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The Foundations of Memory • You are playing a game of Trivial Pursuit, and winning the game comes down to one question: What is the highest waterfall in the world? As you rack your brain for the answer, several fundamental processes relating to memory come into play. You may never, for instance, have been exposed to information regarding the highest waterfall in the world. Or if you have been exposed to it, it may simply not have registered in a meaningful way. • In other words, the information might not have been recorded properly in your memory. • The initial process of recording information in a form usable to memory, a process called encoding, is the first stage in remembering something.
The Highest Waterfall in the World • Angel Falls (Salto Ángel) is the world’s highest uninterrupted waterfall, with a height of 3,212 ft and a plunge of 2,648 ft. The waterfall drops over the edge of the Auyantepui mountain in the Canaima National Park in the state of Bolivar, Venezuela. • The waterfall has been known as the "Angel Falls" since the mid twentieth century; named after Jimmie Angel, a US aviator, who was the first person to fly over the falls.Angel's ashes were scattered over the falls on July 2, 1960.The name "Salto Ángel" derives from his last name. • Angel Falls was used in the film “Up” as “Paradise Falls”. A 2009 American 3D computer-animated comedy-adventure film produced by Pixar Animation Studios, and released by Walt Disney Pictures.
Storage and Retrieval • Even if you had been exposed to the information and originally knew the name of the highest waterfall in the world, you may still be unable to recall it during the game because of a failure to retain it. • Memory specialists speak of storage: The maintenance of material saved in memory. If the material is not stored adequately, it cannot be recalled later. • Memory also depends on one last process— retrieval: Material in memory storage has to be located and brought into awareness to be useful. Your failure to recall Angel Falls, then, may rest on your inability to retrieve information that you learned earlier.
Memory • Psychologists consider memory to be the process by which we encode, store, and retrieve information. Each of the 3 parts of this definition—encoding, storage, and retrieval represents a different process. • You can think of these processes as being similar to a computer’s keyboard (encoding), hard drive (storage), and software that accesses the information for display on the screen (retrieval). Only if all 3 processes have operated, you will experience success and be able to recall information that you learned earlier. • Recognizing that memory involves encoding, storage, and retrieval gives us a start in understanding the concept.
How does Memory Actually Function? • How do we explain what information is initially encoded, what gets stored, and how it is retrieved? • According to the three-system approach to memory that dominated memory research for several decades, there are different memory storage systems or stages through which information must travel if it is to be remembered (Atkinson & Shiffrin, 1968, 1971). • Historically, the approach has been extremely influential in the development of our understanding of memory, and—although new theories have augmented it—it still provides a useful framework for understanding how information is recalled.
The Three-system Memory Theory • The three-system memory theory proposes the existence of the 3 separate memory stores explained as follows: • Sensory memory refers to the initial, momentary storage of information that lasts only an instant. • In a second stage, short-term memory holds information for 15 to 25 seconds and stores it according to its meaning rather than as mere sensory stimulation. • The third type of storage system is long-term memory. Information is stored in long-term memory on a relatively permanent basis, although it may be difficult to retrieve.
Exercise Your Memory(Class Activity) Examine the chessboard on the left for about 5 seconds. Then, follow the instructions that are explained on the worksheet that your teacher will provide you during class.
Exercise Your Memory(Class Activity) Draw the position of the pieces that you remember from the chessboard that was projected on the prior PowerPoint slide. Use the worksheet provided during class , to complete this activity.
Exercise Your Memory • Unless you are an experienced chess player, you are likely to have great difficulty carrying out such a task. Chess masters, those who win tournaments—do this quite well (deGroot, 1966). They are able to reproduce correctly 90% of the pieces on the board. In comparison, inexperienced chess players are typically able to reproduce only 40% of the board properly. The chess masters do not have superior memories in other respects; they generally test normally on other measures of memory. What they can do better than others is see the board in terms of chunks or meaningful units and reproduce the position of the chess pieces by using those units.
Chunks • The specific amount of information that can be held in short-term memory has been identified as seven items, or “chunks,” of information, with variations up to plus or minus two chunks. A chunk is a grouping of information that can be stored in short-term memory. For example, a chunk can be a group of seven individual letters or numbers, permitting us to hold a seven-digit phone number (such as 226-4610) in short-term memory. • A chunk also may consist of larger categories, such as words or other meaningful units. For example, consider the following list of 21 letters: P B S F O X C N N A B C C B S M T V N B C Because the list of individual letters exceeds seven items, it is difficult to recall the letters after one exposure. But, suppose they were presented as follows: PBS FOX CNN ABC CBS MTV NBC In this case, even though there are still 21 letters, you’d be able to store them in short-term memory since they represent only seven chunks. • Chunks can vary in size from single letters or numbers to categories that are far more complicated. The specific nature of what constitutes a chunk varies according to one’s past experience.
Rehearsal • The transfer of material from short- to long-term memory proceeds largely on the basis of rehearsal, the repetition of information that has entered short-term memory.Rehearsal accomplishes two things. First, as long as the information is repeated, it is maintained in short-term memory.More important, however, rehearsal allows us to transfer the information into long-term memory (Kvavilashvili & Fisher, 2007; Jarrold & Tam, 2011). • Whether the transfer is made from short- to long-term memory seems to depend largely on the kind of rehearsal that is carried out. If the information is simply repeated over and over again—as we might do with a telephone number while we rush from the phone book to the phone—it is kept current in short-term memory, but it will not necessarily be placed in long-term memory. Instead, as soon as we stop punching in the phone numbers, the number is likely to be replaced by other information and will be completely forgotten.
Elaborative Rehearsal • In contrast, if the information in short-term memory is rehearsed using a process called elaborative rehearsal, it is much more likely to be transferred into long term memory. Elaborative rehearsal occurs when the information is considered and organized in some fashion. The organization might include expanding the information to make it fit into a logical framework, linking it to another memory, turning it into an image, or transforming it in some other way. • For example, a list of vegetables to be purchased at a store could be woven together in memory as items being used to prepare an elaborate salad, could be linked to the items bought on an earlier shopping trip, or could be thought of in terms of the image of a farm with rows of each item.
Working Memory • Working Memory:A set of active, temporary memory stores that actively manipulate and rehearse information (Bayliss et al., 2005a, 2005b; Unsworth & Engle, 2005; Vandierendonck & Szmalec, 2011). • Working memory is thought to contain a central executive processor that is involved in reasoning and decision making. • The central executive coordinates three distinct storage-and-rehearsal systems: the visual store, the verbal store, and the episodic buffer.
The Central Executive • The central executive coordinates 3 distinct storage-and-rehearsal systems: the visual store, the verbal store, and the episodic buffer.The visual store specializes in visual and spatial information. The verbal store holds and manipulates material relating to speech, words, and numbers. The episodic buffer contains information that represents episodes or events (Rudner & Rönnberg, 2008; Baddeley, Allen, & Hitch, 2011). • Working memory permits us to keep information in an active state briefly so that we can do something with the information. For instance, we use working memory when we’re doing a multistep arithmetic problem in our heads, storing the result of one calculation while getting ready to move to the next stage. (I make use of my working memory when I figure a 20% tip in a restaurant by first calculating 10% of the total bill and then doubling it.)
Working Memory • Although working memory aids in the recall of information, it uses a significant amount of cognitive resources during its operation. In turn, this can make us less aware of our surroundings, something that has implications for why it’s unsafe to use cell telephones while driving. If a phone conversation requires thinking, it will burden working memory and leave drivers less aware of their surroundings, an obviously dangerous state of affairs (Sifrit, 2006; Strayer & Drews, 2007).
Long-Term Memory • Material that makes its way from short-term memory to long-term memory enters a storehouse of almost unlimited capacity. Like a new file we save on a hard drive, the information in long-term memory is filed and coded so that we can retrieve it when we need it. • Evidence of the existence of long-term memory, as distinct from short-term memory, comes from a number of sources. • For example, people with certain kinds of brain damage have no lasting recall of new information received after the damage occurred, although people and events stored in memory before the injury remain intact (Milner,1966). Because information that was encoded and stored before the injury can be recalled and because short-term memory after the injury appears to be operational—new material can be recalled for a very brief period—we can infer that there are two distinct types of memory: one for short-term and one for long-term storage.
LONG TERM MEMORY MODULES • Declarative memory is memory for factual information: names, faces, dates, and facts, such as “a bike has two wheels.” In contrast, procedural memory (or nondeclarative memory ) refers to memory for skills and habits, such as how to ride a bike or hit a baseball. Information about things is stored in declarative memory; information about how to do things is stored in procedural memory (Brown & Robertson, 2007; Bauer, 2008; Freedberg, 2011). • Declarative memory can be subdivided into semantic memory and episodic memory. Semantic memory is memory for general knowledge and facts about the world, as well as memory for the rules of logic that are used to deduce other facts.Because of semantic memory, we remember that the ZIP code for Beverly Hills is 90210 and that Angel Falls is the highest waterfall in the world. Thus, semantic memory is somewhat like a mental almanac of facts(Nyberg & Tulving, 1996; Tulving, 2002).
Episodic Memory • In contrast, episodic memory is memory for events that occur in a particular time, place, or context. For example, recall of learning to hit a baseball, our first kiss, or arranging a surprise 21st birthday party for our brother is based on episodic memories. Episodic memories relate to particular contexts.
SEMANTIC NETWORKS(Exercise Your Memory) • Try to recall, for a moment, as many things as you can think of that are the color red. Now pull from your memory the names of as many fruits as you can recall. Did the same item appear when you did both tasks? For many people, an apple comes to mind in both cases since it fits equally well in each category. And the fact that you might have thought of an apple when doing the first task makes it even more likely that you’ll think of it when doing the second task. • It’s actually quite amazing that we’re able to retrieve specific material from the vast store of information in our long-term memories. According to some memory researchers, one key organizational tool that allows us to recall detailed information from long-term memory is the associations that we build between different pieces of information. In this view, knowledge is stored in semantic networks, mental representations of clusters of interconnected information (Collins & Quillian, 1969; Collins & Loftus, 1975; Cummings, Ceponiene, & Koyama, 2006).
The Hippocampus and Amygdala The hippocampus, a part of the brain’s limbic system, plays a central role in the consolidation of memories.Located within the brain’s medial temporal lobes ,the hippocampus aids in the initial encoding of information, acting as a kind of neurological e-mail system. That information is subsequently passed along to the cerebral cortex of the brain, where it is actually stored (J. Peters et al., 2007; Lavenex & Lavenex, 2009; Dudai, 2011). The amygdala , another part of the limbic system, also plays an important role in memory. The amygdala is especially involved with memories involving emotion. For example, if you are frightened by a large Doberman, you’re likely to remember the event vividly—an outcome related to the functioning of the amygdala. The hippocampus and amygdala, parts of the brain’s limbic system, play a central role in the consolidation of memories. (Source: Van De Graaff , 2000.)
Recalling Long-Term Memories • Tip-of-the-Tongue Phenomenon:The inability to recall information that one realizes one knows—a result of the difficulty of retrieving information from long-term memory.
Retrieval Cues • How do we sort through this vast array of material and retrieve specific information at the appropriate time? One way is through retrieval cues. A retrieval cue is a stimulus that allows us to recall more easily information that is in long-term memory. It may be a word, an emotion, or a sound; whatever the specific cue, a memory will suddenly come to mind when the retrieval cue is present. For example, the smell of roasting turkey may evoke memories of Thanksgiving or family gatherings. Retrieval cues guide people through the information stored in long-term memory in much the same way that a search engine such as Google guides people through the Internet. They are particularly important when we are making an effort to recall information, as opposed to being asked to recognize material stored in memory.
Recall and Recognition • In recall, a specific piece of information must be retrieved—such as that needed to answer a fill-in-the-blank question or to write an essay on a test. • In contrast, recognition occurs when people are presented with a stimulus and asked whether they have been exposed to it previously or are asked to identify it from a list of alternatives. • As you might guess, recognition is generally a much easier task than recall • Recall is more difficult because it consists of a series of processes: a search through memory, retrieval of potentially relevant information, and then a decision regarding whether the information you have found is accurate.
Explicit and Implicit Memory • Explicit memory:Refers to intentional or conscious recollection of information. When we try to remember a name or date we have encountered or learned about previously, we are searching our explicit memory. • Implicit Memory:Refers to memories of which people are not consciously aware but that can affect subsequent performance and behavior. Skills that operate automatically and without thinking, such as jumping out of the path of an automobile coming toward us as we walk down the side of a road, are stored in implicit memory. Similarly, a feeling of vague dislike for an acquaintance, without knowing why we have that feeling, may be a reflection of implicit memories. Perhaps the person reminds us of someone else in our past that we didn’t like, even though we are not aware of the memory of that other individual (Coates, Butler, & Berry, 2006; Voss & Paller, 2008; Gopie, Craik, & Hasher, 2011).
Flashbulb Memories • Do you remember where you were on September 11, 2001? You may recall your location and a variety of other details that occurred when you heard about the terrorist attacks on the United States, even though the incident happened more than a dozen years ago. Your ability to remember details about this fatal event illustrates a phenomenon known as flashbulb memory. A Flashbulb Memory: Is a highly detailed, exceptionally vivid 'snapshot' of the moment and circumstances in which a piece of surprising and consequential (or emotionally arousing) news was heard. Flashbulb memories are far from complete. Evidence has shown that although people are highly confident in their memories, the details of the memories can be forgotten. • Several types of flashbulb memories are common among college students. For example, involvement in a car accident, meeting one’s roommate for the first time, and the night of high school graduation are all typical flashbulb memories (Romeu, 2006; Bohn & Berntsen, 2007; Talarico, 2009).
MEMORY IN THE COURTROOM: THE EYEWITNESS ON TRIAL • For Calvin Willis, the inadequate memories of two people cost him more than two decades of his life. Willis was the victim of mistaken identity when a young rape victim picked out his photo as the perpetrator of the rape. On that basis, he was tried, convicted, and sentenced to life in prison. Twenty-one years later, DNA testing showed that Willis was innocent, and the victim’s identification wrong (Corsello, 2005). • Unfortunately, Willis is not the only victim to whom apologies have had to be made; many cases of mistaken identity have led to unjustified legal actions. Research on eyewitness identification of suspects, as well as on memory for other details of crimes, has shown that eyewitnesses are apt to make significant errors when they try to recall details of criminal activity—even if they are highly confident about their recollections (Thompson, 2000; Zaragoza, Belli, & Payment, 2007; Paterson, Kemp, & Ng, 2011). • One reason is the impact of the weapons used in crimes. When a criminal perpetrator displays a gun or knife, it acts like a perceptual magnet, attracting the eyes of the witnesses. As a consequence, witnesses pay less attention to other details of the crime and are less able to recall what actually occurred (Steblay et al., 2003; Zaitsu, 2007; Pickel, 2009).
MEMORY IN THE COURTROOM: THE EYEWITNESS ON TRIAL • One reason eyewitnesses are prone to memory-related errors is that the specific wording of questions posed to them by police officers or attorneys can affect the way they recall information, as a number of experiments illustrate. For example, in one experiment the participants were shown a film of two cars crashing into each other. Some were then asked the question, “About how fast were the cars going when they smashed into each other?” On average, they estimated the speed to be 40.8 miles per hour. In contrast, when another group of participants was asked, “About how fast were the cars going when they contactedeach other?” the average estimated speed was only 31.8 miles per hour (Loftus & Palmer, 1974).
Children’s Reliability • The problem of memory reliability becomes even more acute when children are witnesses because increasing evidence suggests that children’s memories are highly vulnerable to the influence of others (Loftus, 1993; Douglas, Goldstein, & Bjorklund, 2000). For instance, in one experiment, 5- to 7-year-old girls who had just had a routine physical examination were shown an anatomically explicit doll. The girls were shown the doll’s genital area and asked, “Did the doctor touch you here?” Three of the girls who did not have a vaginal or anal exam said that the doctor had in fact touched them in the genital area, and one of those three made up the detail “The doctor did it with a stick” (Saywitz & Goodman, 1990). • Children’s memories are especially susceptible to influence when the situation is highly emotional or stressful. For example, in trials in which there is significant pretrial publicity or in which alleged victims are questioned repeatedly, often by untrained interviewers, the memories of the alleged victims may be influenced by the types of questions they are asked (Scullin, Kanaya, & Ceci, 2002; Lamb & Garretson, 2003; Quas, Malloy, & Melinder, 2007; Goodman & Quas, 2008).
Memory Dysfunctions:Afflictions of Forgetting • Dementia is a loss of brain function that occurs with certain diseases. • Alzheimer’s Disease:A progressive brain disorder that heads to a gradual and irreversible decline in cognitive abilities. • In the beginning, Alzheimer’s symptoms appear as simple forgetfulness of things such as appointments and birthdays. As the disease progresses, memory loss becomes more profound, and even the simplest tasks—such as using a telephone—are forgotten. Ultimately, victims may lose their ability to speak or comprehend language, and physical deterioration sets in, leading to death. • Alzheimer’s Disease is one of a number of memory dysfunctions. • Alzheimer’s is the fourth leading cause of death among adults in the United States, affecting an estimated 5 million people.
Alzheimer’s Disease • The causes of Alzheimer’s disease are not fully understood. Increasing evidence suggests that Alzheimer’s results from an inherited susceptibility to a defect in the production of the protein beta amyloid, which is necessary for the maintenance of nerve cell connections. When the synthesis of beta amyloid goes awry, large clumps of cells form, triggering inflammation and the deterioration of nerve cells in the brain (Horínek, Varjassyová, & Hort, 2007; Selkoe, 2008; Hyman, 2011; also see Figure 4 Neuroscience in Your Life).
Amnesia • Amnesia: Memory loss that occurs without other mental difficulties. • Retrograde Amnesia: Amnesia in which memory is lost for occurrences priorto a certain event, but not for new events. • Anterograde Amnesia: Amnesia in which memory is lost for events that follow an injury.
Korsakoff’s syndrome • Amnesia is also a result of Korsakoff’s syndrome , a disease that afflicts longtermalcoholics. Although many of their intellectual abilities may be intact, Korsakoff’s sufferers display a strange array of symptoms, including hallucinations and a tendency to repeat the same story over and over (van Oort & Kessels, 2009).
