Anecdotally, when I first started taking (6 normal-strength pills a day) of fish oil in college, I quite unexpectedly noticed my "field of view" expanded when I was driving. Previously I'd been exclusively focused on a smallish area immediately in front my my car, but after a few months of Omega 3s, I noticed I was "noticing" and taking into account traffic that was much further down the street.
Though I kinda suspect that was the result of curing a deficiency, because I plateaued and didn't notice other improvements after continued supplementation. It was also very early in the fish oil/Omega 3 craze, so I suspect the food up to that point was generally more deficient in it (e.g. no feed chickens flax to get "Omega 3" eggs).
Interesting, I actually had an extremely similar experience, except it was when I first took ADHD medicine, and I noticed it most strongly while navigating through the city by foot. "Field of View" is a good sort of description for it though, it was like the amount of information I could passively perceive about my immediate surroundings just increased dramatically.
Though I kinda suspect that was the result of curing a deficiency, because I plateaued and didn't notice other improvements after continued supplementation. It was also very early in the fish oil/Omega 3 craze, so I suspect the food up to that point was generally more deficient in it (e.g. no feed chickens flax to get "Omega 3" eggs).