Short-term Retention

Short-term retention – meaning

Short-term memory (STM) is a temporary store that can hold a limited amount of information for a short period.

The STM store needs to retain the memories for long enough so that they can be elaborately rehearsed and moved to the long-term memory (LTM) store. When trying to recall memories stored in the LTM; the information has to first be moved and retained in the STM store.

Short-term retention can be affected by many factors, such as motivation levels, concentration, injury, and use of social media. As more is discovered about what influences memory, ways to improve our memory have been developed.

Peterson and Peterson (1959)

The aim of the Peterson and Peterson (1959) experiment was to test the duration of STM.

Peterson and Peterson Procedure

The sample pool for the experiment involved 24 psychology students, and the experiment took place in a lab setting.

• The experimenter involved a form of a memory recall test, in which experimenters said a series of trigrams aloud and participants recalled them after completing a distraction task.

• The distraction task involves counting backwards in threes or fours from a random number selected by the researcher. The point of this was to prevent the information from being rehearsed and moved to the LTM store.

• After completing the distraction task, participants were instructed to recall the trigrams.

• A series of trials took place which required participants to recall each after either 3, 6. 9, 12, 15 or 18 seconds for each trigram.

Peterson and Peterson Results

The results of the experiment revealed a trend: the longer that each student had to count backwards (the distraction task), the less accurate they could recall the trigrams.

• 80% of the trigrams were recalled correctly after 3 seconds.
• This fell to 50% after 6 seconds.
• Less than 10% were recalled accurately after an 18-second delay.

The graph shows that participants recalled the trigrams less accurately throughout the time-interval, StudySmarter Original

Peterson and Peterson Conclusion

The study's results indicate that when rehearsal is prevented. As participants more or less could not recall the trigrams after 18 seconds, it can be assumed that the short-term memory has a limited duration of around 18 seconds.

If we are unable to rehearse information, it cannot be passed into the long-term memory, which supports the foundation of the multi-store memory. Information is then lost from the short-term memory through trace decay if there is no rehearsal.

Evaluation of Peterson and Peterson (1959)

Let's discuss the advantages and disadvantages of the Peterson and Peterson (1959) short-term retention study!

Advantages

• Tightly controlled experiment: as the study was carried out in a lab setting, the researchers had a high level of control; this allows the researchers to control for extraneous and confounding variables.

• Use of distraction task: this ensures that the study was measuring what it intended to, the duration of the STM store and not the LTM store. From this, it can be deduced that the study had high internal validity.

• Real-life application: The study is useful to all of us in everyday life, as it suggests that we should learn in 'bits' and rehearse them to retain the information.

Disadvantages

• Low ecological validity: The activity of recalling random nonsense trigrams does not reflect common activities in everyday life. Because of this, it is difficult to establish if the same results would be obtained if the task was something that the average person would do in their everyday life.

• Unable to generalise: The sample pool used for the experiment was a group of 24 psychology students. They all have a similar level of intelligence and are most likely of similar age. When a small sample is used, then it is unlikely to be representative of the wider population, and therefore it is difficult to generalise the Peterson and Peterson results.