chapter-7-slk120 (1).pdf

lOMoARcPSD|26686186 Chapter 7 SLK120 Psychology (University of Pretoria) Scan to open on Studocu Studocu is not sponsored or endorsed by any college or university Downloaded by Karabo Mudau ([email protected]) ...

lOMoARcPSD|26686186 Chapter 7 SLK120 Psychology (University of Pretoria) Scan to open on Studocu Studocu is not sponsored or endorsed by any college or university Downloaded by Karabo Mudau ([email protected])  lOMoARcPSD|26686186 CHAPTER 7: KEY PROCESSES IN MEMORY - Memory involves more than merely taking in The tip-of-the-tongue-phenomenon information and storing it in some mental is the feeling of being aware of compartment. In fact, psychologists investigating the something but you just cannot workings of memory have been particularly interested remember it at that point in time in these three questions - Encoding: Question 1: How does information get into memory? - Storage: Question 2:How is information maintained in memory? - Retrieval: Question 3: How is information pulled back out of memory? - Encoding involves forming a memory code. - Encoding usually requires attention. which is why you might not be able to recall exactly what a ‘familiar’ scene– most people do not pay much attention to their everyday surroundings - Storage involves maintaining encoded information in memory over a period of time. You need to be able to get information out of storage. - Retrieval involves recovering information from memory stores. Research concerned with retrieval includes the study of how people search memory, and why some retrieval strategies are more effective than others. THE ROLE OF ATTENTION - The importance of attention to memory is apparent when participants are asked to focus their attention on two or more inputs simultaneously. - Divided attention can have a negative impact on the performance of quite a variety of tasks, especially when the tasks are complex or unfamiliar research suggests that the human brain can effectively handle only one attention-consuming task at a time - not all attention is created equal. You can attend to things in different ways, focusing on different aspects of the stimulus input. - Fergus Craik and Robert Lockhart (1972) proposed that incoming information can be processed at different levels. Downloaded by Karabo Mudau ([email protected])  lOMoARcPSD|26686186 - They maintained that, in dealing with verbal information, people engage in three progressively deeper levels of processing: structural, phonemic and semantic encoding LEVELS OF PROCESSING - Phonemic encoding involves naming or saying (perhaps silently) the words. - Structural encoding is relatively shallow processing that emphasizes the physical structure of the stimulus. - Semantic encoding emphasizes the meaning of verbal input - Structural, phonemic, and semantic encoding involves progressively deeper levels of processing, which should result in more durable memories. - Numerous subsequent studies have provided further support for the hypothesis that deeper processing leads to enhanced memory Neuroimaging studies have also supported this hypothesis ENRICHING ENCODING Elaboration ¥ There are four dimensions to encoding, dimensions that can enrich the encoding process and thereby improve memory ¥ Semantic encoding can be enhanced through a process called elaboration. Elaboration is linking a stimulus to other information at the time of encoding. ¥ The additional connections created by elaboration usually help people remember information. Differences in elaboration can help explain why different approaches to semantic processing result in varied amounts of retention ¥ Example of Elaboration: You are studying personality types and you relate them back to your own personality. There will be a higher chance of remembering the content Visual Imagery ¥ Imagery, or the creation of visual images to represent words, can be used to enrich encoding. Allan Paivio (1969) pointed out that it is easier to form images of concrete objects than abstract concepts. Downloaded by Karabo Mudau ([email protected])  lOMoARcPSD|26686186 ¥ He posited that this ease of image formation affects memory. Imagery facilitates memory because it provides a second kind of memory code, and two codes are better than one. His dual-coding theory holds that memory is enhanced by forming semantic and visual codes, because either can lead to recall ¥ Example of visual imagery: If I asked you to name the colours of the rainbow, you will picture this in your head and proceed to name all the colours. You will have two codes in your memory now, the colours (1) and the Rainbow image (2) Self-referent encoding - People ’s recall of information tends to be slanted in favour of material that is relevant to them. Self-referent encoding involves determining how (or whether) information is personally relevant. - This approach to encoding was compared to structural, phonemic, and semantic encoding by Rogers, Kuiper and Kirker (1977). The results showed that self-referent encoding led to improved recall of the adjectives - Example of self-referent encoding: If you meet someone for the first time and they say their name is Chloé, you will respond by saying "hey my lecturer's name is Chloé too" and so this will help you remember the person’s name because of personal associations Motivation to Remember - Another factor that appears to influence encoding effectiveness is one ’s motivation to remember (MTR) at the time of encoding. - When MTR is high at the time of encoding – typically because the information is perceived to be important – people are more likely to invest extra effort to attend to and organise information in ways that facilitate future recall. - Example of MTR: When you meet a super pretty girl/handsome guy and they give you their phone number (your phone is dead). At that moment you will be highly motivated to remember their digits! STORAGE Short History o Both Aristotle and Plato compared memory to a block of wax that differed in size and hardness for various individuals. o many theories formulated at the dawn of the computer age drew an analogy between information storage by computers and information storage in human memory Downloaded by Karabo Mudau ([email protected])  lOMoARcPSD|26686186 o According to their model, incoming information passes through two temporary storage buffers – the sensory store and the short-term store – before it is transferred into a long-term store o The three memory stores are not viewed as anatomical structures in the brain, but rather as functionally distinct types of memory. o Atkinson and Shiffrin (1971) proposed that memory is made up of three information stores. Sensory memory can hold a large amount of information just long enough (a fraction of a second) for a small portion of it to be selected for longer storage. o Short-term memory has a limited capacity and, unless aided by rehearsal, its storage duration is brief. o Long-term memory can store an apparently unlimited amount of information for indeterminate periods. Sensory Memory o Sensory memory allows the sensation of a visual pattern, sound, or touch to linger for a brief moment after the sensory stimulation is over. o The brief preservation of sensations in sensory memory is adaptive in that it gives you additional time to try to recognize stimuli. However, you had better take advantage of this stimulus persistence immediately, because it does not last long. o Memory traces in the sensory store decay in about a quarter of a second. o According to some theorists, the brief persistence of stimuli may be more like an echo than a memory. Short term memory o there is a way that you can maintain information in your short-term store indefinitely. How? Primarily, by engaging in rehearsal – the process of repetitively verbalising or thinking about the information o Rehearsal keeps recycling the information through your short-term memory. This reliance on recitation illustrates why short term memory is thought to depend primarily on phonemic encoding o Definition Short-term memory (STM) is a limited-capacity store that can maintain unrehearsed information for 10 to 20 seconds. Downloaded by Karabo Mudau ([email protected])  lOMoARcPSD|26686186 Durability of storage Without rehearsal, information in short-term memory is lost after 10 to 20 seconds. Capacity of storage Short-term memory is also limited in the number of items it can hold. Miller noticed that people could recall only about seven items in tasks that required the use of STM. When short-term memory is filled to capacity, the insertion of new information ‘bumps out’ some of the information currently in STM. This limited capacity of STM constrains people ’s ability to perform tasks in which they need to mentally juggle various pieces of information. It has long been known that people can increase the capacity of their short-term memory by combining stimuli into larger, possibly higher-order units, called chunks. A chunk is a group of familiar stimuli stored as a single unit The effect of chunking by recalling a sequence of 12 letters: FN-BUC-TS-ABET-V As you read the letters, pause at the hyphens. You will probably attempt to remember each letter separately because there are no obvious groups or chunks. Now present the same string of letters, but place the pauses in the following locations: FNB-UCT-SAB-ETV The letters now form four familiar chunks that should occupy only four slots in STM, resulting in successful recall. To successfully chunk the letters FNB, an individual must first recognise these letters as a familiar unit. This familiarity has to be stored somewhere in long-term memory. Thus, in this case, information was transferred from long-term to short- term memory. WORKING MEMORY According to Baddeley (2001), working memory includes four components: a phonological loop, a visuospatial sketchpad, a central executive system and an episodic buffer. 1. The first component is the phonological loop that represented all of short-term memory in earlier models. This component is at work when you use recitation to temporarily hold on to a telephone number. Downloaded by Karabo Mudau ([email protected])  lOMoARcPSD|26686186 2. The second component in working memory is a visuospatial sketchpad, which permits people to temporarily hold and manipulate visual images. This element is at work when you try to mentally rearrange the furniture in your bedroom or map out a route to travel somewhere. 3. The third component is a central executive system. This component controls the deployment of attention, switching the focus of attention and dividing attention as needed. The central executive also coordinates the actions of the other modules. 4. The fourth component is the episodic buffer, which is a temporary, limited-capacity store that allows the various components of working memory to integrate information. It also serves as the interface between working memory and long-term memory. § The concept of working memory still includes the two key characteristics that originally defined short-term memory – limited capacity and storage duration. § Working memory capacity (WMC) refers to one ’s ability to hold and manipulate information in conscious attention. § WMC is a stable personal trait that appears to be influenced to a considerable degree by heredity. § That said, WMC can be temporarily reduced by situational factors such as pressure to perform or excessive worry In other words, high-WMC individuals tend to let their mind wander from the task at hand more than low-WMC individuals when the attentional demands of the task are low – presumably because they can afford to do so – but they are also better at staying focused when they need to do so. § This finding has led some theorists to conclude that WMC is critical to complex cognition and intelligence LONG TERM MEMORY - Long-term memory (LTM) is an unlimited capacity store that can hold information over lengthy periods of time. - LTM can store information indefinitely. In fact, one point of view is that all information stored in LTM is kept there permanently. - According to this view, forgetting occurs only because people sometimes cannot retrieve information from LTM. - He reported triggering memories through the electrical stimulation of the brain (ESB) during neurosurgery. Downloaded by Karabo Mudau ([email protected])  lOMoARcPSD|26686186 - Penfield, and others, inferred that these descriptions were exact playbacks of long- lost memories unearthed by ESB. - Flashbulb memories are unusually vivid and detailed recollections of the circumstances in which people learned about momentous, newsworthy events. - Flashbulb memories initially appear to provide striking examples of seemingly permanent storage - Closer scrutiny eventually showed that the remarkable ‘memories’ activated by ESB in Penfield’s studies often included major distortions or factual impossibilities. - The ESB – induced recollections of Penfield’s participants apparently were hallucinations, dreams or loose reconstructions of events rather than exact replays of the past. - Although flashbulb memories have mostly been studied in relation to negative events, people also report flashbulb memories of positive events. - Although flashbulb memories tend to be strong, vivid and detailed, studies suggest they are neither as accurate nor as special as once believed Like other memories, they become less detailed and complete with time, and are often inaccurate. - Recent research suggests that it is not extraordinary accuracy or longevity that distinguishes flashbulb memories. - Rather, what makes them special is that people subjectively feel that these memories are exceptionally vivid, have exceptional (albeit misplaced) confidence in their accuracy and attach more emotional intensity to them Declarative vs Procedural Memory § The declarative memory system handles factual information. It contains recollections of words, definitions, names, dates, faces, events, concepts and ideas. § Declarative memory is further divided into semantic memory (general knowledge) and episodic memory (dated recollections of personal experiences). § Declarative memory appears to be handled by the medial temporal lobe memory system and the faraway areas of the cortex with which it communicates § The non-declarative memory system houses memory for actions, skills, conditioned responses, and emotional responses. It contains procedural memories of how to execute perceptual-motor skills, such as riding a bike, typing, and tying one ’s shoes. Downloaded by Karabo Mudau ([email protected])  lOMoARcPSD|26686186 § This latter system also includes the memory base for conditioned reflexes and emotional reactions based on previous learning § The extent to which non-declarative memory can be usefully subdivided remains the subject of debate, although many theorists view procedural memory, which handles actions and perceptual-motor skills, as an independent subsystem. § Pinpointing the neural bases of non-declarative memory has proved to be more difficult because it consists of a mixture of memory modules structures such as the cerebellum and amygdala appear to contribute § The notion that declarative and procedural memories are separate is supported by certain patterns of memory loss seen in amnesiacs In many cases, declarative memory is severely impaired, while procedural memory is left largely intact Semantic versus Episodic Memory - The semantic memory system processes general knowledge that is not tied to the time when the information was learned. Downloaded by Karabo Mudau ([email protected])  lOMoARcPSD|26686186 - Such information is usually stored undated. The distinction between episodic and semantic memory can be better appreciated by drawing an analogy to books: episodic memory is like an autobiography, whereas semantic memory is like an encyclopaedia. - Both contain factual information. However, the episodic memory system deals with personal facts, whereas the semantic memory system deals with general facts. The episodic memory system processes chronological, or temporally dated, recollections of personal experiences. - Episodic memory is a record of things you have done, seen and heard. It includes information about when you did these things, or saw them or heard them. - The encoding of episodic memories often occurs in a rapid, automatic fashion, with little or no conscious effort Tulving (2001) emphasises that the function of episodic memory is ‘time travel’ – to allow one to re-experience the past – and that it is unique to humans - Some studies suggest that the episodic and semantic memory systems may have distinct neural bases. - Neuroimaging studies suggest that the retrieval of episodic and semantic memories produces different – but overlapping – patterns of activation However, debate continues about the neural substrates of episodic and semantic memory Prospective versus Retrospective Memory - Prospective memory involves remembering to perform actions in the future. - retrospective memory involves remembering events from the past or recalling previously learned information. Downloaded by Karabo Mudau ([email protected])  lOMoARcPSD|26686186 HOW IS KNOWLEDGE REPRESENTED & ORGANISED IN MEMORY Clustering and conceptual Hierarchies People spontaneously organise information into categories for storage in memory. Bousfield showed that people recalling this list tend to engage in clustering – the tendency to remember similar or related items in groups. A conceptual hierarchy is a multilevel classification system based on common properties among items Schemas A schema is an organised cluster of knowledge about a particular object or event taken from previous experience with that object or event Semantic network Much knowledge seems to be organised into less systematic frameworks, called semantic networks A semantic network consists of nodes representing concepts, joined together by pathways that link related concepts when people think about a word, their thoughts naturally go to related words. This process is called spreading activation within a semantic network. Connectionist Networks and Parallel Distributed Processing (PDP) Models connectionist models of memory take their inspiration from the way neural networks appear to handle information. The human brain appears to depend extensively on parallel distributed processing – that is, simultaneous processing of the same information that is spread across networks of neurons. Based on this insight, and basic findings about how neurons operate, connectionist or parallel distributed processing (PDP) models assume that cognitive processes depend on patterns of activation in highly interconnected computational networks that resemble neural networks A PDP system consists of a large network of interconnected computing units, or nodes, that operate much like neurons. These nodes may be inactive or they may send either excitatory or inhibitory signals to other units. In connectionist networks, a piece of knowledge is represented by a particular pattern of activation across an entire network. Thus, the information lies in the strengths of the connections, which is why the PDP approach is called connectionism Downloaded by Karabo Mudau ([email protected])  lOMoARcPSD|26686186 RETRIEVAL Using cues to aid retrieval Fortunately, memories can often be jogged with retrieval cues – stimuli that help us gain access to memories. Reinstating the Context of an Event Context cues often facilitate the retrieval of information The technique of reinstating the context of an event has been used effectively in legal investigations to enhance eyewitness recall he notion that hypnotists can use age regression to recover long-lost memories by instructing participants to go back in time and relive past events has been discredited research suggests that hypnosis often increases individuals’ tendency to report incorrect information FORGETTING According to Daniel Schacter (1999), you need to forget information that is no longer relevant Forgetting can reduce competition among memories that would otherwise cause confusion HOW QUICKLY WE FORGET: EBBINGHAUS'S FORGETTING CURVE Ebbinghaus studied only one subject – himself He wanted to work with meaningless materials that would be uncontaminated by his previous learning. He tested his memory of these lists after various time intervals. This diagram, called a forgetting curve, illustrates retention and forgetting over time. Ebbinghaus’s forgetting curve shows a steep drop in retention during the first few hours after the nonsense syllables were memorised. Thus, he concluded that most forgetting occurs very rapidly after learning something. Downloaded by Karabo Mudau ([email protected])  lOMoARcPSD|26686186 - Fortunately, subsequent research has shown that Ebbinghaus’s forgetting curve was unusually steep - One problem was that he was working with such meaningless material. When people memorise more meaningful material, such as prose or poetry, forgetting curves are not nearly as steep. different methods of measuring forgetting yield different estimates of how quickly people forget. MEASURES OF FORGETTING - Retention refers to the proportion of material that is remembered (i.e. stored and retained). - The three principal methods used to measure forgetting are recall, recognition and relearning - A recall measure of retention requires participants to reproduce information on their own without any cues. - A recognition measure of retention requires participants to select previously learned information from an array of options. - A re-learning measure of retention requires an individual to memorise information a second time to determine how much time or how many practice trials are saved by having learned it before. Downloaded by Karabo Mudau ([email protected])  lOMoARcPSD|26686186 MEMORY AS A CONSTRUCTIVE PROCESS RECONSTRUCTING MEMORIES AND THE MISINFORMATION EFFECT - Your memories, to some extent, are sketchy reconstructions that may be distorted and may include details that did not actually occur reconstructive distortions show up frequently in eyewitness testimony. - The misinformation effect occurs when an individual’s recall of an experienced event is altered by introducing misleading post-event information. - Studies have demonstrated that the influence of misinformation is not limited to memories of events that one has personally experienced or witnessed; it can also distort one ’s knowledge of basic facts REALITY MONITORING, SOURCE MONITORING, AND DESTINATION MEMORY - Reality monitoring refers to the process of deciding whether memories are based on external sources (one ’s perceptions of actual events in the outside environment) or internal sources (one ’s thoughts and imaginations). Downloaded by Karabo Mudau ([email protected])  lOMoARcPSD|26686186 - Source monitoring involves making attributions about the origins of memories. - Destination memory involves recalling to whom one has told what THE RECOVERED MEMORIES CONTROVERSY SUPPORT § Many psychologists and psychiatrists, especially clinicians involved in the treatment of psychological disorders, largely take recovered memories of abuse at face value § Supporters further assert that there is ample evidence that it is common for people to repress traumatic incidents in their unconscious § The clinicians who accept the authenticity of recovered memories of abuse attribute the recent upsurge in recovered memories to therapists’ and clients’ increased sensitivity to an issue that people were once reluctant to discuss. SCEPTICISM § They point out that the women in the Williams (1994) study may have failed to report their earlier sexual abuse for a variety of reasons besides amnesia, including embarrassment, poor rapport with the interviewer, normal forgetfulness or a conscious preference not to revisit painful experiences from the past § The sceptics do not say that people are lying about their previously repressed memories. Rather, they maintain that some suggestible people wrestling with emotional problems have been convinced by persuasive therapists that their emotional problems must be the result of abuse that occurred years before. BIOLOGICAL BASES OF MEMORY THE NEURAL CIRCUITRY OF MEMORY § One line of research suggests that memory formation results in alterations in synaptic transmission at specific sites. specific memories depend on biochemical changes that occur at specific synapses. § Kandel believes that durable changes in synaptic transmission may be the neural building blocks of more complex memories as well. Richard F. Thompson and his colleagues have shown that specific memories may depend on localized neural circuits in the brain. § In other words, memories may create unique, reusable pathways in the brain along which signals flow. Downloaded by Karabo Mudau ([email protected])  lOMoARcPSD|26686186 § Research suggests that the process of neurogenesis – the formation of new neurons – may contribute to the sculpting of neural circuits that underlie memory § Neurogenesis may provide the brain with a supply of neurons that vary in age, and these variations may somehow allow the brain to ‘timestamp’ some memories § Evidence on long-term potentiation also supports the idea that memory traces consist of specific neural circuits. Long-term potentiation (LTP) is a long-lasting increase in neural excitability at synapses along a specific neural pathway.. THE ANATOMY OF MEMORY ¥ Cases of organic amnesia are another source of clues about the physiological bases of memory. ¥ There are two basic types of amnesia: retrograde and anterograde ¥ Retrograde amnesia involves the loss of memories for events that occurred before the onset of amnesia. Anterograde amnesia involves the loss of memories for events that occur after the onset of amnesia. ¥ Scientists now believe that the entire hippocampal region and adjacent areas in the cortex are critical for many types of long-term memory ¥ Many scientists now refer to this broader memory complex as the medial temporal lobe memory system Many theorists believe that the medial temporal lobe memory system plays a key role in the consolidation of memories ¥ Consolidation is a hypothetical process involving the gradual conversion of information into durable memory codes stored in long-term memory. The hippocampus and adjacent areas in the brain are thought to play an especially central role in memory. Downloaded by Karabo Mudau ([email protected])