Memory I Explicit/Implicit Memory Amnesia Encoding Specifity PrincipleAre there multiple LTM memory systems?A Taxonomy of Memory SystemsImplicit and explicit memorySlide 5Slide 6Memory TestSlide 8Implicit Memory TasksImplicit vs. Explicit MemoryWord-stem completion spared in amnesiacsAmnesiaSourcesSlide 14Retrograde amnesiaAnterograde AmnesiaFamous Anterograde Amnesiac: HMH.MHM able to mirror traceCan amnesics acquire any new knowledge?Learning a new skill: mirror-reverse readingAmnesics can learn to mirror-reverse read and are sensitive to repetitionsSpared (implicit) learning in anterograde amnesiaEncoding & Retrieval EffectsLevels of ProcessingEncoding Specificity PrincipleContext ChangeSlide 28Mood-dependent MemoryState-dependent recallThe Spacing EffectExplanation for spacing effectLong-term effects of spacingMemory IExplicit/Implicit MemoryAmnesiaEncoding Specifity PrincipleAre there multiple LTM memory systems?•How do you learn a new skill?•How do you learn a new fact?•How about learning about an event?•Is there one long-term memory (LTM) system for these types of knowledge or are there multiple LTM systems?A Taxonomy of Memory SystemsLONG TERM MEMORYEXPLICIT(declarative)IMPLICIT(non-declarative)SEMANTIC(facts)EPISODIC(events)PROCEDURAL(skills & habits)PRIMING(perceptual,conceptual)Medial Temporal LobeASSOCIATIVE LEARNING(classical & operant conditioning)Cortex Striatum Amydala/ CerebellumImplicit and explicit memory•Implicit memory: past experiences influence perceptions, thoughts & actions without awareness that any information from past is accessed•Explicit memory:conscious access to info from the past (“I remember that..” ) -> involves conscious recollectionExplicit & Implicit Memory TestsLook at the following words. I will test your memory for these words in various ways.Memory Test•Explicit test of memory: recall–Write down the words you remember from the list in the earlier slide•Implicit test of memory: word fragments–On the next slide, you will see some words missing letters, some “word fragments” and some anagrams. Guess what each word might be.Implicit Memory Tasks•Word-fragment completion is an implicit memory task.Fragments are (often) completed with words previously studied in the absence of an explicit instruction to remember the word•Amnesiacs often showed spared implicit memory  dissociation suggest different systems for implicit and explicit memory systemsImplicit vs. Explicit Memory•Graf, Squire, & Mandler (1984):–Study words: cheese, house, …–Explicit memory test: cued recall. Complete fragment to a word from study list:ch _ _ _ _ –Implicit memory test: word stem completion. Complete fragment to form any word: ch _ _ _ _Word-stem completion spared in amnesiacsGraf et al. (1984).AmnesiaSources•Blow to head, Concussion •Korsakoff syndrome (severe vit. B1 deficiency)•Alzheimer’s•Damage to hippocampus, thalamic structures•ECT (electroconvulsive shock therapy)•Midazolam: artifically induced amnesiaAmnesia•Types:–Retrograde: cannot remember old memories–Anterograde: cannot form new episodic memoriesRetrograde amnesia•Temporal gradient: –early memories are better remembered than memories before trauma (Ribot’s law)–Recently formed memories continue to undergo neurological change: memory consolidation•Retrograde amnesia often becomes less severe over time–Most remote memories are likely to return first•Does not affect overlearned information (e.g. skills)Anterograde Amnesia•Inability to acquire new information –Think of movie “memento”–Does not affect short-term memory–Does not affect general knowledge from the past–But, it is difficult to learn new facts–Affects memory regardless of modality (visual, auditory, tactile, etc). Spares skilled performance–Hyper-specific memory for those skills that are learned after onset – learning is expressed only in context in which it was encodedFamous Anterograde Amnesiac: HM•Severe epilepsy, treated with surgery to bilaterally remove medial temporal lobes, including hippocampus•Operation 9/1953, 27 years oldMEDIAL TEMPORAL LOBESH.M•General knowledge intact but “stuck in time”. –Did not learn words introduced after 1953: “jacuzzi”, “granola”, “flower-child”•Was able to form some memories–Initially couldn’t learn how to get to his new home. Took many years to learn his own house–Could learn to mirror reverse read and mirror traceHM able to mirror traceMilner, 1965improvement in H.M. for mirror tracing task (without conscious recollection of previous training episodes) the medial temporal lobes are not necessary for all types of long-term memory.Can amnesics acquire any new knowledge? Declarative memory (memory for information/knowledge, e.g. episodic & semantic memory)  impairedProcedural memory (e.g., how to ride a bike)  yesImplicit memories (using past information possibly without being aware of it)  yesLearning a new skill: mirror-reverse readingAmnesics can learn to mirror-reverse read and are sensitive to repetitionsSpared (implicit) learning in anterograde amnesia•Claparede study (1911). –Patient never remembered having met Claparede (doctor) before–Claparade offers handshakes with pinprick–Next time, no explicit memory of event (or doctor)–Still, patient refuses to shake hands and offers explanation: “sometimes pins are hidden in people’s hands”•Korsakoff patients & Trivia questions –Given feedback, then retested. No conscious memory for items but better performance. “I read about it somewhere”. (Schacter, Tulving & Wang, 1981).Encoding & Retrieval EffectsLevels of ProcessingLevels of processing effect:Deeper levels of processing (e.g., emphasizing meaning) tend to lead to better recall. (Craik & Lockhart, 1972)Encoding Specificity Principle•Recollection performance depends not only on how the information was encoded but also how the way the information is retrieved at test•Encoding specificity principle: recollection depends on the interaction between the properties of the encoded event and the properties of the retrieval information(Related to “transfer appropriate processing”)Context Change•Information learned in a particular context is better recalled if recall takes place in the same context•Similarly, information learned in a particular context may be difficult to recall in a dramatically different contextContext