Memory
 Short-Term Memory
 activated memory that holds a few items
briefly
 look up a phone number, then quickly dial
before the information is forgotten
 Long-Term Memory
 the relatively permanent and limitless
storehouse of the memory system
 Memory Championships, pi, test your memory
Memory
 Sensory Memory
 the immediate, initial recording of
sensory information in the memory
system
 Working Memory
 focuses more on the processing of
briefly stored information
A Simplified Memory
Model
Sensory input
Attention to important
or novel information
Encoding
External
events
Sensory
memory
Short-term
memory
Encoding
Long-term
memory
Retrieving
Encoding
 Ebbinghaus used nonsense syllables
 TUV ZOF GEK WAV
 the more times practiced on Day 1,
the fewer repetitions to relearn on
Day 2
 Spacing Effect
 distributed practice yields better longterm retention than massed practice
Encoding
Time in
minutes
taken to
relearn
list on
day 2
20
15
10
5
0
8
16
24
32
42
53
Number of repetitions of list on day 1
64
Encoding: Serial Position
Effect
Percent
age of
words
recalled
90
80
Serial Position
Effect--tendency
to recall best
the last items in
a list
70
60
50
40
30
20
10
0
1
2
3
4 5 6 7 8
Position of
word in list
9
10 11 12
What Do We Encode?
 Semantic Encoding
 encoding of meaning
 including meaning of words
 Acoustic Encoding
 encoding of sound
 especially sound of words
 Visual Encoding
 encoding of picture images
Encoding
Encoding
 Hierarchies
 complex information broken down into broad concepts and
further subdivided into categories and subcategories
Encoding
(automatic
or effortful)
Meaning
(semantic
Encoding)
Imagery
(visual
Encoding)
Chunks
Organization
Hierarchies
Chunking…
Storage:
Sensory Memory
 Iconic Memory
 a momentary sensory memory of visual
stimuli
 a photographic or picture image memory
lasting no more that a few tenths of a
second
 Tests of George Sperling
 Echoic Memory
 momentary (3-4 sec) sensory memory of
auditory stimuli
Storage:
Short-Term Memory
Percentage
90
who recalled
consonants 80
70
60
50
40
30
20
10
0
 Short-Term
Memory
3
6
9
12
15
18
Time in seconds between presentation
of contestants and recall request
(no rehearsal allowed)
 limited in
duration and
capacity
 “magical”
number 7+/-2
(Miller, 1956)
Storage:
Long-Term Memory
 How does storage work?
 Karl Lashley (1950) – Searching for “engrams”
 rats learn maze
 lesion cortex
 test memory
 Synaptic changes – “The Brain” Clip
 Long-term Potentiation (LTP)
 increase in synapse’s firing potential after brief, rapid
stimulation
 Strong emotions make for stronger memories
Stress Hormones and
Memory
 Stress hormones aide memory
 Hormone surge alert brain that something
important has happened.
 Physical or psychological pain, trauma create surge
 Rat study – shot of hormones with a leg shock
 Creates a very strong memory
 Biological evidence for why emotional memories
are stronger.
Stress Hormones and
Memory
 Stress hormones block and destroy memory
 Prolonged stress corrodes neural connections
 Memories can be blocked by stress hormones
 Rats trying to find a hidden target
 Public speaking
Storage:
Long-Term Memory
 Amnesia--the loss of memory
 Retrograde Amnesia – mass forgetting of
old information
 Antrograde Amnesia – inability to form new
memories
 Oliver Sacks – “Jimmie” (earth from the moon
example), H.M., Clive Wearing
 Childhood Amnesia – Why? (3 min)
 Amnesiacs demonstrate 2 forms of memory…
Storage:
Long-Term Memory
 Amnesiacs
 Deny having seen an article and then read it faster
 Deny abilities to solve puzzle then complete it easily
 Childhood Amnesia – must have implicit memory in tact
 Explicit Memory (Declarative Memory)
 memory of facts and experiences that one can consciously
know and “declare”
 Episodic Memory – personally experienced events
 Semantic Memory – facts, general knowledge
 Implicit Memory (Non-declarative Memory)
 retention independent of conscious recollection
 Skills (procedural memory), classical-conditioned responses
Storage: Long-Term
Memory Subsystems
Types of
long-term
memories
Explicit
(declarative)
With conscious
recall
Facts-general
knowledge
(“semantic
memory”)
Personally
experienced
events
(“episodic
memory”)
Implicit
(nondeclarative)
Without conscious
recall
Skills-motor
and cognitive
Dispositionsclassical and
operant
conditioning
effects
Storage:
Long-Term Memory
 hippocampus--neural center in limbic system that
helps process explicit memories for storage
 Processes explicit memories – then sent to
multiple different regions.
Hippocampus
Storage:
Long-Term Memory
Cerebellum
• Process implicit
memories
Ex: classicalconditioned eyeblink disappears
when you remove
cerebellum