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Memory and encoding Memory as Information Processing – similar to a computer • write to file • save to disk • read from disk • Encoding – the processing of information into the memory system Storage and retrieval • Storage – the retention of encoded information over time • Retrieval – process of getting information out of memory Memory Sensory Memory the immediate, initial recording of sensory information in the memory system If you can recall information, it must first be stored! According to Atkinson and Shiffrin’ 3-step model, the first stop is sensory memory or the sensory registers. Sperling’s experiment Sperling’s partial report technique illustrates the limitation of sensory memory. When subjects were told to report ALL 9 letters flashed for a fraction of a second, they could not, but when subjects instructed to report 3 of the letters (one row of 3 letter row display of 9 total letters) they could do so with few errors This proved that sensory memory could hold the information, but only very briefly Storage: Sensory Memory Sensory memory holds information just long enough to recognize and transfer it to STM for further processing This happens through selective attention Selective attention allows only a small percentage of sensory messages that bombard us to enter conscious awareness. It is controlled not only by the focus of our attention but also the expectancies we have prior to exposure Storage: Sensory Memory Iconic Memory a momentary sensory memory of visual stimuli a photographic or picture image memory lasting no more that a few tenths of a second Tests of George Sperling Echoic Memory momentary (3-4 sec) sensory memory of auditory stimuli term memory • Short Term Memory/Working Memory – activated memory that holds a few items briefly – look up a phone number, then quickly dial before the information is forgotten • Long Term Memory – the relatively permanent and limitless storehouse of the memory system A Simplified Memory Model Sensory input Attention to important or novel information Encoding External events Sensory memory Short-term memory Encoding Long-term memory Retrieving Automatic Processing We process an enormous amount of information effortlessly, such as the following: 1. Space: While reading a textbook, you automatically encode the place of a picture on a page. 2. Time: We unintentionally note the events that took place during the day. 3. Frequency: You effortlessly keep track of things that happen to you. DEMO DO NOT write down the following list. Listen and read them, then try to recall them when prompted: CLINTON RUJ FET TEXTBOOK NAV BUSH FULFILL GEF MANDATE FET 47 TAL Effortful Processing While some information is automatically and effortlessly processed, some requires focus and attention Attention is defined as selection certain information for further processing We normally pay attention to only a small portion of incoming information We pay attention to things according to… Meaningfulness Distinctiveness Repetition Broadbent’s Cocktail Party Phenomenon: we tune out other sounds to focus on what is important Ebbinghaus and Rehearsal Effortful learning usually requires rehearsal or conscious repetition Ebbinghaus studied rehearsal by using nonsense syllables: TUV YOF GEK XOZ The more times practiced on Day 1, the fewer repetitions to relearn on Day 2 Spacing Effect distributed practice yields better long- term retention than massed practice Memory: Ebbinghaus’ Contributions The more the syllables were rehearsed (practiced) on the first day of learning, the fewer rehearsals it took to relearn them on the second. Encoding: Serial Position Effect Percent age of words recalled 90 80 Serial Position Effect--tendency to recall best the last items in a list, and then the items at beginning 70 60 50 40 30 20 10 0 1 2 3 4 5 6 7 8 Position of word in list 9 10 11 12 The Serial Position Effect: Benefits of Rehearsal + Working Memory When we are given a list of things to remember, we often remember the first items and last items on the list. This is called the serial position effect. We are able to rehearse those at the beginning the most and those at the end are still in our working memory! Primacy Effect: tendency to recall the first items on the list Recency Effect: tendency to recall the last items on the list Making Memories Last… Information quickly learned is information quickly lost! Spacing Effect: distributed study time yields better longterm retention than massed practice (cramming)! Testing Effect: more frequent quizzing or previously studied material yields better long-term retention Bottom line: spread your studying out over time and quiz yourself frequently! This is sooooo much fun! I will do it every night until the test! Unless evil clowns stop you! Chunking Organizing items into a familiar, manageable unit. Try to remember the numbers below. 1776149218121941 Chunking If you are well versed with American History, chunk the numbers together and see if you can recall them better. 1776 1492 1812 1941 What Do We Encode? Semantic Encoding encoding of meaning including meaning of words Acoustic Encoding encoding of sound especially sound of words Visual Encoding encoding of picture images What We Encode: Levels of Processing Which type of encoding – visual, acoustic or semantic – helps us to remember best? Craik and Tulving (1975) Subjects forced to encode words in the three ways Visually (is it capitalized?) Acoustically (does it rhyme with…) semantically (Would it fit into the sentence?) Found that semantic encoding yielded best recall! Spend TIME learning and make MEANING out of what you wish to recall! Self-Reference Effect: meaning that is personal – relate information to ourselves. Bransford and Johnson (1972) had subjects read the following paragraph: The procedure is actually quite simple. First you arrange things into different groups depending on their makeup. Of course, one pile may be sufficient depending on how much there is to do. If you have to go somewhere else due to lack of facilities that is the next step, otherwise you are pretty well set. It is important not to overdo any particular endeavor. That is, it is better to do too few things at once than too many. In the short run this may not seem important, but complications from doing too many can easily arise. A mistake can be expensive as well. The manipulation of the appropriate mechanisms should be self-explanatory, and we need not dwell on it here. At first the whole procedure will seem complicated. Soon, however, it will become just another facet of life. It is difficult to foresee any end to the necessity for this task in the immediate future, but then one never can tell. Without the context of “doing laundry, subjects could not recall much! Storage: Short-Term Memory Percentage 90 who recalled consonants 80 70 60 50 40 30 20 10 0 Short-Term Memory 3 6 9 12 15 18 Time in seconds between presentation of contestants and recall request (no rehearsal allowed) limited in duration and capacity “magical” number 7+/-2 (Miller, 1956) Storage: Short Term Memory Unless information in STM is important/meaningful or is actively rehearsed, it quickly vanishes from STM and is displaced by whatever comes into our minds next Displacement occurs, then, when new information enters STM and pushes old out STM storage capacity is limited: the average adult can hold about 5-9 bits or chunks of information in STM George Miller (1956) Magical Number Short Term Memory Capacity STM (working memory) is what is in your mind RIGHT NOW. Information in STM only remains there for about 20-30 seconds STM is very sensitive to interruption and interference Memory Span Memory span is a measurement of STM capacity It measures the largest number of items that can be recalled perfectly from STM after only one presentation No study/rehearsal time is allowed Sometimes used as a component of IQ tests Information in STM may be new or retrieved from LTM to be thought about and used. Storage: Long-Term Memory How does storage work? (p.268) Karl Lashley (1950) – Searching for “engrams” rats learn maze lesion cortex test memory Synaptic changes Long-term Potentiation (LTP) (p.269) increase in synapse’s firing potential after brief, rapid stimulation Stress Hormones and Memory (p.270-271) Stress hormones aide memory Hormone surge alert brain that something important has happened. Physical or psychological pain, trauma create surge Rat study – shot of hormones with a leg shock Creates a very strong memory Biological evidence for why emotional memories are stronger. Stress Hormones and Memory Stress hormones block and destroy memory Prolonged stress corrodes neural connections Memories can be blocked by stress hormones Rats trying to find a hidden target Public speaking Flashbulb Memory (p.271) A clear moment of an emotionally significant moment or event. Where were you when? 1. You heard about 9/11 2. You heard about the death of a family member Storage: Long-Term Memory Amnesiacs Deny having seen an article and then read it faster Deny abilities to solve puzzle then complete it easily Childhood Amnesia – must have implicit memory in tact Explicit Memory (Declarative Memory) memory of facts and experiences that one can consciously know and “declare” Episodic Memory – personally experienced events Semantic Memory – facts, general knowledge EG. Sematic (facts and general knowledge) and episodic (birthdays) Implicit Memory (Non-declarative Memory) retention independent of conscious recollection Skills (procedural memory), classical-conditioned responses (Eg. Swimming) Storage: Long-Term Memory Amnesia--the loss of memory Retrograde Amnesia – mass forgetting of old information Antrograde Amnesia – inability to form new memories Oliver Sacks – “Jimmie” (earth from the moon example), H.M., Clive Wearing Amnesiacs demonstrate 2 forms of memory… Storage: Long-Term Memory Subsystems Types of long-term memories Explicit (declarative) With conscious recall Facts-general knowledge (“semantic memory”) Personally experienced events (“episodic memory”) Implicit (nondeclarative) Without conscious recall Skills-motor and cognitive Dispositionsclassical and operant conditioning effects Clive Wearing - the Man with no short term memory. Storage: Long-Term Memory (p.272) hippocampus--neural center in limbic system that helps process explicit memories for storage Processes explicit memories – then sent to multiple different regions. Hippocampus Storage: Long-Term Memory (p.273) Cerebellum • Process implicit memories Ex: classicalconditioned eyeblink disappears when you remove cerebellum Retrieval is the process of getting information out of memory storage. Recall Versus Recognition (pp.274-275) Recall you must retrieve the information from your memory fill-in-the blank or essay tests Recognition you must identify the target from possible targets multiple-choice tests Practising Recall Which strategy worked for you? Priming The more retrieval cues you have (like strings attached to whatever it is you wish to remember), the more likely you are to recall. Priming The activation of associations in memory – often unconscious. Can shape our interpretation of events Mnemonics A trigger to aid memory, involving prompts such as visual imagery or sounds. Since imagery is at the heart of memory. Mnemonic techniques use vivid imagery in aiding memory. 1. Method of Loci 2. Link Method 3. Context Effects Context Effects (p.276) It helps to put yourself back in the same context you experienced (encoded) something. If you study on your favorite chair at home, you will probably score higher if you also took the test on the chair. Deja Vu Or something else? If you have a strong emotional reaction to a remembered event, does that mean your memory is accurate? Mood-Congruent Memory (pp.277-278) The tendency to recall experiences that are consistent with one's current good or bad mood. If you are depressed, you will more likely recall sad memories from you past. Moods also effect that way you interpret other peoples behavior