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Memory
Living with Yesterday
Fundamental Memory Processes
Encoding
Organizing and transforming incoming information
to be entered into memory
Storage Retaining information in memory
Retrieval Accessing information previously stored in memory
Rehearsal The continued activation of information to retain it in
short-term memory
Different Memory Stores
We have three different memory stores, or
sets of neurons that maintain information
Each memory store has a different…
Duration: the length of time information is
maintained
Capacity : the amount of information that is
maintained
Different Memory Stores
Fundamental distinctions among memory
stores were first characterized by Atkinson
and Shiffrin (1968, 1971) and Waugh and
Norman (1965)
Sensory
Memory
Short-Term
Memory
Rehearsal
Long-Term
Memory
Sensory Memory: Lingering sensations
Very short memory store arising from the temporary
activation of perceptual areas of the brain
Characteristics
Duration: Very short, typically less than 1 second
Capacity: Large
Investigation : Sperling’s partial report technique
George Sperling’s classic 1960 experiments
Sensory Memory
ZRAT
BS LD
QEKR
Sperling’s partial
report technique: a
tone indicated which
row to report after the
stimuli disappeared
High tone = Top
Medium tone = Middle
Low tone= Bottom
Sensory Memory
Sperling’s partial report technique
Findings Full report: 4-5 items correctly recalled
Partial report: 4 items correctly recalled based on tone
presented after the stimuli disappeared
Conclusions Large-capacity memory store that fades very quickly
Information must be accessed before it fades or it is lost
Attention is necessary to move information from SM to
STM
Short-Term Memory:
the contents of consciousness
Short-term memory store is the only memory
store whose contents you are aware of
Characteristics
Duration: Several seconds without rehearsal,
typically 30 seconds with rehearsal
Capacity: Small, typically 5-9 items, Miller(1956)Magic 7+_27 2
Processes in STM
Chunking : A chunk is a unit of
information, such as a digit, letter, or word
Rehearsal
Short-Term Memory
Original conceptualization of STM criticized
for…
Not emphasizing active processing of information
Rehearsal is relatively passive and does not sufficiently
explain other processes for keeping information active
in memory
Not emphasizing visual information Original focus was on auditory information
Not emphasizing the role of attention Working Memory (WM)
WM was proposed by Baddeley (1986) to
address the limitations of the original STM
model
Three components of WM
Central executive
Articulatory loop
Visuospatial sketch pad (VSSP)
Working Memory
Central
Executive
Functions of WM
Central Executive
Controls activity of the
articulatory loop and
VSSP
Articulatory Loop
Articulatory
Loop
Visuospatial
Sketch Pad
Tape recorder
Most similar to original
concept of STM
VSSP
Maintains mental
images, location of
objects, etc.
Long-Term Memory: records of experience
Long-term memory store containing the
accumulated knowledge base
Characteristics
Duration: Hours to years
Capacity: Huge-possibly limitless Long-Term Memory
Computer Analogy Inactive information resides in LTM (Hard
Drive)
When you retrieve information you are
moving it from LTM (Hard Drive) to STM
(RAM)
RAM = STM
Hard Drive = LTM
Long-Term Memory
Hermann Ebbinghaus (1850–1909)
Learned lists of nonsense syllables such as cac,
rit, and dax
Later recalled nonsense syllables to investigate
forgetting
Found that syllables early and late in a list are
most likely to be recalled
Percentage Recalled
Serial Position Effect
Recency
Effect
Primacy
100 Effect
5 0
0
E a r ly
M id d le
Serial Position
L a te
Serial Position Effect
Based on what you now know about the different
memory stores, how would you explain…
The primacy effect? The recency effect? The poor recall for words in the middle of the list?
How would the results change if…
The words were presented at a very fast rate?
After hearing the list of words, you had to count
backward from 4321 before writing down your answers?
Making Memories: Code
A code is a type of mental representation,
an internal “re-presentation” of a stimulus
or event
You can store information in a visual or
verbal code
vs.
“Coffee and a muffin”
Making Memories: Code
Information stored as one type of code
does not need to match the original input
Visual stimuli can be coded verbally
Verbal stimuli can be coded visually
Information stored and accessed as visual
code will activate the visual processing
areas of the brain (occipital lobe )
Consolidation : lodged in memory
The process of converting information stored
dynamically in LTM into a structural changes in the
brain.
The process of forming a relatively permanent
memory trace in LTM may take several years!
(Manns et al., 2003)
Patients who receive electroconvulsive therapy( ECT) experience disruption of memory for recent
events, even those that are no longer in STM. Older
memories are unaffected. Consolidation of explicit memories involves the
hippocampus Reconsolidation
The simple act of recalling information can
change the information. These changes
are reconsolidated, restabilized as a
stored structure.
Different proteins undergo consolidation
Not all activated memories go through
reconsolidation
Depth of Processing
The success of learning new information
depends upon the depth at which it is processed
Shallow : based on characteristics of
appearance
Moderate : based on characteristics of the
sound
Deep : based on characteristics of the
meaning
Depth of Processing
An example : A word is used as a
stimulus in all three questions below, each
of which requires a yes/no response. The
difference is in the type of processing
required to answer the questions.
Stimulus: GAIN
Depth of processing questions
Shallow: Is this word printed in capital letters?
Moderate: Does this word rhyme with “train”?
Deep: Does this word fit in the following sentence?
I have nothing to _______ by helping you.
Transfer Appropriate Processing
You have better memory for information if you use
the same type of processing when you try to
retrieve it as you did when you originally studied it
An example
Stimulus: GAIN
Study: Does this word rhyme with “train”?
Same processing at retrieval: A word that rhymes with
“brain”
Different processing at retrieval: A word that means “to
attain more”
Breadth of Processing
Elaborative encoding involves organizing and integrating new
information into what you already know
Rehearsal in STM is not very effective for
encoding new information in LTM
Flashbulb Memories Flashbulb memory, an unusually vivid and
accurate memory of a dramatic event.
As if a flashbulb in the mind goes off at key
moments, creating instant records of the
events.
Highly emotional and detailed memories of
personal experiences
Where were you on September 11, 2001?
Who were you with?
What were you doing?
How did you feel when you heard the news?
Types of LTM
Long-Term Memory
Explicit Memory
Implicit Memory
Semantic
Memory
Episodic
Memory
Implicit vs. Explicit
Memories
Implicit memories
Cannot be voluntarily called to mind and
verbalized
Include motor skills
Explicit memories
Can be voluntarily called to mind and verbalized
Consist of both factual knowledge (semantic )
and memory for personal experiences (episodic
)
Semantic versus episodic memory
Semantic memories are memories
of the meanings of words, concepts and
general facts about the world.
Information in semantic memory is organized
into semantic memory networks.
Episodic memories are memories of
events that are associated with a particular
time, place, and circumstance , episodic
memories provide a context .
Implicit Memories Five major types
Classically conditioned responses
Memories formed through nonassociative
learning
Habits
Skills
Priming
Implicit Memories: Skills
Skills are sets of behaviors that can be
applied to a variety of stimuli within a
domain, such as riding a bike
Initially, skills rely on controlled processing
and given enough practice shift to rely on
automatic processing
Priming
Priming, the effect that occurs when having just
performed a task makes it easier to perform the
same or an associated task more easily in the
future.
Priming occurs when a preexisting memory or
combination of memories is activated and the
activation lingers.
Priming that makes the same information more
easily accessed in the future is called repetition
priming.
The act of remembering:
reconstructing buried cities
The fragmentary nature of memory is
revealed in the tip-of-the-tongue
phenomenon. TOT! " # $ %
Retrieval: More Than the Past
False memories
Loftus and colleagues (1978)
People watched a series of slides that showed a red
Datsun stopping at a stop sign and then proceeding
into an accident
Participants were asked
• “Did another car pass the red Datsun while it was
stopped at the stop sign?”
OR
• “Did another car pass the red Datsun while it was
stopped at the yield sign?”
Recognition
versus recall
Recall is the intentional bringing to mind of
explicit information or, put more technically,
the transfer of explicit information from
LTM to STM.
Recognition occurs when you match an
encoded stimulus to one that has been
stored in memory.
What Causes Forgetting?
Decay
Theory that memories fade over time because
relevant connections between neurons are lost
Interferences Theory that the disruption of the ability to remember
one piece of information is caused by the presence
of other information
Retroactive! " : New information interferes with old
Proactive# " : Old information interferes with new
Amnesia: not just forgetting to remember
Amnesia& ' , a loss of memory over an
entire time span.
Organic amnesia( ) * & arises after
the brain has been damaged, by stroke+
,, injury, or disease; functional amnesia
- . * & typically arises after
psychological trauma/ 0 1 2 , and there
is no obvious problem in the brain itself.
Amnesia
Retrograde amnesia3 4 & '
previous memories
disrupts
Infantile amnesia ; Movie: 50 First Dates
Anterograde amnesia5 4 & ' leaves
already consolidated memories intact but
prevents the learning of new facts
Patient H.M.
Movie: Memento
Improving Memory
Depth and breadth of processing
Transfer appropriate processing
Distributed practice6 7 8 9
Mnemonic devices :
Visualize interacting objects
Method of loci:(loci, means “places” in Latin), first
memorize a set of locations
Pegword system$ % & :memorize a set of objects in
order.one is a bun, two is a shoe, three is a tree, four
is a door, five is a hive
Acronyms$ ' (
State-dependent retrieval the right frame of mind helps
:
We remember information better if we are
in the same mood or psychological state.
This effect is called state-dependent
retrieval.
Information is better remembered if recall
is attempted in the same psychological
state as when the information was first
encoded.
Hypermnesia: persistence helps
If at first you don’t remember, try, try again.
Improved memory over time, without
feedback, is called hypermnesia.
Hypermnesia probably occurs because
you remember different aspects of the
information each time you try to recall it,
and each bit that is remembered is then
used as a retrieval cue.
Hypnosis and memory
In many—if not most—cases, however,
hypnosis increase people’s confidence in
their recollections but not their accuracy.
Try other mnemonic devices
You can use mnemonics for material
throughout this book, setting up mental
connections or associations from one thing
to another, perhaps with the use of imagery.
In addition, you can remember information
by stringing it into a story.
One of the fundamental facts about learning
is that you will learn better if you are
actively involved.
Enhancing memory retrieval:
knowing where and how to dig
Remember the context.
Focus.
Keep trying.
Seize fragments.
Structure the environment.