An interesting question regarding lighting's effect on studying + retaining material + focus ; Does the entire space need to be well lit - or the object of you

An interesting question regarding lighting's effect on studying + retaining material + focus ; Does the entire space need to be well lit - or the object of your focus (which can require the entire scene (such as a lab etc) - but when it comes to reading and computing. If you have a spot on your book or your computer that was of the sun-like quality, (obviously without glare on screens), would that suffice to aid in focus and retention. I assume that a well lite complete space serves a more biological soothing and depression help. So it would be interesting to know if there are differing applications of sun-like light based on the goals. At late actual night, a sun-like spotlight on your focus might be good. When you're up and active, then light the whole space...