TSR Wiki > Study Help > Subjects and Revision > Revision Notes > Psychology
Encoding, Capacity and Duration
AS level psychology, cognitive psychology. AQA spec A.
Sensory, Short term and Long term memory differ in three main ways, which are the duration, capacity and encoding of them.
The differences
- Encoding: The way that information is changed so it can be stored in the memory.
- Capacity: How much can be held in memory
- Duration: How long information can remain in the memory
|
| Sensory memory
| Short term memory
| Long term memory
|
| Encoding
| Modality free - takes information from any of the senses
| Acoustic or visual although acoustic is prefered
| Semantic - stores information in terms of it's meaning
|
| Capacity
| Enough for you to be able to switch your attention
| 7 +- 2 objects
| No upper limit
|
| Duration
| Half a second
| 15 seconds
| Potentially 100+ years
|
Case Study
Peterson & Peterson
- Trying to study the duration of short term memory with rehearsal prevented
- 24 participants, each given two practice trials initially.
- They then got 8 trials, on each trial the retention interval was different: 3, 6, 9, 12, 15 or 18 seconds
- Recall was tested by the experimenter saying a nonsense trigram followed by a three digit number
- Then the participant had to count backwards before being asked to recall the nonsense syllable.
- Counting backwards prevented rehearsal
- The research found participants remembered about 90% with only 3 seconds interval but about 2% with an 18 second interval
- There was a rapid rate of forgetting and very little information remained after 18 seconds
- Findings suggest that information is lost rapidly when held in the short term memory if there is little or no chance to rehearse it.
