Peterson and Peterson, 1959

Peterson and Peterson

1959

Aim

To investigate the duration of short term memory

Area

Short term memory, models of memory

Research method

True exp

IV- Time of intervals between learning and recall

DV- Number of correctly recalled trigrams

Participants

24 psychology students

Procedure

The participants had to recall trigrams, which are three meaningless constant syllables. They were presented one by one and had to be recalled in intervals of 3,6,9,12,15 or 18 seconds depending on the trail. None of the trigrams had two of the same letters. After hearing the trigram the participants were asked to countdown in threes or fours from a specific number until they saw a red light and then recalled the trigram. There was six trials in total.

Results

The results showed that the longer the participant had to count backwards the less accurate the recalls were. After 3 seconds, 80% was recalled correctly. After 6 seconds this fell to 50%. And after 18 seconds less than 10% of the trigrams were recalled correctly.

Conclusion

Short term memory has a limited duration of about 18 seconds when rehearsal is prohibited. If a person is not able to rehearse then the input will will not be able to be transferred to long term memory. Information from short term memory by memory decay.

Multi-Store Memory Model (MSM)

Developed in 1968 and 1971 by Richard Atkinson and Richard Shiffrin. The model describes how information flows through the memory system. The model suggests that memory is made up of three different systems.

The sensory register - Receives a stimulus from the environment, for example someone's name.

Short-term memory (STM) - STM is what is known as a limited capacity store. Information is coded acoustically and lasts 30 seconds unless it is rehearsed. It only passes to the LTM if it is rehearsed enough.

Long-term memory (LTM) - This is a potentially permanent memory store for information that has been rehearsed for long periods of time. psychologists believe that its capacity is unlimited and can last for very many years. It is coded semantically. When we want to recall it, we have to bring it back to our STM through the retrieval process.

sensory memory

the immediate, very brief recording of sensory information in the memory system

short-term memory (STM)

the memory system in which information is held for brief periods of time while being used