Implicit memory

Chapter 5 Learning and Long-term Memory

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A Little History Ebbinghaus (1885) - nonsense syllable method (e.g., DAX, BUP, GEJ) Tested his own memory Each list learned to criterion of 2 errorless tests. GP Mem(1)

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IV: Retention time (minutes, hours, days) Dependant Measures 1) Number recalled - fast loss at beginning, then levels out.

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2) Savings # of trials to relearn Large Savings at short retention, Rapid decreased with longer retention Then leveled out.

E.g., After 6 days 30% savings.

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3) Overlearning - learn to criterion then rehearsed thirty times more. Greatly increased savings. E.g., At 6 days 64% savings.

Appears Rehearsal leads to Memory.

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Does Rehearsal transfer information to LTM?

Glenberg, Smith and Green (1977) Study. - subjects presented 4 digit numbers - each digit followed by word to repeat for 2, 6 or 18 secs. Told to remember digits (word repetition just distracter) Tested for the words.

Increased rehearsal did not lead to better recall from LTM. Incidental Learning Task – Participants did not intend to learn the words. GP Mem(1)

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Recall vs. Recognition Glenberg, Smith and Green Study (Revisited) Incidental recall test showed no effect of rehearsal. Incidental recognition test showed that the more rehearsed words were recalled better.

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Rehearsal increased the familiarity of the words, but not the ability to recall the words. Recognition depends on familiarity Recall requires that you find the words in LTM and then recognize that they are the words you are trying to recall.

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Depth of Processing (Craik and Lockhart) Transfer to LTM requires processing for meaning.

Incidental vs. Intentional Learning. LTM is like a library!

To encode information, there must be a place for it. Added to similar information. Elaborative Rehearsal - thinking about meaning. - relate to other things you know. cogltm(1)

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Depth of Processing (Craik and Lockhart) Transfer to LTM requires processing for meaning.

Incidental vs. Intentional Learning. When you experience a stimuli you retrieve information from LTM to make sense of it. The new information is added to the old information. To figure out these are dogs You retrieve your general knowledge about dogs. Then you add the new information, “Some dogs play cards”! New is stored with old. cogltm(1)

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Slamecka and Graf (1978) conducted studies in which they compared students’ ability to recall information when they had been provided with cues, and when they were required to make-up their own memory cues. They found that when students generated their own cues they were more likely to recall the information they were required to encode. This is called the Generation Effect.

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Bransford et al. (1979) showed that long-term memory depends on the kind of elaboration as well as the amount. Minimally elaborated similes “A nurse is like a mosquitoes because they both draw blood.” Multiple elaborative similes “A nurse is like a raccoon because they both have heads, legs, jaws, ears” Minimally elaborated were better recalled were better recalled perhaps because they are more distinctive. GP Mem(1)

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Self-Reference Effect Tendency for individuals to have better memory for information that relates to oneself in comparison to material that has less personal relevance.

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Many researchers became interested in exactly what produced deep processing: Elaboration: Craik and Tulving (1975) found complex semantic processing produced better recall e.g. “The great bird swooped down and carried off the struggling ___” produced better recall than “She cooked the ___” Distinctiveness: Eysenck and Eysenck (1980) found that words processed phonetically even were better remembered when they were distinctive or unusual (e.g., Yatch, Comb, or Paradigm).

Effort: Tyler et al. (1979) found there was better recall with difficult anagrams than simple anagrams e.g. “ORTODC” had better recall than “DOCTRO” GP Mem(1)

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Von Restorff Effect (named after Hedwig von Restorff, 1933) predicts that salient items, those that "stands out like a sore thumb", (called distinctive encoding) will be more likely to be remembered than other items. Salience can be anything that makes the item stand out!

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What is deeper processing???? “Deeper” processing connects the material to be recalled to other material, integrating it with already stored information. - Mental work - Organization

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But what is Deeper? The term “deep” is not well defined. • Depth of processing also tends to mean more time spent processing; it might be that it is the length of time spent processing which affects the memory trace, not the depth of processing • There may be more effort involved in “deeper” processing and the greater effort might account for the better recall. GP Mem(1)

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Focuses only on encoding. Transfer-Appropriate Processing Memory will be best when the processes engaged in during encoding match those engaged in during retrieval.

What to do if you catch on fire!

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The Testing Effect

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Implicit and Explicit Learning • Explicit learning: deliberate learning that one is consciously aware of • Implicit learning: learning that is acquired without awareness – Can we learn without awareness?

Research into Implicit Learning Sequence Learning Serial reaction time task • The task was to hit the key (corresponding to where the “X” appeared) as fast as possible.

Computer screen

X

• Unknown to participants, the appearance was based on an underlying sequence (8-12 items long) Response key pad

• Over time, people might get faster due to anticipation of this sequence • The question is, would the improvement be accompanied by explicit knowledge of the sequence?

Serial reaction time task –findings • In many cases, the sequence group were unable to report the sequence, despite vast improvements in RT • Seemed to have something to do with the complexity of the sequence, and the length of practice • What is with B10?

800 700 600 500 400 300 200 100 0

B1

B2

B3

B4

B5

B6

Sequence

B7

B8

B9

Random

The sequence is broken.

When questioned the participants show no conscious awareness of the sequence!

B10

B11

B12

Retrospective problem – people may be consciously aware of what they have learned at the time of the task, but have forgotten at then end of the experiment when asked for their explicit knowledge. Wilkinson & Shanks (2004) Inclusion task (try to guess next location) Exclusion task (don’t try to guess) - Better when asked to guess indicating that there is some conscious knowledge! GP Mem(1)

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Artificial Grammars Study the following letter strings for 5 minutes: A-D C-D-B-D A-C-A-D-B C-A-D A-C-A-C-A-D-B-D-B C-A-D-B A-D-B A-B-B-B C-A-B-B C-D-B-D-B C-A-B A-C-A-C-D-B GP Mem(1)

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TEST PHASE : For each of the following, simply tick those that are legal and place a cross against those that are illegal C-B B-D-B C-A-D-B-D C-B-D-B C-A-B-D-B-D C-D-B-A C-D A-B-D C-A-D-C-D-C A-B-D-B-D

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The grammar contains a fixed number of letters, and a fixed number of rules that determine the order and length in which “words” (strings of letters) can be created. For example, suppose I create a grammar consisting of three letters, A, B, C, and I make three rules: If there is an A, it must always precede C; each letter can appear only once, except B, which can be repeated up to three times. Under this grammar, I can create several words, such as A-C, A-B-C, B-C, B-B-C, A-B-B-C, C-B, and so on. However, other combinations such as, A-A-C, and C-B-A, are illegal, since they break the rules of the grammar. GP Mem(1)

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Diagrams

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Shows a form of implicit learning, since one measure has shown that you have learned something (recognition task), while a second measure of your awareness of what you have learned (stating the rules of the grammar) indicates poor explicit learning. It may be that this is how many people acquire grammar in natural language. Do you think that people who have not been taught the rules of grammar can still detect when a rule is broken, yet be unable to state what the rule is? GP Mem(1)

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Differences between Implicit and Explicit Learning 1. Robustness – unaffected by disorders. 2. Age independent 3. Low variability (individual differences)

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3. IQ independent 4. Commonality of process – all species

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Age and Intellegence Differences in Implicit and Explicit Memory Howard & Howard (1992) Serial Reaction time study with older and younger adults. Both groups showed implicit learning – did not differ from each other. Explicit test (predict the next position) – younger group was better. Gebauer & Mackintosh (2007) - same type of results found in relation to intelligence. GP Mem(1)

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Evidence from Neuropsychology Parkinson’s Disease Damage to Basal Ganglia which is thought to play a role in implicit memory. Show larger impairment of implicit than explicit learning.

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Parkinson’s patients however also have impaired explicit learning when the task is difficult. Conclusions: Basal Ganglia plays a role in implicit memory – and perhaps a smaller role in explicit memory.

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Double Dissociation – Damage to Medial Temporal lobes and Hippocampus Amnesiacs have damage to Medial Temporal lobes and Hippocampus. Show Implicit learning and no Explicit Learning.

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Brain Imaging In general these are consistent with the evidence from brain damaged patients.

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Long Term Memory systems Declarative Memory – conscious recollection Memories can be “declared” or “described” Nondeclaritive Memory – no conscious recollection

Claparede "Sometimes people hide pins in their hands". GP Mem(1)

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Divisions of Declarative LTM Episodic/Semantic (Tulving, 1972): Researchers seemed to be studying two kinds of memory when you looked at the experiments closely. Episodic Organized around time cues and experience cues. E.g., when remembering a word list, it is not just the words we are recalling but that they are tied together by the fact that they were learned at the same time from the same list. (what, where, when). Autobiographical Memory similar to is episodic but there’s a sense of your presence associated with the GP Mem(1) 39 memories.

Semantic Memory: Fact knowledge. This is like compiled episodic memories. Memories are organized around meaning cues and are divorced from your experience of the episode in which they were learned.

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Nondeclarative Memory Implicit memory: Memory that does not involve conscious recollection of information.

Procedural memory: Skill learning and habits. (e.g., keyboard skills, bike riding) Serial reaction time task is a test of procedural knowledge.

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Structure of LTM Non-Declarative

Declarative

Implicit Memory

Episodic Memory

Procedural Memory

Semantic Memory

Episodic Memory Does not work like a Video Tape.

What if it did?? Jill Price remembers all the sad and bad things in her life – the death of loved ones, for instance, like it’s happening right now. Time heals all wounds, but not for Jill Price.

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Solomon Shereshevskii The Mind of a Mnenonist (Luria, 1968) Eidetic memory - Solomon remembered nearly everything that ever happened to him in his entire life, even his mother's face as she stood over him in his crib as an infant. He could remember a passing car's license plate number from twenty years past. He was able to memorize lists of 70 numbers after being read them once, then repeat them forwards and backwards and retain them for upwards of 15 years. Synesthesia - if a doorbell rang, he wouldn't just 'hear' it. He wouldn't even 'hear' and 'feel' it. He would hear, see, taste, feel and smell the doorbell. Anything that he experienced was not only stamped in his mind for good, it was stuck there with a connection to all five of his senses.

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Solomon tried out several different methods of making his memories less invasive. One method was to write down all the things that he no longer wanted to remember and then burn up the paper he'd written them on. Another was to imagine covering up all the memories he didn't want with a blank canvas in his mind. He was eventually able to will some of his memory away, but not much. Shereshevskii eventually quit his reporting gig and bounced around from job to job for a while. He ended up becoming a professional mnemonist, wowing folks with neat memory tricks and getting paid for it. Want to know more? GP Mem(1)

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Reconstructive Memory Remembering the past and imagining the future are neurologically similar. Both utilize area associated with semantic information about one’s life, self-referential processing.

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Remembering

Imagining

Asked to either conjure up a memory or imagine a future scenario about some particular cue-word the same sites in the brain light up in both cases. GP Mem(1)

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Research with Amnesiacs Amnesic patients with primary damage to the hippocampus bilaterally were markedly impaired relative to matched control subjects at imagining new experiences. “The patients' imagined experiences lacked spatial coherence, consisting instead of fragmented images in the absence of a holistic representation of the environmental setting” (Hassabis, 2007). GP Mem(1)

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Recognition Memory Remember/ Know Task (Tulving) • Know = no contextual details; just a feeling of familiarity with the item. • Remember = contextual details (e.g., associations). On recognition task participants indicate whether they “know” a word was on the list or “Remember” that it is. GP Mem(1)

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“What” and “Where/How” Pathways Binding together of the two types of information is needed for recollection, but not for familiarity. Binding appears to depend on the hippocampus.

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Skinner & Fernandes (2007) – amnesiacs with hippocampus damage show impaired recollection compared to controls, but comparable familiarity judgments. Figure 5.5 Mean recollection and familiarity estimates for healthy controls, patients with medial temporal lobe (MTL) lesions or brain damage, and patients with non-MTL lesions. Reprinted from Skinner and Fernandes (2007). Copyright © 2007, with permission from Elsevier.

Semantic Memory Consists of general knowledge about the world, concepts and language. Some Examples of Semantic Memory The meaning of letters The concept of what a cat is The sounds that letters make The idea of what a car is How letters put together can make a word Knowledge that Annapolis is the capital city in Maryland Word definitions The dates of when World War II began and ended Knowing what a dinosaur is Recalling who wrote "Walking Through Woods on a Snowy Night" Knowledge of what a phone is used for Knowing how to make a pulley Recognizing color names Knowing where Mongolia is located on a map Remembering what a computer is The knowledge that fish swim in water Knowledge that owls are nocturnal Knowing deer can be hunted Knowledge of what constitutes a chair Knowing what a broom is used for To know where to find a parrot Remember what foods are popular in Cambodia Knowledge of what a book is GP Mem(1) Recollection of customs of regarding weddings in Syria

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Tulving suggests episodic memory is more recently evolved, later developing (i.e., infantile amnesia) and earlier deteriorating than semantic memory. Amnesias often retain semantic memory while having greatly impaired episodic memory. GP Mem(1)

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Schemas Organized packets of knowledge about the world.

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Read the following; ‘When the man entered the kitchen, he slipped on a wet spot and dropped the delicate glass pitcher on the floor. The pitcher was very expensive and everyone watched the event with horror.’ (Bransford, 1979)

Now write out the paragraph you have read, word for word. How much can you remember?

The Constructive approach Bartlett (1932) proposed the constructive approach of Memory Existing knowledge (schemas) are used to understand new information. Memories are changed to fit in with what we already know We tend to see and in particular interpret and recall what we see according to what we expect and assume is 'normal' in a given situation

Schemas • These are mental structures that represent an aspect of the world, such as an object or event. • Schemas help us to make sense of the world, by providing short cuts to identifying things that we come across (our building blocks of knowledge).

Schemas  For example,  It has a large metal door  Buttons and knobs  Gets hot inside  Has hot metal rings on top  It’s probably a stove. You don’t need to have seen this particular stove before to identify it. Your schema for “stoves” allows you to be able to identify all stoves so long as they don’t differ too much from your mental schema.

Bartlett 1932 Study Aim To investigate whether memories can be altered due to own values/culture Method Participants read a story called ‘The war of the ghosts’. Story based upon Native American culture Participants asked to recall the story repeatedly over days, weeks and months.

Results Participants distorted the story when asked to recall it Recall errors conformed to recaller’s culturally expectations (e.g. discussion about the spirits, swapped word canoe for boat). Rationalization. Conclusion Precise information is lost over time. Memory for schema are not. More rationalization errors over time. Memory is distorted to try and fit with a person’s current schemas (at retrieval)

Anderson and Pichert (1978) Participants read a description of a home from one of the two following perspectives. • Burglar Group • Homebuyer Group Recalled the story again either from the same or the opposite.

Schemata and Memory (Anderson & Pichert, 1978)

Proportion Recalled

Recall #1

Identity

Items

Schemata and Memory (Anderson & Prichert, 1978)

Change in proportion recalled

Distracter task....then....switch perspectives and try to recall again

First identity/second identity

Items

Figure 5.6 The “graduate student’s” room used by Brewer and Treyens (1981) in their experiment. Copyright © 1981 Elsevier. Photo reproduced with kind permission of Professor Brewer.

Participants spent 35 in this room.

Given Recall and or Recognition Test

Both things that we expect to see and those that, for whatever reason, we are surprised to see (that stand out) tend to get noticed and remembered. Schemas effect memory.

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