Chapter 7?Everyday Memory and Memory Errors Prospective Memory: What I?m Going to Do Later Prospective Memory?remembering to perform intended actions, such as going to class, keeping an evening appointment, or taking medication Two components that are necessary for successful prospective memory performance: Remembering what you want to do Remembering to do it at the right time Einstein and McDaniel (1990) hypothesized that prospective memory might be better when the cues are distinctive than when they are familiar Proposed that distinctive cues are more effective that familiar cues Example: remembering to relay a message to your friend Ralph (familiar) than remembering to relay a message to a stranger (distinctive) Devised an experiment on prospective memory?results show that unfamiliar cues result in better prospective memory correct responses were 3 times more likely for unfamiliar cues that for the familiar cues Event-based task?the task (pushing a button) is triggered when an external event occurs (presentation of the cue word) Example: remembering to tell Ralph the message when you see him Time-based task?task is to remember to do something at a particular time Example: taking a pill every morning for the next 2 weeks More difficult than an event-based task because there is no cue Schacter suggests that a solution to this problem is to create cues that turn time-based tasks into event-based tasks For example: one way to remember to take a pill everyday is to place it next to your toothbrush, so when you brush your teeth in the morning you remember to take the pill Autobiographical Memory: What Has Happened in My Life Autobiographical Memory?recollected events that belong to a person?s past (memory for events we have experienced in the past) ?mental time travel??placing ourselves back in the specific situations Episodic memory Autobiographical episodic memories can be experienced in 2 ways: Field Perceptive?remembering an event as if you are seeing it Recent memories Observer Perspective?remembering an event as observed from the outside, so you see yourself in the event More ?remote memories Although autobiographical memories are usually considered to be episodic memories, they can also have semantic components as well Personal semantic memories?facts we know about ourselves, such as where we lived at various times, the schools we went to, or names of childhood friends Note that these facts we can remember without actually re-experiencing events Taking into account personal semantic memories such as these, we can define autobiographical memory as episodic memory for events in our lives plus personal semantic memories of facts about our lives The Multidimensional Nature of Autobiographical Memory Autobiographical memories are multidimensional because they consist of spatial, emotional, and sensory components Visual experience plays an important role in autobiographical memories Brain-scanning study done by Cabeza (2004) illustrates the differences between autobiographical and laboratory memory Measured brain activation caused by 2 sets of stimulus photographs?one set that the participant took (autobiographical photos) and another set that was taken by someone else (laboratory photos) More brain activation for photos taken by participant reflecting the richness of experiencing autobiographical memories, as compared to laboratory memories Memory Over the Life Span Personal milestones such as graduating from college or receiving a marriage proposal stand out, as do highly emotional events such as surviving a car accident Transition points in people?s lives appear to be particularly memorable Alumni remembering more events from the beginning of their freshman year and end of their senior year, than any other time period in college?transition points Reminiscence Bump?the empirical finding that people over 40 years old have enhanced memory for events in their adolescence and early adulthood, compared to other periods in their lives Life-Narrative Hypothesis?an explanation for the reminiscence bump, which states that memories are better for adolescence and early adulthood because people assume their life identities during that time It is the time of ?our? generation and the time people return to when they become nostalgic for the ?good old days? It is also a time when a lot of ?firsts? occur?going to college, committing to a partner, starting a career, etc. Cognitive Hypothesis?another explanation for the reminiscence bump, states that encoding is better during periods of rapid change that are followed by stability Adolescence and early adulthood fit this description because the rapid changes that occur during these periods are followed by the relative stability of adult life Test by finding people who have experienced rapid change in their lives that occurred after adolescence or young adulthood Immigrants who came to US in early 20?s and mid-30?s Results showed normal reminiscence bump for those who emigrated in early 20?s and a shift of 15 years for those who emigrated later in life, just as the cognitive hypothesis would predict Cultural Life Script Hypothesis?another explanation for the reminiscence bump, which distinguishes between a person?s life story, which is all of the events that have occurred in a person?s life, and a cultural life script, which is the events that commonly occur in a particular culture Berntsen and Rubin (2004) asked people to list when important events in a typical person?s life usually occur, some of the more common responses were falling in love (16 years), college (22 years), marriage (27 years), and having children (28 years) A large number of the most commonly mentioned events occur during the period associated with the reminiscence bump This does not mean that events in a specific person?s life always occur at those times, but according to the cultural life script hypothesis, events in a person?s life become easier to recall when they fit the cultural life script for that person?s culture It is likely that each of the explanations (life narrative, cognitive hypothesis, and cultural life script hypothesis) makes some contributions to creating the reminiscence bump Flashbulb Memories Flashbulb Memories?refers to a person?s memory for circumstances surrounding hearing about shocking, highly charged important events It is important to emphasize that the term flashbulb memory refers to memory for the circumstances surrounding how a person heard about an event, not memory for the event itself Events that are brief, unexpected, and emotionally charged are highly memorable Example: a flashbulb memory for 9/11 would be memory for where you were and what you were doing when you found out about the terrorist attack Brown and Kulik argue there is something special about the mechanisms responsible for flashbulb memories They not only occur under highly emotional circumstances, but they are remembered for long periods of time and are especially vivid and detailed Mechanism responsible for these vivid and detailed memories is called the ?Now Print? mechanism, as if these memories are created like a photograph that resists fading Brown and Kulik concluded that people could often describe in some detail what they were doing when they had heard about these highly emotional events (assignations of JFK and MLK) Flawed because the only data they collected was what people remembered years later and there was no way to determine whether the memories were accurate Repeated Recall?recall that is tested immediately after an event and then is retested at various times after the event Research using the repeated recall task has shown that flashbulb memories are not like photographs Unlike photographs, which remain the same for many years, people?s memories for how they heard about flashbulb events change over time In fact, one of the main findings of research on flashbulb memories is that although people report the memories surrounding flashbulb events are especially vivid, they are often inaccurate or lacking in detail Studies suggest that perhaps memories that are supposed to be flashbulb memories may decay just like regular memories The idea that flashbulb memories are special appears to be based partially on the fact that people think the memories are stronger and more accurate; however, this study found that, in reality, there was little or no difference between flashbulb and everyday memories in terms of the amount remembered and the accuracy of what is remembered Results for both the Talarico and Rubin (2003) and Davidson and coworkers (2006) experiments showed that memory for the flashbulb event declined over time Davidson suggests 2 characteristics for better memory of flashbulb events: Involved high emotions (surprise, disbelief, anger, or fear) Added rehearsal Narrative Rehearsal Hypothesis?idea that we remember some life events better because we rehearse them (proposed by Neisser as an explanation for flashbulb memories) The Constructive Nature of Memory Constructive Approach to Memory?states that what people report as memories are constructed by the person based on what actually happened plus additional factors, such as the person?s knowledge, experiences, and expectations Called constructive because the mind constructs memories based on a number of sources of information Bartlett?s ?War of the Ghosts? Experiment Repeated Reproduction?a method of measuring memory in which a person reproduces a stimulus on repeated occasions so his or her memory is tested at longer and longer intervals after the original presentation of the material to be remembered The same participants came back to a number of times to try to remember the story at longer and longer intervals after they first read the story Similar to the repeated recall technique used in flashbulb memory experiments One of the first experiments to use the repeated reproduction technique Considered important because of the nature of errors Bartlett?s participants made and how Bartlett interpreted those errors Reproductions were shorted than the original and contained many omissions and inaccuracies One thing related to the errors was the strangeness of the story?a myth from an unfamiliar culture Bartlett noticed that the changes that occurred in remembering the story tended to reflect the participants own culture Educated Guesses About High School Grades Another example of memory that appears to involve constructive process is provided by the study in which college students were asked to remember high school grades Accurately remembered A grades 89% of time but accurately remembered D grades only 29% of the time 79 of the 99 students inflated their grades by remembering them being higher than what they actually received Possible reasons for these results: People tend to remember positive events more readily than negative events Memory is constructive Someone who is a good student, but doesn?t remember the grade they received in a specific class might base their guess on the fact that most of their grades were A?s or B?s Because a guess of A or B would have a good chance of being correct, they take the ?best guess? approach and guess Source Monitoring and Source Monitoring Errors Source Monitoring (Source Memory)?the process by which people determine the origins of memories, knowledge, or beliefs Example: remembering that you heard about something from a particular person Source Monitoring Error (Source Misattributions)?misidentifying the source of memory Also called Source Misattributions because the memory is attributed to the wrong source Source monitoring provides an example of constructive nature of memory because when we remember something, we usually retrieve the memory first (?I heard about Brokeback Mountain?) and we then use a decision process to determine where the memory came from (?It must have been from reading the article in the paper?) Jacoby and coworkers (1989) demonstrated the effects of source monitoring errors by testing participants ability to distinguish between famous and non-famous people?s names Acquisition (read non-famous names)(Immediate Test (read non-famous names from acquisitions plus new non-famous names and me famous names Q: which are famous?)(Delayed Test (same as immediate test but 24-hours later) Immediate Test results?most non-famous names correctly identified as non-famous Delayed Test results?some non-famous names misidentified as famous (?Becoming Famous Overnight?) Making Inferences Idea of constructive nature of memory by suggesting that memory reports can be created by inferences based on a person?s experiences and knowledge Pragmatic Inference?inference that occurs when reading or hearing a statement leads a person to expect something that is not explicitly stated or necessarily implied by the statement Inferences are based on knowledge gained through experience Bransford and Johnson (1973) experiment that tested people?s memory for the wording of action statements More errors were made by participants in the experimental group because they identified more sentences as being originally presented, even though they had not Experimental (?pounding nails?) Control (?looking for nail?) Have you seen this? (?hammer?) Experimental group more likely to say ?yes? to seeing the word hammer (57%) because ?pounding nails? refers to a hammer being used, rather than the control group who saw ?looking for nail?, which does not imply a hammer being used Schemas and Scripts Schema?a person?s knowledge about what is involved in a particular situation or experience Example: things that happen at a baseball game, working at a particular job, or being in a campus organization Information is schemas can provide a guide for making inferences about what you remember Script?a type of schema in which the conception of the sequence of actions that describe a particular activity or occur during a particular experience Example: the sequence of events that are associated with going to class would be ?going to class? script (includes get to class 10 minutes early, wait for students from previous class to leave, enter class and find seat, take notes on lecture, and leave when the professor is done lecturing) Scripts can influence our memory by setting up expectations about what usually happens in a particular situation Remembering a List of Words--False memories Advantages and Disadvantages of Construction Constructive property of memory reflects the creative nature of our mental processes, which enables us to do things like understand language, solve problems, and make decisions This creativity helps us ?fill in the blanks? when there is incomplete information Even though creativity serves a good purpose, it sometimes results in errors of memory Memory Can Be Modified or Created by Suggestion Advertisements and Political campaigns are examples of things that might influence a person?s attitudes, beliefs, or behaviors The Misinformation Effect Misinformation Effect?misleading information presented after a person witnesses an event can change how that person describes the event later Misleading Post-event Information (MPI)?the misleading information that causes the misinformation effect MPI can alter not only what participants report they saw, but their conclusions about other characteristics of the situation Misinformation effect shows not only how false memories can be created by suggestion but also provides an example of how different researchers can interpret the same data in different ways The question posed by the misinformation effect is, ?what is happening that changes the participant?s memory reports?? Different researchers have proposed different answers to this question Memory-Trace Replacement Hypothesis?(Loftus)states that MPI impairs or replaces memories that were formed during the original experiencing of the event According to this idea, seeing a stop sign creates a memory trace for a stop sign, but presentation of MPI that a yield sign was present causes the memory for the stop sign to be replaced by a new memory for a yield sign According to the idea of reconsolidation, reactivating a memory can form new memory traces Retroactive Interference?occurs when more recent learning interferes with memory for something that happened in the past Example: retroactive interference would be involved if studying for your Spanish exam made it more difficult to remember some of the vocabulary words you had studied for your French exam earlier in the day This explanation is similar to the memory-trace replacement hypothesis in that the new information affects the old information, however in this case the old information isn?t eliminated, it is simply interfered with Another explanation for the misinformation effect is based on the idea of source monitoring According to source monitoring, a person incorrectly concludes that the source of their memory for the incorrect event was a slide show, even though the actual source was the experimenters statement after the slideshow Results of Lindsay?s (1990) source monitoring experiment investigated source monitoring and MPI by asking whether participants who were exposed to MPI really believe they saw something that was only suggested to them Results indicate that for the misled items with female voice, 27% of the responses corresponded to the incorrect information in the second story, which compares to only 9% of incorrect responses in the control group These responses to misled items where source monitoring errors because the participants were confusing the information from the second story with the information from the first story Lack of source monitoring error with original story told by female voice and second story told by male voice because it was easier to distinguish which information came from which story Thus, using the same female voice for both stories created source monitoring errors that lead participants to believe they saw something they didn?t see Creating False Memories for Early Events in People?s Lives Hyman Jr. and coworkers (1995) created false memories for long-ago events in an experiment and had participants elaborate on them Participants couldn?t recall the false memory on first occasion, but remembered it on the second occasion First exposure probably caused the participant to accept the event as having actually happened Similar to Jacoby?s ?becoming famous overnight? experiment Illustrates source monitoring errors because the participants interpreted the source of their familiarity to something that had never happened Adding a picture to the experiment to reinforced and enhanced the false memory effect, with participants having twice as many false memories than the group who did not see the picture Why Do People Make Errors in Eyewitness Testimony? Eyewitness Testimony?testimony by an eyewitness to a crime about what he or she saw during commission of the crime One of the most convincing types of evidence to a jury, and the more confident the person giving the testimony, the more convincing it is High confidence is a poor indicator of witness accuracy Errors of Eyewitness Identification The Crime Scene and Afterward Errors Associated with Attention: One mechanism that may be operating during a crime has to do with how emotions may affect a person?s field of attention Easterbrook (1959) suggests that attention narrows as arousal increases Thus, if arousal is very low, attention is spread over a broad area, resulting in attention to irrelevant information Moderate arousal narrows attention, so more relevant information is attended, and very high arousal focuses attention to narrowly, so some relevant information may be missed Weapons Focus?the tendency to focus attention on a weapon, narrows attention because of high arousal, and results in less attention to relevant information such as the perpetrator?s face Errors Due to Familiarity Bystanders add another dimension to the testimony of eyewitnesses because there is a chance that the bystander could mistakenly be identified as a perpetrator because of familiarity from some other context Errors Due to Suggestion Post-event information can influence eyewitness testimony Increasing Confidence Due to Post-event Questioning What is Being Done? The first step towards correcting problems caused by inaccurate eyewitness testimony is to realize that the problem exists, and the second step is to proposed specific solutions Cognitive Psychologists suggest the follow solutions: When asking a witness to pick the perpetrator from a line-up, inform the witness that the perpetrator may not be in the particular line-up they are viewing When constructing a line-up, use ?fillers? who are similar to the suspect When presenting a line-up, use sequential rather than simultaneous presentation Improve interviewing techniques Cognitive Interview? interview procedure developed by cognitive psychologists which is based on what is known about memory retrieval which involves letting the witness talk with minimal interruption and also uses techniques that help the witness recreate the situation, using emotions, appearance, etc. Chapter 8?Knowledge Categories Are Essential, but Definitions Don?t Work Concepts?a mental representation that is used for a variety of cognitive functions, including memory, reasoning, and using and understanding language Categorization?most commonly studied function of concepts, which is the process by which things are placed into groups called categories Two approaches to categorization: Comparison Approach?based on the idea that we decided whether something belongs in a category by comparing it to a standard Network Approach?based on the idea that knowledge about categories can be represented by networks, which are diagrams that indicate how information about categories is organized in the mind Why Categories Are Useful One of the most important functions of categories is to help us understand individual cases we have never seen before Categories have been called ?pointers of knowledge? because once you know something is in a category, whether it is a cat, gas station, or a painting, you know a lot of general things about it and can focus your energy on specifying what?s special about it Categories not only provide information about the basic properties of things that belong to that category, but also serve as a valuable tool for making inferences about things that belong to other categories Why Definitions Don?t Work for Categories Definitional Approach to Categorization?the idea that we can decide whether something is a member of a category by determining whether the object meets the definition of the category However, for most natural objects (such as birds, trees, and plants) and many human made objects (like chairs) definitions do not work well at all Problem is that not all of the members for everyday categories have the same features Family Resemblance?(Wittgenstein) refers to the facts that things in a particular category resemble one another in a number of ways Allows for some variation within a category Definition Approach to categorization is based on determining whether the properties of a particular object match a definition Determining Categories by Similarity: Using Prototypes or Exemplars The prototype and exemplar approaches to categorization are both based on the idea that membership in a category can be determined by comparing an object to a ?standard? that represents the category Differ in that the prototype approach states that the standard is determined by averaging category members while the exemplar approach states that the standard is created by considering a number of typical members of a category The Prototype Approach: Finding the Average Case Prototype Approach to Categorization?we decide whether an object belongs to a category by determining whether it is similar to a standard representation of the category called a prototype Prototype?(Rosch)formed by averaging the category members we have encountered in the past (is not an actual member of the category, but an average representation of the category) Prototypicality?the degree to which a particular member of a category matches the prototype for that category High Prototypicality?a category member that closely resembles the category prototype Low Prototypicality?a category member that does not resemble the category prototype Prototypical Objects Have High Family Resemblance When an item?s characteristics have a large amount of overlap with the characteristics of other items in the category, this means the family resemblance is high, however, little overlap means the family resemblance is low Rosch and Mervis also showed that there is a strong relationship between family resemblance and prototypicality, because items high on prototypicality had high family resemblance Statements About Prototypical Objects Are Verified Rapidly Smith and coworkers (1974) used a procedure called the sentence verification technique to determine how rapidly people could answer questions about an objects category Sentence Verification Technique? Typicality Effect?ability to judge highly prototypical objects more rapidly Prototypical Objects Are Named First When participants are asked to list as many objects as possible, they tend to list the most prototypical members of the category first Example: sparrows would be named before penguins Prototypical Objects Are Affected More by Priming Priming occurs when presentation of one stimulus facilitates the response to another stimulus that usually follows closely in time Prototypical members of a category are affected by priming stimulus more than non-prototypical members The principle behind priming is that the prime will facilitate the participants response to a stimulus if it contains some of the information needed to respond to the stimulus The Exemplar Approach: Thinking About Exemplars Exemplar Approach to Categorization?like the prototype approach, involves determining whether an object is similar to a standard object, however the standard for the exemplar approach involves many examples, each one called an exemplar Exemplar?are actual members of the category that a person has encountered in the past Example: deciding whether a particular animal is a dog involves comparing it to dogs that have been experienced in the past Exemplar approach explains the typicality effect (in which reaction times for the sentence verification task are faster for better examples of the category than for less-good examples) by proposing that objects that are like more of the exemplars are classified faster Example: a sparrow is closer to other exemplars, so it is classified faster than a penguin, which is similar to few exemplars Which Approach Works Best: Prototypes or Exemplars? One advantage of the exemplar approach is that by using real examples, it can more easily take into account atypical cases such as a flightless bird Exemplar approach?s ability to take into account individual cases means that it doesn?t discard information that might be useful (rather than becoming lost in the overall average that creates a prototype) Exemplar approach can also deal more easily with variable categories like games Research indicates that the exemplar approach may work best for small categories, such as ?US Presidents?, and the prototype approach may work best for larger categories, such as ?birds? or ?automobiles? Blending of prototype and exemplar: We generally know what cats are (the prototype), but we know specifically our own cat best (the exemplar) Is There a Psychologically ?Privileged? Level of Categories? Hierarchical Organization?larger, more general categories are divided into smaller, more specific, categories to create a number of level of categories Research indicates that there is a basic level of categories with special psychological properties, but in some cases, the basic level may not be the same for everyone Rosch?s Approach: What?s Special About Basic-Level Categories? Rosch?s research starts with the observation that there are different levels of categories, ranging from general (like furniture) to specific (like kitchen table), and when people use categories they tend to focus on one of these levels Three Levels of Categories: Superordinate Level--furniture Basic Level--table Subordinate Level?kitchen table Rosch proposed that the basic level is psychologically special because it is the level above which much information is lost and below which little information is gained How Knowledge Can Affect Categorization Rosch?s experiments showed that there is a level of category, which she called ?basic?, that reflects people?s everyday experience Experts in certain categories have learned to pay attention to features of the objects that non-experts are unaware of Thus, in order to fully understand how people categorize objects, it is necessary to consider not only the properties of the objects, but the learning and experience of the people perceiving the objects Representing Relationships Between Categories: Semantic Network Semantic Network Approach?proposes that concepts are arranged in networks that represent the way concepts are organized in the mind Explain how hierarchical organization can represent how categories are organized in the mind Introduction to Semantic Networks: Collins and Quillan?s Model The network consists of nodes that are connected by links Each node represents a category or concept, and concepts are placed into networks so that related concepts are connected Specific nodes at the bottom and general nodes at the top of the skeleton Cognitive Economy?a feature of some semantic networks models in which properties of a category that are shared by many members of a category are stored at a higher-level node in the network Although cognitive economy makes the network more efficient, it does create a problem, for example, not all birds can fly This model predicts that by using the sentence verification technique, in which participants are asked to answer ?yes? or ?no? to statements about concepts, it should take longer to answer ?yes? to the question a canary is an animal than a canary is a bird This predict follows from the fact that it is necessary to travel along two links to get from canary to animal but only one to get to bird Spreading Activation?the activity that spreads out along any link that is connected to an activated node For example, Activation spreads the concepts that are connected to bird, such as animal and other types of birds The result of this spread of activation is that the additional concepts that receive this activation become ?primed? and so can be accessed more easily from memory Lexical Decision Task?task it to indicate whether presented words are words or non-words as quickly as possible The key variable in this experiment was the association between the pairs of real words Reaction time was faster when the 2 presented words were associated, which might have occurred because retrieving one word from memory triggers a spread of activation to other nearby locations in a network, and the more activation will spread to words that are related so that the response to the related words will be faster than the response to unrelated words Criticism of the Collins and Quillan Model Theory couldn?t explain the typicality effect, in which reaction times are faster for more typical members of a category than for less typical members Researchers also questioned the concept of cognitive economy because of evidence that many people may, in fact, store specific properties of concepts (like has wings for canary) right at the node for that concept Sentence Verification results, and other criticisms to the model lead to the proposal of a new semantic network model designed to handle problems the old one couldn?t Collins and Loftus Answer to Criticism Collins and Loftus?s (1975) model can deal with the typicality effect by using shorted links to concepts that are more closely related, and longer links for those that are less closely related but still categorized in the same category New model abandons the hierarchical structure meaning that spacing between various concepts can differ for various people depending on their experience and knowledge about specific concepts This modification made it possible to explain just about any result of categorization experiments Assessment of Semantic Network Theories Properties of good psychological theories: Explanatory power?theory can explain why a particular result occurred by making a statement like ?Behavior A occurred because?? Predictive power?theory can predict the results of a particular experiment by making a statement like ?under these circumstances, Behavior B will occur? Falsifiability?theory or part of a theory can potentially be shown to be wrong when a particular experimental result occurs Generation of experiments ?good theories generally stimulate a great deal of research to test the theory, determine ways of improving the theory, study new questions raised by the theory etc. Representing Concept in Networks: The Connectionist Approach (Rumelhart & McClelland) -concepts are represented in networks that contain nodes and link like semantic networks -operate very differently -"Neuron-like units" -input units- activated by stimulation from environment -hidden units- receive input from input units -output units- receive input from hidden units -known as the parallel distributed processing approach -knowledge represented in the distributed activity of many units -weights at each connection determine how strongly an incoming signal will activate the next unit; can be positive (excitation in neurons) or negative (inhibition in neurons) How learning occurs: -network responds to stimulus -provided with correct response; back propagation transmits error signal back toward the circuit -modifies responding to match correct response Error signal- difference between actual activity of each output unit and the correct activity Back propagation- error signal transmitted back through the circuit; indicates how weights should be changed to allow the output signal to match the correct signal -the process repeats until the error signal is zero Advantages: -slow learning process that creates a network capable of handling a wide range of inputs -information about each input is contained in the distributed pattern of activity across a number of units -system is not totally disrupted by damage; graceful degradation- disruption of performance occurs gradually as parts of the system are damaged -learning can be generalized -successflu computer models have been developed Categories in the Brain Difference areas of the brain may be specialized to process info about different categories -inferior temporal cortex damage can cause people to lose ability to recognize living things, wile retaining the ability to recognize tools and furniture -visual agnosia- people can see objects perfectly, but cannot name them -double dissociation for categories "living things" and "non-living things" Categories are represented by distributed activity -more similar patterns of brain activity for categories with similar features -category-specific neurons- in temporal lobe that respond best to specific objects Chapter 9: Visual Imagery Mental imagery- experiencing a sensory impression in the absence of sensory input Visual imagery- a type of mental imagery involving vision, in which an image is experienced in the absence of a visual stimulus ?seeing? in the absence of a visual stimulus The Uses of Visual Imagery: - visual imagery provides a way of thinking that adds another dimension to purely verbal techniques Mental imagery is experiencing a sensory impression in the absence of a sensory input. Visual imagery is ?seeing? in the absence of a visual stimulus. Imagery has played an important role in the creative process and as a way of thinking, in addition to purely verbal techniques Early Ideas About Imagery: imageless-thought debate- the debate about whether thought is possible without an image Imagery & the Cognitive Revolution: Paired-associate learning- learning that occurs when a participant is presented with a pair of words during a study period and then is tested when one of the words is presented and the task is to recall the other world ex: boat-hat or car-house Conceptual-peg hypothesis- a hypothesis associated with Pavio?s dual coding theory stating that states that concrete nouns create images that other words can hang on to, and that this enhances the memory for these words ex: hotel-student vs. knowledge-honor (concrete nouns like hotel & student are much easier to ?hang onto? than abstract nouns like knowledge and honor) Early ideas about imagery included the imageless-thought debate and Galton?s work with visual images, but imagery research stopped during the behaviorist era. Imagery research began again in the 1960?s, with the advent of the cognitive revolution. Imagery & Perception: Do they share the same mechanisms? mental scanning- a process of mental imagery in which a person scans a mental image in his or her mind Kosslyn?s Mental Scanning Experiments- In one experiment, Kosslyn asked participants to memorize a picture of a BOAT and then create an image of that object in their mind and then focus on one part of the boat, such as the anchor. They were then asked to look for another part of the boat, such as the motor, and to press ?True? when they found this part or ?false? if they couldn?t find it Kosslyn reasoned that if imagery, like perception, is spatial, then it should take longer for the participants to find parts located farther from the initial point of focus because they would be scanning across the image of the object. imagery debate- a debate about whether imagery is based on spatial mechanisms such as those involved in perception, or is based on mechanisms related to language, which are called propositional mechanisms. The idea that imagery shares the same mechanisms as perception (that is, creates a depictive representation in the person?s mind) was suggested by Kosslyn?s mental scanning experiments, but these results and others were challenged by Pyllyshyn, who stated that imagery is based on a mechanism related to language (that is, it creates a propositional representation in the person?s mind.) The Imagery Debate: Is Imagery Spatial or Propositional Kosslyn: spatial representation- a representation in which different parts of an image can be described as corresponding to specific locations in space\ - most researchers accept the spatial representation of visual imagery Pylyshyn: believes the spatial experience of mental images is an epiphenomenon- something that accompanies the real mechanism but is not actually part of the mechanism believes that mental images indicate that something is happening in the mind, but they don?t tell us how it is happening - proposes that the mechanism underlying imagery is not spatial but is propositional ( propositional representation- a proposition in which representations are represented by symbols, as when the words of language represent objects and the relationships between objects thus, the propositional representation of a cat under the table would be the notation UNDER (CAT, TABLE) in contrast, the spatial representation would involve a spatial layout showing the cat and table ( this is called depictive representations- corresponds to spatial relationships; the spatial relationship is depicted by the picture Motor ( rear deck ( cabin ( front deck ( anchor tacit-knowledge explanation- states that participants unconsciously use knowledge about the world in making their judgments - Pylyshyn argues against the idea of a depictive representation using this tacit knowledge explanation Both the spatial and propositional approaches to imagery show how data can be interpreted in different ways. Pylyshyn?s criticisms stimulated a large number of experiments that have taught us a great deal about the nature of visual imagery. This evidence supports the idea that imagery is served by a SPATIAL mechanism. and that it shares mechanisms with perception. 4. One of Pylyshyn?s arguments against the idea of a depictive representation is the tacit-knowledge explanation, which states that when asked to imagine something, people ask themselves what it would look like to see it, and then they simulate this staged event. Comparing Imagery & Perception Kosslyn?s other experiment: looks at how imagery is affected by the size of an object in a person?s visual field Size in the Visual Field Does the relationship between viewing distance and the ability to perceive details also occur for mental images? So, Kosslyn says: Imagine an elephant and rabbit ( elephant fills visual field Imagine rabbit and fly ( rabbit fills visual field mental-walk task- a task used in imagery experiments in which individuals are to imagine they are walking toward their mental image of an object the task was to estimate how far away they were from the animal when they began to experience ?overflow??when the image filled the visual field or when its edges started becoming fuzzy. Results: participants had to move closer for smaller animals and farther for larger animals Conclusion: Therefore, images are SPATIAL (we imagine things big or small), just like perception Interactions of Imagery & Perception Another way to demonstrate connections between imagery and perception is to show that they interact with one another; basic rationale: if imagery affects perception, or perception affects imagery, this means that imagery and perception both have access to the same mechanism Is there a way to resolve the imagery debate? Despite all the evidence, we still cannot rule out the propositional explanation difficult to rule out Pylyshyn?s tacit knowledge explanation instead of relying solely on behavioral experiments, we should investigate how the brain responds to visual imagery Fink and Pinker?s ?flashed dot? experiment argued against the tacit-knowledge explanation. The following experiments also demonstrated parallels between imagery and perception: 1. size in the visual field (visual-walk task) 2. interaction between perception and imagery, and 3. physiological experiments. Imagery and the Brain There is a TON of evidence that points to a connection between imagery and perception Imagery Neurons in the Brain there are neurons that respond to some objects, but not others there are neurons that respond to specific objects, called category0specific neurons imagery neurons- a type of category-specific neurons that respond to both perceiving an object and to imagining it. Brain Imaging Both perception and imagery activate the visual cortex there is an overlap between areas activated by perceiving an object and those activated by creating a mental image of the object, however, there are also several differences too Basically, imagery and perception share some mechanisms! 6. Parallels between perception and imagery have been demonstrated physiologically by the following methods: 1. recording from single neurons (imagery neurons) 2. brain imaging (demonstrating overlapping activation in the brain) 3. transcranial magnetic stimulation experiments (comparing effect of brain inactivation on perception and imagery), and 4. neuropsychological case studies (removal of visual cortex affects image size; unilateral neglect). There is also physiological evidence for differences between IMAGERY and PERCEPTION. This evidence includes 1. differences in areas of the brain activated and 2. brain damage causing dissociations between perception and imagery. Transcranial Magnetic Stimulation: Although many brain imaging experiments are consistent with the idea that imagery and perception share the same mechanisms,. showing that an area of the brain is activated by imagery does not PROVE that this activity CAUSES imagery. According to Pylyshyn, brain activity in response to imagery may be indicating that something is happening, but may have nothing to do with causing imagery. To deal with this possibilitiy, there was an experiment done using a technique called: transcranial magnetic stimulation (TMS): a procedure in which magnetic pulses are applied to the skull in order to temporarily disrupt the functioning in a part of the brain ( Kosslyn concluded that the brain activation that occurs in response to imagery is not an epiphenomenon and that brain activity in the visual cortex plays a causal role in both perception and imagery. 8. Most psychologists, taking all of the above evidence into account, have concluded that imagery is closely related to perception and shares some (but not all) mechanisms. Neuropsychological Case Studies -using people with brain damage to help us understand imagery Removing Part of the Visual Cortex Decreases Image Size- this supports the idea that the visual cortex is important for imagery Perceptual Problems are Accompanied by Problems with Imagery people who lost the ability to see color are unable to create colors through imagery@@@ unilateral neglect- a problem caused by brain damage, usually to the right parietal lobes, in which a patient ignores the left half of their visual field ex: eating food on one side of the plate; shaving one side of face Dissociations between Imagery & Perception there have been dissociations between imagery and perception; for example. a person?s brain damage had little effect on his ability to perceive but caused neglect in his mental images another case of normal perception but impaired images is a case where the dude could not visually recognize objects but he could draw objects from memory in rich detail Making Sense of the Neuropsychological Results: The neuropsychological cases present a paradox: On one hand, there are many cases in which there are close parallels between perceptual deficits and deficits in imagery. On the other hand, there are a number of cases in which dissociations occur, so that perception is normal but imagery is poor, or vice versa. How to explain this paradox? Basically, the mechanisms for perception and imagery overlap only PARTIALLY According to this idea, visual perception involves bottom up processing, which starts when the light enters the eye and an image is focused on the retina, then continues as signals are sent along the visiual pathways to the visual cortex and then to higher visual centers. The visual cortex is crucial for perception because it is here that objects begin being analyzed into components and orientations. In contrast, imagery is a TOP-DOWN process, which originates in HIGHER brain areas that are responsible for memory. Mental images are therefore ?preassembled? and do NOT depend on activation of the visual cortex CONCLUSIONS from the imagery debate: SHARED MECHANISMS for IMAGERY and PERCEPTION Imagery and perception are closely related and share some, but not all, mechanisms Using Imagery to Improve Memory Visualizing Interacting Images participants who created IMAGES based on two paired words (like BOAT and TREE) remembered over twice as many words visualization is most effective when objects are paired in an interactive way ( bizarreness has NO effect method of loci- a method in which things to be remembered are placed at different locations in a mental image of a spatial layout Associating Images with Words pegword technique- things to be rememberd associated with concrete words ex: one-bun, two-shoe, three-tree, four-door, five-hive, six-sticks, etc? 9. The action of imagery can improve memory in a number of ways: 1. visualizing interacting images 2. organization using the method of loci, 3. associating items with nouns using the pegword technique. 10. Solving problems using mechanical reasoning can be carried out using either mental simulation or rule-based approaches. Experiments with the water-pouring problem show that it is unlikely that tacit knowledge is involved in using imagery to solve this problem. Experiments with the pulley problem indicate that people direct their attention to imagining specific areas of the problem. Quiz: Ira and his sister are playing "Name that Tune." The object of the game is to name the title of the song when given the song's first line. Ira suggests the first line "Sleigh bells ring, are you listening?" His sister can't come up with the answer at first, but realizing that the title is often embedded in the lyrics, she tries to sing them silently to herself. She then bursts out "Ah! It's "Winter Wonderland." It is most likely that Ira's sister used ________ in playing the game. inner audition ?Early? researchers of imagery proposed all of the following ideas: imagery is not required for thinking images are one of the three basic elements of consciousness thought is impossible without an image NOT: imagery requires a special mechanism Shepard?s and Metzler?s image rotation experiment was so influential and important to the study of cognition because it demonstrated: ?imagery and perception may share the same mechanisms Which of the following has been used AGAINST the idea that imagery is spatial in nature? TACIT-KNOWLEDGE EXPLANATION= an explanation proposed to account for the results of some imagery experiments that states that participants unconsciously use knowledge about the world in making their judgments. This has been used as one of the arguments AGAINST describing imagery as a depictive or spatial representation Perk?s experiment, in which participants were asked to ?project? visual images of common objects onto a screen showed that: imagery and perception can interact with one another Perception = __________ and Imagery= __________ (according to Behrmann) perception = bottom-up imagery= top-down The pegword technique relies on: rhymes visualizations associations pegword technique- a method of remembering things in which things are associated with words The mental simulation approach for solving mechanical problems is analogous to the idea that visual imagery involves ________ respresentations. spatial
Want to see the other 14 page(s) in Exam 3 Study Guide?JOIN TODAY FOR FREE!