brains: image codes and verbal codes. image codes are things like thinking of a picture of a dog when you are thinking of a dog, whereas a verbal code would be to think of the word "dog". another example is the difference between thinking of abstract words such as justice or love and thinking of concrete words like elephant or chair. when abstract words are thought of, it is easier to think of them in terms of verbal codes—finding words that define them or describe them. with concrete words, it is often easier to use image codes and bring up a picture of a human or chair in your mind 