MemoryMemory

Memory ModelsMemory Models

Memory—An internal record or representation of Memory—An internal record or representation of some prior event or experience.some prior event or experience.

Three-stage model—humans need to store Three-stage model—humans need to store information for different lengths of time—sensory information for different lengths of time—sensory memory, short-term memory, long-term memorymemory, short-term memory, long-term memory

Encoding, storage and retrieval—(computer Encoding, storage and retrieval—(computer model) memory is a process of encoding, model) memory is a process of encoding, storage and retrievalstorage and retrieval

Biological Approach—memory is explained by Biological Approach—memory is explained by looking at biological changes in synapseslooking at biological changes in synapses

Three-Stage Memory ModelThree-Stage Memory Model

Sensory Memory—First memory stage Sensory Memory—First memory stage that holds sensory information; relatively that holds sensory information; relatively large capacity, but duration is only a few large capacity, but duration is only a few secondsseconds Retains a relatively exact image of sensory Retains a relatively exact image of sensory

experienceexperience (think of your “shopping cart”)(think of your “shopping cart”)

Three-Stage Memory ModelThree-Stage Memory Model Short-term memory—Second memory Short-term memory—Second memory

stage that temporarily stores sensory stage that temporarily stores sensory information and decides whether to send it information and decides whether to send it on to long-term memory; capacity limited on to long-term memory; capacity limited to 5-9 items and duration is about 30 to 5-9 items and duration is about 30 seconds (think “cupboard or closet”)seconds (think “cupboard or closet”) Maintenance rehearsal—repeating Maintenance rehearsal—repeating

information over and over to maintain it in information over and over to maintain it in STMSTM

Chunking—grouping pieces of information to Chunking—grouping pieces of information to form a single unit (or chunk)form a single unit (or chunk)

Short-term memoryShort-term memory

Visuospatial sketchpad—holds and Visuospatial sketchpad—holds and manipulates visual images and spatial manipulates visual images and spatial informationinformation

Phonological rehearsal loop—holds and Phonological rehearsal loop—holds and manipulates verbal informationmanipulates verbal information

Central executive—supervises and Central executive—supervises and coordinates the other two components as coordinates the other two components as well as retrieval from LTM.well as retrieval from LTM.

Long-Term MemoryLong-Term Memory

Third stage of memory that stores Third stage of memory that stores information for long periods of time’ its information for long periods of time’ its capacity is virtually limitless and its capacity is virtually limitless and its duration is relatively permanent duration is relatively permanent

(think “those boxes of important purchases (think “those boxes of important purchases that are in your attic”)that are in your attic”)

Encoding, Storage and Retrieval Encoding, Storage and Retrieval ModelModel

Memory is like a computer (or computers Memory is like a computer (or computers are modeled after our memory)are modeled after our memory)

Information is Information is EncodedEncoded, that is it is , that is it is translated into neural codestranslated into neural codes

Neurally coded information is retained Neurally coded information is retained over time (over time (storage)storage)

Information stored in memory can be Information stored in memory can be recovered (recovered (retrieval)retrieval)

A problem and solutionA problem and solution

Unlike computers which store and retrieve Unlike computers which store and retrieve information sequentially or linearly, the information sequentially or linearly, the brain stores and retrieves information brain stores and retrieves information simultaneously through multiple networkssimultaneously through multiple networks

Parallel Distributed Processing (PDP)Parallel Distributed Processing (PDP)——Memory results from connections among Memory results from connections among interacting processing units, distributed in interacting processing units, distributed in a vast network and all operating parallela vast network and all operating parallel

Integrating the two modelsIntegrating the two models

Stimulus

Sensory Memory Storage

Short Term Memory Storage

Long Term Memory Storage

Encoding

Encoding

Retrieval

Integrating EncodingIntegrating Encoding Organization—information is organized to Organization—information is organized to

aid in its encoding. STM may use aid in its encoding. STM may use chunking whereas LTM may use chunking whereas LTM may use hierarchies (arranging items into broad hierarchies (arranging items into broad categories that are further divided and categories that are further divided and subdivided)subdivided)

Rehearsal—in STM, maintenance Rehearsal—in STM, maintenance rehearsal is used. In LTM, rehearsal is used. In LTM, elaborative elaborative rehearsalrehearsal Linking new information to previously stored Linking new information to previously stored

materialmaterial

Elaborative rehearsal techniquesElaborative rehearsal techniques

Create a personal exampleCreate a personal example Expand or elaborate on the informationExpand or elaborate on the information Actively explore and question new Actively explore and question new

informationinformation Try to find meaningfulnessTry to find meaningfulness

Integrating StorageIntegrating Storage Explicit/Declarative Memory—Subsystem Explicit/Declarative Memory—Subsystem

within long-term memory that consciously within long-term memory that consciously stores facts, information and personal life stores facts, information and personal life experiences.experiences. Semantic Memory—a part of explicit/ Semantic Memory—a part of explicit/

declarative memory that stores general declarative memory that stores general knowledge; a mental encyclopedia or knowledge; a mental encyclopedia or dictionarydictionary

Episodic Memory—a part of explicit/ Episodic Memory—a part of explicit/ declarative memory that stores memories of declarative memory that stores memories of personally experienced events; a mental diary personally experienced events; a mental diary of a person’s life.of a person’s life.

Integrating StorageIntegrating Storage Implicit/nondeclarative Memory—Implicit/nondeclarative Memory—

Subsystem within LTM that consists of Subsystem within LTM that consists of unconscious procedural skills, simple unconscious procedural skills, simple classically conditioned responses and classically conditioned responses and primingpriming Priming—prior exposure to a stimulus (or Priming—prior exposure to a stimulus (or

prime) facilitates or inhibits the processing of prime) facilitates or inhibits the processing of new information, even when one has no new information, even when one has no conscious memory of the initial learning or conscious memory of the initial learning or storagestorage

Integrating RetrievalIntegrating Retrieval

Retrieval Cue—a clue or prompt that helps Retrieval Cue—a clue or prompt that helps stimulate recall and retrieval of a stored stimulate recall and retrieval of a stored piece of information from LTMpiece of information from LTM Recognition—retrieving a memory using a Recognition—retrieving a memory using a

specific cue (i.e., multiple choice and specific cue (i.e., multiple choice and matching exam questions)matching exam questions)

Recall—retrieving a memory using a general Recall—retrieving a memory using a general cue (i.e., f-i-b, short answer and essay exam cue (i.e., f-i-b, short answer and essay exam questions)questions)

Encoding Specificity PrincipleEncoding Specificity Principle

Retrieval of information is improved when Retrieval of information is improved when conditions of recovery are similar to the conditions of recovery are similar to the conditions when the information was conditions when the information was encodedencoded Context and retrievalContext and retrieval Mood congruenceMood congruence State-dependent retrievalState-dependent retrieval

Biological PerspectiveBiological Perspective

Neuronal and Synaptic ChangesNeuronal and Synaptic Changes Long-Term Potentiation (LTP)—long-lasting Long-Term Potentiation (LTP)—long-lasting

increase in excitability believed to be a biological increase in excitability believed to be a biological mechanism for learning and memorymechanism for learning and memory

Hebb’s Law—If neuron Hebb’s Law—If neuron ii is near enough to excite is near enough to excite neuron neuron jj and repeatedly participates in its and repeatedly participates in its activation, the synaptic connection between activation, the synaptic connection between these two neurons is strengthened and neuron these two neurons is strengthened and neuron jj becomes more sensitive to stimuli from neuron becomes more sensitive to stimuli from neuron ii..

Hebb’s Law in Plain LanguageHebb’s Law in Plain Language

Neurons that fire together get wired Neurons that fire together get wired together.together.

On a neurological level, memory is On a neurological level, memory is demonstrated through the sensitivity of demonstrated through the sensitivity of one neuron to another and the formation one neuron to another and the formation of neural pathways in the brain.of neural pathways in the brain.

Biological PerspectiveBiological Perspective

Hormonal ChangesHormonal Changes Hormones such as epinephrine and cortisol Hormones such as epinephrine and cortisol

increase the encoding and storage of increase the encoding and storage of memoriesmemories

Flashbulb memories—vivid images of Flashbulb memories—vivid images of circumstances associated with surprising or circumstances associated with surprising or strongly emotional events.strongly emotional events.

Memory FailuresMemory Failures

Serial position effect—remembering Serial position effect—remembering information at the beginning and the end information at the beginning and the end of a list better than material in the middle.of a list better than material in the middle.

Spacing of practiceSpacing of practice Distributed practice—practice (or study) Distributed practice—practice (or study)

sessions are interspersed with rest periodssessions are interspersed with rest periods Massed practice—time spent learning is Massed practice—time spent learning is

grouped (or massed) into long, unbroken grouped (or massed) into long, unbroken intervals (a.k.a., cramming)intervals (a.k.a., cramming)

Theories of ForgettingTheories of Forgetting Decay theory—(Hebb’s law in reverse) like Decay theory—(Hebb’s law in reverse) like

all biological processes, memory degrades all biological processes, memory degrades over time.over time.

Interference theory—one memory Interference theory—one memory competes with or tries to replace another competes with or tries to replace another memorymemory Retroactive—new information interferes with Retroactive—new information interferes with

remembering old informationremembering old information Proactive—old information interferes with Proactive—old information interferes with

remembering new information.remembering new information.

Theories of ForgettingTheories of Forgetting

Motivated Forgetting Theory—we may Motivated Forgetting Theory—we may have reasons to try to forget, such as have reasons to try to forget, such as unpleasant or anxiety-producing memoriesunpleasant or anxiety-producing memories Suppression—consciously trying to forgetSuppression—consciously trying to forget Repression—unconsciously forgetting Repression—unconsciously forgetting

anxiety-producing memoriesanxiety-producing memories Encoding Failure—during encoding, we Encoding Failure—during encoding, we

decided that the information was not worth decided that the information was not worth remembering, so, it did not get encodedremembering, so, it did not get encoded

Theories of ForgettingTheories of Forgetting Retrieval Failure Theory—(cue-dependent Retrieval Failure Theory—(cue-dependent

theory) memories are not forgotten but are theory) memories are not forgotten but are momentarily inaccessible due to momentarily inaccessible due to interference, faulty cues, emotional states, interference, faulty cues, emotional states, etc.etc.

Tip-of-the-Tongue Phenomenon—a Tip-of-the-Tongue Phenomenon—a retrieval failure that involves a sensation of retrieval failure that involves a sensation of knowing that specific information is stored knowing that specific information is stored in long-term memory but of being in long-term memory but of being temporarily unable to retrieve it.temporarily unable to retrieve it.

Organic Causes for Memory Organic Causes for Memory ProblemsProblems

Brain InjuryBrain Injury Retrograde Amnesia—Loss of memory for Retrograde Amnesia—Loss of memory for

events before an injury; backward-acting events before an injury; backward-acting amnesiaamnesia

Anterograde Amnesia—Inability to form new Anterograde Amnesia—Inability to form new memories after and injury; forward-acting memories after and injury; forward-acting amnesiaamnesia

Organic Causes for Memory Organic Causes for Memory ProblemsProblems

Alzheimer’s Disease—Progressive mental Alzheimer’s Disease—Progressive mental deterioration characterized by sever deterioration characterized by sever memory lossmemory loss

External Causes for Memory External Causes for Memory ProblemsProblems

Since memory is a Since memory is a Constructive ProcessConstructive Process problems may be created within the problems may be created within the processes of encoding and retrievalprocesses of encoding and retrieval Constructive ProcessConstructive Process—Organizing and —Organizing and

shaping of information during encoding and shaping of information during encoding and retrieval that may cause memory errors and retrieval that may cause memory errors and distortionsdistortions

External Causes for Memory External Causes for Memory ProblemsProblems

Source Amnesia—attributing to a wrong Source Amnesia—attributing to a wrong source an event that we have source an event that we have experienced, heard about, read about or experienced, heard about, read about or imagined.imagined.

Sleeper Effect—Tendency to initially Sleeper Effect—Tendency to initially discount information from an unreliable discount information from an unreliable source, but later consider it more source, but later consider it more trustworthy because the source is trustworthy because the source is forgottenforgotten

External Causes for Memory External Causes for Memory ProblemsProblems

Eyewitness testimonyEyewitness testimony Repressed/Recovered Memory DebateRepressed/Recovered Memory Debate

Improving Memory—Helpful TipsImproving Memory—Helpful Tips

Pay attention and reduce interferencePay attention and reduce interference Use rehearsal techniques (maintenance and Use rehearsal techniques (maintenance and

elaborative)elaborative) Improve your organization (chunking, Improve your organization (chunking,

hierarchies)hierarchies) Counteract the serial position effectCounteract the serial position effect Manage your time (distributed vs. massed Manage your time (distributed vs. massed

practice)practice) Use the encoding specificity principleUse the encoding specificity principle Employ self-monitoring and overlearningEmploy self-monitoring and overlearning

Mnemonic DevicesMnemonic Devices

Mnemonic (from the Greek for “memory”)Mnemonic (from the Greek for “memory”)—memory-improvement technique based —memory-improvement technique based on encoding items in a special wayon encoding items in a special way Method of loci—imagining the different pieces Method of loci—imagining the different pieces

of information as rooms within a houseof information as rooms within a house Peg-word—rhyming words with position on a Peg-word—rhyming words with position on a

list (one in a bun, etc.)list (one in a bun, etc.) Substitute word—i.e., occipital—ox sip it allSubstitute word—i.e., occipital—ox sip it all Word associations—i.e., Roy G. Biv, etc.Word associations—i.e., Roy G. Biv, etc.

Seven Sins of MemorySeven Sins of Memory Sins of forgettingSins of forgetting

Transcience—information not used is lostTranscience—information not used is lost Absentmindedness—lack of attention during encodingAbsentmindedness—lack of attention during encoding Blocking—retrieval process is unable to happenBlocking—retrieval process is unable to happen

Sins of DistortionSins of Distortion Misattribution—incorrectly identifying the time, place, Misattribution—incorrectly identifying the time, place,

or person related to memoryor person related to memory Suggestibility—incorporating information suggested Suggestibility—incorporating information suggested

by someone else into our memoryby someone else into our memory Bias—current knowledge or needs distort memory of Bias—current knowledge or needs distort memory of

pastpast Sin of Persistence—traumatic or emotional Sin of Persistence—traumatic or emotional

events may cause memories to persist even events may cause memories to persist even when we would like to forgetwhen we would like to forget