Human Memory
It is good to have an end to
journey towards; but it is the
journey that matters, in the
end.
Ursula K. Le Gui
MEMORY
System that allows for retention of
what is Learned
Ten Principles of Memory
 Recite often !
 Reinforce what you’ve learned through repetition
 If there is a basis for doing so, divide and group
 Organize the material so that it can be stored
 Associate new material with related facts you know
 Involve your ego, if possible
 Try to see the significance of what you’re learning
 Be sure you fully understand
 Get the info right the 1st time
 Pay attention
Three Kinds of Memory
1.Episodic – memories of personal experience
2.Semantic – general knowledge or memory for facts
3. Procedural or Implicit – memory for skills
Episodic – Do you remember your first interaction
with a personal computer?
Semantic – Do you know the meaning of personal
computer?
Procedural or Implicit– Are you fluent in the use of
a personal computer?
Mnemonic Device
System for remembering in which items are related to easily
recalled sets of symbols, such as acronyms, phrases, or jingles
EXAMPLES
“i” before “e” except after “c”
“Be, all that you can be!”
“Every Good Boy Does Fine!”
“Like a Rock”
Which is involved?
1.First Kiss
10.Use a computer
2.Riding a bike
11.Spell C-A-T
3.Walking through a maze
12.Driving a car
4.List the 50 states
13.H²0
5.Define Memory
14.Describe a fight to someone
6.Cut and Paste an art project
15.First day in high school
7.Writing notes off an overhead
8.Formula for classical conditioning
9.Witness a car accident
Three Processes of Memory
1.ENCODING - modifying information so that it can be placed in
memory
a. visual code
b. acoustic code
c. semantic code
2.STORING - maintenance of information over time
a.
maintenance rehearsal (157)
b. elaborative rehearsal
c.
organizational systems (superordinate & subordinate)
3.RETRIEVING - location of stored information and its return to
consciousness
a. proper cues
b. context-dependent memory
c. state-dependent memory
• Stores all the stimuli that register on the
senses
RETRIEVING
STORING
ENCODING
Information-Processing Model of Memory
• Computer as a model for our
memory
• Three types of memory
– Sensory memory
– Short-term memory (STM)
– Long-term memory (LTM)
• Can hold vast quantities of information
for many years
Three Stages of Memory
1. Sensory Memory - the type or stage of memory
first encountered by a stimulus. Sensory memory holds
impressions briefly, but long enough so that series of
perceptions are psychologically continuous.
• Saccadic Eye Movement
• Memory trace
• Sensory Register
Iconic memory
Echoic memory
Sensory Memory
• Lasts up to three seconds
• Two types
– Iconic memory
Sensory
Input
Sensory
Memory
• Visual
• Usually lasts about 0.3
seconds
• Sperling’s tests (1960s)
– Echoic memory (we’ll
come back to this)
2. Short Term Memory
(STM)
[ 7+/-2 - about 1 min.]
SERIAL POSITION EFFECT – the tendency to recall
more accurately the first and last items in a series.
PRIMACY EFFECT – the tendency to recall
the initial items in a series of items.
RECENCY EFFECT – the tendency to recall
the last items in a series of items.
Short Term Memory (STM)
Pages 162-163
OTHER KEY TERMS:
Chunk – a mental process for organizing information into
meaningful units, or “chunks,” (162)
Interference – the process that occurs when new information
appears in short-term memory and replaces what was
already there
Memory
• Process by which information is:
– Acquired
• Encoding
– Stored in the brain
• Storage
– Later retrieved
• Retrieval
– Eventually (possibly) forgotten
Information-Processing Model of Memory
Retrieval
Stimulus
Sensory
memory
Attention
Forgetting
Short-term
memory
Encoding
Forgetting
Long-term
memory
Forgetting
3 Stages of Memory
Sperling’s Experiment
• Presented matrix of letters
for 1/20 seconds
– Report as many letters as
possible
• Subjects recalled only half of
the letters
• Was this because subjects
didn’t have enough time to
view entire matrix?
– No
• How did Sperling know this?
Sperling’s Iconic Memory Experiment
Sperling’s Iconic Memory Experiment
Sperling’s Iconic Memory Experiment
Sperling’s Iconic Memory Experiment
Sperling’s Experiment
• Sounded low, medium or
high tone immediately
after matrix disappeared
– Tone signaled 1 row to
report
– Recall was almost perfect
• Memory for images fades
after 1/3 seconds or so,
making report of entire
display hard to do
High
Medium
Low
Sensory Memory
• Echoic memory
– Sensory memory for auditory input that
lasts only 2 to 3 seconds
• Why do we need sensory memory?
Short-term Memory
• Function
– Conscious processing of information
– Attention is the key
• AKA working memory
Sensory
Input
Sensory
Memory
Attention
Working or
Short-term
Memory
Memorize the following list of numbers:
18121941177614922001
Write down the numbers in order.
Now, try again…
1812
1941
1776
1492
2001
Short-term Memory
• Limited capacity
– Can hold 7 ± 2 items for about 20 seconds
– Maintenance rehearsal
• The use of repetition to keep info in short-term memory
• CHUNK
– Meaningful unit of information
– Without rehearsal, we remember 4 ± 2 chunks
– With rehearsal, we remember 7 ± 2 chunks
– Ericsson & Chase (1982)
893194434925021578416685061209488885687727
31418610546297480129497496592280
Long-term Memory
• Once information passes from
sensory to short-term memory, it can
be encoded into long-term memory
Retrieval
Sensory
Input
Attention
Sensory
Memory
Working or
Short-term
Memory
Encoding
Long-term
memory
Long-term memory - Encoding
• Elaborative rehearsal
– A technique for transferring information into longterm memory by thinking about it in a deeper way
• Levels of processing
– Semantic is more effective than visual or acoustic
processing
– Craik & Tulving (1975)
• Self-referent effect
– By viewing new info as relevant to the self, we
consider that info more fully and are better able to
recall it
Long-term memory
• Procedural (Implicit)
– Memories of behaviors, skills, etc.
• Demonstrated through behavior
• Declarative (Explicit)
– Memories of facts
• Episodic – personal experiences tied to
places & time
• Semantic – general knowledge
– Semantic network
Semantic Networks
Bus
Truck
Ambulance
Orange
House
Fire Engine
Fire
Yellow
Green
Red
Apples
Cherry
Roses
Sunrise
Daisies
Flowers
Sunsets
Clouds
Retrieval
• Retrieval
– Process that controls flow of information
from long-term to working memory store
• Explicit memory
– The types of memory elicited through the
conscious retrieval of recollections in
response to direct questions
• Implicit memory
– A nonconscious recollection of a prior
experience that is revealed indirectly, by
its effects on performance
Retrieval – Explicit Memory
• Free-recall test
– A type of explicit memory task in which a
person must reproduce information without the
benefit of external cues
• Recognition task
– A form of explicit memory retrieval in which
items are presented to a person who must
determine if they were previously encountered
• Retrieval failure
– Tip-of-the-tongue (Brown & McNeill)
Retrieval – Explicit Memory
• Context-Dependent Memory
– We are more successful at retrieving
memories if we are in the same
environment in which we stored them
• State-Dependent Memory
– We are more successful at retrieving
memories if we are in the same mood as
when we stored them
Retrieval – Implicit Memory
• Showing knowledge of something without
recognizing that we know it
• Research with amnesics
• Déjà vu
– The illusion that a new situation is familiar
• Eyewitness testimony
– Eyewitness transference
• Unintentional plagiarism
Forgetting
If we remembered everything, we should on
most occasions be as ill off as if we
remembered nothing.
William James
• Lack of encoding
– Often, we don’t even encode the features
necessary to ‘remember’ an object/event
• Decay
– Memory traces erode with the passage of time
– No longer a valid theory of forgetting
– Jenkins & Dallenbach (1924)
Interference theory
• Forgetting is a result of some
memories interfering with others
– Proactive interference
• Old memories interfere with ability to
remember new memories
– Retroactive interference
• New memories interfere with ability to
remember old memories
– Interference is stronger when
material is similar
Forgetting
• Repression
– There are times when we are unable
to remember painful past events
– While there is no laboratory
evidence for this, case studies
suggest that memories
can be repressed for a
number of years and
recovered in therapy
Memory Construction
• Schema theory
– Preconceptions about persons, objects, or
events that bias the way new information is
interpreted and recalled
• Misinformation effect
– The tendency to incorporate false postevent
information into one’s memory of the event
itself
• Illusory memories
– People sometimes create memories that are
completely false
Improving Memory
• Practice time
– Distribute your studying over time
• Depth of processing
– Spend ‘quality’ time studying
• Verbal mnemonics
– Use rhyming or acronyms to reduce the
amount of info to be stored
Improving Memory
• Method of loci
– Items to be recalled are mentally placed in
familiar locations
• Interference
– Study right before sleeping & review all the
material right before the exam
– Allocate an uninterrupted chunk of time to
one course
• Context reinstatement
– Try to study in the same environment &
mood in which you will be taking the exam