Long Short-Term Memory

1. CH. 6: Memory

2. The Nature of Memory
Memory – refers to ability to retain & retrieve information &
to the structures that give us the ability.
3 Basic Memory Processes
1st ~ Encoding – putting information into a form the brain can put
into memory and use.
• Types of Memory Codes –
1. Acoustic – sound memories
2. Visual – visual memories
3. Semantic – experiences by their general meaning
2nd ~ Storage – maintaining information in memory over time.
• Types of Long-Term Memory
1. Episodic – memory of events in one’s own past.
2. Procedural – memories of how to do things.
3. Semantic – generalized knowledge about the world.

3. 3rd ~ Retrieval – recalling information stored in memory.
• Types of Retrieval
1. Recall – retrieve information w/o much help
• Essay ?’s, Jeopardy, Trivial Pursuit
2. Recognition – retrieval aided by clues
• Multiple-choice, Who Wants To Be A Millionaire
Visual recognition has highest accuracy rate at about 90%.
3 Types of Memory – Episodic, Procedural, Semantic
Recalling these memories rely on . . .
Explicit memory – deliberately remember something
Implicit memory (Priming)- prior memorized info helps to memorize
new or similar info.

4. Models of Memory - PLIT
Parallel Distributed Processing (PDP)
•New facts combined w/ info already in memory
•Creates a network between info that gets stronger as experienced
together.
•Allows quick & efficient inferences & generalizations of world.
Levels of Processing (LP)
•Differences in how well something is remembered reflect depth of
mental processing.
•Maintenance rehearsal – repetition to memorize information.
•Elaborative rehearsal – relating new info w/ info already in memory.
•Memory improved when info memorized this way.
•Allows for more “deeper” processing.

5. Information Processing
•For deep processing information must go through 3 stages of
processing – Sensory, Short-term, & Long-term.
•Sensory Memory – is held for only 1 sec unless perceived and
transferred to short-term memory.
•Short-term Memory (working memory) - info not transferred to
long-term memory in 20 –30 sec then info is lost.
•Long-term Memory – stored indefinitely, possibly for life.
Transfer-Appropriate Processing
•Memory depends on how the encoding process matches up w/ what
is later retrieved.

6. Sensory
Memory
Retains for ½ sec
to 2 sec.
Short-term
Memory
Retains for
20-30 sec.
Stored
Retrieved
Retrieved
Long-Term
Memory
Retention is
unlimited and
permanent
Information
Processing Model

7. Storing New Memories – Sensory Memories, STM, WM, & LTM
Sensory Memory
• External stimuli held for about 1 second & if processed then “perceived”
• Sensory Registers - stores info in sensory bins for each sense.
• Helps keep a constant flow of information.
• Selective Attention -only focusing on part of the stimulus field.
~ Can’t deal w/ all sensations at one time, or sensory overload.
Short-term Memory & Working Memory
• STM holds info. 18-30 sec., either moved to LTM or dumped.
• STM Holds 7-9 “chunks” of information at a time.
• STM is a component of Working memory.
• WM holds retrieved info. from LTM to be worked on.
• Wm has 2 components: maintenance & manipulation

8. Encoding in STM
• Acoustic dominates – conclusion by mistakes in sound
substitution of similar sounds, different sounds are easier to
remember.
•E C T V G B
•K R L D Q S
•Encoding visually, semantically, & kinesthetically occurs, same
mistakes are made w/ similar looks, meaning & movements.

9. Storage Capacity of STM
•What is your Immediate Memory Span?
9 2 5
8 6 4 2
3 7 6 5 4
6 2 7 4 1 8
0 4 0 1 4 7 3
1 9 2 2 3 5 3 0
4 8 6 8 5 4 3 3 2
2 5 3 1 9 7 1 7 6 8
8 5 1 2 9 6 1 9 4 5 0
9 1 8 5 4 6 9 4 2 9 3 7
Average span is 7 +/- 2 or 5 to 9 characters.

10. Storage Capacity of STM (Con’t)
Chunking – meaningful groups of information
•Sentences usually considered to be one chunk of information.
•Better sense you can make w/ the information the more
information you can chunk together.
•Size of chunks can vary greatly.
Grandma is buying an apple.
Het plape si Dre
The apple is red
LCDN BCF BIU NC IAC IF
LCDN BCF BIU NC IAC IF
LCD NBC FBI UN CIA CIF

11. Duration of STM
• Distraction will cause loss of info if not processed yet.
•Brown-Peterson Procedure – used to measure duration of STM. Shown
info but before you recall you count backwards by 3’s from some number
then try to recall info.
•18 seconds most remember nothing.
Long-term Memory
Encoding in LTM
•Can happen unconsciously but more often occurs consciously.
•Semantic Encoding is usually the way info is encoded, general meaning
remembered not details.
Storage Capacity of LTM
• Unlimited capacity
• Retains info for long periods, even for life.
•Accurate w/ faces and foreign languages or Algebra
•LTM is subject to distortion & most are unaware of the distortion.

12. Only one of these images of a penny is correct. Which
one is it?
Memory - ©1998 Exploratorium
A is Correct!!!

13. Distinguishing Between STM & LTM
Serial Position – where a word is on a list.
Primacy Effect – good recall for the first 2-3 words on a list.
•May reflect rehearsal that puts word in LTM.
Recency Effect – ease of recalling words near the end of list.
•May occur because the last few words are still in STM.
Retrieving Memories
Retrieval Cues – stimuli that allows or helps people to recall info.
Context and state of mind can act as cues.
Context-Dependent memories – help or hindered by similarities or
differences in environment.
State-Dependent memories – help or hindered by internal state of
being.
Encoding Specificity Principle - Effectiveness of these cues depends
on how strongly the cues tap into the information.

14. Retrieval from Semantic Memory
Semantic Memory Network – everything we know about is
represented in a network.
Spreading Activation – questions can activate concepts in network
and spread along paths until paths intersect resulting in an answer.
•Some connections are stronger than others.
•Incomplete knowledge can occur if you cannot come up w/ a particular
answer & you get the Tip-Of-The-Tongue phenomenon.

16. Constructing Memories
We use existing knowledge to organize new information & fill in gaps
as we encode & retrieve it.
Parallel Distributed Processing can explain how semantic & episodic
information are integrated in constructive memory.
Spontaneous Generalization - occurs when you hear new info but
can create errors based on limited or biased experiences; racism,
prejudice.
Schemas - mental representations of categories of objects, places,
events & people.
•Generalized knowledge of schemas is the basis for our ability to
make assumptions or generalizations about new information.

17. Forgetting
Method of Savings – to learn how much we forget over time.
• Ebbinghaus’s research had 2 discoveries:
1. Shape of forgetting curve sharp initial drop-off then
moderate decline over time.
2. Info is retained for decades & what you forgot can be
more easily relearned later.
Why we forget?
• Decay(STM) – gradual disappearance of information
• Interference(LTM) – storage or retrieval of info impaired
by presence of other information: displacement or blocking
• Retroactive interference – new info interferes w/ old info.
• Proactive interference – old info interferes w/ new info.
• Retrieval cues can help overcome interference.

18. Desk
Teacher
Student
Book
Pencil
Chalk
Paper
Cloud
Rain
Wind
Sun
Cold
Warm
Humid
Home plate
Bat
Ball
Mitt
Cap
Cleats
Base
Dress
Pants
Shoes
Socks
Shirt
Sweater
Hat
Lake
Ocean
Sea
Stream
River
Brook
Creek
Hut
Cottage
Cabin
Hotel
Mansion
Apartment
Castle
Test by Endel Tulvig & Joseph Psotka

19. Biological Basis of Memory
Biochemistry of Memory
New memories can change synapses in 2 ways:
1. Stimuli can promote the formation of new synapses
2. Stimuli can change the operation of existing synapses.
• Occurs in synapses that use glutamate (neurotrans.)
• Alzheimer’s seems to have a lack of nerons that use
acetylcholine & send fibers to hippocampus & cortex.
Brain Structures & Memory
Memory stored in both specific parts & other areas of brain.
• Anterograde Amnesia – (damage to hippocampus) can’t form new
memories but can remember implicit memories.
• Retrograde Amnesia – loss of memory for info prior to damage.
• Usually, memory returns but for a few seconds before injury.