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Flashcards in Short Term Memory Deck (32):

Characteristics of STM

  • Temporary storage info
  • Rehersal, maintenance- increases probability of LTM transfer


STM Capacity

  • limited capacity shorter than sensory memory or long term memory
  • duration depends


In the study, "Does Rehersal Deposit info into LTM?" what is the task procedure?


  • 20 nouns presented one at a time in 5s intervals
  • STUDY: repeat aloud words on the list during each interval
  • RECALL: after the last noun, free recall


Results of the "Does Rehersal Deposit info into LTM?" Study

  • the number of times rehearsed influences recall probability
  • hightened recall for early and later items recalled
  • last 5-7 items tend to be 1st items recalled
  • primacy and recency effects


Primacy effect

extra rehearsal for first few items, which are transferred to LTM


Recency Effect

in study/recall tasks, when list ends, the last few items are till in STM


What other aspects of rehearsal might affecct primacy and recency?

  • delay between study and recall
  • amount of time to rehearse
  • number of items on study list


Backward Counting Between Study and Recall Task

  • Ps are given words to rehearse and have to count backwards between nouns aloud
  • Primacy is due to rehearsal
  • The longer the distrator task, the less likely items are still present in STM at recall


Rate of Presentation During Study

  • IV: presentation time (1s, 2s, 3s)
  • Strong recency effect for all 3 variables
  • Substantial primacy effect
  • For middle words, stronger recall with slower presentation rates
  • Rate of presentation doesn't affect recency


Manipulations of List Length

  • 1s/ item, 20-40 items
  • strong primacy and recency effects for all list lengths


Brown-Peterson Task

  • 3 letter trigram then 3 digit #
  • count backwards out loud from that # by 3s until told to stop
  • IV= time spent counting backwards
  • DV= recall accuracy
  • Ps asked to recall letters


Results of Brown-Peterson Task

  • info decays from STM as duration of distractor task increases
  • without rehearsal, info is forgotten very quickly


Causes of Forgetting

  • decay due to passage of time
  • interference due to shifting attention to new material
  • BP Task- time and amount of interference confounded
  • Probe Digit Tast- used to disentangle effects of time and interference


Probe Digit Task

  • Ps heard a list of 16 digits
  • final digit was a repeat called the probe digit which was a cue to recall the digit that followed the first appearance of the probe
  • IV= reading rate (1 item/ sec....4 items/ sec)
  • IV2= # of items between probe and its first appearance
  • DV= correct recall


Probe Digit Task Results

  • Both decay and interference predict a drop in recall with more items between probe appearances
  • % correct recall is identical in both presentation rates
  • amount of forgetting is similar for slow/fast
  • # of intervening items is critical


Retroactive Interference

  • Memory for one even is impaired by later events
  • ex) trouble remembering where you park
  • RI in PD task= Ps heard list of 16 digits and the last was a repeat
  • RI in BP task= counting backwards


Proactive Interference

  • Memory for one event is impaired by an earlier event
  • ex) trouble remembering where you parked today because of where you park tuesday


Evidence for Proactive Interference (Wickens 1972)

  • Build up of PI is stronger when to be remembered items across successive trials are more similar
  • TRIAL 1: Plum Apricot Lime > Count backwards by 3s (8 secs) > RECALL
  • Recall declines as a function of trial numbers due to proactive interference


Evidence for Proactive Interference with Category Switch

  • Trial 1,2,3: Artist Teacher Doctor
  • Trial 4: Orange Cherry Apple
  • This results in a release from proactive interference
  • Depends on how different items in trial 4 are


Category Switch Trials

  • Fruits > Fruits
  • Veggies > Fruits
  • Flowers > Fruits
  • Professions > Fruits


Variables Affecting Transfer of info to LTM

  • Type of Rehearsal
  • Depth of Processing Theory


Maintenance Rehearsal

  • Rote Repetition
  • less likely to leave permanent record of info in LTM


Elaborative Rehearsal

  • think about what the to be remembered info means and how it is relatd to other things we know
  • ex) repeating definitions vs thinking of examples


Depth of Processing Theory (Levels of Processing)

Craik and Lockhart

  • strength of representation in memory depends on depth of processing
  • Shallow.........................Deep
  • Shallow= attention to perceptual features
  • Deep= attention to meaning



  • 26 words presented, 2 tasks
  • task A (shallow): count vowels in each word
  • task B (deep): write down first word that comes to your mind related to meaning
  • incidental memory test


Level of Processing Effects (Kapur, Craik)

  • 2 encoding conditions
  • SHALLOW: does word contain letter S?
  • DEEP: does word describe living thing?
  • incidental memory test
  • The more effort, the stronger memory processing


Generation Effects

  • connections you generate yourself are better remembered than those provided by others
  • Generate Synonym (deep):
  • Sea-O > Ocean
  • Read Only (shallow):
  • Sea-Ocean
  • Intentional memory test for targets
  • Generate synonym trials have better scores on % correct recall
  • Generate Rhyme (medium):
  • Save-C  > Cave
  • Read Only:
  • Save-Cave
  • Info still better remembered when generated
  • memory is better for generated meaning vs generated sound and memory is better for read-synonym vs read rhyme.


Transfer Appropriate Processing (TAP)

  • aka Encoding Speificity, State Dependent Learning
  • The probability of remember is better when condition at test (retrieval) match those at studying (encoding).
  • Match between levels of processing


Shallow- Rhymes with cave?
Deep: Weather Condition?

Cued Recall

Shallow-Rhymes with cave
Deep: Weather condition


TAP Results

  • Encoding/Recall: Deep/Deep= .78, Shallow/ Shallow= .40
  • Best performance when encoding and retrieval conditions match


Tap Location

  • Divers learn list of 40 unrelated words on land or 20ft underwater
  • Recall Test on land of underwater
  • Under-Under=32
  • Land-Land=32
  • Under-Land=23
  • Land-Under=24


TAP Mood Inductions

  • movies ellicit moods (sad, happy)
  • Happy-Happy= 80
  • Sad-Sad= 82
  • H-S= 68
  • S-H= 65