I also feel that there would be a likely Time-of-Day difference in test results. For example (although only indirectly related), I can do Sudoku puzzles really

I also feel that there would be a likely Time-of-Day difference in test results. For example (although only indirectly related), I can do Sudoku puzzles really well after I've been awake for a while. But for the first few hours of the day, I make lots of mistakes that I simply don't make once I'm fully awake and mobilized for the day.