Memory

Most research on long-term memory is highly specialized, focusing on particular types of information storage and the various retrieval processes associated with them. In the research laboratory memory is most often assessed by recognition, recall, or relearning tasks.

In recognition tasks, research subjects are commonly shown lists of words or groups of visual stimuli, such as pictures of faces. After a period of time subjects are then presented with new lists or groups of visual stimuli in which some of the original material is embedded or mixed in. They are then asked to indicate which items they recognize from the original material. In order to assess different aspects of memory, researchers may vary the amount of material presented, how long they let the subject study it, how much time passes between presentation of the original and altered material, and any number of other variables. Recognition is often quite accurate, especially if the subject is asked only if they have seen an item before. An example of a recognition task in which the subject is asked to choose a correct answer from among incorrect ones is a multiple-choice test.

In recall tasks, subjects are asked to reproduce material that was previously learned. The material may consist of lists of words, stories, or visual stimuli. They may be asked to report the material in exactly the same way it was presented, or to report as much of the material as they can remember in any order at all (this is called "free recall"). In "cued recall" the subject is given clues to aid their recall. Giving clues can improve recall greatly. As in recognition tasks, many variables, such as the amount of material, and time between learning and testing, can be manipulated to test different aspects of memory. An essay test is an example of a recall task.

In relearning studies, the time it takes to learn material initially is compared to the time it takes to learn the same material a second time after it is forgotten. Findings consistently show relearning time is much less than original learning time. The difference between the two learning times is called the "savings score." The high savings scores found across almost all relearning studies indicates that once something is learned, it is never really forgotten completely. It seems some of the original learning remains, although how much and in what form remains unclear.