Long Term Memory PDF

In this topic, we will discuss: Long Term Memory  Are there different types of LTMs?  How does STMs become LTMs (encoding)?  How are LTM memori...

In this topic, we will discuss: Long Term Memory  Are there different types of LTMs?  How does STMs become LTMs (encoding)?  How are LTM memories stored in the brain KMF 1023 (storage)? COGNITIVE PSYCHOLOGY  How are LTM lost? Lecturer: Norehan Zulkiply  How are LTMs retrieved (retrieval)? FSKPM Universiti Malaysia Sarawak  What memory research tells us about how to study more effectively? Long-Term Memory (LTM) Long-Term Memory (LTM)  LTM:  An archive of information about past events in our lives and knowledge that we have learned  Covers a large span of time Eg. Do you remember what you had for dinner last night? What did you do on your birthday last year? LTM Who was your favorite teacher in primary school? Long-term memory covers a span that stretches from about 30 seconds ago to your earliest memories. Thus, all of this student’s memories, except the memory “I just sat down,” would be classified as long-term memories. What is LTM? Different Types of Memories  Long-term memory can be divided into declarative (explicit) memory and implicit memory.  We can also distinguish between two types of declarative memory and two ways to demonstrated implicit memory. 1 Different Types of LTM 2 types of memory  Declarative: Conscious recollections of events or facts that we have experienced or learned in the past Declarative Memory (episodic & semantic)  Implicit (non-declarative): Memory that occurs when a past experience influences behavior, but we are not aware of the experience that is influencing the behavior Different Types of LTM Different Types of LTM  Declarative Memory  Difference between Episodic & Semantic  Two types: Episodic: memory for Yesterday I did  Which sentence matches episodic or some shopping specific events that have semantic? happened to a person. Involves knowledge for time when the event happened I remember cooking with my mother when the tsunami came Semantic: knowledge about Unimas is located in Kota Samarahan the world that is not tied to I got married on 30 May, 1956. any specific personal event or time (eg. facts, numbers, The occipital lobe is responsible for processing concepts) visual information The concept of ‘gravity’ Different Types of LTM: Implicit Memory  We are not conscious of implicit memory  Past experience influences a person’s Implicit Memory behaviour even though the person is not aware of having those experiences  First demonstrated in people suffering from Korsakoff’s syndrome (memory affected) Destruction of areas in the frontal and temporal lobes causes severe impairment in memory 2  Implicit Memory  Warrington & Weiskrantz (1968) study on priming effect:  Priming: seeing a stimulus can affect our response to it when we see it again later Priming Asked Karsakoff patients to identify incomplete pictures Patients got better at identifying the pictures over days, fewer errors even though they cannot remember the previous day’s training Improvement in patients’ ability shows an effect of implicit memory  Patients had learned from the experience but cannot remember having had the experience Implicit Memory  Other examples of priming effects: Advertisements Movies: Subliminal messages work; still a good example) (although, there is little support they Procedural Memory Propaganda effect: participants are more likely to rate statements they have read or heard before as being true, simply because they’ve heard them before…eg during elections Propaganda effect works even when told statements are untrue (you’ll believe just about anything if it’s repeated often enough!) Procedural Memory  procedural = actions, skills, operations (perceptual-motor)  Memory for carrying out highly practiced skills 3 basic questions about  memory for skills is usually unconscious Human Memory  Procedural memory can remain even when semantic and episodic memory is lost Typing swimming How to drive Tying a shoe a car 3 There are three basic questions to ask about human memory: 1. how are memories formed? (encoding) 2. how are memories retained? (storage) 3. how are memories recalled? (retrieval) How does STM become LTM? How does STM become stored in LTM? (Encoding) How does STM become stored in LTM?  Encoding: the process of placing 1. Rehearsal information into long-term memory  Rehearsal = repeat an information to  Four ways: yourself over and over again Rehearsal Rehearsal is an effective means for learners Levels of processing (deep vs. shallow) to remember something for a long time. Making connections with other But repetition of more complex and meaningful information information will not ensure its being fully processed into LTM Organising information Elaborative rehearsal will How does STM become stored in LTM? How does STM become stored in LTM?  Maintenance rehearsal: 2. Levels of Processing theory Maintains information in memory but not effective way of transferring info into LTM Eg. “961-5000... 961-5000... 961-5000... 961-5000...  Craik & Lockhart (1972): memory 961-5000” depends on how information is encoded  Elaborative rehearsal: The process of connecting new material to information  Memory depends on the ‘depth’ of or ideas already in the learner’s mind processing (shallow vs. deep) Better way to store information in LTM Eg. “ 961-5000 is the number to Pizza Joint in Desa Ilmu”  Maintenance rehearsal < Elaborative rehearsal 4 How does STM become stored in LTM? How does STM become stored in LTM? 2. Levels of Processing theory 3. Making connections with other ‘depth’ of processing information Shallow Processing: Deep Processing:  Memory is affected by the way info is Does not focus Focus attention on programmed into the mind: attention on meaning of meaning of an item and  Forming connections with other an item relate the meaning to something else information is beneficial Focus attention on physical features, eg Eg. Create an image of  Information to be remembered is number of vowels in a an item by relating it to organised word (contoh: apple) another item Happens in Happens in elaborative maintenance rehearsal rehearsal How does STM become stored in LTM? How does STM become stored in LTM?  Connections with other information improves  Imagery enhances encoding: encoding (Bower & Winzenz, 1970)  Memory is better for complex sentence Help to create connection that will enhance memory Eg. Remember the word ‘chicken’ “She cooked the chicken” “The great bird swooped down and carried off the  2 groups were struggling chicken” presented with 15 pairs Complex sentences: of words of nouns creates more connections between the word to be Silently repeat the pairs remembered and other things. Provide cues to recall vs. create a mental information (Craik & Tulving, 1975) picture in which 2 items were interacting How does STM become stored in LTM? How does STM become stored in LTM?  Self reference effect  4. Organising information - Memory as an Organised storage device  Memory is better if you relate an item to Libraries be remembered to yourself Filing cabinets  Self provide cues to help remember Semantic networks ALL used to access information quickly  Memory system also use organization to access information E.g given list of words…apple, blue, pen, book, white, durian, eraser, paper file, brown , and etc… 5  How does STM become stored in LTM?  Eg. Concept maps Where are memories stored in the brain? LTM’s physiological mechanisms  Where are memories stored in the brain?  Learning and memory are stored in the synaptic changes LTM Storage is at synapse How do we lose memories?  Changes in our experience provide a neural record of experience New experiences LTM’s physiological mechanisms The Hippocampus & LTM 2. Case of patient H.M.(1953)  1. Traumatic accident – eg. you got hit on  the head (football match) 27 year old man who had epilepsy (penyakit sawan) Had surgery to remove his hippocampus from both hemispheres of his brain Became well from his epilepsy seizures, but experienced  Disruption during memory consolidation severe memory loss Memory of childhood and events before surgery- OK = the period of time needed for But memory for events after the surgery – not OK Cannot remember new conscious(declarative) memories strengthening the neural information  Eg. What are the current news events, what is the date, where is his address HM lost his declarative memory but his implicit memory was e.g: retrograde amnesia (loss information OK Can still learn new skills that did not require conscious from before trauma)  remembering, eg mirror drawing  Can’t remember attending any practice sessions but he got better at the skill 6 The Hippocampus & LTM  What we know about the function of Hippocampus from H.M’s case:  Needed for forming new conscious How do we retrieve LTMs our memories?  Not needed for STM/WM  Not where LTMs are stored  Not needed for implicit memory How are LTM’s recalled? (Retrieving) How are LTM’s retrieved?  Now that we know how memories are 1. Retrieval Cues formed or lost, how do we retrieve them?  Retrieval cues: a signal (sign, word, action) that gives you information about what to do when you have forgotten something  Retrieval: the process of recovering previously encoded information in LTM  Eg.of retrieval cues: Complex sentences (Craik & Tulving, 1975) Visual imagery (Bower & Winzenz, 1970)  Retrieval Cues & Processing Self Environment (example from the textbook) 1. Retrieval cues  Intend to bring something to class, leave your home and 2. Transfer–appropriate processing and after a short while you realize that you have forgotten to bring that “thing”…so you turn back home and find using 3. Encoding specificity any cues that can help you to locate that “thing” 4. State dependent learning How are LTM’s retrieved? 2. Transfer–Appropriate Processing (TAP) How are LTM’s retrieved?  Memory performance is enhanced if the type of encoding that 3.Encoding Specificity occurs during acquisition matches the type of retrieval  We learn info together with its context Context can be a retrieval cue  Learn items using shallow or deeper processing Memory improved if conditions for retrieval are Ability to remember is better if you are asked to recall those similar to conditions that occurred during items using the same type of processing encoding E.g : encode information in acronym , and later retrieved by Eg. place of encoding matches the place of acronym retrieval E.g.Experiment by Donald Morris and coworkers (1977) –pg. Case of Angela, from the textbook (pg. 209) 212  angela’s memories came flashing back when she  Semantic Acqusition (SA)  Rhyming Test (RT) : Retrieved less returned to her grandparents’ house – how to ride a  Rhyming Acquistion (RA) Rhyming Test (RT) : Retrieved more bicycle, smelling specific smells Encoding rhyme = Retrieving rhyme 7  Matching place & Memory How are LTM’s retrieved? 4. State Dependent Learning  Memory is best if a person is in the same state for encoding and retrieval  Effect of place and mood on memory Match place during encoding and retrieval Match mood during encoding and retrieval Design for Godden and Baddeley (1975) “diving” experiment. (b) Results for each test condition are indicated by the bar directly underneath that condition. Asterisks indicate situations in which study and test conditions matched. Matching place & Memory Matching mood & Memory (a) Design for Grant et al.’s (1998) “studying” experiment. (b) Results of the experiment. Asterisks indicate situations in which study and test conditions matched. (a) Design for Eich and Metcalfe’s (1989) “mood” experiment. (b) Results of the experiment. What memory research tells us about how to study more effectively?  Five tips to study more effectively: So how can we study 1. Elaborate more effectively? 2. Organize 3. Associate 4. Take Breaks 5. Match learning & testing conditions 8 Five tips to study more effectively Five tips to study more effectively  1. Elaborate  3. Associate Question asking and answering about a Associate what you have learned to what you text before, during, or after reading already know Eg creating images  2. Organise Organising helps relate information to other  4. Take study breaks information to make it more meaningful Study in a number of shorter study sessions Helps reduce load on memory Don’t cram especially at the last minute Eg. Concept maps, chunking  Distributed vs massed practised effect Five tips to study more effectively Summary  5. Matching Learning and Testing  LTM is divided into declarative and implicit conditions memory Better to match study and tests conditions or else  Declarative- conscious Study at a number of different places Episodic- memory for personal experiences Semantic-memory for facts  All these 5 techniques make use of effective encoding and retrieval strategies  Implicit – unconscious Priming – memory better for items you’ve been exposed to Procedural –memory for skilled tasks Summary Summary  LTM is stored in the brain through: Synapses To retrieve info from LTM, you need to know how to use Retrieval Cues & types and  To store info in LTM, you need to have effective encoding and retrieval strategies ways of processing the info:  Encoding: placing information into LTM Transfer–appropriate processing  Retrieval: the process of recovering info from Encoding specificity LTM State dependent learning  HM’s case tells us that the hippocampus helps us to store new information in LTM 9  In this topic, we will discuss: Everyday Memory – And  Memory for Personal Events Memory Errors Autobiographical memories Flashbulb memories KMF 1023  Causes of Memory Errors: COGNITIVE PSYCHOLOGY Inferred memories Lecturer: Norehan Zulkiply FSKPM False memories Universiti Malaysia Sarawak  Practical consequences Eyewitness testimony errors Memory for traumatic events Memory for Personal Experiences: Autobiographical Memory  Autobiographical memory Recollected events that belong to a person’s past (Rubin, 2005). Includes.. Memory for Personal Events  Episodic memory for dated events in our lives (i.e., must be part of our life stories)  Semantic memory (e.g., knowledge about your birth date, where did you celebrate it last 2 years)  Example: Your arrival at UNIMAS…  How are these events remembered? Episodic memory can fade with time, leaving semantic memory.  Memory for distant events become more semantic Memory for Personal Experiences: Life Life Span Memory: Span Memory The Reminiscence Bump  Life Span Memory : Schrauf & Rubin (1998): Enhanced memory for (episodic and semantic) facts of adolescence & young adulthood  Some events (about your own life) are remembered better than others Examples: milestones, transition periods… Percentage of memories People tend to have enhanced memory for from different ages, beginning of college year and end of college recalled by a 55-year old, showing the year. reminiscence bump (Rubin et al., 1998). The Reminiscence Bump phenomenon (reminiscence – to recall/ remember the past) People at this period of age (RB) assumes that “it is the time of our generation” 1 Hypotheses about the reminiscence bump Hypotheses about the reminiscence bump  Self-image hypothesis Memory is enhanced for events that occur as a person’s self-  Cognitive hypothesis image or life identity is being formed Memories during RB period are remembered best People assume identities during adolescence and young because they occur during a period of rapid change and adulthood stability  Many transitions occur between ages 10 and 30  Cultural life-script hypothesis Each person has  A personal life story  An understanding of culturally expected events Personal events are easier to recall when they fit the cultural life script. When does each of these event usually occur in a typical person’s life  Falling in love  Graduated from University/College  Marriage  Having children Memory for Personal Experiences: Flashbulb Memories (FbM)  Phenomenon: Shocking and emotionally charged events tend to be remembered very vividly (and more detailed than other events) Examples: Tsunami, Highland tower tragedy, the day the Penang jetty collapsed  Demonstration: What did you do on Aug 31 2001? Memories of personal experiences which are shocking and comprises of emotionally charged events. What did you do on Dec 26 2005? Not only occurs under highly emotional circumstances that What did you do on Sep 11 2001? are remembered for long periods of time BUT that they are vivid and detailed memories FbM: Evidence for a Special Mechanism  Strong Emotions Can Enhance Memory  Hamann et al. (1999): Use of PET scans to measure brain activity Emotionally charged images (pleasant and unpleasant) lead to higher amygdala How is Memory Constructed? activation and were more likely to be remembered (than neutral pictures)  Cahill et al. (1995): Case of patient B.P. who had amygdala damage Resulted in no enhanced memory for emotional events 2 How is Memory Constructed? The Constructive Nature of Memory  Bartlett’s “war of the ghosts” experiment Had participants read a story from Canadian folklore (about the sailing expedition of two Canadian men) and  Constructive approach to memory: asked participants to recall it as accurately as possible. The mind constructs memories based on a Used “Repeated Reproduction” - Participants came back number of sources of information a number of times to try to remember the story at longer and longer intervals after they first read it Knowledge,  Results  Memory = Actual event + experience & Over time, reproduction became shorter, contained expectations omissions and inaccuracies based on cultural expectations (e.g. the word “canoe” reproduced as “boats” (fits the England culture) Participants changed to make the story more consistent with their own culture Cultural expectations/knowledge can caused errors in memory 1. False Inferred Memories due to Evidence for Constructive Memory Experience  Possible memory ‘errors’: Omissions (when you omit or neglect)  Knowledge about our particular culture and day- to-day experience can lead to false memories Changes Role of schema & scripts Constructions (fabrications) Sets up expectations about what usually happened  Making errors in constructing memory  Schema : (false memories) due to : knowledge of the typical components of an experience Eg. Schema for studying at university, working as a Experience – eg. Inferred Memories, Schemas waiter at KFC and scripts Personal Bias Suggestions False Inferred Memories due to Experience False Inferred Memories due to Experience  Script :  Brewer & Treyens (1981) Type of Schema study: Schema for sequence of action that describe a  False memories due to highly familiar activity “office schema” Eg. Script for going to the cinema, for dining at a restaurant, for visiting the dentist  Result: Participants reported seeing items that were not in the real office but fitted into the regular schema of “office” 3 False Inferred Memories due to Experience False Inferred Memories due to Experience  Example of a script  Bower et al.’s (1979) study on script for  If you go to a new restaurant, in a city you have visiting a dentist never visited, you use a script that you usually Results: Participants added their own use in restaurants: knowledge on the script for visiting a dentist in You expect on entry to be greeted by a host/hostess. their memory recall test Shown to a table that is available. Reported remembering events they had not Given a menu. been shown in the test but which were Given some time to decide what you want to eat. consistent with the visiting a dentist script Waitress comes to your table to take you order Tell waitress clearly what you want. Waitress repeats your order…………………………. False Inferred Memories due to Experience 2.False Memories due to Personal Bias  Memory can be affected, and sometimes  Results from schema and scripts show distorted, by common biases that are how knowledge can affect memory related to personal and social factors such  People’s knowledge about the world has as : caused errors in their episodic memory how people perceive themselves and how they think about events in their lives False Memories due to Personal Bias 3.False Memories due to Suggestion  People are suggestible  Three types of false memories from our  Question: How easily can memory be modified by personal bias: suggestion? Eg: Advertisements, Political propaganda  Egocentric bias Tendency to remember positive traits about oneself  Misinformation effect : memory modification by misleading post-event  Consistency bias: information (MPI) Tendency to remember attitudes and behavior consistent with past attitudes and behavior. MPI: Misleading information presented after a person has witness an event can change how that person describes that event later  Positive change bias : Tendency to perceive things as ‘getting better’ Study by Loftus et al. 4 False Memories due to Suggestion Memory ≠ Video Recording A) Loftus et al. (1978): Stop vs. ‘yield’ sign …  Memory record is ‘imperfect’ Ps saw a series of slides depicting a – Errors of omission (incomplete, selective) traffic accident in which one car runs a stop sign & hit another car. – Errors of commission (distortions, Some Ps then listened to an accurate modifications) description of the event, but others heard MPI (that it was a yield sign at the intersection instead)  Question: Why has our memory system Those in MPI later reported they saw a yield sign been ‘designed’ (evolved in) that way? B) Loftus & Palmer (1974): cars ‘hit one another’ vs. ‘smashed’ into each other’ Speed estimates: 34 (hit) vs. 41 mph(smash) Picture of traffic accident similar to one seen by the participants in the ‘Broken glass’: Loftus et al. (1978) “misleading 14(hit) vs. 32% yes(smash) postevent information “ experiment. Why it is better to forget or have a Not so Perfect Memory? Analogy: ‘Fast & frugal’ Memory  Luria (1975): case of “S”- ‘virtually limitless’ memory  Like our perceptual system (see Ch. 3) our – could not forget irrelevant details memory system is primarily designed to work – bad at inductive reasoning (‘filling in the blanks’) efficiently  her ability to record massive amount of information and her inability to erase it may hinder her ability to perform IR  Anderson & Schooler (1991):  Tradeoff: Speed vs Accuracy  We remember relevant and frequent information to avoid system overload system design to selectively remember things that are important and often occur Eyewitness Testimony  Eyewitness testimony Testimony by an eyewitness to a crime about what he or she saw during the crime Eyewitness Testimony  People can make errors in giving eyewitness testimony 5  Errors Due to Emotions Errors in Eyewitness Testimony Stanny & Johnson (2000): The use of weapons…  The Problem: Fact 1: 200 people/day are incriminated based on eyewitness testimony Ps were asked to watch a Fact 2: Errors occur. film simulated crime and later asked to remember  Innocent people are convicted the details of it. 2 groups: Shoot – the gun was  Reasons for this phenomena: fired No shoot - a gun was Emotions present but not fired Familiarity (& source misattribution) Suggestion (& consistency bias) Results of Stanny and Johnson’s (2000) weapons-focus experiment. Presence of a weapon that was fired is associated with a decrease in memory about the perpetrator, the victim, and the weapon. Errors Due to Familiarity Errors Due to Familiarity Ross et al. (1994)’s study: Results of Ross et al. (1994): Note: Photospread included male teacher, but not actual robber! (b) Results of experiment when the actual robber WAS NOT in the photospread. In this condition, the male teacher was erroneously identified as the robber 60 percent of the (a) Design of Ross et al.’s (1994) experiment on the effect of familiarity on eyewitness time. testimony (continued on next slide). (c) Results when the actual robber WAS in the photospread. In this condition, the male teacher was erroneously identified less than 20 percent of the time. Errors Due to Suggestion Can Lost Memories be Recovered?  Recovered Memories: Wells & Bradfield (1998)’s study: Memories that occur when a situation caused the ‘Good, you identified the suspect…’ person to relive the memory Hypothesis: Past painful memories are repressed in a person’s unconsciousness until it is brought up years 1. Ps watched a video of an actual later usually through therapy crime 2. Ps were then asked to identify the  But there are reported cases of false Recovered perpetrator from a photospread Memories (that did not actually contain the pic of the perpetrator) no convincing evidence that the hypothetical 3. Ps received one of the 3 types of mechanism of repression actually exists feedback 4. A short time later, Ps were asked It is proposed that remembering painful experiences how confident were about their from the past involves the same mechanisms of identification/choice memory (due to creative mental processes)  Difficult to determine which recovered memories are true or false 6 Summary Summary What you need to know:  Autobiographical memories  Constructive memory A form of episodic memory for dated events Memory is constructed based on the actual event and additional information surrounding  Life span memory the actual event Memory for significant events in our life The constructive approach to memory also The Reminiscence Bump – better memory for allows for errors in remembering an event events in adolescence & young adulthood But can be shifted  False constructive memories can be due to  Flashbulb memories a person’s: Memory for shocking and emotionally charged events Experience – eg schema & script There are evidence for and against a special memory Personal bias mechanism for flashbulb memories Suggestions by others Summary  It is better to have an imperfect memory where we only remember relevant and frequent information Case patient S  Eyewitness testimony errors due to: Emotions Familiarity (& source misattribution) Suggestion  Recovery of lost memories is possible but sometimes you remember false lost memories 7  Knowledge In today’s lectures, we will discuss: Explain concepts and categories Three ways of categorisation  The Definitional Approach  The prototype approach  The exemplar approach KMF 1023 Relationship between Categories COGNITIVE PSYCHOLOGY  Semantic Networks Lecturer: Norehan Zulkiply FSKPM How are categories stored in the brain Universiti Malaysia Sarawak Knowledge Organisation through Knowledge Organisation through Concepts & Categories Concepts & Categories Concepts and Categories Basic important processes that allows us to car bicycle lettuce organise our experience of the world so that we can function in it carrots What are concepts? What are categories? truck broccoli train peas bus corn Knowledge Organisation through Knowledge Organisation through Concepts & Categories Concepts & Categories Item Vehicle Vegetable Concepts – mental representation 1 car peas consisting of general idea or understanding 2 truck carrots Themeaning of words and symbols 3 bus broccoli facts about the world 4 train lettuce What objects look like 5 bicycle corn Stored in Long term memory 1 Knowledge Organisation through Knowledge Organisation through Concepts & Categories Concepts & Categories How do you know you have understood a Categories – placing things into groups, or a class of similar things concept? Categories have been called ‘pointers to If a person has mastered a concept, knowledge’ he/she should be able to categorize  provide basic knowledge about concepts objects or events of a domain  valuable tool for making inferences about members from the same category  help understand new situations How do we Categorise? Three possible ways: Three Ways of Categorising Concepts 1. through definitions 2. through prototypes 3. through exemplars 1. The Definitional Approach 1. The Definitional Approach Based on determining whether the E.g.: “Cat” E.g.: “bachelor” properties of a particular object match a  Has fur  “adult”, definition  Likes milk, fish  “human”,  Dislikes water Categorisation through definitions  “male”  Has four legs E.g....  “unmarried”  Meows  Has a tail  Has whiskers  Chases mice  Belongs to the cat family 2 1. The Definitional Approach Wittgenstein (1953)  E.g. “chair”  a piece of furniture Proposed family resemblance – to deal  consisting of a seat, legs, back, often with the fact that definitions often do not arms, include all members of a category  designed to accommodate one person BUT  Things in a particular category resemble one  beanbag & car seat do not meet our another in a number of ways. definition Limitation of using the definition Instead of setting definite criteria that approach: Definitions do not, and every member of a category must meet, cannot, include all members of a the approach allow for some variations category within a category 2. The Prototype Approach Bird Example Eleanor Rosch (1973) We decide what belongs to a category by determining the similarity between the object in question and a prototype Prototype: a “typical” member of a particular category; the average representation of the category (formed from averaging the category members After having seen lots of birds in your life you would have formed a prototype of what a typical encountered in the past) bird would look like Prototypicality Eleanor Rosch (1973) incorporated the Variations within categories represent Wiitsgentein’s idea of family resemblance differences of prototypicality into the prototype approach to the study High-prototypicality - category member of categorization closely resembles the category prototype  allow variations within a category Low-prototypicality - category member distantly resembles the category prototype 3 Quantified Prototypicalities (Rosch, Quantified Prototypicalities 1975) Typicality ratings for members of three categories (Rosch, 1975) Quantified this idea by presenting a category title, such as furniture, and a list of 50 members of the category Participants were ask to rate the extent to which each member represented the category title on a 7 point-scale. Rating 1-means that member is a very good example of what that category is Rating 7 – means member fits poorly within the category/ is not a member at all Effects related to prototypicality Prototypical objects have high family resemblance They have more in common with other members of the category Prototypical objects have high family Rosch & Mervis (1975) – demonstration resemblance - ask participants to list as many attributes that they feel are common to the following objects: Statements about prototypical objects are  chair verified rapidly (reaction time faster in high  sofa  mirror protypical items than to low)  Telephone Results: Prototypical objects are named first  Characteristics overlap: many for chair and sofa ( means that family resemblance of these items is high), far less for mirror and telephone (family resemblance is low)  Chair, sofa –indicate good examples of the furniture (share many attributes with other members of the category). While mirror and telephone are bad examples of category furniture Statements about prototypical objects Sentence-verification Data: are verified rapidly Sentence-verification technique (Smith et al., 1974) Answer yes if you think the statement is true:  An apple is a fruit A pomegranate is a fruit Participants responded faster for objects that are high in prototypicality (first statement) 4 Prototypical objects are named first 3. The Exemplar Approach When participants are asked to list as Involves comparing object seen in a new many objects as possible, they tend to list instance to examples (whether the object is the most prototypical members of the similar to a standard object) category first (Mervis et. Al., 1976) Exemplars: examples of actual members of the Name some vehicles: category, previously encountered  car  truck This approach assumes that people categorize  plane new instances by comparing them to  train representations of previously stored examples in  submarine memory 3. The Exemplar Approach Which Approach Works Best? Eg. You have already seen Both prototype and exemplar approaches have their advantages and disadvantages Some researchers believe that both approaches are used Others suggest exemplars work best for small categories and prototypes work best So how would you categorize this? for large categories New Instance Categories – is there a privileged level? Rosch’s Approach (1976) Hierarchical categorisation Basic level is ‘special’ – above this level Which level is more important in this much information is lost, and below this hierarchy? Is there a privileged tier? level little information is gained 5 Demo of Rosch’s Approach How Knowledge Affects Categorisation e.g naming things For the following categories, list as many features that would be common to all, or most, of Stimuli for the “naming things” demonstration the objects in the category. For example, for E.g. Named guitar (basic level) rather than table you might list ‘legs’ musical instrument (superordinate) or rock guitar Results: (subordinate) How Knowledge Affects Categorisation How Culture Affects Categorisation Experts vs. Nonexperts Maya Itza, in Guatemala  identify plants and animals at the subordinate level (due to close contact with natural environment)  E.g an oak tree is classified as an oak tree rather than a tree Results of J. W. Tanaka and Taylor’s (1981) “expert” experiment. Experts (left pair of bars) used more subordinate categories to name birds and nonexperts (right pair of bars) used more basic categories. Relationships between Categories How are categories organized? Semantic networks : Relationship between Categories  concepts arranged in networks  arrangement represents organization in the mind  Based on Collins & Quillian’s (1969) research  Model of memory suitable for computer simulation 6  Components of Semantic Networks Components of Semantic Networks Nodes Links Concepts Properties of a concept Building a semantic network. (a) The skeleton-nodes connected by links. (b) Adding concept names to the nodes, which more specific ones at the bottom and more general ones at the top. Components of Semantic Networks Cognitive Economy in semantic network Store shared properties at a higher- level node  Exceptions added at lower nodes when necessary (c) Adding properties of each concept. This is the Why? Storing e.g “can network proposed by fly” at the node of Collins and Quillian every bird (canary, (1969). robin, etc)is inefficient and would use up too much storage space Testing Collin’s & Quillian’s Model Testing Collin & Quillian’s Model Provides testable predictions for concept recall Results: Greater distances are associated with longer reaction times, both when verifying statements about The time to recall information is determined by properties of canaries (top) and about categories of which the distance between info in the network canary is a member (bottom) Example...”A canary is an animal”, “A canary is a bird” 7  Theory of Spreading Activation Property of Collin’s & Quillian’s model Spreading activation -- activity that spreads out along any link that is connected to an activation node How are categories stored in the brain Categories in the Brain Categories in the Brain Specific or distributed? Areas of the brain are selective for categories (based on Different categories of objects are represented neuropsychological research) by activity in the specific areas of the brain Warrington & Shallice (1984):  Examples of areas for categories inferior temporal (IT) lobe damage related with inability to FFA –responds to faces recognize living things while retaining the ability to PPA – responds to houses, rooms, places recognize human made artifacts (such as tools and E.g., the representation of a cat activate: furniture)  sensory areas (for how a cat looks like) later research find some patients who had difficulty  Motor area ( for how it moves) recognizing tools, but not living things  Higher level areas (for knowledge about the cats’  Visual Agnosia –can see objects perfectly well, but they cannot name these objects behavior)  Emotional areas (for the emotional response elicited by the cat) Summary – What do you need to know? Summary Differences between concepts and Relationships between Categories categories  Collins & Quillan’s Semantic Networks Theory of spreading activation Three ways of categorisation  The definitional Approach How are categories stored in the brain  The prototype approach  The role of the IT lobe  The exemplar approach How are categories affected by  having expert knowledge  Different cultures 8  Visual Imagery In today’s lectures, we will discuss: What is Mental Imagery? What is Visual Imagery? The Imagery Debate Spatial vs Propositional representations in the mind Imagery & Perception Imagery & Memory Imagery & the Brain KMF 1023 COGNITIVE PSYCHOLOGY Lecturer: Norehan Zulkiply FSKPM, Universiti Malaysia Sarawak What is imagery? Mental imagery: forming images in your mind even though the actual stimulus that you are The Imagery Debate: imagining is not present experiencing a sensory impression in the absence Spatial vs Propositional of a sensory input representations Visual imagery: “seeing” in the absence of a visual stimulus (eg. counting the number of windows in your home, describe your mother’s face.) Applies to other senses too, eg: smell, taste, touch Visual Imagery Visual Imagery Shepard & Metzler (1971)’s Results: experiment on Mental Rotation Linear relationship Participants were asked to look at the two pictures and decide quickly between reaction whether they represent two different time(RT) and angle of views of the same object OR two orientation different objects Showed that Measured the time taken to participants were rotate abstract objects rotating image of the RT for (b) > RT for (a) objects in their mind It took longer to compare 2 objects during the that are separated by a large angle, experiment then it took to compare 2 objects that are separated by a smaller angle Prove the existence of Mental Rotation 1  Visual Imagery Shepard & Metzler (1971)’s experiment on Mental Rotation was so influential Imagery & Perception – do they share the Demonstrated a parallel between imagery and same mechanism in the brain? perception Imagery is not vivid/long lasting BUT shares many We see an object moving through space when we properties with Perception see a real object rotating, and that we have Linear trend in rotation...suggests spatial similar experience of movement through space correspondence when we rotate an object in our mind The spatial experience for both imagery and perception match the layout of the actual SEE (perceive) object rotates & IMAGINE object stimulus. rotates Further support from Steven Kosslyn – image scanning experiment Participants create mental images and then scan Do they share the same mechanism? them in their minds Visual Imagery: Image Experimental evidence for image Scanning scanning Stephen Kosslyn (1980, 1994) To investigate the time it takes to Visual imagery is spatial in scan between two locations on a nature mental image (spatial = involving space)  a representation in which different parts of an image can be described as corresponding to specific locations in space It should take longer to find things within imagery that are further apart Experimental evidence for Experimental evidence for image scanning You are Here image scanning Participants are shown a map of an Results: island containing a The farther apart the two objects were, the greater hut, a tree, a rock, the reaction time a well, a lake, sand, and grass When people operate on mental images they appear to Learn the map of the go through a process analogous to actually operating island then imagine on a physical object the whole map Although they did not have the actual map in their Participants were then heads, they were going through a process similar to asked to mentally the physical operation travel between the various locations on the island and be the time it takes to scan between objects in a mental aware of about how image is a function of distance between the objects. long it took to move between the locations 2 Image scanning : Associated data Visual Imagery Linear relationship Support for visual imagery as a spatial between distance and representation: response time Mental rotation (remember mental Mental scanning rotation) Further support Is there another explanation to the that imagery is spatial in nature mental rotation and scanning data? The Imagery Debate Propositional nature of Imagery The imagery debate... Pylyshyn: Just because we experience imagery spatially,doesn’t mean the underlying representation Zenon Pylyshyn (1973): is spatial Proposed that imagery is related to Imagery has a propositional representation – in mechanisms associated with language which relationships can be represented by symbols. use words to represent objects and relationship between Imagery is propositional in nature objects instead of visual / spatial as suggested by eg. In (dog, bathtub) Kosslyn A spatial (depictive) representation of “in(dog, bathtub)” would look something like this... Propositional nature of Imagery Propositional nature of Imagery Spatial (depictive) Propositional Another eg.: Propositional representation Spatial (depictive) representation representation representation Door beneath In (dog, bathtub) window Has 6 tires; 3 on each side Tires are black and round Many researchers more agreed with the Kosslyn’s idea that visual imagery is spatial in nature 3  Comparing Imagery & Perception Size in the visual field: Relationship between viewing distance and the ability to perceive details – similar in perception and imagery Imagery & Perception > the size, the > detail available with visual imagery Perceiving a car from far away would only allow it to fill only a portion of your visual field; difficult to see details – but as you move closer, it fills more of your visual field and allow you see the details of the car Comparing Imagery & Perception Conclusion to Imagery & Perception Imagery & perception are closely Mental walk task: related Imagine walking Share some but not all mechanisms toward the ostrich Perception occurs automatically when we look at something but imagery needs to be estimate how far you are generated with some effort from the ostrich when you begin to experience Perception is stable but imagery is fragile overflow Harder to manipulate mental images than When the image fills your images that are created perceptually visual field Provide evidence that images are spatial Imagery & Memory Paivio’s - Dual-coding theory: Memory is served by 2 Imagery & Memory systems:  1. Verbal  2. Nonverbal Each handles different kinds of information, and that the two can communicate with. each other too. 4 Imagery & Memory Imagery & Memory Support for dual-coding theory. Concrete nouns create images that other Paivio’s experiment: Paired-associate learning task: words can “hang onto” Participants were presented with pair of words during learning such as “pen-honor”, “boat-hat”, “car-house” Eg “boat-hat” can create image of a boat During recall test later, they were presented with one of the then can hang image of the the hat on the words and asked to recall the word it had been paired with boat Results: Memory for concrete nouns (hotel, Paivio’s theory highlight role of imagery as a garden) which can cause us to create images is way of encoding material in memory much better than memory for abstract nouns (knowledge, honor, custom) which are less likely for Important: Memory is better if material is imagery to happen encoded in both the verbal (language) & In parallel with Conceptual Peg Hypothesis  nonverbal (visual) systems concrete nouns create images that other words can “hang onto”. Using imagery to improve 1. Visualizing interacting images memory enhances memory Pictures used by Wollen (1972) to study the role of creating 2 ways imagery can improve memory: bizarre images in memory, eg. “piano-cigar” 1. Visualizing interacting images enhances memory 2. Organizational effect of imagery enhances memory  Method of Loci  Pegword technique Visualizing interacting images 2. Organizational effect of imagery enhances memory enhances memory Results: “Method of Loci” Visualisation is most effective when A method of which things to be remembered images of objects are paired in an are placed at different locations in a mental interactive way image of a spatial layout. Memory is better for interacting images Pick a route that is familiar to you eg. the rooms in compared to non-interacting images your house. Pick 5-7 objects/events that you want to remember. Create an image representing each ( c)& (d) better remembered than (a) & (b) object/event and place each image at a location in the house so that they will be encountered in the correct Bizarreness had no effect order. Retrace the path in your mind to see if the (d ) was not better remembered than (c) image helps you to remember the objects/events. 5 Organizational effect of imagery Organizational effect of imagery enhances memory enhances memory “Pegword method” Eg. First item you need to associate imagery with concrete words remember is a dentist’s Eg. One-bun, two-shoe, three-tree, four-door, five-hive,six-sticks, seven-heaven, eight-gate, appointment nine-mine, ten-hen Imagine your teeth biting into a bun (one) (first Easy to remember order as created by rhyming them with the number item) Pair each object to be remembered with each Useful to identify objects to pegword by creating a vivid image of the be remembered based on object with the pegword the order on the list Imagery & the Brain Evidence from: ERP’s Brain Imaging Imagery & the Brain Imagery neurons Neuropsychological case studies Transcranial Magnetic Stimulation Imagery & the Brain Imagery & the Brain ERP’s (Event related potential) Brain Imaging studies Conducted experiment asking participants to read concrete nouns(can create images – like Confirmed that imagery creates activity truck and house) or abstract nouns (more in area V1, the primary visual receiving difficult to create images – like peace and area (occipital lobe) ethics) Area V1 is involved in imagery Results: Imagery response occurred in two areas that are associated with object perception in the brain occipital lobe especially area Visual receiving area (V1) temporal lobe 6 Imagery & the Brain Imagery & the Brain Neuropsychological case studies There is evidence that some neurons Case of patient M.G.S are category specific Had part of visual cortex removed as treatment for epilepsy Eg. responded to baseballs but not faces Task: Imagine walking towards a horse Before removal of visual cortex, she can get to within 15 Same neurons responded when feet of the horse in her imagination. After removal of visual cortex, the horse started to overflow imagining the baseball but not when at an imagined distance of about 35 feet. imagining faces (imagery neuron) Results: Removing part of the visual cortex reduces the size of her Imagery Neurons field of view, so the horse filled up when she was farther away. Area V1 in visual cortex is important for imagery Transcranial Magnetic Stimulation Summary (in new book pg. 282) Function of imagery Mental imagery - Mental representation of stimuli that are not physically present Function: To temporarily disrupt the functioning of a brain area (by applying a pulsating magnetic field to the skull using a stimulating coil) The imagery debate: Spatial vs Propositional representation During disruption, a participant’s behavior is tested (asked Kosslyn vs Pylyshn participants to carry out a perception task or an imagery task) If the behavior is disrupted, it is concluded that the deactivated Evidence for Spatial representation area of the brain is causing that behavior Results: visual cortex (V1) plays a causal role in both Perception Mental rotation- For every equal increment in amount of rotation, an equal increment in reaction and Imagery time is required Image scanning- the time it takes to scan between objects in a mental image is a function of the distance between the objects Summary Summary Imagery & Memory Imagery in the Brain Paivio’s Dual Coding theory The occipital lobe especially area V1 is  2 forms of encoding in memory (verbal and important for imagery nonverbal) There exists Imagery neurons in the brain- respond only to images of specific How imagery helps to organise memory objects  Interacting vs non interacting images  Method of Loci