Notice 

One of my students asked me why I said the word “notice” so much.  I said because I want them to “see” with their eye and not their brain.  The intellectual brain imposes previously stored data into the drawing.  As an example, you want to draw a hand, the problem between what you know (intellectual, analytical) and what you see (visual, spatial) is very clear.

You want to draw the hand, but there is a dilemma.  What you see does not match what your brain is telling you.  The eye sees the shape and all the individuality of the hand, the brain sees the shape of the hand.  Both are correct.

To draw a hand you must focus on the shapes, the value, the angles you see.  The task in drawing is to turn off the brain and let the eye tell you what it is seeing.