Memory

• Goal How do we encode information for memory?

• Learning Target: Describe memory in terms of information processing, and explain the encoding process.

The Memory ProcessThree step process….

1. Encoding: The processing of information into the memory system.

2. Storage: The retention of encoded material over time.

3. Retrieval: The process of getting the information out of memory storage.

Three Box Model of Memory

Info-Processing• Automatic– Parallel processing

(brain does many things at once)

– Remembering space, time, frequency, well-learned info

• Effortful– Rehearsal/repetition

Encoding Process

Encoding

Effortful Automatic

Ebbinghaus 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 – memory is better for info learned over time

• Ebbinghaus’ Forgetting Curve

Encoding Information

Serial Position Effect =•Primacy Effect – better remember items earliest in a series

•Recency Effect – better memory for items at the end of a series

The ways we can encode…

• Visual Encoding: the encoding of picture images.

• Acoustic Encoding: the encoding of sound, especially the sounds of words.

• Semantic Encoding: the encoding of meaning.

Encoding Imagery

mental pictures a powerful aid to effortful processing,

especially when combined with semantic encoding

Mnemonics memory aids especially those techniques that use vivid

imagery and organizational devices Acronyms Method of Loci Peg-word system

Encoding Chunking

organizing items into familiar, manageable units like horizontal organization--

1776149218121941

often occurs automatically use of acronyms

HOMES--Huron, Ontario, Michigan, Erie, Superior

ARITHMETIC--A Rat In Tom’s House Might Eat Tom’s Ice Cream

Encoding: Chunking Organized information is more easily recalled

Encoding Hierarchies (Semantic Networks)

complex information broken down into broad concepts and further subdivided into categories and subcategories

Encoding(automatic or effortful)

Imagery(visualEncoding)

Meaning(semanticEncoding)

Organization

Chunks Hierarchies

• Goal Describe memory in terms of information processing, and distinguish among sensory, short-term, and long-term memory.

Storage: Sensory Memory

• Iconic memory– Brief sensory

memory of images (tenths of a second)

• Echoic memory– Brief sensory memory

of sounds (2-4 secs)

Storage: Short-Term (STM)/Working Memory

• Limited duration & capacity

• Magical number (7+/-2 items)

• Events are encoded visually, acoustically or semantically.

• We recall digits better than letters.

How does storage work? Karl Lashley (1950)

rats learned maze, lesioned cortexes, retested memory still partial memory

Synaptic changes Long-term Potentiation

increase in synapse’s firing potential after brief, rapid stimulation

Storage: Long-Term Memory (LTM)

Strong emotions make for stronger memories = FLASHBULB MEMORIES

- Not necessarily more accurate

• Mood-congruent memory remember when in same mood as learned/rehearsed

• State-dependent memory remember when in same conscious state as learned/

rehearsed

Storage: Long-Term Memory (LTM)

Storage: Long-Term Memory Subsystems

Types oflong-termmemories

Explicit(declarative)

With consciousrecall

Implicit(nondeclarative)

Without conscious recall

Facts-generalknowledge(“semanticmemory”)

Personally experienced

events(“episodic memory”)

Skills-motorand cognitive

Dispositions-classical and

operant conditioning

effects

Storage: Long-Term Memory MRI scan of hippocampus (in red)

Hippocampus

Retrieval• Recall v. recognition tasks• Relearning - how much less time it

takes to learn material the second time

• Priming - activation of unconscious associations in memory

Retrieval: Context Effects• Godden and Baddeley (1975)

0

10

20

30

40

Water/land

Land/water

Water/water

Different contexts for hearing and recall

Same contexts for hearing and recall

Land/land

Percentage ofwords recalled

Retrieval: Context & Mood• Déjà Vu (French)-”already seen”

• cues from the current situation may subconsciously trigger retrieval of an earlier similar experience

•Mood-congruent memory

• State-dependent memory

• What is the color of the top stripe of the American flag?

• Most wooden pencils are not round. How many sides do they typically have?

• In what hand does the Statue of Liberty hold her torch?

• The White House is pictured on the back of a $20 bill. What is the on the back of a $10 bill? $5 bill? $1 bill?

• What four words besides “In God We Trust” appear on most U.S. coins?

Forgetting: Encoding Failure• Info never gets to LTM (not attended to or

rehearsed)

Externalevents

Sensorymemory

Short-term

memory

Long-term

memory

Attention

Encoding

Encoding

Encodingfailure leadsto forgetting

Forgetting: Storage Decay

Ebbinghaus forgetting curve over 30 days-- initially rapid, then levels off with time

12345 10 15 20 25 30

10

20

30

40

50

60

0

Time in days since learning list

Percentage oflist retainedwhen relearning

Forgetting: Storage Decay The forgetting curve for Spanish learned in school

Retentiondrops,

then levels off

1 3 5 9½ 14½ 25 35½ 49½Time in years after completion of Spanish course

100%

90

80

70

60

50

40

30

20

10

0

Percentage oforiginal

vocabularyretained

Forgetting: Retrieval Failure

Forgetting can result from failure to retrieve information from long-term memory

Externalevents

Attention

Encoding

Encoding

Retrieval failureleads to forgetting

Retrieval

Sensorymemory

Short-termmemory

Long-termmemory

Forgetting: Interference• Proactive (forward-

acting) interference old info disrupts memory of new info

• Retroactive (backward-acting) interference new info disrupts memory of old info

Forgetting

Forgetting can occur at any memory stage

As we process information, we filter, alter, or lose much of it

Repression?

Forgetting- Interference

Motivated Forgetting (retrieval failure) people unknowingly revise memories

Repression defense mechanism that banishes from

consciousness anxiety-arousing thoughts, feelings, and memories

Amnesia• Infantile amnesia: difficult

to remember vivid memories from before ages 2-3

• Dissociative amnesia: inability to remember info due to psychological trauma

Amnesia• Retrograde amnesia: inability to

remember info before a trauma• Anterograde amnesia:

inability to remember info after a trauma

What kind of forgetting?• Ellen can’t recall the reasons for the Webster-

Ashburton Treaty because she was daydreaming in class the day it was discussed.

Encoding failure• Rufus hates his job at Taco Heaven and is always

forgetting when he is schedule to work.

Retrieval failure (motivated forgetting)

What kind of forgetting?• Ray’s new assistant in the shipping department is named

Jason Timberlake. Ray keeps calling him Justin, mixing him up with the singer Justin Timberlake.

Proactive interference

• Tania studied history on Sunday morning and sociology on Sunday evening. It’s Monday, and she’s struggling with her history test because she keeps mixing up prominent historians with influential sociologists.

Retroactive interference

What kind of forgetting?• Mark was in a near fatal car accident on his way to work.

At the hospital, he cannot remember what he was doing that morning up until the accident (stopping for coffee, calling his wife), but still can form new memories.

Retrograde amnesia

• Ally was sexually assaulted, and when reporting the event has trouble remembering what happened after the assault (where she went, who she spoke to).

Anterograde amnesia

Memory Construction We filter information and fill in

missing pieces Misinformation Effect

incorporating misleading information into one's memory of an event

Source Amnesia attributing to the wrong source an

event that we experienced, heard about, read about, or imagined (misattribution)

Memory Construction

Eyewitnesses reconstruct memories when questioned

Depiction of actual accident

Leading question:“About how fast were the carsgoing when they smashed intoeach other?”

Memoryconstruction

Memory Construction Memories of Abuse

Repressed or Constructed? Child sexual abuse does occur Some adults do actually forget such episodes

False Memory Syndrome condition in which a person’s identity and

relationships center around a false but strongly believed memory of traumatic experience

sometimes induced by well-meaning therapists

Memory Construction Most people can agree on the following:

Injustice happens Incest happens Forgetting happens Recovered memories are commonplace Memories recovered under hypnosis or drugs are

especially unreliable Memories of things happening before age 3 are

unreliable Memories, whether false or real, are upsetting

Improve Your Memory Study repeatedly to boost recall Spend more time rehearsing or actively thinking

about the material Make material personally meaningful Use mnemonic devices

associate with peg words--something already stored make up story chunk--acronyms

Improve Your Memory Activate retrieval cues--mentally

recreate situation and mood Recall events while they are fresh--

before you encounter misinformation Minimize interference Test your own knowledge

rehearse determine what you do not yet know