum-physics-behind-your-brains-ability-to-think/) article (I couldn't read the full thing but it looked pretty similar to this discussion). Thank you for reading, and feel free to reach out.