Chapter 5: Memory Structures Flashcards
Modal Model
Sssumes that info is received, processed, and stored differently for each kind of memory
Short term, long term, & sensory memory
Sensory Memory
Unattended information presented quickly stored briefly
Closely connected to perception
Separate sensory memories for each sensory modality (visual, auditory, olfactory, gustatory, and tactile)
Short Term Memory
Attended information is held for up to 20-30 seconds
Primary memory or short term storage
Long Term Memory
Information needed for longer periods of time
Place for storing large amounts of info for indefinite periods of time
The Icon Letter Matrix
Whole report
Report as many of letters as possible
Participants reported about 4 items
Partial report
Presented a high medium or low pitch tone after the letter matrix
Tone level determines which row participants had to report
Reported about 3 items (equivalent to 9 letters out of the 12)
Partial report shows that we encode in sensory memory all three rows
The Echo
Participants given a four eared listening task
In one condition participants had to report whole string of letters
In other condition a light board cued which string of letters to listen to
Partial reports can remember more letters
Masking
Icon can be erased by other stimuli presented immediately after the icon
E.g. if follow display of letters with display of circles, the circles erase memory trace of original letters
Suffix Effect
Recall cue functions as an auditory mask preventing participants from reporting as many items
Iconic Vs. Echoic Memory
Iconic:
Less than one second
The visual field
Physical features
Echoic:
4-5 seconds
Less than iconic memory
Categorical
Short Term Memory Capacity
7 +/- 2 bits of information
Capacity
Max number of items correctly recalled (tone discrimination, spatial discrimination, letter & digit span, etc)
Can increase capacity by chunking
Reorganize info into meaningful units
Free Recall Experiments
Participants given a list of words to remember, then asked to recall in any order
Serial Position Effect
People are best at remembering words in the first and last half of the list (not good at the middle part)
Primacy Effect
Improved recall of words at beginning of list
Primacy eliminated without rehearsal
Recency Effect
Improved recall of words at end of list
Recency effects are eliminated with delay
Rehearsal
Repetition of items
Thought to help items enter long term storage
Primacy effect disappears if words are read fast enough to avoid rehearsing
Coding
Way info is mentally represented (form in which info is held)
Similar sounding words make for poor immediate recall
But similar meaning words don’t
Reverse is true for delayed recall
Short Term Memory: Retention Duration
If info is not rehearsed, only held for about 20 sec
Brown Peterson task
Participants presented with three consonant trigrams (e.g. BGK) and a number (e.g. 347)
Asked to count backward out loud by threes, in time with metronome
Longer participants had to count backward for decreased the ability to recall
Memory Trace
Encoded mental representation of to be remembered info that is not rehearsed
STM: Decays
Unrehearsed info decays/breaks apart within 20 seconds
Trace Decay Theory
Automatic fading of the memory trace
Interference Theory
Disruption of the memory trace by other traces
Where the degree of interference depends upon the similarity of the two memory traces
Proactive Interferences
Older info makes it difficult to learn new information
Retroactive Interferences
Newer information makes it hard to recall old information
