In the case of piano sight reading in particular, part of the issue is also the size of the task. Reading two lines of music at once, with correct notes and rhythm, is hard. There is no doubt about that! But there are many things we can do to repackage the challenge as something fun, accessible and rewarding.
Sight reading is the ability to play a piece of music that you’ve never played before simply by reading it off of a page of written music. In many ways, this skill is no different than an actor’s ability to convincingly perform a section of dialogue by reading it straight off the page.
Sight reading is difficult for guitar because there is obviously more than one place to play a single note. Also, there are “on-the-fly” decisions about which right and left hand finger to use to play notes.
Because of this, for most of us, sight-reading is a skill that takes time to develop, often improving in the background alongside overall musical ability.
In general, spending 45 minutes to an hour every day is a sufficient amount of time to improve your piano skills. If you wish to practice for several hours every day, you may want to consider breaking these practice sessions into smaller portions spaced throughout the day.
When the musicians played, the area of the brain that is typically associated with meaning did not activate. So, music can be used to communicate broad emotions and ideas, but the specifics are lost in the absence of text. Music isn’t exactly a language, but it is very language-like.
In my experience, it takes four to six months of piano lessons before students have mastered the necessary basics and then a sight reading practice can be successfully introduced.