MemoryMemory

Memory ProcessesMemory Processes

Encoding--transforming information into a Encoding--transforming information into a form that can be entered and retained in form that can be entered and retained in the the memory systemthe the memory system

Storage--retaining information in memory Storage--retaining information in memory so that it can be used at a later timeso that it can be used at a later time

Retrieval--recovering information stored Retrieval--recovering information stored in memory so that we are consciously in memory so that we are consciously aware of itaware of it

Three Stages of Three Stages of MemoryMemory

Three memory stores that differ in function, Three memory stores that differ in function, capacity and durationcapacity and duration

Long-term memory

Working orShort-term

Memory

Sensory

Input

Sensory Memory

AttentionEncoding

Retrieval

Maintenance Rehearsal

Sensory MemorySensory Memory Function —Function —process for basic process for basic

physical characteristicsphysical characteristics Capacity—largeCapacity—large

can hold many items at oncecan hold many items at once Duration—very brief retention of Duration—very brief retention of

imagesimages .3 sec for visual info.3 sec for visual info 2 sec for auditory info2 sec for auditory info

Divided into two types:Divided into two types: iconic memory–visual informationiconic memory–visual information echoic memory– auditory echoic memory– auditory

informationinformation Attention is needed to transfer Attention is needed to transfer

information to working memoryinformation to working memory

Sensory

InputSensoryMemory

Sensory MemorySensory Memory

Visual sensory memory—brief memory of Visual sensory memory—brief memory of an image or icon. Also called iconic an image or icon. Also called iconic memory.memory.

Auditory sensory memory—brief memory Auditory sensory memory—brief memory of a sound or echo. Also called echoic of a sound or echo. Also called echoic memory.memory.

Auditory sensory memories may last a bit Auditory sensory memories may last a bit longer than visual sensory memorieslonger than visual sensory memories

Short Term or Working Short Term or Working MemoryMemory

Working orShort-term

Memory

Sensory

Input

Sensory Memory

Attention

Short-Term MemoryShort-Term Memory

Function—conscious processing of informationFunction—conscious processing of information where information is actively worked onwhere information is actively worked on

Capacity—limited (holds 7+/-2 items) Capacity—limited (holds 7+/-2 items) Duration—brief storage (about 30 seconds)Duration—brief storage (about 30 seconds)

Working orShort-term

Memory

Sensory

Input

Sensory Memory

Attention

Maintenance Rehearsal Maintenance Rehearsal

Mental or verbal repetition of information allows Mental or verbal repetition of information allows information to remain in working memory longer information to remain in working memory longer than the usual 30 secondsthan the usual 30 seconds

Working orShort-term

Memory

Sensory

Input

Sensory Memory

Attention

Maintenance Rehearsal

ChunkingChunking

Grouping small bits of information Grouping small bits of information into larger units of informationinto larger units of information expands working memory loadexpands working memory load

Which is easier to remember?Which is easier to remember? 4 8 3 7 9 2 5 1 64 8 3 7 9 2 5 1 6 483 792 516483 792 516

Long-Term MemoryLong-Term Memory

Once information passes from sensory to Once information passes from sensory to working memory, it can be encoded into working memory, it can be encoded into long-term memory long-term memory

Long-term memory

Working orShort-term

Memory

Sensory

Input

Sensory Memory

AttentionEncoding

Retrieval

Maintenance Rehearsal

Long-Term MemoryLong-Term Memory

Function—organizes and stores informationFunction—organizes and stores information more passive form of storage than working memorymore passive form of storage than working memory

Unlimited capacityUnlimited capacity Duration—thought by some to be permanentDuration—thought by some to be permanent

Long-term memory

Working orShort-term

Memory

Sensory

Input

Sensory Memory

AttentionEncoding

Retrieval

Maintenance Rehearsal

Long-Term MemoryLong-Term Memory

Encoding—process that controls movement from Encoding—process that controls movement from working to long-term memory storeworking to long-term memory store

Retrieval—process that controls flow of information Retrieval—process that controls flow of information from long-term to working memory storefrom long-term to working memory store

Long-term memory

Working orShort-term

Memory

Sensory

Input

Sensory Memory

AttentionEncoding

Retrieval

Maintenance Rehearsal

Automatic vs. Effortful Automatic vs. Effortful Encoding Encoding

Automatic processingAutomatic processing Unconscious encoding of informationUnconscious encoding of information Examples:Examples:

What did you eat for lunch today?What did you eat for lunch today? Was the last time you studied during the day or night?Was the last time you studied during the day or night? You know the meanings of these very words you are You know the meanings of these very words you are

reading. Are you actively trying to process the reading. Are you actively trying to process the definition of the words?definition of the words?

Automatic vs. Effortful Automatic vs. Effortful Encoding Encoding

Effortful processingEffortful processing Requires attention and conscious effortRequires attention and conscious effort Examples:Examples:

Memorizing your notes for your upcoming Memorizing your notes for your upcoming Introduction to Psychology examsIntroduction to Psychology exams

Repeating a phone number in your head until Repeating a phone number in your head until you can write it downyou can write it down

Types of Long-Term Types of Long-Term MemoryMemory

Explicit memory—memory with Explicit memory—memory with awareness; information can be awareness; information can be consciously recollected; also called consciously recollected; also called declarative memorydeclarative memory

Implicit memory—memory without Implicit memory—memory without awareness; memory that affects behavior awareness; memory that affects behavior but cannot consciously be recalled; also but cannot consciously be recalled; also called nondeclarative memorycalled nondeclarative memory

Explicit MemoryExplicit Memory

Declarative or conscious memoryDeclarative or conscious memory Memory consciously recalled or Memory consciously recalled or

declareddeclared Can use explicit memory to directly Can use explicit memory to directly

respond to a questionrespond to a question Two subtypes of explicit memoryTwo subtypes of explicit memory

Explicit MemoryExplicit Memory

Episodic information—information about Episodic information—information about events or “episodes” events or “episodes”

Semantic information—information about Semantic information—information about facts, general knowledge, school workfacts, general knowledge, school work

Episodic MemoryEpisodic Memory

Memory tied to your own personal experiencesMemory tied to your own personal experiences Examples:Examples:

What month is your birthday?What month is your birthday? Do you like to eat caramel apples?Do you like to eat caramel apples?

Q: Why are these explicit memories? Q: Why are these explicit memories? A: Because you can actively declare your A: Because you can actively declare your

answers to these questionsanswers to these questions

Semantic MemorySemantic Memory

Memory not tied to personal eventsMemory not tied to personal events General facts and definitions about General facts and definitions about

the worldthe world Examples:Examples:

How many tires on a car?How many tires on a car? What is a cloud?What is a cloud? What color is a banana?What color is a banana?

Does NOT depend on tying the item to your Does NOT depend on tying the item to your pastpast

Implicit MemoryImplicit Memory

Nondeclarative memoryNondeclarative memory Influences your thoughts or Influences your thoughts or

behavior, but does not enter behavior, but does not enter consciousnessconsciousness

Procedural MemoryProcedural Memory

Memory that enables you to perform specific Memory that enables you to perform specific learned skills or habitual responseslearned skills or habitual responses

Examples:Examples: Riding a bikeRiding a bike Using the shift stick while drivingUsing the shift stick while driving Tying your shoe lacesTying your shoe laces

Q: Why are these procedural memories implicit?Q: Why are these procedural memories implicit? A: Don’t have to consciously remember the steps A: Don’t have to consciously remember the steps

involved in these actions to perform theminvolved in these actions to perform them Try to explain to someone how to tie a shoelaceTry to explain to someone how to tie a shoelace

How are memories How are memories organized?organized?

Clustering--organizing items Clustering--organizing items into related groups during into related groups during recall from long-term memoryrecall from long-term memory

Semantic Network ModelSemantic Network Model

Mental links between conceptsMental links between concepts common properties provide basis for mental linkcommon properties provide basis for mental link

Shorter path between two concepts = Shorter path between two concepts = stronger association in memorystronger association in memory

Activation of a concept starts Activation of a concept starts decremental spread of activity to nearby decremental spread of activity to nearby concepts concepts

Semantic Network ModelSemantic Network Model

Red

FireHouse

CherryAppleRose

Pear

Ambulance

Fire Engine

TruckBusCar

FlowerViolet

Hot

Pot

Stove

Pan

Pie

Why do we forget?Why do we forget?

Forgetting Forgetting can occur can occur at any at any memory memory stagestage

Retrieval from long-term memoryDepending on interference, retrieval

cues, moods, and motives, some things get retrieved, some don’t

Long-term storageSome items are altered or lost

Short-term memoryA few items are both noticed

and encoded

Sensory memoryThe senses momentarily register

amazing detail

Forgetting as retrieval Forgetting as retrieval failurefailure

Retrieval—process of accessing stored informationRetrieval—process of accessing stored information Sometimes info IS encoded into LTM, but we can’t Sometimes info IS encoded into LTM, but we can’t

retrieve itretrieve it

Retrieval failureleads to forgetting

RetrievalX

Encoding

Short-termmemory

Long-termmemory

Measures of RetrievalMeasures of Retrieval

Recall—test of LTM that involves retrieving Recall—test of LTM that involves retrieving memories without cues, also termed free recallmemories without cues, also termed free recall

Cued recall—test of LTM that involves remembering Cued recall—test of LTM that involves remembering an item of information in response to a retrieval cuean item of information in response to a retrieval cue

Recognition—test of LTM that involves identifying Recognition—test of LTM that involves identifying correct information from a series of possible choicescorrect information from a series of possible choices

Serial position effect—tendency to remember items Serial position effect—tendency to remember items at the beginning and end of a list better than items at the beginning and end of a list better than items in the middlein the middle

Encoding SpecificityEncoding Specificity

– – When conditions of retrieval are similar to When conditions of retrieval are similar to conditions of encoding, retrieval is more conditions of encoding, retrieval is more likely to be successfullikely to be successful

– – You are more likely to remember things if You are more likely to remember things if the conditions under which you recall the conditions under which you recall them are similar to the conditions under them are similar to the conditions under which you learned themwhich you learned them

Encoding SpecificityEncoding Specificity

Context effects—environmental cues to Context effects—environmental cues to recallrecall

State dependent retrieval—physical, State dependent retrieval—physical, internal factors internal factors

Mood Congruence—factors related to Mood Congruence—factors related to mood or emotionsmood or emotions

Flashbulb MemoriesFlashbulb Memories

Recall of very specific images or details Recall of very specific images or details about a vivid, rare, or significant eventabout a vivid, rare, or significant event

May seem very vivid and specific, but May seem very vivid and specific, but they are not more accurate than ordinary they are not more accurate than ordinary memoriesmemories

Memory DistortionMemory Distortion

Memory can be distorted as people try Memory can be distorted as people try to fit new info into existing schemasto fit new info into existing schemas

Giving misleading information after an Giving misleading information after an event causes subjects to unknowingly event causes subjects to unknowingly distort their memories to incorporate the distort their memories to incorporate the new misleading informationnew misleading information

Loftus ExperimentLoftus Experiment

Subjects shown video of Subjects shown video of an accident between two an accident between two carscars

Some subjects asked: Some subjects asked: How fast were the cars How fast were the cars going when they going when they smashed into each other?smashed into each other?

Others asked: How fast Others asked: How fast were the cars going when were the cars going when the hit each other?the hit each other?

AccidentLeading question:

“About how fast were the cars goingwhen they smashed into each other?”

Memory construction

The Forgetting CurveThe Forgetting Curve

Hermann Ebbinghaus first began to study forgetting using nonsense syllables

Nonsense syllables are three-letter combinations that look like words but are meaningless (ROH, KUF)

Forgetting TheoriesForgetting Theories

Encoding failureEncoding failure Interference Interference

theoriestheories Motivated Motivated

forgettingforgetting DecayDecay

Forgetting as encoding Forgetting as encoding failurefailure

Info never encoded into LTMInfo never encoded into LTM

EncodingX Long-termmemory

Encoding failureleads to forgetting

Short-termmemory

Which is the real penny?Which is the real penny?

(a) (b) (c) (d) (e)

(f) (g) (h) (i) (j)

(k) (l) (m) (n) (o)

(a) (b) (c) (d) (e)

(f) (g) (h) (i) (j)

(k) (l) (m) (n) (o)

AnswerAnswer

Encoding FailuresEncoding Failures

Even though you’ve seen Even though you’ve seen thousands of pennies, you’ve thousands of pennies, you’ve probably never looked at one probably never looked at one

closely to encode specific closely to encode specific featuresfeatures

Interference TheoriesInterference Theories

““Memories interfering with memories”Memories interfering with memories” Forgetting NOT caused by mere Forgetting NOT caused by mere

passage of timepassage of time Caused by one memory competing Caused by one memory competing

with or replacing another memorywith or replacing another memory Two types of interferenceTwo types of interference

Two Types of Two Types of Interference Interference

Types of Interference

RetroactiveInterference

ProactiveInterference

Retroactive InterferenceRetroactive Interference

When a NEW memory interferes When a NEW memory interferes with remembering OLD informationwith remembering OLD information

Example: When new phone Example: When new phone number interferes with ability to number interferes with ability to remember old phone numberremember old phone number

French 101Mid-term

exam

Retroactive Retroactive InterferenceInterference

Example: Learning a new language Example: Learning a new language interferes with ability to remember interferes with ability to remember old languageold language

F-Study French

papier

livre plume

école

Study Spanish

papel

libro pluma

escuela

retroactive interference

Proactive InterferenceProactive Interference

Opposite of retroactive Opposite of retroactive interferenceinterference

When an OLD memory When an OLD memory interferes with remembering interferes with remembering NEW informationNEW information

Example: Memories of Example: Memories of where you parked your car where you parked your car on campus the past week on campus the past week interferes with ability find car interferes with ability find car today today

Motivated ForgettingMotivated Forgetting

Undesired memory is held back form Undesired memory is held back form awarenessawareness Suppression—conscious forgettingSuppression—conscious forgetting Repression—unconscious forgetting Repression—unconscious forgetting

(Freudian)(Freudian)

Decay TheoriesDecay Theories

Memories fade Memories fade away or decay away or decay gradually if unusedgradually if unused

Time plays critical Time plays critical role role

Ability to retrieve Ability to retrieve info declines with info declines with time after original time after original encodingencoding

Average percentage

of information

retained

20mins

1hr

8hrs

24hrs

2days

6days

31days

Interval between original learning of nonsense syllables

and memory test

100%

Decay TheoriesDecay Theories

Biology-based theoryBiology-based theory When new memory formed, it creates When new memory formed, it creates

a a memory tracememory trace a change in brain structure or chemistrya change in brain structure or chemistry

If unused, normal brain metabolic If unused, normal brain metabolic processes erode memory trace processes erode memory trace

Theory not widely favored today Theory not widely favored today

Biological Basis of Biological Basis of MemoryMemory

Karl Lashley searched for a localized memory trace or engram

Found that maze-learning in rats was distributed throughout the brain

Richard Thompson found that memory for simple classically conditioned responses was localized (in the cerebellum)

AmnesiaAmnesia

Amnesia—severe memory lossAmnesia—severe memory loss Retrograde amnesia—inability to Retrograde amnesia—inability to

remember past episodic information; remember past episodic information; common after head injury; need for common after head injury; need for consolidationconsolidation

Anterograde amnesia—inability to form Anterograde amnesia—inability to form new memories; related to hippocampus new memories; related to hippocampus damagedamage