Now listen to part of a lecture on this topic in a psychology class.

(male professor)
OK, um, the first kind of memory, we’re all very familiar with this,right? You probably remember what you had for dinner last night. You have a conscious memory of last night’s dinner so, um, if I ask you what did you eat last night, you could tell me.

But these other kinds of memories, implicit memories, they work differently. Let’s take an example from the world of advertising. When you are driving along a highway,you see plenty of billboards, you know, road side advertisements. You certainly don’t remember them all, but they still affect you. Marketing researchers have shown, well to be specific, let’s say there’s a billboard on the highway advertising, uh, a car called the Panther. The ad shows a big picture of the car and above the car, in huge letters, is the name of the car, Panther. A lot of people drive by the billboard, but ask those drivers later if they saw any advertisements for cars, and well, they’ll think about it and a lot of them will say no. They honestly don’t remember seeing any. They have no conscious memory of the Panther billboard.

So, you ask these same people a different question. You ask, um, OK, you ask them to name an animal starting with a letter P. What do you think they’ll answer? Do they say Pig? Pig is the most common animal that starts with the letter P. But they don’t say Pig. They say Panther! The billboard had an effect, even though the drivers don’t remember ever seeing it.