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  • Created on: 05-01-13 12:43


Key Terms

Short-term memory Memory for immediate events, last for a very short time and disappear unless they are rehearsed - limited capacity and duration.

Long term memory Memory for events that have happened in the past - from 2 mins to 100 years. Potentially has unlimited capacity and duration.

Encoding The way information is changed so that it can be stored by the brain. Info enters the brain via the senses and is then stored in various forms such a visual code, acoustic forms , or semantic form. STM = acoustic, LTM= semantic, in general terms. 

Duration A measure of how long a memory lasts until it is no long available. STM has a very limited duration whereas LTM has a potentially limitless duration. 

Capacity Measure of how much can be held in memory, measured in terms of bits of info such as numbers and digits. STM has limited capacity while LTM has limitless capacity. 

Eye-witness testimony A legal term, referring to the use of a eye witness to give evidence in court concerning the identity of someone who has committed a crime. Accounts of an event from someone who was at the crime. 

Misleading information A question, that either by its form or content, suggests what answer is desirable or leads them to the desired answer. 


6 marks for description

6 marks of evaluation 

(validity and ethics)

Capacity KEY EXPERIMENT: Jacobs

ppts were presented with a string of letters or numbers. They had to repeat them in the same order and the number increased until they could not repeat them back. Results: 9 digits, and 7 letters, results increased with age during childhood. Conclusion: STM has capacity of 5-9 items - digits may be remembered better as there are 9 digits and 26 letters. Evaluation: artifical and lacks validity - not a task done in real life. Meaningful may be recalled better, demand characteristics present and confusing.

Millers magic number: 7+/- 2 - we use the technique of chunking to remember more. 

Capacity of LTM may be limitless but impossible to measure. 

Duration KEY EXPERIMENT STM: Peterson and Peterson. Ppts shown nonsense trigrams and recalled them after 3,6,9,12,15 or 18 seconds.  During the pause, asked to count back in 3s to stop rehearsal - interference task.  After 3 seconds, recall was 80%, after 18 seconds, recall was about 10%. Conclusion: when rehearsal is prevented, very little can stay in STM for more than 18 seconds.   Evaluation: reliable as in a lab so variables are tightly controlled - however - nonsense trigrams are artificial so the study lacks ecological validity. Meaningful or ‘real-life’ memories may last much longer in STM, such as phone number, address of someone we know. Only one type of stimulus was used, may have a longer duration with a different stimulus, eg) pictures, sounds. Lots of trigrams may have left to confusion. 

KEY STUDY LTM: Bahrick 1975. LTM memory investigated in a natural setting (field experiment). 392 people were…



so helpful!!1

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