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
Parallel Search
Looking for items in short term memory by simultaneously comparing to items
Serial Search
Comparisons done one at a time
Longer lists take longer to search through
Exhaustive Search
Self Terminating Search
Exhaustive Search
Way we typically retrieve info - search process has momentum and is hard to stop
Even if match is found, continue looking through every other item (takes just as long for successful vs unsuccessful searches)
Self Terminating Search
Stops when match is found (successful searches take less than unsuccessful ones)
Long Term Memory Capacity
Cannot name a specific numerical capacity
Virtually unlimited storage
Not all info is retrievable at any given moment
Long Term Memory Coding
Semantic coding
Errors made while recalling info from LTM are likely semantic concessions
Participants had harder time learning semantically similar words
Acoustic similarity affects STM, semantic similarity affects LTM
LTM Retention Duration
Some info can last for decades or lifetime
Permastore
Forgetting Curves
For first 3-6 years recall declines
Next 3 decades is a plateau
After about 30-35 years show a final decline
Paired Associates Learning
participants hear list of pairs of words
Researcher presents participants with first word of pair, asked to recall the original word paired with it
Used this task to study proactive interference (previous learning makes retention of subsequent learning more difficult)
Retroactive interference (current learning makes recall of previous learning more difficult)
Retrieval Cue
Points to and leads to the recovery of a target memory
If cue becomes associated with other targets, during retrieval second target competes with the first
Fan Effect
As participants study more facts about a concept, time they need to retrieve a particular fact about the concept increases
LTM Retrieval: Categorization
Material organized into categories or other units is more easily recalled than information with no apparent organization
Participants presented with words scrambled but from 4 categories
Participants recalled words in clusters
LTM Retrieval: Encoding Specificity
Memory is improved when info available at encoding is also available at retrieval
E.g. is best to test students in the same room they studied in
LTM Retrieval: Context Effect
Info unrelated to material (e.g. environmental stimuli) present at time of encoding can be retrieval cue
Participants recalled more words when in the same environment as when learned them
Recognition memory does not show the same context effects
LTM Retrieval: State Dependent Learning
Material learned while someone is intoxicated is usually recalled better when in the same intoxicated state
Found only with recall and not recognition tasks
Working Memory
Limited capacity workspace that can be divided between storage and control processing
Central Executive
Phonological Loop
Visuospatial Sketch Pad
Central Executive
Directs flow of info, chooses which info will be operated on, when, how
Has limited amount of resources and capacity to carry out its tasks
Functions more as an attentional system than a memory store
Phonological Loop
Carry out subvocal rehearsal to maintain verbal material
Important role in learning to read, comprehending language, and acquiring vocab
Short term phonological buffer
Subvocal Rehearsal Loop
Visuospatial Sketch Pad
Maintain visual material through visualization
Creation and use of mental images
Mentally rotating luggage in a trunk to visualize how pieces fit
Short Term Phonological Buffer
Holds on to verbal info for short periods of time, assuming rehearsal is not prevented
Subvocal Rehearsal Loop
Compensate for the rapid decay of info in phonological buffer
Episodic Buffer
Required when remembering specific events from past
Needed to link information across domains (visual, spatial, verbal)
Allows one to sequence various events in chronological order
Episodic Memory
Memories of specific events in which you somehow participated (personal experiences)
Contains memories that are temporally dated
Any memories that can be traced back to single time
Effortful process, requires frontal lobe engagement
Semantic Memory
Holds info that has entered general knowledge base
General info about language and world knowledge
Facts, concepts, ideas
Clive Wearing
Encephalitic in March of 1985
Affected areas include temporal lobes
These structures involve remembering and laying down new memories
Resulted in severe case of amnesia
Hebb Rule
If a synapse between two neurons is repeatedly activated at about the same time a postsynaptic neuron fires, the structure/chemistry of synapse changes
Long Term Potentiation
Neural circuits in hippocampus that are subjected to repeated and intense electrical stimulation develop hippocampal cells that become more sensitive to stimuli
Effect of enhanced response can last for weeks or longer
Method for long term learning and retention
Permastore
Large portions of originally acquired info remind accessible for over 50 years in spite of not being used or rehearsed
Long Term Memory: Forgetting
Forgetting is rapid at first and then levels off
Interference responsible (both proactive and retroactive)
Maintenance Rehearsal
Repetition
Maintain or hold information without transferring it into a deeper code
Elaborative Rehearsal
Elaborate on meaning
Transfers info to deeper code
Provides richer multimodal codes
Makes memory more unique and thus easier to retrieve
Generation Effect
Have people generate a word based on a cue (e.g. present save, ask for rhyming word starting with C)
Massive memory benefit for generated items
Personality & Context Effect
Asked individuals with dissociative identity disorder to learn and recall list of words in each of four personalities
Recalled words better when studied and recalled in same personality
