Long-term Memory Explicit Memory Implicit Memory Semantic Memory Episodic Memory Perceptual learning Classical Conditioning Motor Skills Possible architecture of: Other types Affected by Amnesia ?
Long-term Memory
Explicit Memory
Implicit Memory
SemanticMemory
EpisodicMemory
Perceptuallearning
ClassicalConditioning
Motor Skills
Possible architecture of:
Other types
Affected by Amnesia
?
• Explicit Memory (consciously available)– Semantic memory: World knoweldge. (The sky is blue. Dogs
are pets. Ferraris are expensive.) – Episodic Memory: Specific personal experience from a
particular time and place. • Implicit Memory (not consciously accessible)
– Classical conditioning: e.g., salivating when I say “cheesecake!” Or fear when you smell rubbing alcohol.
– Perceptual learning: e.g., a new friend’s accent– Skills: e.g., driving, mirror-tracing
EXPLICIT MEMORY
Semantic Memory• Capacity is huge (unlimited?)• Structure of encoding is associative/conceptual
– Evidence: Semantic Priming in a Lexical-Decision Task• Priming: prior exposure to some stimulus modifies subsequent processing of
a target• Lexical Decision Task: Subject is shown a target word or pronounceable
non-word (eg. gap or fap) and must respond “word” or “non-word.” We care about the words.
• Prime is either related or unrelated to target word• Faster “word” response when preceded by semantically related prime
Prime then Target Response“space” “gap” fast“truck” “gap” slow
•So when a concept is activated, it partially activates other concepts it’s related to.•This speeds up access to the second concept and makes responding faster.
•This shows that representation of information in semantic memory is associative. (Stuff is stored “near” stuff it’s meaningfully related to, not randomly, and not near stuff that it’s only shalowly related to.)
Episodic Memory
• Memory for an episode or event in your own life
• Has temporal context (entails a sense of duration and date)
• examples:– my trip to New Orleans– your memory of having heard of the downed
airliner last week
Recalling Episodic Memory
• Recall is highly sensitive to context - Similarities in context can trigger vivid recollections. (We’ll talk about this more next time.)
Stages of Explicit Long-Term Memory
Encoding Storage Retrieval
Establish a ‘permanent record’
Reactivate the permanent record
Acquire information via perceptual system
EpisodicMemoryEncoding(new memory)
temporal lobe is the hub that relates all object’s properties into an integrated memory
In Context: ‘today’ ‘at home’
Storage(Consolidation)
temporal lobe is not needed anymore
Old memory(10 years later)
Storage of Memories (consolidation)
EpisodicMemoryEncoding(new memory)
temporal lobe is the hub that relates all object’s properties into an integrated memory
In Context: ‘today’ ‘at home’
Storage(Consolidation)
temporal lobe is not needed anymore
Old memory(10 years later)
RECENT MEMORIES ARE LOST
OLDMEMORIES
ARE SPARED
1990’s1980’s1960’s 1970’s
Brain Damage(1975)
Retrograde Amnesia(Pre-Damage)
Recent memory(lost)
Old memory(spared)
Anterograde Amnesia(Post-Damage)
New memories(not encoded)
Imagine a 1975 accident that severely damages the temporal lobe...
Evidence for double dissociation betweenimplicit and explicit memory
Middle temporal lobe lesion (e.g., patient HM)• Impaired explicit memory• Spared perceptual priming
Visual cortex lesion (e.g., patient MS):• Spared explicit memory• Impaired perceptual priming
This demonstrates that there are (at least) two separate systems, each responsible for a different type of memory.
Implicit and explicit memory can be dissociated in the lab.
• Explicit memory tested with direct tasks (e.g., recall, recog). – You’re asked directly about targets.
• Implicit memory tested with indirect tests. – Task seems unrelated. E.g., – Word fragments
– Perception of degraded stimuli
– Anagrams
– Free Association
– Prediction
– Mood
– Preference
– Performance
EGNOPS *AN*Y *OL*H**PACKAGE P*S*E* LICORICE*E*RA SE*T*O* C**OU*LA*E*I*TA*E PORTAL KNAPSACKCOFFEE*U*IL AEILNP*AN*LE *A*T*Y ACEPRT*A*E* C*L** *RE*S**EAALLM EILOOR *C*ID
Rajaram & Roediger, 1993
PHASE 1: Read words (e.g., unicorn) and rate pleasantness. PHASE 2: RecallPHASE 3: Word fragment completion
_ n i _ o r _
Rajaram & Roediger, 1993
PHASE 1: Read words (e.g., unicorn) and rate pleasantness. PHASE 2: RecallPHASE 3: Word fragment completion
Word stem completionuni_ _ _ _
Rajaram & Roediger, 1993
PHASE 1: Read words (e.g., unicorn) and rate pleasantness. PHASE 2: RecallPHASE 3: Word fragment completion
Word stem completion Word identification (flashed)
Rajaram & Roediger, 1993
PHASE 1: Read words (e.g., unicorn) and rate pleasantness.PHASE 2: Recall PHASE 3: Word fragment completion
Word stem completion Word identification
Anagram: corunni
More "unicorn“s in Phase 3 than if hadn't had Phase 1.I.e., “unicorn” was primed, even without explicit memory (recall). Even when recall had failed.This dissociation shows unconscious processing differs from conscious processing.
Implicit Memory in Korsakoff Patients
Damage to hippocampusAmnesia
Cued recall terrible, but stem completion as high as for normals.
Subliminal Perception
Auditory: Direct task: What do you hear?Indirect: "ESP" task -- was the tone
you didn't hear high or low?
Even if items not consciously heard, performance on indirect task better than chance.
Subliminal Perception
Visual: Direct task: See a flash?Indirect: "ESP" -- red or green?
Again, indirect performance better than direct. So: unconscious processing.
Subliminal Perception
Social: Subliminally flash words on screen.0%, 20%, or 80% hostile (e.g., "kill")
Direct task: What word was flashed?Indirect: Rate likeability of neutral person
The more hostile words flashed, the worse the judgment of the person.
How do you walk?Conduct memory search? Use chopsticks?Put in contacts?How do you know when your car is in the
wrong gear?Expertise (e.g., medical diagnosis)
Why fire a sea dart at a plane?
Persian Gulf, February 1991: Lt. Michael Riley, Radar Operator on the
HMS Gloucester (British Destroyer)decides to fire two sea darts….
How do objects fall?
Rules of Your LanguageIsraeli
FinlanderFrenchman
GreekJapanesePeruvian
Does This Sound Right As An English Sentence?
Does This Fit The Rules For A Well-Formed English Word?
GRAMMAR RULES
You learn a bunch of instancesYou learn a bunch of instances VJVJ VTVJJVTVJJ XXXXVJTXVXJJJJXXXXVJTXVXJJJJ XVXJXVXJ XVJTVXVJTV VJTXXVXVJTXXVXThen two different tests...Then two different tests...
GRAMMAR RULES
Direct Test: Tell me the rules.Indirect Test: Does this seem right to you?
VTJXV
People typically can't express the rules, but can tell legal from illegal. So do know the grammar rules, but implicitly.
More Rule/Skill Learning
• Tower of Hanoi task– Amnesics cannot remember playing, but they
get faster at solving the game.
Start Position Goal 2 (2 moves) Goal 10 (5 moves)
Covariation Learning in Visual Search
Ray & Reingold:
Eye movements monitored during search task in flicker paradigm, Task: Which letter has changed?
Two conditions: Background luminance varied with the target, or not.
Ss better at search when covariation existed.
Didn't need to consciously know the rule.
Preference
We tend to like things we've been exposed to.
Direct Test: Which of these have you seen?Indirect: Which of these do you like more?
ConclusionsMuch of cognition is unconscious.We can perceive, learn, & perform skills that we aren't fully aware of.
Examples: automatic skillslow-level perceptionmemorygrammar rulespreference
Entirely different brain systems may underlie explicit & implicit processing.