The tendency to note and remember things not directly relevant to the activity at hand. It is often described as unintentional, and also latent, since it takes place without awareness and the information we acquire remains hidden until an occasion for its use arises. *We learn a great deal without making any conscious attempt to learn andwithout making any kind of overt response. When we are a passenger in an automobile, without responsibility for reaching the destination, we still learn something about the route. Without fully realizing it we notice certain turns, outstanding houses and other landmarks. If we take the same route alone at a later date, we find it easier to get to our destination than if we had never been on the road before. Similarly, we often note that a store sells a certain line of goods we are not shopping for at the moment. If we wish to purchase these goods on another occasion, we will head directly for them.The existence of this type of learning is accepted by most investigators, but there is some controversy over its origin. Some psychologists contend that no learning whatever can take place unless there is a motive to learn. For these investigators, learning is always in response to an interest, an incentive or a need. They therefore conclude that at the very least an exploratory drive must be operating in incidental learning. The person who learns the route even when he is not driving must have a curiosity about the road or a notion that he might need to take the route himself at a later date. Likewise the shopper makes an incidental note of a line of goods because he is already interested in it, even if he does not intend to purchase it at the moment.Opponents of this interpretation maintain that we acquire a startling amount of information without the slightest intention or motivation. So long as we are awake, and even perhaps when we are asleep, our senses receive constant stimuli, and these are transmitted to the brain whether we wish it or not. Compelling evidence for this view can be found in the quantity of incidental information that can be elicited under hypnosis. Experiments have shown that if you ask a student in his waking state about the color of the shirts of his two nearest neighbors in the preceding class, you will almost certainly draw a blank—but if he is put into a trance and then asked the same question, he will practically always give a correct answer.Samuel Taylor Coleridge has given us a case that supports the idea of unmotivated incidental learning. A domestic servant he once employed became ill and had to be taken to the hospital. There she developed a delirium, and —though totally illiterate—astonished the doctors by speaking phrases and entire sentences in Latin, Greek, and Hebrew. Subsequent investigation revealed that she had once worked for a learned clergyman who made a practice of walking up and down the corridors of the house declaiming biblical quotations in the three languages.The idea of incidental learning is frequently used to explain the deja vu experience. Sometimes new experiences have a familiar ring: we feel we have been in this room before, even though we know we have never seen it. Quite probably we have at one time been in a similar room, and have noted at least its general pattern without realizing it.