When people think about how to solve a problem, they typically manipulate verbal concepts.
For example, you solved the candle problem by manipulating the concepts "candle," "match," and "lighting a candle"
until you arrived at a plan of action: "Move the match to the candle wick."
But not all thinking depends on verbal concepts.
A quite different form of thinking involves manipulating mental images--the "pictures in your head"
that allow you to think about things that can't be expressed easily in words.
These mental images can be moved and rotated “in your head” to solve problems and make decisions.
The amount of time required to rotate an object “in your head” increases predictably
as the amount of rotation (angular distance) increases, just as it would if you were rotating the actual object in your hand.