Gazzaniga • Heatherton • Halpern Psychological Science FOURTH EDITION Chapter 7 Attention and Memory ©2013 W. W. Norton & Company, Inc. “Coffee Break Brain” Here’s a reason to tell your boss to “give you a break.” As this ScienCentral News video explains, scientists working with rats say breaks from activities may help your memory. Attention and Memory • In 1953, doctors took a radical surgical approach to quiet the seizures of Henry Molaison, aka H.M. • Sadly and unexpectedly, the surgery caused H.M. to lose the ability to remember things over long periods of time • Over the course of 40 years, H.M. participated in countless experiments and became one of the most famous people in memory research 7.1 What Is Memory? • Describe the three phases of memory. • Identify brain regions involved in learning and memory. • Describe the processes of consolidation and reconsolidation. Memory Is the Nervous System’s Capacity to Acquire and Retain Usable Skills and Knowledge • Identity is made up of memories, including recollections and knowledge of skills • Memories are often incomplete, biased, and distorted – Can you think of an instance where you and a friend or relative have had different memories of the same event? • We have multiple memory systems, and each memory system has its own “rules” Memory Is the Processing of Information • The information processing model compares the working of memory to the actions of a computer • Memory operates over time in three phases: – encoding: the processing of information so that it can be stored – storage: the retention of encoded representations over time – retrieval: the act of recalling or remembering stored information when it is needed Memory Is the Result of Brain Activity • Memory researchers have made tremendous progress over the past two decades in understanding what happens in the brain when we acquire, store, and retrieve memories • What role does biology play in the processing of information? Memory’s Physical Locations • Lashley’s term engram refers to the physical site of memory storage; the place where memory “lives” • Equipotentiality: the idea that memory is distributed throughout the brain rather than confined to any specific location • In Hebb’s interpretation, memories are stored in multiple regions of the brain, and they are linked through memory circuits • Multiple brain regions have been implicated in memory, including the hippocampus, temporal lobes, cerebellum, amygdala, and the brain structures involved in perception Consolidation of Memories • Consolidation: a process by which immediate memories become lasting (or long-term) memories • The medial (middle) temporal lobes may be responsible for coordinating and strengthening the connections among neurons when something is learned and play an important role in the formation of new memories • Actual storage occurs in the particular brain regions engaged during the perception, processing, and analysis of the material being learned, e.g. sound is stored in the areas involved in auditory perception • Remembering something seen or heard involves reactivating the cortical circuits involved in the initial seeing or hearing • Once the connections are strengthened sufficiently, the medial temporal lobes become less important for memory • Sleep may play an important role in the consolidation of memories “Magnetic Brain Boost” Whether we’re hitting the books for exams or in an extreme situation like combat, we often lack sleep just when we need to perform at our best. Now as this ScienCentral News video reports, brain researchers studying how sleep deprivation impairs memory have found a potential remedy. Reconsolidation of Memories • Nader and LeDoux proposed that once memories are activated, they need to be consolidated again to be stored back in memory – reconsolidation: neural processes involved when memories are recalled and then stored again for later retrieval, e.g. a librarian returning a book to a shelf • The reconsolidation process repeats itself each time a memory is activated and placed back in storage, and it may explain why our memories for events can change over time • Using extinction during the period when memories are susceptible to reconsolidation can be an effective method of altering bad memories – What drawbacks might there be from altering or losing memories? “Your Memory Is Bigger and Better Than Scientists Expected” Good news about our brains—turns out our visual memory is bigger and better than previously thought. The study authors even offer a tip to help improve your memory, and keep you from losing your keys. 7.2 How Does Attention Determine What We Remember? • Distinguish between parallel processing and serial processing. • Describe filter theory. • Define change blindness. “Attention Training” Just five days of special training improves young children’s attention spans, and it makes the biggest difference for those with attention deficits. As this ScienCentral News video explains, it also improved one aspect of intelligence. 7.2 How Does Attention Determine What We Remember? • To get information into memory, a person needs to attend. • Attention is the ability to focus on certain stimuli; this ability is adaptive in that it facilitates functioning by enabling us to block out irrelevant information. • Attention can be distracted by external sensory cues or by internal thoughts and memories. – In what situations are you easily distracted? Our Visual Attention Works Selectively and Serially • Using visual search tasks, researchers like Anne Treisman have found that we process basic features of stimuli (e.g., color, motion, orientation, shape, and size) in parallel – parallel processing: processing multiple types of information at the same time • Parallel processing allows us to process information from different visual features at the same time by focusing on targets instead of distractors – targets:objects that differ from the others in only one feature – distractors:other objects in the display • Single-feature searches are fast and automatic and occur via parallel processing • Conjunction tasks are serial and effortful; they take longer and require more attention because you need to process each stimulus individually • Synesthetes may excel at visual search tasks because they may perceive numbers in a particular color even if all the numbers are black Our Auditory Attention Allows Us to Listen Selectively • Because attention is limited, it is hard to perform two tasks at the same time, especially if the two tasks rely on the same sensory or mental mechanisms – How can talking on a cell phone affectdriving ability? • Cherry’s cocktail party phenomenon highlights how a particularly pertinent stimulus can capture your attention • Cherry developed selective-listening studies to examine what the mind does with unattended information when a person is engaged in a separate task – shadowing: in this procedure, the participant receives a different auditory message in each ear. The participant is required to repeat, or “shadow,” only one of the messages What would happen if your own name were spoken into the unattended ear? Through Selective Attention, We Filter Incoming Information • Broadbent’s filter theory maintains that attention is selective • Stimuli that evoke emotions may readily capture attention because they provide important information about potential threats • Socially relevant information, like a face, also captures attention • To some extent, however, we process information contained in sensory stimuli to which we are not consciously attending Through Selective Attention We Filter Incoming Information • Because we cannot attend to everything in the vast array of visual information available, often we are “blind” to large changes in our environments – change blindness: a failure to notice large changes in one’s environment • Change blindness illustrates that our perceptions can be inaccurate Critical Thinking Skill: Recognizing When “Change Blindness Blindness” May Be Occurring • Change blindness blindness is our unawareness that we often do not notice apparently obvious changes in our environments • Attention influences memory – How might your perception of a car accident as an eyewitness differ from the driver’s? – What factors may have distracted you from witnessing critical moments of the incident? • Recognizing the limitations of attention may help prevent us from misleading ourselves about our perceptions “Time Flies” Scientists have discovered why time flies. As this ScienCentral News video reports, researchers have found it’s all about grabbing your attention. 7.3 How Are Memories Obtained Over Time? • Distinguish between sensory memory, shortterm memory, and long-term memory. • Describe working memory and chunking. • Review evidence that supports the distinction between working memory and long-term memory. • Explain how information is transferred from working memory to long-term memory. 7.3 How Are Memories Obtained Over Time? • In the information processing model, information is encoded in the brain during learning, stored in memory, and then retrieved for later use. • Alternatively, Atkinson and Shiffrin’s three-part model consists of sensory memory, short-term memory, and long-term memory. • Atkinson and Shiffrin’s model emphasizes that memory storage varies in duration and capacity. Sensory Memory Is Brief • Sensory memory: a memory system that very briefly stores sensory information in close to its original sensory form • Sensory memory consists of brief traces on the nervous system that reflect perceptual processes. • Sperling concluded that sensory memory persists for about one-third of a second and then progressively fades • Sensory memories enable us to experience the world as a continuous stream rather than in discrete sensations, e.g. the way a movie projector plays a series of still pictures Working Memory Is Active • Material is passed from sensory memory to short-term memory. More recently, psychologists have come to think of short-term memory as working memory. – short-term memory: a memory storage system that briefly holds a limited amount of information in awareness – working memory: an active processing system that keeps different types of information available for current use, e.g. sounds, images, ideas • Information remains in working memory for about 20 to 30 seconds unless you actively prevent it from disappearing by thinking about or rehearsing the information – How long can you remember the three-letter string of consonants, XCJ? Try to retain this information while counting backward in threes from the number 309 • Retrieval, transformation, and substitution make distinct and independent contributions to updating the contents of working memory “Memory Storage” The movie Eternal Sunshine of the Spotless Mind depicts a fictional way to erase the past, but what keeps our memories around in the first place? As the ScienCentral News video reports, brain researchers are beginning to unwind a new twist on how we maintain memory. Memory Span and Chunking • Memory span refers to the amount of information held in working memory • George Miller noted a typical limit of 7 +/– 2 items in working memory, although more recent evidence suggests it may be limited to as few as 4 chunks of information – chunking: organizing information into meaningful units to make it easier to remember • The capacity of memory span can vary among individuals, and increases as children develop and decreases with advanced aging What strategies do you use for remembering? Why do they work? Long-Term Memory Is Relatively Permanent • Long-term memory is a relatively permanent, virtually limitless store • Long-term memory enables you to remember nursery rhymes from childhood, the meanings and spellings of words you rarely use, what you had for lunch yesterday, etc. – What are some of your earliest memories? Distinguishing Long-Term Memory From Working Memory • The distinction between working memory and longterm memory has been demonstrated by studies that investigated the serial position effect and studies that investigated memory impairments – serial position effect: The ability to recall items from a list depends on order of presentation, with items presented early or late in the list remembered better than those in the middle – This data pattern includes: • primacy effect: better memory for items at the beginning of the list (reflects long-term memory) • regency effect: better memory for the items at the end of a list (reflects working memory) What Gets Into Long-Term Memory? • Information is most likely to be transferred from working memory to long-term memory if it is repeatedly retrieved, deeply processed, or helps us adapt to an environment • Evolutionary theory helps explain how we decide in advance what information will be useful • Animals that can use past experiences to increase their chances of survival have a selective advantage over animals that fail to learn from past experiences How can you apply this knowledge to your daily life? 7.4 How Is Information Organized in Long-Term Memory? • Discuss the levels of the processing model. • Explain how schemas influence memory. • Describe spreading activation models of memory. • Identify retrieval cues. • Identify common mnemonics. 7.4 How Is Information Organized in Long-Term Memory? • When an event or some information is important enough, you want to remember it permanently. • Human memory is stored according to meaning. Long-Term Storage Is Based on Meaning • Perceptual experiences are transformed into representations and stored in networks of neurons • Mental representations are stored by meaning • Craik and Lockhart’s levels of processing model suggests the more deeply an item is encoded, the more meaning it has, and the better it is remembered – maintenance rehearsal: repeating the item over and over – elaborative rehearsal: encodes the information in more meaningful ways • The more an item is elaborated at the time of storage, the richer the later memory will be because more connections can serve as retrieval cues • Brain imaging studies have shown that semantic encoding activates more brain regions than shallow encoding and this greater brain activity is associated with better memory “Tip of the Tongue Learning” When can’t quite remember somebody’s name, trying to excavate if from your memory might be the worst thing you can do, according to new psychology research. This ScienCentral News video explains. Schemas Provide an Organizational Framework • Decisions about how to chunk information depend on schemas – schemas: cognitive structures that help us perceive, organize, process, and use information • Culture shapes our schemas and can lead to biased encoding • Schemas influence memory Information Is Stored in Association Networks • Collins and Loftus’s model of networks of associations where each unit of information about an item is a single node in the network – For example, “red,” “vehicle,” “emergency” for “fire truck” • The closer the nodes, the stronger the association between them and therefore the more likely it is that activating one node will activate the other • Spreading activation models: stimuli in working memory activate specific nodes in long-term memory, making retrieval easier • Activation of a node spreads throughout its network, enhancing memory of related items • Semantic links exist between related items • Associative networks are organized by category and structured in a hierarchy; they provide a blueprint for where to find information Retrieval Cues Provide Access to Long-Term Storage • Retrieval cues, including contextual cues and internal states, help us access stored information – retrieval cue: anything that helps a person (or a nonhuman animal) recall information stored in long-term memory • According to Tulving’sencoding specificity principle, any stimulus encoded along with an experience can later trigger a memory of the experience • Memory may be enhanced by: – context-dependent memory: when the recall situation is similar to the encoding situation – state-dependent memory: when a person’s internal states match during encoding and recall “Bloody Teeth Boost Memory” Why do we remember emotional events so well? One memory researcher says it’s not just because they’re important to us. As this ScienCentral News video reports, the findings suggest that we can manipulate emotion to help improve our memory. Mnemonics • Mnemonics, such as the method of loci and verbal mnemonics, involve the use of retrieval cues to improve recall – mnemonics: learning aids, strategies, and devices that improve recall through the use of retrieval cues – method of loci (memory palace): consists of associating items you want to remember with physical locations 7.5 What Are the Different Long-Term Memory Systems? • Distinguish between episodic, semantic, implicit, explicit, and prospective memories. • Generate examples of each of these types of memory. 7.5 What Are the Different Long-Term Memory Systems? • Long-term memory is composed of multiple systems. • Long-term memories can differ in how they are acquired and how they are stored and retrieved. Explicit Memory Involves Conscious Effort • Fundamental differences exist among episodic and semantic memory, explicit and implicit memory, and prospective memory – implicit memory: the system underlying unconscious memories – explicit memory: the system underlying conscious memories • declarative memory : the cognitive information retrieved from explicit memory; knowledge that can be declared Explicit Memory Involves Conscious Effort • In 1972, Tulving found that explicit memory can be divided into: – episodic memory: memory for one’s personal past experiences, e.g. remembering aspects of your 16th birthday – semantic memory: memory for knowledge about the world, e.g. knowing what Jell-O is • Evidence that episodic and semantic systems of explicit memory are separate can be found in cases of brain injury in which semantic memory is intact even though episodic memory is impaired Implicit Memory Occurs Without Deliberate Effort • Implicit memory consists of memories that exist without our awareness of them and that do not require conscious attention • Jacoby’s false fame effect demonstrated how our implicit formation of attitudes can affect our beliefs about people • Examples of implicit memory include procedural (motor) memory and attitudes influenced by implicit learning: – procedural (motor) memory: involves motor skills, habits, and other behaviors employed to achieve goals, e.g. coordinating muscle movements to ride a bicycle • Procedural memories are generally so unconscious that most people find that consciously thinking about automatic behaviors interferes with the smooth production of those behaviors Prospective Memory Is Remembering to Do Something • Prospective memory involves remembering to do something at a future time. If a cue to remember is available in the person’s environment, prospective memory can operate automatically • Remembering to do something takes up valuable cognitive resources and reduces the number of items we can deal with in working memory or the number of things we can attend to • Without a retrieval cue, remembering requires conscious effort – What sort of retrieval cues do you use to jog your memory? 7.6 When Do People Forget? • List the seven sins of memory. • Explain transience, blocking, and absentmindedness. • Distinguish between retrograde and anterograde amnesia. • Discuss methods to reduce persistence. 7.6 When Do People Forget? • Forgetting is the inability to retrieve memory from long-term storage. • The ability to forget is as important as the ability to remember. – What would life be like if you could not forget? • Normal forgetting helps us remember and use important information. • Ebbinghaus’ so-called methods of savings provided compelling evidence that forgetting occurs rapidly over the first few days but then levels off. • Schacter identified what he calls the seven sins of memory: – transience, absentmindedness, blocking, and persistence are related to forgetting and remembering – misattribution, suggestibility, and bias are distortions of memory Transience Is Caused by Interference • Transience results from proactive or retroactive interference – proactive interference: when prior information inhibits the ability to remember new information – retroactive interference: when new information inhibits the ability to remember old information Blocking Is Temporary • Blocking is a temporary inability to retrieve specific information, as exemplified by the tipof-the-tongue phenomenon • Blocking often occurs because of interference from words that are similar in some way, such as in sound or meaning, and that recur Absentmindedness Results From Shallow Encoding • Absentmindedness is caused by shallow encoding, which occurs when people fail to pay sufficient attention – In what ways can multi-tasking lead to absentmindedness? • During most of our daily activities we are consciously aware of only a small portion of both our thoughts and our behaviors Amnesia Is a Deficit in Long-Term Memory • Amnesia is a deficit in long-term memory. This condition results from disease, brain injury, or psychological trauma – retrograde amnesia: a condition in which people lose past memories, such as memories for events, facts, people, or even personal information – anterograde amnesia: a condition in which people lose the ability to form new memories • H.M. had a classic case of anterograde amnesia; he could remember old information, but after his surgery he lost the ability to form new memories Persistence Is Unwanted Remembering • Persistence is the recurrence of unwanted memories; This problem is characteristic of posttraumatic stress disorder • The most common triggers of PTSD include events that threaten people or those close to them • Emotional events are associated with amygdala activity, which might underlie the persistence of certain memories • Contemporary researchers are investigating methods to erase unwanted memories – Will reducing memories to take the emotional sting out of life make us less human? “Stress and Memory” It’s as much a part of the holidays as presents and food. We’re talking about stress. As this ScienCentral News video explains, scientists are learning more about how it affects our brains, from memory to the ability to make decisions. 7.7 How Are Memories Distorted? • Define memory bias. • Generate examples of source misattribution. • Identify factors that contribute to errors in eyewitness testimony. • Discuss susceptibility to false memories. • Describe contemporary views on repressed memories. • Discuss neuroscientific advancements in the identification of true and false memories. 7.7 How Are Memories Distorted? • Memory is far from a faithful, objective recorder of facts and events. • Research has shown that human memory is biased, flawed, and distorted. People Reconstruct Events to Be Consistent • People tend to recall their past beliefs and past attitudes as being consistent with their current ones – memory bias: the changing of memories over time so that they become consistent with current beliefs or attitudes • Groups’ collective memories can seriously distort the past. • Most societies’ official histories tend to downplay their past behaviors that were unsavory, immoral, and even murderous • Individuals also tend to remember events as casting them in prominent or favorable roles Flashbulb Memories Can Be Wrong • Some events cause people to experience what Brown and Kulik termed flashbulb memories – flashbulb memories: vivid episodic memories for circumstances in which people first learned of a surprising, consequential, or emotionally arousing event • They do not reflect the problem of persistence, however, in that they are not recurring unwanted memories Do You Remember Where You Were When…? • Flashbulb memories can also be biased and inaccurate – For example, studies of the Challenger explosion and 9/11 demonstrate diminished recall several years later • Timing affects research on the accuracy of flashbulb memories • Conway’s research showed that subjects who found an event surprising and important had the strongest flashbulb memories “9-11 Flashbulb Memories” Brain researchers have found that proximity counts when it comes to how strong our memories are. While everyone remembers where they were on September 11, 2001, when they heard the news of the attacks on the World Trade Center, this ScienCentral News video explains how those who were close to the scene formed memories that still provoke the brain’s response to danger. Emphasis and Memory • Any event that produces a strong emotional response is likely to produce a vivid, although not necessarily accurate, memory – von Restorff effect:Adistinctive event might be recalled more easily than a trivial event, however inaccurate the result • Greater media attention and exposure to detail may encourage better memory People Make Source Misattributions • source misattribution: memory distortion that occurs when people misremember the time, place, person, or circumstances involved with a memory – false fame effect: an effect that causes people to mistakenly believe that someone is famous simply because they have encountered the person’s name before – sleeper effect: an argument initially is not very persuasive because it comes from a questionable source, but becomes more persuasive over time Source Amnesia • source amnesia: a type of amnesia that occurs when a person shows memory for an event but cannot remember where he or she encountered the information • The absence of early memories, childhood amnesia, may be due to the early lack of linguistic capacity as well as to immature frontal lobes Cryptomnesia • Cryptomnesia: a type of misattribution that occurs when a person thinks he or she has come up with a new idea, yet has only retrieved a stored idea and failed to attribute the idea to its proper source • This mistake can later lead to an accusation of plagiarism – Do you agree with the judge’s ruling against Beatle George Harrison, whose song “My Sweet Lord” sounded similar to the Chiffons’ “He’s So Fine”? People Are Bad Eyewitnesses • Research has demonstrated that very few jurors are willing to convict an accused individual on the basis of circumstantial evidence alone • People tend to make poor eyewitnesses: they often fail to pay attention to the incidents and people they observe, and they are suggestible to misleading information – How might change blindness affect an eyewitness’ testimony? Cross-Ethnic Identification • People are particularly bad at accurately identifying individuals of other ethnicities or races • Possible explanations: – Greater activation in the fusiform face area may be responsible for stronger memory of same-race faces – People may encode race and ethnicity according to rules of categorization, and they do not notice much about individuals beyond this group description Suggestibility and Misinformation • Elizabeth Loftus’s studies on suggestibility concluded that people can “remember” seeing nonexistent objects • Different wordings of questions altered the participants’ memories of the event – suggestibility: the development of biased memories from misleading information • Eyewitnesses might inadvertently develop stronger memories for inaccurate details due to reconsolidation, e.g. retelling their stories to police, friends, and relatives Eyewitness Confidence • Eyewitnesses who are wrong are just as confident as (or more confident than) eyewitnesses who are right • Strong confidence for minor details may be a cue that the memory is likely to be inaccurate or even false; eyewitnesses to real crimes tend to be focused on the weapons or on the action People Have False Memories • According to research by Loftus, you might remember an incident, even if it did not happen • Memories can be distorted, or even implanted, by false information • Imagining an event might lead to confusion of the mental image with a real memory • Children are particularly susceptible to false memories being induced – “Lost in the mall” incident example Confabulation • Confabulation, or “honest lying,” has been documented among individuals with Capgras syndrome, characterized by damage to the frontal lobes and limbic system – confabulation: the unintended false recollection of episodic memories • When questioned, patients try to make sense of their recollections by adding facts that make the story more coherent Critical Thinking Skill: Recognizing How the Fallibility of Human Memory Can Lead to Faulty Conclusions • Patterson refers to the tyranny of the eyewitness: people generally believe eyewitnesses even though, as memory researchers have shown, eyewitnesses are frequently wrong • Unless an independent party can verify the information, it is difficult to distinguish between a valid memory and a faulty one • When a memory is important to some outcome, consider that memory’s likely accuracy and check it against related objective facts – Have you ever been an eyewitness to an accident or crime? – Did your memory of the incident differ from someone else’s? Psychology: Knowledge You Can Use— How Can I Study More Effectively for Exams? • • • • • • Distribute your learning Elaborate the material Practice Overlearn Use verbal mnemonics Use visual imagery To use all of these strategies, you need to remember them. As a first step toward improving your study skills, create a mnemonic to remember these strategies! Repressed Memories Are Controversial • The legitimacy of repressed memories continues to be debated by contemporary psychologists, many of whom argue that such memories may be implanted by suggestive techniques, e.g. hypnosis and guided recall • While research shows that some therapeutic techniques seem especially likely to foster false memories, it would be a mistake to dismiss all adult reports of early abuse Neuroscience May Make It Possible to Distinguish between “True” and “False” Memories • Neuroscientists are attempting to develop techniques to distinguish between true and false memories on the basis of patterns of brain activation • One problem with this method is that false memories tend to be similar in many ways to true memories and may activate the same area of the brain during retrieval “False Food Memories” If your first taste of potato chips or chocolate had made you sick, your eating habits today might be different. As this ScienCentral News video explains, psychology researchers suggest that changing memories about food could change what we choose to eat. “Brain Viagra, Part 1” Companies that sell herbal supplement gingko biloba say it can enhance your memory. But as this ScienCentral News video reports, scientific evidence on whether gingko works is controversial at best. “Brain Viagra, Part 2” There’s a huge market for substances that claim to boost memory, but when can we expect drugs designed and proven to do so? As this ScienCentral News video reports, advances in genetics research may help to make effective memory drugs a reality.