PSYC1021 - Memory and Learning

Forgetting

Forgetting is the inability to access a memory - the memory itself may or may not be present.

Bahrick (1984) tested people's knowledge of Spanish (which they had learned as a foreign language). Two findings stand out. First, the better Spanish was originally learned, the better it was retained. Second, knowledge of Spanish declined for the first two to three years, after which it remained constant for the next 25 to 30 years. Then it started to decline again, probably part of the normal ageing process. Bahrick came to the conclusion that knowledge was held in a memory storage system he called the permastore.

Memory for skills (nondeclarative knowledge)

It is often thought that certain skills, such as learning to ride a bike, once learned are never forgotten. In reality, the situation is a little more complicated. If skills are very well learned, (overlearned) and practiced repeatedly, then even after several years of not using the skills, with a little effort the skills seem to return quickly. However, if the skills are learned in only one or two sessions and practiced sparingly, then they are forgotten much like declarative knowledge.

Theories of forgetting

The law of disuse (decay theory) - the original view on memory failure. This is probably the main reason for forgetting with regard to sensory memory and STM. But for LTM what happens during the time period is likely to be much more important than the simple passage of time. Bjork and Bjork (1992) have proposed a new Theory of Disuse. This states that there is no limit on our storage capacity, but that there is a limit on our ability to retrieve information. Unless information is periodically retrieved, it will become inaccessible because of the learning and/or retrieval of similar information.

Interference theory - forgetting occurs because other information interferes with retention. In retroactive interference newer information interferes with older information. In proactive interference previously learned information interferes with newer information.

Motivated forgetting - occurs when a person wants to forget something. Supression is when this is done consciously, repression when it is done unconsciously.

Cue-dependent forgetting - occurs when there are insufficient retrieval cues available.

Baddeley, A.D. (1999). Essentials of human memory. Hove, East Sussex: Psychology Press, pps 109-129.
Bahrick, H.P. (1984). Semantic memory content in permastore: Fifty years of memory for Spanish learned in school. Journal of Experimental Psychology: General, 113, 1-35.
Bjork, R.A. & Bjork, E.L. (1992). A new theory of disuse and an old theroy of stimulus fluctuation. In A.F. Healy, S.M. Kosslyn & R.M. Shiffrin (Eds.), From learning processes to cognitive processes: Essays in honor of William K. Estres (Vol. 2, pp. 35-67). Hillsdale, NJ: Erlbaum.
 

Dave Rowley - 0.120 Scraptoft Campus -
dtr@dmu.ac.uk
How to get to Scraptoft 

Dave Rowley, Acting Head of the School of Health and Applied Social Sciences
De Montfort University, Scraptoft, Leicester, LE7 9SU, UK
Tel. Direct: 0116 257 7766, PA: 0116 257 7889, from outside the UK replace the 0 by +44