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Memory Studying Memory Building Memories: Encoding Memory Storage Retrieval: Getting Information Out Forgetting Memory Construction Errors Improving Memory. Studying Memory. An information-processing model. Studying Memory. Memory
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Memory • Studying Memory • Building Memories: Encoding • Memory Storage • Retrieval: Getting Information Out • Forgetting • Memory Construction Errors • Improving Memory
Studying Memory • An information-processing model
Studying Memory • Memory • Persistence of learning over time through the encoding, storage, and retrieval of information • Information-processing models • Used to help us think about how the brain forms and retrieves memories
Encoding • Process of getting information into the memory system • Storage • Process of retaining encoded information over time • Retrieval • Process of getting information out of memory storage
An Information-Processing Model • Atkinson and Shiffrin (1968): Three stages • We first record to-be-rememberedinformation as a fleeting sensory memory. • From there, we processinformation into short-term memory, where we encodeit through rehearsal. • Finally, information moves into long-termmemory for later retrieval.
Atkinson and Shiffrin’s classic three-step model helps us to think about how memories are processed, but today’s researchers recognize other ways long- term memories form. For example, some information slips into long-term memory via a “back door,” without our consciously attending to it (automatic processing). And so much active processing occurs in the short- term memory stage that many now prefer to call that stage working memory. A MODIFIED THREE-STAGEINFORMATION-PROCESSING MODEL OF MEMORY
Information-Processing • Working memory • Processes important, focused information • Makes sense of new input • Links with long-term memory • Uses a central executive (Baddeley)
WORKING MEMORY Alan Baddeley’s (2002) model of working memory, simplified here, includes visual and auditory rehearsal of new information. Part of the brain functions like a manager, a central executive focusing attention and pulling information from long-term memory to help make sense of new information.
What two new concepts update the classic Atkinson-Shiffrin three-stage information processing model? What are two basic functions of working memory?
Building Memories: Encoding • Our two-track memory system • Automatic processing and implicit memories • Effortful processing and explicit memories
Building Memories: Encoding • Our two-track memory system • Explicit memories (declarative memories) of conscious facts and experiences encoded through conscious, effortful processing • Implicit memories (nondeclarative memories)that form through automatic processes and bypass the conscious encoding track
Building Memories: Encoding • Automatic processing and implicit memories • Implicit memories include automatic skills and classically conditioned associations • Information is automatically processed about • Space • Time • Frequency • Effortful processing and explicit memories • With experience and practice, explicit memories become automatic
Sensory memory • What is sensory memory? • First stage in forming explicit memories • Immediate, very brief recording of sensory information in the memory system • Iconic memory: Picture-image memory • Echoic memory: Sound memory TOTAL RECALL—BRIEFLY When George Sperling (1960) flashed a group of letters similar to this for one-twentieth of a second, people could recall only about half the letters. But when signaled to recall any one row immediately after the letters had disappeared, they could do so with near-perfectaccuracy.
Capacity of Short-Term and Working Memory • Short-termmemory • Activated memory that holds a few items briefly (such as the seven digits of a phone number while dialing) before the information is stored or forgotten • Working memory • Newer understanding of short-termmemory that stresses conscious, active processing of incoming auditory and visual-spatial information, and of information retrieved from long-term memory
Capacity of Short-Term and Working Memory • Short-termmemory • George Miller (1956) • Magical Number Seven: People can store about seven bits of information (give or take two) • Baddeley and colleagues ( 1975) • Without distraction, about seven digits or about six letters or five words • Working memory • Capacity varies by age and distractions at the time of memory tasks
SHORT-TERM MEMORY DECAY • Unless rehearsed, verbal information may be quickly forgotten (From Peterson & Peterson, 1959; see also Brown, 1958.)
Building Memories: Encoding Effortful processing strategies • Chunking: Organizing items into familiar, manageable units; often occurs automatically • Mnemonics: Memory aids, especially techniques that use vivid imagery and organizational devices • Peg-word system (From Hintzman, 1978.)
Building Memories: Encoding • Spaced study and self-assessment • Spacing effect: Encoding is more effective when it is spread over time • Distributed practice: Produces better long-term recall • Massive practice: Produces speedy short term learning and feelings of confidence • Repeated self-testing (testing effect) effect: Encoding is very effective
Building Memories: Encoding • Making new information meaningful • Spaced practice is most effective when new information is meaningful • Ebbinghaus • Estimated that, compared with learning nonsense material, learning meaningful material required one-tenththe effort
Which strategies are better for long termretention: cramming and rereading material, or spreading out learning over time and repeatedly testing yourself?
Memory Storage • Retaining information in the brain • Synaptic changes
Memory Storage: Retaining Information in the Brain • Past research • Whole past is contained in memory—waiting to be relived • Newer findings • Flashbacks during surgery are new creations of a stressed brain • Information is not stored in a single, specific spot • Perception, language, emotions and more require brain networks
Explicit- Memory System: Hippocampus and Frontal Lobes Roger Harris / Science Source • The brain registers and temporarily stores event aspects in the hippocampus • Memories then migrate for storage in memory consolidation process • Right and left frontal lobes store different information • The hippocampus and the brain cortex display rhythmic patterns of activity during sleep THE HIPPOCAMPUS Explicit memories for facts and episodes are processed in the hippocampus and fed to other brain regions for storage.
Retaining Information in the Brain • Implicit memory system: Cerebellum and basal ganglia • The cerebellum plays an important role in forming and storing memories created by classical conditioning • Memories of physical skills are also implicit memories • Basal ganglia help form memories for these skills • Infantile amnesia • Conscious memory of the first three years is blank • Command of language and a well-developed hippocampus are needed
Review Key Memory Structures in the Brain Frontal lobes and hippocampus: explicit memory formation Cerebellum and basal ganglia: implicit memory formation Amygdala: emotion-related memory formation
Which parts of the brain are important for implicit memory processing, and which parts play a key role in explicit memory processing? Your friend has experienced brain damage in an accident. He can’t remember anything told to him during a conversation. What’s going on here?
Retaining Information in the Brain • Excitement or stress trigger hormone production and provoke the amygdala to engage memory • Emotions often persist with or without conscious awareness • Flashback memories occur via emotion-triggered hormonal changes and rehearsal
Synaptic Changes • Long-term potentiation (LTP) • Increase in a synapse’s firing potential • After LTP, the brain will not erase memories • Believed to be a neural basis for learning and memory • Kandel and Schwartz (1982) • Pinpointed changes in sea slugs’ neural connections • With learning more serotonin is released and cell efficiency increased—number of synapses increase
Which brain area responds to stress hormones by helping to create stronger memories? The neural basis for learning and memory, found at the synapses in the brain’s memory connections, results from brief, rapid stimulation. It is called ________.
Retrieval: Getting Information Out • Measuring retention • Retrieval cues
Retrieval: Getting Information Out • Three types of evidence indicate memory retention • Recall • Recognition • Relearning
EBBINGHAUS’ RETENTION CURVE • The more times Ebbinghaus practiced a list of nonsense syllables on day 1, the less practice he needed to relearn it on day 2 • Speed of relearning is one way to measure whether something was learned and retained (From Baddeley, 1982.)
Multiple-choice questions test our recall. c. relearning. recognition. d. sensory memory. Fill-in-the blank questions test our ________. If you want to be sure to remember what you’re learning for an upcoming test, would it be better to use recall or recognition to check your memory? Why?
Retrieval: Getting Information Out • Memory retrieval • Memories are held in storage by a web of associations • Retrieval cues serve as anchor points for pathways to memories suspended in this web • Priming • Activation, often unconsciously, of particular associations in memory
Retrieval Cues PRIMING—AWAKENING ASSOCIATIONS After seeing or hearing rabbit, we are later more likely to spell the spoken word as h-a-r-e Associations unconsciously activate related associations This process is called priming (Adapted from Bower, 1986.)
Retrieval Cues • Context effects • Priming memory is often helped by returning to the context of the experience • State-dependent memory • There is a tendency to recall events consistent with current good or bad mood(mood-congruent memory) • Serial position effect • There is a tendency to recall best the last and first items in a list
The Effects of Context on Memory Alexis Rosenfeld / Science Source Words heard underwater were best recalled underwater; words heard on land were best recalled on land. (Adapted from Godden & Baddeley, 1975.)
What is priming? When we are tested immediately after viewing a list of words, we tend to recall the first and last items best, which is known as the ________ effect.
Forgetting • Forgetting and the two-track mind • Encoding failure • Storage decay • Retrieval failure
Forgetting and the Two-track Mind John Gibbins/ZUMApress/Newscom • Humans have two distinct memory systems, controlled by different parts of the brain • Forgetting has several causes • Encoding failure • Storage decay • Retrieval failure • Interference • Motivated forgetting Let’s look more closely at these causes. STUDYING A FAMOUS BRAIN Jacopo Annese and of California are preserving Henry Molaison’s brain for the benefit of future generations. Their careful work will result in a freely available online brain atlas.
Forgetting: Encoding and Storage Decay • Encoding failure • Age: Encoding lag is linked to age-related memory decline • Attention: Failure to notice or encode contributes to memory failure • Storage decay • Course of forgetting is initially rapid, and then levels off with time • Physical change in the brain occur as memory forms (memory trace)
We cannot remember what we have not encoded. FORGETTING AS ENCODING FAILURE
The Forgetting Curve For Spanish Learned In School Bill Aron / Photo Edit Compared with others just completing a Spanish language-learning course, people 3 years out of the course remember much less. Compared with the 3-year group, however, those who studied Spanish even longer ago did not forget much more. (Adapted from Bahrick, 1984.)
Forgetting: Retrieval Failure • Reason for failure • Events and memories are not available because they were never acquired • Memories have been discarded due to stored memory decay • Insufficient information to access memories make these out of reach
Reason for failure • Events and memories are not available because they were never acquired • Memories have been discarded due to stored memory decay • Insufficient information to access memories make these out of reach RETRIEVAL FAILURE
Forgetting • Interference • Proactive: Occurs when older memory makes it more difficult to remember new information • Retroactive: Occurs when new learning disrupts memory for older information • Motivated forgetting • Freud: Repressed memories protect self-concept and minimize anxiety • Today: Attempts to forget are more likely when information is neutral, not emotional
People forgot more when they stayed awake and experienced other new material. (From Jenkins & Dallenbach, 1924.) RETROACTIVE INTERFERENCE
WHEN DO WE FORGET? • Forgetting can occur at any memory stage • As we process information, we filter, alter, or losemuch of it