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A pioneer of the scientific study of memory:
Hermann Ebbinghaus (1850 – 1909)
Worked as philosopher at University in BerlinPerformed experiments on himself published in classic volume entitled: ‘Über das Gedächtnis’ (1885)
Hermann Ebbinghaus
Serial Learning Experiments A list of items presented one at a time Memorizing lists in sequence until they can be
recalled perfectly in order they were presented Ran tests on himself for six years Memorized thousands of lists of nonsense
syllables (ZAB, VUB, etc.) Invented 2300 of these syllables, arranged them in
random lists and tested them after various delays
What problems do you see with this methodology?
Ebbinghaus' ExperimentsSerial Learning Experiments Learning to criterion
Ebbinghaus would repeatedly attempt to learn the material until he achieved a perfect reproduction (every item memorized in the order originally presented)
“Method of savings“Subtracting the number of repetitions required
to relearn material to a criterion from the number originally required to learn the material to the same criterion
Serial Position Effect (primacy/recency effect)Subjects are much more likely to remember
items at the beginning of a list (primacy effect) and at the end of the list (recency effect)
Invented lists of 16 nonsense syllables to minimize influence of meaningful associations and learner’s historygoal: study memory in ‘pure’ formIntroduced criterion for successful learning (2 errorless recitations)Introduced savings method to measure retention/forgetting of lists
Memory experiments of Ebbinghaus:Focus on retention of newly learnt
material
List-length effectEase of learning and amount of information not
related in linear one-to-one fashionDisproportionate increase in difficulty with more
than 7 syllables
Distributed practiceBeneficial effects of distributed practice for
repetitions
Memory experiments of Ebbinghaus…
Other important findings
Memory Testing Research Methods
Serial Learning ExperimentsThese were Ebbinghaus’ experiments
A list of items presented one at a time Subjects are asked to recall them in
order Memorizing lists in sequence until they
can be recalled perfectly
Memory Testing Research Methods
Free Recall In this experimental procedure the subjects are asked to
recall the items presented to them in any order they wishProbably this is the simplest way to test the effects of
subjects studying verbal material
Murdock (1962) Used common unrelated English words and found the
probability of their recall depended on their position in the list
What effects do you think this researcher found???
Memory Testing Research Methods
Free Recall (cont.)Glanzer and Cunitz (1966)
Same type of experiment as Murdock (1962) except put certain delays into equation
Like AM PMWhat do you think happened here?
Memory Testing Research Methods
Paired-Associate Learning This experiment requires subjects to learn a
set of stimulus-response pairingsOften, subjects are exposed to the list with the
usage of a "flash-card" techniqueEach complete presentation of the list
constitutes a trial and items are presented in a different order on each trial
Most researchers consider this the most challenging type of memory testing
Information Processing
Our memory system works much like that of a computer:Research suggests (Craik & Lockhart, 1972)
that the most important determinant of memory is how extensively memory is encoded or processed when it is first received
How extensively is the encoding (acquisition of information processed) during the initial formation of memory?
Encoding
Information in sensory stores and STM is lost unless it is encoded, or processed into long term memory…Does encoding occur in a special short term
memory (Atkinson and Shiffrin Model) or in rehearsal systems?
3 stages of processing for manipulation of mental representations:
Encoding (acquisition of info)
Storage (retention of info)
Retrieval (recovery of info)
Information-processing approach to memory:
Basic framework
time
Encoding Retrieval
Information Processing: Automatic Processing
Processing that doesn’t require person to consciously attend to something
Information Processing: Effortful Processing
How does storage of this information take place? Imagery
Mnemonic devices Chunking
Organizing information into meaningful units so that it can better be remembered
Mental Rehearsal Maintenance Rehearsal
Repeating things over and over Spacing effect
Elaborate Rehearsal Involves thinking about how new material relates to
information already stored in memory
Information Processing Model: Atkinson & Shiffrin (1968)
Most influential historically & most comprehensive model… In order for info to become firmly
embedded in memory, must pass through 3 stages of mental processing:
Sensory MemoryShort-Term Memory (working memory)Long-Term Memory
Sensory Memory
Major function is to hold info long enough so that it can be processedSight (usually less than a second)Sound (a little longer maybe up to 3
seconds)
Also referred to as “Transient Memories”
Visual sensory memoryThe iconic store
Auditory sensory memoryThe echoic store
Auditory Sensory Memory
Several studies have shown analogous results in auditory memory…Echoic store studies often use dichotic listeningEchoic memory disappears by 5 seconds
Information Processing Model: Atkinson & Shiffrin (1968)
Short-term memoryResearchers differ saying that without
maintenance rehearsal something stays in STM for between 6-30 seconds.
After this its either lost forever or somehow makes its way into LTM
Long-term memory Infinite
Testing STM
Immediate Memory SpanThe maximum # of items you can recall
perfectly after one presentation Miller (1956)
7 +/- 2 meaningful groupings
Brown-Peterson Procedure A method for preventing rehearsalCounting backwards by 3’s
Crowder & Morton (1969): The Suffix Effect
Their directions to participants: I am going to say some numbers At some point, I will say the number zero When you hear me say zero, ignore the zero and repeat
all the numbers that preceded it
Their directions to participants: I am going to say some numbers When you hear the tone, ignore it and repeat all the
numbers that preceded it
STMBaddeley (1986) “Working memory” is the more contemporary term for
short-term memory, is conceptualized as an active system for temporarily storing and manipulating information needed in the execution of complex cognitive tasks
Primacy and recency effects are seen in STMLimits of working memory Phonological working memory Visual working memory
STM vs. LTM
STM – here we can hold only a few items very brieflyLTM – relatively permanent and limitlessMain differences dependence on retrieval cues
they help in LTM; no help in STM differences in capacity
LTM is immeasurable; STM is relatively small and easily measured (Miller, 1956)
differences in duration (decay over time) LTM are not affected by the passage of time much….STM can
disappear in a blink of the eye
LONG TERM MEMORY
Long term memory stores our knowledge of the world It enables us to recall events, solve
problems, comprehend, recognize patterns, etc. (permastore)
Bahrick, Bahrick, and Witlinger (1975)
Memory for picture recognition and matching of names with faces of yearbook portraits was remains pretty accurate even after decades…
1. Picture Recognition Test (shown a year-book picture and asked to recall the name of the person)
2. Multiple-Choice Name Matching Test (match names with pictures) Each picture had 4 names with it – multiple choice test
Bahrick, Bahrick, and Witlinger (1975)
Findings
Picture Recognition Test 50% recall after 34 years
Name Matching Test 75% recall at 34 years 60% recall after 47 years
The memory for faces of high school classmates seems quite durable
Forgetting is rather gradual
LONG TERM MEMORY
Bahrick & Hall (1991) High school Spanish was tested 30 years later Most subjects had no use of the language since
finishing the course So this was recall without intervening practice Retention seems to “level out” after very long periods of
time But we don’t lose all of it – seems some memory is
retained in a “permastore”Unaffected by the passage of time Interestingly, who had gotten the highest grades
remembered the most 30 years later
Types of Interference
Proactive interference The disruptive effect of prior learning on
the recall of new information (old materials increasing the forgetting of new materials)
Retroactive interference The disruptive effect of new information on
the recall of previous information (new materials increasing the forgetting of old materials)
Types of Interference
Examples:
Time 1 Time 2 Test InterferenceCh. 1 Ch. 2 Ch. 2 Ch. 1 pro
w/ch2Ch. 1 Ch. 2 Ch. 1 Ch. 2 ret
w/ch1
Study French Study Sp. Recall Sp. Fr. pro. w/SpStudy French Study Sp. Recall Fr. Sp. ret. w/Fr
Some Memory Distinctions
Procedural memoryA memory of how to do something
Fix a tire, ride a bike, bake a cake, etc.
Declarative memory The ability to state a fact
Such as names or events, etc.
Types of Declarative Memory
Semantic MemoryMemory of general principlesknowledge of concepts and meaningKnowledge of all the information needed to
use language, verbal information, visual-spatial information, etc.
Ex: rules of how to play chess
Types of Declarative Memory
Episodic Memory Memory for specific events in one’s life Autobiographical memory, time and place dependent,
it conveys the conditions of occurrence Knowledge about personally experienced events
Ex: when and who you played chess with the last time
Flashbulb Memories These are extremely vivid episodic memories,
usually attached to a surprising, significant, or vivid event
Memory and Retrieval Cues
How do we recall or retrieve information that is not presently in conscious awareness?Retrieval cues
Stimuli that help us to get information stored in LTMSeems to help the best if it taps into information
that was encoded at the time of learning (encoding specificity principle)
Retrieval Cues
TheoriesRecognition cue
Identifying items from choices
Bahrick (1975)Relearning cue
Material already learned is relearned more quickly than new materials
Memory and Retrieval Cues
Moods Cue The things we learn in one emotional state are are best
remembered in the same state (this is referred to as state-dependent memory)
State Dependent Memory – theory that information learned in a particular state of mind (e.g., depressed, happy, somber) is more easily recalled when in that same state of mind
Seems to have added effectiveness with recollections of everyday events (episodic memory)
Memory and Retrieval Cues
Context Effects Cue Putting yourself in the same context in which
you have experienced something can help with retrieval
See Gooden and Baddeley (1975) – next slide
Memory and Retrieval Cues
Gooden and Baddeley (1975)
Listen/Recall
Group 1: water/land
Group 2: land/water
Group 3: water/water
Group 4: land/land
Memory and Retrieval Cues
Von Restorff Effect (1933) Cue This is our tendency to remember unusual items
better than more common onesVery tall or very short people; unusual names
Cued Recall Method of receiving hints to help with memory
Example: initials in front of picturesTulving and Pearlstone (1966)
Category prompting led to better recall
Available vs. Accessible Memories
Accessible Memories These memories can be recalled or retrieved
Available Memories Memories that contain learned information, but
may not be retrievable (at least not at the present time)
Brown and McNeil (1966) Referred to available memories as "tip-of-the-
tongue“
Absent Mindedness
Absent mindedness means preoccupied, forgetful, inattentive
Includes” “action slips”The performance of unintended actions
Implications: May cause accidents – some that are fatal Workplace deaths, car crashes, etc.
Absent Mindedness
Problems with MethodologyExperimenters can’t seem to obtain these
in the laboratory settingsSo, instead they tell their participants to
keep diary records of any action slips that they detect in their everyday lives…
Do you see a problem with this…
Absent Mindedness: Reason (1979)
35 volunteers asked to keep a diary of their slips of action for two weeks
Some participants reported a total of 400
Reason (1979): Five Categories of Action Slips
(1) Repetition errors (40%) Forgetting a action has been performed and repeating it
(2) Goal switches (20%) Forgetting a goal of a sequence of actions and switching to
a different goal
(3) Omissions and Reversals (18%) Omitting or wrongly ordering the component actions of a
sequence
(4) Confusions or blends (16%) Confusing objects involved in one action sequence with
those involved in another action sequence
(5) Unclassified (6%) These remaining slips did not fit neatly into the other
categories