Encoding, capacity, duration Flashcards
Encoding
The brain taking in and processing information
Capacity
How much information a store can hold
Duration
How long a store can hold information
Sensory memory encoding
The sensory memory takes information from the sense organs and holds them in that form.
Echoic
Auditory input from the ears. Stored as sounds.
Iconic
Visual information from the eyes. Stored as images.
Haptic
Tactile input from the body. Stored as images.
Research into sensory memory
Information is stored in an unprocessed form.
Transferred to short term memory through attention.
Crowder (1993)
Sensory register retains iconic information fir a few milliseconds.
Echoic store lasts 2/3 seconds.
Sensory memory capacity
Based on Sperling (1960)
Presented a grid of letters for less than a second.
Sperling used tones to cue participants to recall a specific row.
Recall on the specified row was high.
Demonstrates we have a large capacity in our sensory memory.
Sensory memory encoding
Conrad (1964)
Visually represented students with letters one at a time.
Found that letters which are acoustically similar (rhyming) are harder to recall from STM than those which are acoustically dissimilar (non-rhyming).
This suggests that STM mainly encodes things acoustically even though items were presented visually.
Capacity of STM
Miller (1956): The STM can hold ‘the magic number 7, plus or minus 2’.
Miller found that the capacity of STM could be considerably increased by combining/organising separate bits of I formation I to larger chunks.
Chunking involves making the information more meaningful, through organising it in line with existing knowledge from your LTM.
Duration of STM.
The duration for which STM can retain information is temporary.
Some findings suggest only a few seconds before it decays (unless we rehearse it).
Duration of STM research.
Peterson and Peterson (1959).
Got students to recall combinations of 3 letters, After longer and longer intervals.
During the intervals, they were prevented from rehearsing by a counting task.
Concluded that STM is between 18-30 seconds.
Long term encoding research
Based on Baddeley (1966).
Presented list of 10 short words at one time.
Some lists were semantically similar, others not.
Tested immediately and then after a 20 minute delay.
Found that after 20 minutes, they did poorly on the semantically similar words.
This suggests that we encode LTM according to what they mean, so we get similar-meaning things confused.
Long term encoding
Encoding in LTM is ‘semantic’-meaning based.
Long term memory capacity
Capacity is potentially unlimited.
LTM duration
Duration is anything up to a lifetime (minutes to years).
Difficult to test the exact duration.
LTM duration research
Bahrick et al. (1975) tested US graduates.
Shown classmates photos years later.
90% accuracy for remembering faces and names 34 years after graduation.
Declined after 48 years, especially for faces.
AO3: Artificial stimuli
Baddeley’s study used artificial stimuli rather than meaningful material as they had no personal meaning to participants.
Need to be cautious about generalising findings to different kinds of memory tasks.
Findings from study have limited application.
AO3: not so many chunks
Miller may have overestimated the capacity of the STM.
Cowan (2001) reviewed other research and concluded the capacity of STM is only about four chunks.
AO3: meaningless stimuli
Peterson and Peterson study used artificial stimulus material.
It does not reflect most real-life memory activities.
Lacked external validity.
AO3: high external validity
Bahrick et al. studied real-life meaningful memories.
High external validity.
However, confounding variables were not controlled.
AO3: criticising Peterson and Peterson
Memory trace may just disappear if not rehearsed.
Or information in STM is displaced.
STM has limited capacity and new information pushes out what is already there.
