Presentation on theme: "Dec 10 th, 2012. Memory Memory: Active system that receives, stores, organizes, alters, and recovers (retrieves) information Acquired Encoding "— Presentation transcript:
Memory Memory: Active system that receives, stores, organizes, alters, and recovers (retrieves) information Acquired Encoding Stored in the brain Storage Later retrieved Retrieval Eventually (possibly) forgotten
Figure 7.2 FIGURE 7.2 Remembering is thought to involve at least three steps. Incoming information is first held for a second or two by sensory memory. Information selected by attention is then transferred to temporary storage in short-term memory. If new information is not rapidly encoded, or rehearsed, it is forgotten. If it is transferred to long-term memory, it becomes relatively permanent, although retrieving it may be a problem. The preceding is a useful model of memory; it may not be literally true of what happens in the brain
Sensory Memory Function - holds information long enough to be processed for basic physical characteristics Capacity - large can hold many items at once Duration - very brief retention of images 0.3 sec for visual info 2 sec for auditory info Sensory Input Sensory Memory
Sensory Memory Divided into two subtypes: iconic memory - visual information echoic memory - auditory information Visual or iconic memory was discovered by Sperling in 1960 Sensory Input Sensory Memory
Sperling’s Experiment Presented matrix of letters for 1/20 seconds Whole-report procedure Participants are asked to report all the items of a display Partial-report procedure Participants are cued to report only some of the items in a display
Sperling’s Experiment Sounded low, medium or high tone immediately after matrix disappeared Tone signaled 1 row to report Recall was almost perfect Memory for images fades after 1/3 seconds or so, making report of entire display hard to do High Medium Low
Results from Sperling’s experiment demonstrating the existence of a brief visual sensory store. Participants were shown arrays consisting of three rows of four letters. After the display was turned off, they were cued by a tone, either immediately or after a delay, to recall a particular one of the three rows. The results show that the number of items reported decreased as the delay in the cuing tone increased.
Sensory Memory Sensory memory forms automatically, without attention or interpretation Attention is needed to transfer information to working memory Sensory Input Sensory Memory
Short-Term Memory (STM) A proposed intermediate system in which information has to reside on its journey from sensory memory to long-term memory
Atkinson and Shiffrin (1968) Model Proposes that as information is rehearsed in a limited-capacity STM, it is deposited in long-term memory
Memory span The number of elements one can immediately repeat back Typical short-term memory span is about seven items of information (i.e., words) George Miller (1957) Shepard and Teghtsoonian (1961) Information cannot be kept in STM indefinitely
George Miller “The magical number seven, plus or minus two: Some limits on our capacity for processing information” (1956)
Working Memory Holds the Information Needed to Perform a task Memory system that provides temporary storage for information that is currently being used in some conscious capacity (Baddeley, 1986) Function - conscious processing of information where information is actively worked on Capacity - limited (holds 7 +/- 2 items) Duration - brief storage (about 30 seconds) Code - often based on sound or speech even with visual inputs
Baddeley’s theory of working memory in which a central executive coordinates a set of slave systems.
Working Memory The Central Executive An attentional control mechanism for working memory Coordinating between the various subsystems Temporary activation of long-term memory Shifting between tasks or retrieval strategies Relying on the frontal lobe, mainly in the left hemisphere Use of language clearly relies on the central executive
Working Memory The visuospatial sketchpad Integrating spatial, visual, and kinesthetic information Phonological loop Articulatory loop ‘Inner voice’ used during rehearsal of verbal information Able to maintain about 1.5 to 2 sec worth of material in the loop Phonological store An ‘inner ear’ that hears the inner voice and stores the information in phonological form
Word length effect wit, sum, harm, bay, top University,opportunity,aluminum,constitutional,auditorium
Phonological similarity effect "G, C, B, T, V, P” vs. “F, L, K, S, Y, G.” Performance is usually _____ when the items sound similar than when the items sound different. The phonological store retains speech-based memory for a brief period of time and unless material is rehearsed, it usually decays within 2 seconds. The articulatory control process, which is responsible for translating visual information into speech-based codes, as well as transfering it to the phonological store.
Processing depth Elaboration leads to better recall than shallow processing Type of Processing Shallow -Acoustic Deep Shallow - Visual 1020304050607080901000 Percent of words recalled 1020304050607080901000
Working Memory measures Digit span(Wechsler, 1974) Forward digit span (Botwinick & Storandt, 1974) Forward digit span Backward digit span (Gathercole & Alloway, 2008) Letter-number sequencing (Wechsler, 1997) Letter-number sequencing Nonword repetition(Obrien et al., 2006) Wisconsin Card Sorting Test (WCST) (Miyake et al., 2000) Tower of Hanoi (TOH)/London (Korkman, Kirk, & Kemp, 1998) Random number generation (RNG) (Baddeley, 1998) Operation span (Miyake et al., 2000) Dual task (Papagno et al., 1991) N-back (Smith & Jonides, 1999) Delayed-recognition (Jha & McCarthy, 2000)
An illustration of the delayed match-to-sample task
Working Memory The Frontal Cortex and Primate Working Memory •Delayed match-to-sample tasks with monkeys ( Goldman-Rakic, 1992) •Monkeys with lesions in the frontal cortex cannot perform this working memory task. •Human infants cannot perform similar tasks successfully until their frontal cortices have somewhat matured (around 1 year)
Lateral views of the cerebral cortex of a human (top) and of a monkey (bottom). Area 46 is the region shown in darker color.
• Auditory-Verbal maintenance deficit following Left Supramarginal / Inferior Parietal lesions, eg KF (Warrington & Shallice, 1969) • Visual-spatial maintenance deficit following Right Inferior Parietal lesion, eg ELD (Hanley et al 1991) • Frontal patients impaired on manipulating information in Working Memory on tasks such as card sorting (Milner, 1963) and selection-without-repetition (Petrides & Milner, 1982) • Age-related Working Memory deficits following frontal-striatal decline (Gabrieli, 1996) Modality-specific, passive stores in posterior parietal/temporal cortex Common executive processes in frontal cortex Working Memory - Neuropsychology
Neural Correlates of Working Memory The phonological loop – Speech Left hemisphere: frontal and parietal regions The visuo-spatial sketchpad – Nonspeech Right hemisphere The central executive – Domain general Frontal lobe and ACC (anterior cingulate cortex)
Anderson, Cognitive Psychology and Its Implications, Edition 7e – Chapter 6
Awh et al., 1996 Anderson, Cognitive Psychology and Its Implications, Edition 7e – Chapter 6
Modality independent (Schumacher et al., 1996) Anderson, Cognitive Psychology and Its Implications, Edition 7e – Chapter 6
Memory aids Chunking Hierarchical organization Rehearsal
Chunking Grouping small bits of information into larger units of information expands working memory load Which is easier to remember? 4 8 3 7 9 2 5 1 6
Related items clustered together to form categories Related categories clustered to form higher-order categories Remember list items better if list presented in categories poorer recall if presented randomly Even if list items are random, people still organize info in some logical pattern Hierarchical Organization
Figure 7.4 FIGURE 7.4 A hypothetical network of facts about animals shows what is meant by the structure of memory. Small networks of ideas such as this are probably organized into larger and larger units and higher levels of meaning.
Working Memory Baddeley’s Theory of Working Memory (2003)
Memory Formation Retrograde Amnesia: Forgetting events that occurred before an injury or trauma Anterograde Amnesia: Forgetting events that follow an injury or trauma Consolidation: Forming a long-term memory Electroconvulsive Shock (ECS): Mild electrical shock passed through the brain, causing a convulsion; one way to prevent consolidation
Amnesia Retrograde Amnesia Loss of past memory Anterograde Amnesia Can’t form new memories Anterograde Amnesia
Figure 7.5 FIGURE 7.5 The tower puzzle. In this puzzle, all the colored disks must be moved to another post, without ever placing a larger disk on a smaller one. Only one disk may be moved at a time, and a disk must always be moved from one post to another (it cannot be held aside). An amnesic patient learned to solve the puzzle in 31 moves, the minimum possible. Even so, each time he began, he protested that he did not remember ever solving the puzzle before and that he did not know how to begin. Evidence like this suggests that skill memory is distinct from fact memory.
ExplicitImplicit Available to conscious retrieval Can be declared (propositional) Examples “What did I eat for breakfast?” (episodic) “What is the capital of Spain?” (semantic) “What did I just say?” (working) Experience-induced change in behaviour Cannot be declared (procedural) Examples Subliminal advertising? (priming) How to ride a bicycle (skills) Phobias (conditioning)
Long-term Memory DeclarativeNon-declarative SemanticEpisodicPrimingProceduralConditioning What did I have for breakfast? What is the capital of France? Facilitated processing Reflex response to new stimuli How to ride a bicycle
Explicit Memory Also known as declarative or conscious memory Properties: memory consciously recalled or declared Can use to directly respond to a question Two subtypes of explicit memory
Episodic Memory Memory tied to your own personal experiences Examples: what did you have for dinner? do you like to eat caramel apples? Why are these explicit memories? Because you can actively declare your answers to these questions
Semantic Memory Memory not tied to personal events General facts and definitions about the world Examples: who was George Washington? what is a cloud? what is the climate at the north pole? These are explicit memories because you can describe what you know about them. Unlike episodic memories, your knowledge does NOT include your personal experience i.e., You may never have been to the north pole but do know about it.
Implicit Memory Also known as nondeclarative memory Influences your thoughts or behavior, but does not enter consciousness Three subtypes
Classical Conditioning Studied earlier Implicit because it is automatically retrieved
Priming Priming is influence of one memory on another priming is implicit because it does not depend on awareness and is automatic Here is a demonstration Unscramble the following words: O R E S L T E P A K T A L S TSME L O B S O M S ELAF
Procedural Memory Memory that enables you to perform specific learned skills or habitual responses Examples: Riding a bike How to speak grammatically Tying your shoe laces Why are these procedural memories implicit? Can’t readily describe their contents try describing how to tie your shoes They are automatically retrieved when appropriate
Procedural Memory Mirror Tracing (e.g. Corkin, 1968) Rotary–Pursuit (e.g. Gabrieli et al., 1997) Serial Reaction Task (e.g. Hazeltine et al., 1997)
Procedural - Neuropsychology Amnesic patients show intact: Rotary Pursuit (Corkin 1968) Serial Reaction Task (Nissen & Bullemer 1987) Alzheimer’s patients show intact: Rotary Pursuit (Gabrieli et al 1993) Mirror Tracing (Heindel et al 1989) Parkinson’s patients impaired on: Rotary Pursuit (Heindel et al 1989) Serial Reaction Task (Ferraro et al 1993) Huntington’s patients impaired on: Rotary Pursuit (Gabrieli et al 1997) Serial Reaction Task (Willingham & Koroshetz 1993) but not: Mirror Tracing (Gabrieli et al 1997) Cerebellar lesions impair Mirror Tracing (Sanes et al 1990)
Procedural - Neuroimaging Rotary Pursuit learning correlates with activity in Primary and Secondary Motor Cortex (Grafton et al 1992) Serial Reaction Task correlates with activity in Primary and Secondary Motor Cortex, and Basal Ganglia (Hazeltine et al 1997) Two hypotheses: 1.Learning repetitive sequence involves Basal Ganglia-Thalamic-Motor Cortical loop Learning new visual-motor mappings involves Cerebellar-Motor Cortical loop 2.Open-loop learning (minimal feedback): Basal Ganglia-Thalamic-Motor Cortical loop Closed-loop learning (continual feedback): Cerebellar-Motor Cortical loop Rotary Pursuit and Serial Reaction Task involve open-loop motor learning with little visual feedback (impaired by Basal Ganglia lesions) Mirror Tracing involves much visual feedback (impaired by Cerebellar lesions) Need to examine nonvisual feedback
• MTL activations during episodic encoding (Tulving et al 1996) and retrieval (Schacter et al. 1996) Anterior-Posterior dissociation? (Lepage et al. 1998; Schacter et al. 1999) • Left Frontal during Encoding (Shallice et al., 1994), right during Retrieval “HERA: Hemispheric Encoding Retrieval Asymmetry” (Tulving et al., 1994) • Posterior cingulate / Precuneus (Fletcher et al., 1996) • Left lateral inferior parietal cortex (Henson et al., 1999) Network of Frontal - Medial Temporal – Posterior areas all involved: Frontal areas control encoding and retrieval of memories? Posterior association areas store components of memories? Medial Temporal regions (temporarily) bind different components? •Finer spatial resolution (fMRI) beginning to dissociate MTL regions, eg Hippocampus / Perirhinal for “Recollection / familiarity”? (Aggleton & Brown, 1999) Episodic Memory - Neuroimaging
• Common activation in Left Inferior Frontal, Inferior Temporal, Angular gyrus and Temporal pole for semantic judgments to words and pictures (Vandenberghe et al 1996) • Left Inferior Temporal activations for animal and tool naming, Temporal Pole for people naming (Damasio et al., 1996) • Left Inferior Temporal activation for category- versus letter-fluency (Mummery et al 1996) • Left Middle Temporal and Premotor activations for tool vs animal naming, Left Middle Occipital for animal vs tool naming (Martin et al 1996) Distributed representations, with activations reflecting object’s interaction with world? E.g., tool naming activates motor regions Semantic Memory - Neuroimaging McClelland and Rogers, 2003
Basic Neuroanatomy of Memory A) Subcortical structures Basal ganglia and cerebellum – Procedural memory. Caudate nucleus involved particularly with habit formation (unconscious learning) Thalamus – Temporal sequencing information. Also supplementary role to medial temporal lobes in new learning Basal forebrain – The binding together of different modal components in episodic memory
B. Cortical structures Hippocampus – Acquisition of new factual knowledge Primary association cortex – Visual, auditory and somatosensory data Non-medial temporal – Retrieval of previously learned material e.g. autobiographical info, names, faces Ventromedial frontal lobes – Memory traces linking facts and emotion Dorsolateral frontal lobes – Recency and frequency memory. Working memory
Memory DeclarativeNon-declarative SemanticEpisodicPrimingProceduralConditioning What did I have for breakfast? What is the capital of France? Facilitated processing Reflex response to new stimuli Medial temporal Diencephalon Mammillary bodies Frontal lobe Lateral Temporal / Frontal lobes Many cortical regions… Cerebellum/ Amygdala (MTL?) How to ride a bicycle Basal Ganglia Cerebellum Motor cortex
Measuring Memory Tip-of-the Tongue (TOT): Feeling that a memory is available but not quite retrievable Feeling of Knowing: Feeling that allows people to predict beforehand if they will be able to remember something (typically seen on game shows like Jeopardy) Recall: Supply or reproduce facts or information with some external cues; direct retrieval of facts or information Hardest to recall items in the middle of a list; known as Serial Position Effect Easiest to remember last items in a list because they are still in STM
Figure 7.7 FIGURE 7.7 The serial position effect. The graph shows the percentage of subjects correctly recalling each item in a 15-item list. Recall is best for the first and last items.
Measuring Memory (cont'd) Recognition Memory: Identifies correctly previously learned material Usually superior to recall Distractors: False items included with a correct item Wrong choices on multiple-choice tests False Positive: False sense of recognition
Figure 7.8 FIGURE 7.8 (a) “Treasure map” similar to the one used by Kosslyn, Ball, and Reiser (1978) to study images in memory. (b) This graph shows how long it took subjects to move a visualized spot various distances on their mental images of the map.
Eidetic Imagery (Somewhat Like Photographic Memory) Occurs when a person (usually a child) has visual images clear enough to be scanned or retained for at least 30 seconds Usually projected onto a “plain” surface, like a blank piece of paper Usually disappears during adolescence and is rare by adulthood
Figure 7.9 FIGURE 7.9 Test picture like that used to identify children with eidetic imagery. To test your eidetic imagery, look at the picture for 30 seconds. Then look at a blank surface and try to “project” the picture on it. If you have good eidetic imagery, you will be able to see the picture in detail. Return now to the text and try to answer the questions there. (Redrawn from an illustration in Lewis Carroll’s Alice’s Adventures in Wonderland.)
Relearning Learning again something that was previously learned Used to measure memory of prior learning Savings Score: Amount of time saved when relearning information
Forgetting Nonsense Syllables: Meaningless three-letter words (fej, quf) that test learning and forgetting Curve of Forgetting: Graph that shows the amount of memorized information remembered after varying lengths of time Encoding Failure: When a memory was never formed in the first place Memory Traces: Physical changes in nerve cells or brain activity that occur when memories are stored Memory Decay: When memory traces become weaker; fading or weakening of memories Disuse: Theory that memory traces weaken when memories are not used or retrieved often
Figure 7.10 FIGURE 7.10 The curve of forgetting. This graph shows the amount remembered (measured by relearning) after varying lengths of time. Notice how rapidly forgetting occurs. The material learned was nonsense syllables. Forgetting curves for meaningful information also show early losses followed by a long gradual decline, but overall, forgetting occurs much more slowly.
Additional Theories of Forgetting Memory Cues: Any stimulus associated with a memory; usually enhance retrieval of a memory A person will forget if cues are missing at retrieval time State-Dependent Learning: When memory retrieval is influenced by body state; if your body state is the same at the time of learning AND the time of retrieval, retrievals will be improved If Robert is drunk and forgets where his car is parked, it will be easier to recall the location if he gets drunk again!
Figure 7.12 FIGURE 7.12 The effect of mood on memory. Subjects best remembered a list of words when their mood during testing was the same as their mood was when they learned the list.
Even More (!) Theories of Forgetting Interference: Tendency for new memories to impair retrieval of older memories, and vice versa Retroactive Interference: Tendency for new memories to interfere with retrieval of old memories Proactive Interference: Prior learning inhibits (interferes) with recall of later learning
Figure 7.13 FIGURE 7.13 The amount of forgetting after a period of sleep or of being awake. Notice that sleep causes less memory loss than activity that occurs while one is awake.
Figure 7.14 FIGURE 7.14 Effects of interference on memory. A graph of the approximate relationship between percentage recalled and number of different word lists memorized. (Adapted from Underwood, 1957.)
Figure 7.15 FIGURE 7.15 Retroactive and proactive interference. The order of learning and testing shows whether interference is retroactive (backward) or proactive (forward).
More on Forgetting Repression: Unconsciously pushing painful, embarrassing or threatening memories out of awareness/consciousness Motivated forgetting, according to some theories Suppression: Consciously putting something painful or threatening out of mind or trying to keep it from entering awareness
Flashbulb Memories Memories created during times of personal tragedy, accident, or other emotionally significant events that are especially vivid Where were you when you heard that the USA was attacked on September 11 th, 2001? Includes both positive and negative events Not always accurate Great confidence is placed in them even though they may be inaccurate
Improve Your Memory Study repeatedly to boost recall Spend more time rehearsing or actively thinking about the material Make material personally meaningful Use mnemonic devices associate with peg words--something already stored chunk information into acronyms Study in spaced intervals
Improve Your Memory Activate retrieval cues--mentally recreate situation and mood Minimize interference Test your own knowledge to rehearse it to determine what you do not yet know
Scientific explanations Dual processing (2 cognitive processes momentarily out of synchrony) Neurological (seizure, disruption in neuronal transmission) Memory (Implicit familiarity of unrecognized stimuli) and attentional (unattended perception followed by attended perception)