Lesson 6 Memory. Models and Research Methods

LESSON 6: MEMORY: MODELS AND RESEARCH METHODS Memory - The means by which we retain and draw on our past experiences to use that information in the present. As a process, it refers to the dynamic mechanisms associated with storing, retaining, and retrieving information about past experience. 3 OPERATIONS OF MEMORY - Encoding - you transform sensory data into a form of mental representation. Storage - you keep encoded information in memory. Retrieval - you pull out or use information stored in memory. TASKS USED FOR MEASURING MEMORY (RECALL VS. RECOGNITION) 1. Recall - You may produce a fact, a word, or other item from memory. Ex. Fill in the blank and most essay tests. - Require expressive knowledge, in which you have to produce an answer. Ex. “The term for persons who suffer severe memory impairment is ____” 2. Recognition - You select or otherwise identify an item as being one that you have been exposed to previously. Ex. Multiple choice or true or false tests. - Referred to as tapping receptive knowledge. Receptive means “responsive to stimulus.” You respond to stimuli presented to you and decide whether you have seen them before or not. Ex. “The term for people with outstanding memory ability is (1) amnesics (2) semanticists (3) mnemonists, or (4) retrograders.” 3 MAIN TYPES OF MEMORY RECALL 1. Serial Recall - You recall items in the exact order in which they were presented. For example, remember the following list of comedians in order: Stephen Colbert, Jon Stewart, David Letterman, Conan O'Brien, Jay Leno. - Repeat the digits in the exact order, 287164. 2. Free Recall - You recall items in any order you choose. Ex. Repeat the items in the list in any order in which you can recall them: Dog, pencil, time, hair, money, restaurant. 3. Cued Recall - You are first shown items in pairs, but during recall you are cued with only one member of each pair and are asked to recall each mate. Also called “pairedassociates recall.” - For example, you could ask people to learn the following pairings: Colbert-apple, Stewart-grape, Letterman-lemon, O’Brien-peach, Leno-orange, and then ask them to produce the pairing for Stewart (grape). IMPLICIT VS. EXPLICIT MEMORY TASKS 1. Explicit Memory - Participants engage in conscious recollection. Ex. They might recall recognize words, facts, or pictures from a particular prior set of items. 2. Implicit Memory - We use information from memory, but are not consciously aware that we are doing so. Ex. You can read the word in the photo without problems, although a letter is missing. - Every day you engage in many tasks that involve your unconscious recollection of information. PRIMING TASK Word-completion tasks - Based on the priming effect. Participants received a word fragment, such as the first 3 letters of a word. They then complete it with the first word that comes to mind. For ex. Imp ____ Priming is the facilitation of your ability to utilize missing information. In general, participants perform better when they have seen the word on a recently presented list, although they have not been explicitly instructed to remember words from that list. Procedural Memory - Memory for processes. Examples: riding a bike, driving a car. Many of the activities that we do every day fall under the purview of procedural memories; From brushing your teeth to writing. 1. Rotary Pursuit Task - Requires participants to maintain contact between an L-shaped stylus and a small and a small rotating disk. - When a new disk or speed is used, participants do relatively poorly. But with the same disk and speed, they do as well as they had after learning the task, even if they do not remember previously completing the task. 2. Mirror Tracing - A plate with the outline of a shape is drawn on it is put behind a barrier where it cannot be seen. - With practice, however, participants become quite efficient and accurate with this task. - Used to study the impact of sleep on procedural memory. Process-Dissociation Model - Postulates that only one task is needed to measure both implicit and explicit memory. The model assumes that implicit and explicit memory both have a role in virtually every response. INTELLIGENCE AND THE IMPORTANCE OF CULTURE IN TESTING - Culture-relevant tests - measure skills and knowledge that relate to the cultural experiences of the test-takers. MODELS OF MEMORY (Traditional Model of Memory) 1. William James - Two structures of memory  Primary memory – holds temporary information currently in use  Secondary memory – holds information permanently or at least for a very long time - Stores – structures for holding information - Memory – the information stored in the structure  The stores are hypothetical constructs - Concepts that are not themselves directly measurable or observable, but that serve as mental models for understanding how a psychological phenomenon works. 2. Atkinson-Shiffrin Model - Richard Atkinson and Richard Shiffrin (1968) proposed an alternative model that conceptualized memory in terms of three memory stores: sensory store, shortterm store, long-term store. - This emphasizes the passive storage areas in which memories are stored; But it also alludes to some controlled processes that govern the transfer of information from one to another. Sensory Store - The initial repository of much information that eventually enters the short and long term stores. Capable of storing relatively limited amounts of information for very brief periods. ICONIC STORE – a discrete visual sensory register that holds information for very short periods. SPERLING’S DISCOVERY - - George Sperling (1960) – made the initial discovery regarding the existence of the iconic store. He addressed the question of how much information we can encode in a single, brief glance at a set of stimuli.  Whole-report procedure – participants report every symbol they have seen  Partial-report procedure – participants need to report only part of what they see Display from a visual-recall task - These data suggest that the iconic store can hold about 9 items. They also suggest that information in the store decays very rapidly. Subsequent Refinement - Averbach and Coriell (1961): iconic memory can be erased. Backward visual making – mental erasure of stimulus caused by the placement of one stimulus where another one had appeared previously. To summarize, visual information appears to enter our memory system through an iconic store. Erasure occurs if other information is superimposed on it before there is sufficient time for the transfer of the information to another memory store. Short-Term Store - Capable of storing information for somewhat longer periods, but of relatively limited capacity as well. It holds memories for a few seconds and occasionally up to a couple of minutes. In general, our immediate short term memory capacity for a wide range of items appears to be about 7 items, plus or minus 2. An item can be something simple, such as a digit, or something more complex, such as a word. – if we chunk string of numbers into larger units, we probably will be able to reproduce easily the 21 numerals as 6 items. Long-Term Store - Capable of storing information for very long periods, perhaps even indefinitely. Here we keep memories that stay with us over long periods. We hold in it information we need to get us by in our day-to-day lives – people’s names, where we keep things, how we schedule ourselves on different days, and so on. What is stored in the brain? - Wilder Penfield addressed this question while performing operations on the brains of conscious patients afflicted with epilepsy. He used electrical stimulation of various parts of the cerebral cortex. to locate the origins of each patient's problems. His work was instrumental in plotting the motor and sensory areas of the cortex. He found that patients sometimes would appear to recall memories from their childhoods. These data suggested to Penfield that long-term memories might be permanent.  Permastore – refers to the very long-term storage of information, such as knowledge of a foreign language and of mathematics. Schmidt and colleagues (2000) studied the permastore effect for names of streets near one’s childhood home. Indeed, the author just returned to his childhood home of more than 40 years ago and perfectly remembered the names of the nearby streets. These findings indicate that permastore can occur even for information that you have passively learned. THE LEVELS-OF-PROCESSING MODEL Levels-of-Processing Framework - Postulates that memory does not comprise 3 or even any specific number of separate. Of course, but rather varies along a continuous dimension in terms of depth of encoding. (Craik & Lockhart, 1972). There are theoretically an infinite number of levels of processing (LOP) at which items can be encoded through elaboration – or successively deeper understanding of material to be learned (Craik & Tulving, 1975) The deeper the level of processing, the higher, in general, is the probability that an item may be retrieved  Physical – visually apparent features of the letters  Phonological – sound combinations associated with the letters (e.g., rhyming)  Semantic – meaning of the word Self-reference effect - Participants show very high levels of recall when asked to relate words meaningfully to the participants by determining whether the words describe them. The highest levels of recall occur with words that people consider self-descriptive. Objects can be better remembered, for example, if they belong to the participant. Self-schema - Is an organized system of internal cues regarding our attributes, our personal experiences, and ourselves. Thus, we can richly and elaborately encode information related to ourselves, much more so than other information about other topics. Two other variables may be of more importance: the way people process (elaborate) the encoding of an item (e.g., phonological or semantic), and the way the item is retrieved later on. Two kinds of strategies for elaborating the encoding:  Within-item elaboration – it elaborates encoding of the particular item in terms of its characteristics, including the various levels of processing.  Between-item elaboration – it elaborates encoding by relating each item’s features to the features of items already in memory. AN INTEGRATIVE MODEL: WORKING MEMORY - Most widely used and accepted model today (Baddeley, 2007, 2009) (Unsworth, 2009) Working Memory - Holds only the most recently activated, or conscious, portion of long term memory, and it moves these activated elements into and out of brief, temporary memory storage. (Dosher, 2003) Components of Working Memory: 1. Visuospatial Sketchpad – briefly holds some visual images 2. Phonological Loop – briefly holds inner speech for verbal comprehension and for acoustic rehearsal - We use the phonological loop for a number of every day tasks, including sounding out new and difficult words and solving word problems. - 2 critical components:  Phonological storage – holds information in memory  Subvocal rehearsal – used to put the information into memory in the first place - When subvocal rehearsal is inhibited, the new information is not stored. This phenomenon is called articulatory suppression. - Articulatory suppression is more pronounced when the information is presented visually versus aurally (e.g., by hearing). Thus, we can remember fewer long words compared with short words. Without this loop, acoustic information decays after about 2 seconds. 3. Central Executive – both coordinates attentional activities and governs responses. - Critical to working memory because it is the gating mechanism that decides what information to process further and how to process this information. - It decides what resources to allocate to memory and related tasks, and how to allocate them. Involved in higher-order reasoning and comprehension and is central to human intelligence. 4. Subsidiary Slave System – perform other cognitive or perceptual tasks 5. Episodic Buffer - A limited-capacity system that is capable of binding information from the visuospatial sketchpad and the phonological loop as well as from long-term memory into a unitary episodic representation. Integrates information from different parts of working memory-that is, visual-spatial and phonological-so that they make sense to us. - This incorporation allows us to solve problems and reevaluate previous experiences with more recent knowledge. Neuroscience and Working Memory - Phonological loop - Left hemisphere of the lateral frontal and inferior parietal lobes as well as the temporal lobe. Visuospatial sketchpad – (short intervals) occipital and right frontal lobes, (longer intervals) parietal and left frontal lobes. Central executive – frontal lobes Episodic buffer – bilaterial activations of the frontal lobes and portions of the temporal lobes, including the left hippocampus MEASURING WORKING MEMORY - Retention-delay task (old or new?) Temporally ordered working memory load task (old or new?) N-back task (find and repeat n-back) Temporally ordered working memory load task (reproduce in current order – also referred to as digit-span task) Temporally ordered working memory load task (reproduce final items in correct order) MULTIPLE MEMORY SYSTEMS (2 kinds of Explicit Memory) - Endel Tulving (1972)  Semantic Memory – stores general world knowledge. It is our memory for facts that are not unique to us and that are not recalled in any particular temporal context.  Episodic Memory – stores personally experienced events or episodes. HERA (hemispheric encoding/retrieval asymmetry) - Attempts to account for differences in hemispheric activation for semantic versus episodic memories. According to this model, there is greater activation in the left than in the right prefrontal hemisphere for tasks requiring retrieval from semantic memory. In contrast, there is more activation in the right than in the left prefrontal hemisphere for episodic retrieval tasks. Connectionist Network - - Consists of many different nodes. Unlike in semantic networks, it is not a single node that has a specific meaning, but rather the knowledge is represented in a combination of differently activated nodes. This integrated view suggests that part of the reason we humans are as efficient as we are processing information is that we can handle many operations at ones. Effectively explains priming effects, skill learning (procedural memory), and several other phenomena of memory. PDP (Parallel distributed processing model) - The key to knowledge representation lies in the connections among various nodes, or elements, stored in memory, not in each individual node. Priming effect - - Is the resulting activation of the node.  Prime – a node that activates a connected node. Ex. Where we ate and whom we were with (episodic), nature of the food we ate (semantic), skills in chopsticks (procedural), embarrassment in spilling tea (emotional). Mnemonist – someone who demonstrates extraordinarily keen memory ability, usually based on using special techniques for memory enhancement. - Synesthesia – experience of sensations in a sensory modality different from the sense that has been physically stimulated (hearing colors, tasting sounds) Hypermnesia – a process of producing retrieval of memories that would seem to have been forgotten Sometimes loosely referred to as, “unforgetting.” Unusual power or enhancement of memory, typically under abnormal conditions such as trauma, hypnosis, or narcosis. DEFICIENT MEMORY Amnesia – sever loss of explicit memory - Retrograde amnesia – individuals lose their purposeful memory for events prior to whatever trauma induces memory loss. Anterograde amnesia – the inability to remember events that occur after a traumatic event. Infantile amnesia – the inability to recall events that happened when we were very young. Alzheimer's Disease - A disease of older adults that causes dementia as well as progressive memory loss. First identified by Alois Alzheimer in 1907. Dementia – loss of intellectual function that is severe enough to impair one’s everyday life.  Atrophy – decrease in size of the brain; especially in the hippocampus and frontal and temporal brain regions. The brains of people with the disease show plaques and tangles that are not found in normal brains.  Plaques – dense protein deposits found outside the nerve cells of the brain.  Tangles – pairs of filaments that become twisted around each other. The symptoms are of gradual onset, and the progression is continuous and irreversible. Donepezil (Aricept) – may slightly slow progression of the disease but that it cannot reverse it; slows destruction of the disease but that it cannot reverse it; slows destruction of the neurotransmitter acetylcholine in the brain. Memantine (Namenda or Ebixa) – inhibits a chemical that overexcite the brain cells and leads to cell damage and death. - - The incidence of Alzheimer's disease increases exponentially with age. About 1% of people between 70-75 years of age experience an onset of Alzheimer's. But between ages 80-85, the incidence is more than 6% a year. Early-onset, linked to genetic mutation, before even 50 years of age and sometimes as early as the 20s. HOW ARE MEMORIES STORED? - - Frontal lobe – store semantic and episodic memories Motor cortex – procedural memories Prefrontal cortex - short-term memories Temporal lobe – formation and storage of longterm semantic and episodic memories and contributes to the processing of new material in short-term memory Amygdala – vital to the formation of new emotional memories Hippocampus – plays a pivotal role in the formation of new long-term semantic and episodic memories Cerebellum – plays an important role in the storage of procedural memories.