April 4th, 2003
Yong Ho Kim
Kalat (2002) summarizes the traditional consensus in the psychological community regarding short-term and long-term memory. Short-term memory is a “temporary storage of the information that someone has just experienced’ and long-term memory is “a relatively permanent store of mostly meaningful information”. Additionally, short-term memory stores up to seven (plus or minus two) bits of distinct information for a few seconds, and can store an kind of information. For the long-term memory, the capacity is not known but certainly very large, and the information needs to be closely tied down inside the learner’s mind to be successfully stored.
Often information is first stored in the short-term memory and then passed to the long-term memory. This is called consolidation. Controversy in the psychological community arises on the understanding of this process. Traditionally it has been understood that it is a matter of repetition for the information to pass to the long-term memory. However, recent research disagrees based on the fact that some very personal information don’t require several rehearsals for them to be learnt. It is suggested that the information must be meaningfully and emotionally tied to the learner in order to be transferred to the long-term memory.
Jacoby (1973) tested the effect of rehearsal on memory improvement. By “rehearsal” Jacoby means “a subject’s covert or overt repetition of an item”, so that “increasing rehearsal frequency simply means that the person says the item more often”. He asked a random group of college students to memorize words from a pool of 200 words rated A and AA (obtained from Thorndike and Lorge word book). Ten lists were presented to subjects with a delay interval between each list. Each list consisted of 20 words. During the delay, some subjects were instructed to study the words in silence. Other group was instructed to study the words aloud, and another was instructed to perform arithmetic calculations. After a delay, the subjects were requested to recall all 20 words.
In a laboratory hour of an Introduction to Psychology course in Macalester College, 35 students replicated Jacoby’s experiment with a slight modification. Instead of studying the words aloud, the students were instructed to say the word “Hello” aloud throughout the delay. Instead of performing random arithmetic calculations, students were instructed to think of a 3-digit number and keep subtracting 3 from the number throughout the delay. Instead of studying in silence, students were instructed to remain silent, with no specific duties. The subjects were not divided in groups, but were all asked to perform the same task at a given time.
Based on Jacoby’s results, it is expected that students remembered words better for lists followed by silent study. In my individual test, I remembered 37 words for the interrupted and non-interrupted free recall test, and 14 words when asked to recall the whole list. For recognition, I recognized 37 words. It seemed like recognition would be much an easier task, but I recognized as the exact same amount of words that I recalled during the list-by-list free recall. It might be the case that the number of words recognized dropped from their expected number because that was the last activity and the total list free recall activity interfered with the memory.
Jacoby, L. L. (1973). Ending Processes, Rehearsal, and Recall Requirements. Journal of Verbal Learning and Verbal Behavior, 12, 302-310
Kalat, J. W. (2002). Introduction to Psychology. Pacific Groove, CA: Wadsworth