Memory is concerned with the encoding, storing and retrieval of information. Because we deal with so much information all the time, it is necessary to sift the important from the unimportant. For this to happen, though, we must know what the information is, which means we need to store it somewhere temporarily first. This temporary area is called sensory memory, and it holds information for a short time (about 2 seconds) until it is either processed further or ignored. Assuming we decide to do more with the information, it is then passed to short term memory. This area is where we actually think about things, and where information that is temporarily important (such as how much change you should get after a purchase) is stored. Anything that isn't important, or becomes unimportant, is discarded at this stage - the rest, information we want to keep, is encoded and passed into long term memory. This encoding process is done on meaning - how the new information relates to information already stored within long term memory. The more meaning a new item of information has, the more likely it is to be remembered (Coon, 1992).
There are two types of memory retrieval, these being recall and recognition. The essential difference between the two is that recognition involves selecting a correct response from a number of choices, while with recall the subject must retrieve the information and decide that it is accurate. In scholastic terms, these could be considered to be multiple choice vs. paragraph answers (Leahey & Harris, 1993). In this experiment, recall is being tested.
Mnemonics work by exploiting the feature of the brain that makes things easier to remember if they are associated with other, previously remembered items. Additionally some mnemonics, such as the pegword, use bizarre imagery; the visualising of an improbable scene. It has been shown that the more bizarre the image, the better the recall (Wollen et al, 1972).
There are various forms of mnemonic. One such is the Method of Loci; this works by associating items to be remembered with physical points, for example, a list of things to do could be associated with rooms in a house; bathroom, brush teeth, bedroom, make bed, study, study, and so on. To retrieve the information the subject "walks through" the house and "picks up" the items that have been associated with the various parts of it. The chores and house example might seem obvious but it could equally be a shopping list, song titles or anything at all (Leahey & Harris, 1993).
Another form of mnemonic invents stories. The subject makes up a story using all of the words in the list. To recall, the subject simply tells the story.
In general, mnemonics make use of "paired-associate" tools, where a common object or sequence, such as a bun, a colour or rhyme, is paired with another, and the subject associates the two (Calkins, 1894, cited in Leahey & Harris, 1993). Given that memory is most effective when new information is related to old, the paired-associate technique is powerful.
Bugelski, Kidd and Segmen (1968) have shown that pegword mnemonics, which use this paired-associate technique, aid subjects in their recall when the subject is exposed to the word for 2,4 and 8 seconds. This experiment attempts to reproduce their results using a 6 second exposure.
Bugelski, B.: Kidd, E. & Segmen, J. (1968) Image as a mediator in one-trial paired-associate learning. Journal of Experimental Psychology, 76, pp69-73
Leahey, T. & Harris, R. (1993) p74, p154, pp156-157. Learning and Cognition, 3rd Edition. Prentice Hall, New York
Houston, J. (1986) pp318-322. Fundamentals of Memory and Learning, 3rd Edition. Harcourt Brace Jovanovich, Inc. 1986.
Wollen, K, Weber, A. & Lowry, D. (1972) Bizarreness versus interaction of mental images as determinants of learning. Cognitive Psychology, 2, pp518-523