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Published byPercival Stephens Modified over 8 years ago
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The modal model because of the huge influence it has had on memory research.
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Structure Sensory Short-term Long-term Processes Encoding: activities taking place during presentation of information (study phase) Storage: activities taking place during the study-test interval Retrieval: activities taking place when stored information is utilized (test phase) ▪ Failure to retrieve – forgetting
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Purpose Passively registers input & briefly retains stimulus trace after stimulus vanishes Functions Helps us retain info that doesn’t last long Aids perception by allowing you to continue processing after the stimulus is gone Keeps accurate record of stimulation so most important can be processed further
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DURATION< 30 sec lifetime CAPACITY~7 chunks unlimited MAIN CODE acoustic- semantic articulatory RETRIEVAL serialparallel FORGETTING decay, interference displacement STMLTM
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Memory span the number of items that can be correctly recalled in order (e.g., digit span test). Miller (1956) “The Magical Number Seven, Plus or Minus Two” Limit of 7 + 2 chunks in STM Chunk: unit of info organized according to a rule or some familiar pattern Chunk: collection of elements that are strongly associated.
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B V S M T A U I vs. T V U S A I B M 1 4 9 2 1 7 7 6 1 9 4 5 1 9 6 3... F B I J F K F D R L B J Task: immediate serial recall (“memory span”) Capacity of STM: "about seven chunks”
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Demo
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Support for A & S model Two serial position effects Primacy Effect Better recall for words at beginning of list Recalled from LTM Recency Effect Better recall for words at end of list Recalled from STM
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Support for A & S model Effect on serial position curve Speeding up presentation rate? Eliminate primacy effect Delaying the start of recall with an interfering task? Eliminate recency effect
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Task: free recall of word lists Primacy effect: better recall of first few words Recency effect: better recall of last few words Glanzer & Cunitz (1966): delay between study and test eliminates recency effect :
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Which list is faster to read aloud? Which list is harder to recall? STM CAPACITY AND REHEARSAL TIME
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Number of syllabesReading Rate 1mumps2.2 words/sec 2measles2.0“ 3leprosy1.7“ 4diphteria1.5“ 5tuberculosis1.3“ Task: immediate serial recall of 6-item lists The word length effect
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% words in correct TYPE OF SERIAL position RECALL TASK: A S C STM: 5 words, one trial, no delay__%__%76% LTM: 10 words, four trials, delay__%__%72% Acoustically similar lists: mad, plan, nap, bag…. Semantically similar lists: big, large, huge, great… Control lists: pen, day, wish, bill…..09.70.64.53
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Varied set of digits held in STM E.g., memory set size of four: 2, 5, 8, 1 Task: is it in the set? 2yes 7no Retrieval for STM: parallel or serial?
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Conclusions: STM duration: most info was gone after about 18 seconds. Why do we forget? Strong support for decay? Lachman, Lachman, & Butterfield (1979)
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Replicated the Peterson & Peterson Task. But, they also analyzed their data by trial number. 1 st trial is 1 st word presented to participants Conclusion: Forgetting almost does not occur at the first trial, But more forgetting with each succeeding trial. Why? Adapted from Keppel & Underwood (1962)
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Things learned prior to study can proactively interfere with memory STUDY phase. Things learned between study and test can retroactively interfere with memory TEST phase.
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Proactive Interference (PI) also occurs. Proactive interference refers to forgetting that occurs due to prior learning.
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Clive Wearing: impaired STM but LTM deficit Case of H. M. – Bilateral medial temporal lobectomy (amygdala, uncus, hippocampal gyrus and anterior 2/3 of hippocampus were removed) in 1953 to control for epileptic seizures. The resulting effect was profound anterograde amnesia – loss of LTM Case of K. F. (Shallice & Warrington, 1970) – who suffered brain damage because of motorbike accident had normal LTM but poor STM. Evidence in digit span task performance (commonly used in ability tests).
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Current status Sensory memory is part of perception, rather than memory Short-term memory is more flexible than just a passive storehouse working memory Parallel processing
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