memory

PSYCHOLOGYPSYCHOLOGYAN EXPLORATIONAN EXPLORATION

PSYCHOLOGYPSYCHOLOGYAN EXPLORATIONAN EXPLORATION

CHAPTER

Second EditionSecond Edition

Psychology: An Exploration, Second EditionSaundra K. Ciccarelli • J. Noland White

memory

5


why study memory?Without memory, how would we be able to learn anything? The ability to learn is the key to our very survival, and we cannot learn unless we can remember what happened the last time a particular situation arose. Why study forgetting? If we can learn about the ways in which we forget information, we can apply that learning so that forgetting occurs less frequently.


Learning Objectives

• LO 5.1Memory and the three processes of memory• LO 5.2Sensory memory• LO 5.3Short-term or working memory• LO 5.4Long-term memory• LO 5.5Different types of long-term memory• LO 5.6Kinds of cues that help people remember• LO 5.7How recall and recognition differ• LO 5.8How long-term memories are formed• LO 5.9False memory syndrome• LO 5.10Different causes of forgetting• LO 5.11How and where memories are formed in the brain• LO 5.12How does amnesia occur?• LO 5.13What are the facts about Alzheimer’s disease


Memory and Its Processes

• Memory – Active system that receives information

from the senses– Organizes and stores it– Retrieves information from storage

LO 5.1 Memory and the three processes of memory


Memory and Its Processes

• Processes of Memory:– Encoding

Converts sensory information to a form usable in the brain’s storage systems

– Storage Holding onto information for some period

of time

– Retrieval Recalling stored information in a form that

can be used



Models of Memory

• Information-processing model– Information is processed across three

stages– Encoding, storage and retrieval



Models of Memory

• Levels-of-processing model – Information is “deeply processed” – Processed according to meaning rather

than just sound or physical characteristics of words

– How well item is remembered depends on depth remembered



Models of Memory

• Parallel distributed processing (PDP) model– Simultaneous processing, memories

stretched across brain– Able to retrieve many aspects of a

memory at once– Roots in artificial intelligence model



Figure 5.1 Three-Stage Process of MemoryInformation enters through the sensory system, briefly registering in sensory memory. Selective attention filters the information into short-term memory, where it is held while attention (rehearsal) continues. If the information receives enough rehearsal (maintenance or elaborative), it will enter and be stored in long-term memory.


Sensory Memory

• First stage of memory• Information enters nervous system

through sensory systems– Encodes information into neural

messages

LO 5.2 Sensory memory


Sensory Memory

• Two types of sensory memory studied:– Iconic

Visual sensory memory

– Echoic Auditory sensory memory



Iconic Memory

• Visual sensory memory• Lasts only a fraction of a second• Helps visual system view surroundings

continuously– Long enough for brain stem to evaluate

importance



Iconic Memory

• Partial report method (Sperling 1960)– Revealed iconic memory captures

information all at once Masking

– Information is pushed out of iconic memory quickly

– Replaced by new information Eidetic imagery

– Ability to access a visual memory for 30 seconds or more



Figure 5.1 Three-Stage Process of MemoryInformation enters through the sensory system, briefly registering in sensory memory. Selective attention filters the information into short-term memory, where it is held while attention (rehearsal) continues. If the information receives enough rehearsal (maintenance or elaborative), it will enter and be stored in long-term memory.


Figure 5.2 Iconic Memory TestSample grid of letters for Sperling’s test of iconic memory. To determine if the entire grid existed in iconic memory, Sperling sounded a tone associated with each row after the grid’s presentation. Participants were able to recall the letters in the row for which they heard the tone. The graph shows the decrease in the number of letters recalled as the delay in presenting the tone increased.


Echoic Memory

• Brief memory of something just heard• Allows memory to remain long enough

for meaningful conversation– Capacity

Limited to what can be heard at any one moment

Smaller than capacity of iconic memory



Echoic Memory

• Allows memory to remain long enough for meaningful conversation– Duration

Lasts longer than iconic 2 to 4 seconds



Once these piano strings have been attached to the tuning pins, the piano can be tuned. Tuning a piano requires the use of echoic sensory memory. What other occupations might find a good echoic memory to be an asset?


Short-Term Memory

• Memory system in which information is held for brief periods of time while being used– Selective attention

Ability to attend to one stimulus apart from total sensory input

LO 5.3 Short-term or working memory


Short-Term Memory


“Cocktail party effect”– Able to hear own name

mentioned across a noisy room



Short-Term Memory


Two stage process– Stimuli filtered based on

physical characteristics– Processed based on importance



Each person at this gathering is involved in a conversation with others, with dozens of such conversations going on at the same time all around. Yet if a person in another conversation says the name of one of the people in the crowd, that person in the crowd will be able to selectively attend to his or her name. This is known as the “cocktail party effect.”


Short-Term Memory

• Working Memory– Not really short term memory but a

process– Active system that processes information

in short-term memory– Consists of three processes:

Central “executive” - controls other processes

“Sketchpad” - visual “Recorder” - auditory



This woman must hold the phone number she is reading in short-term memory long enough to dial it on the phone next to her.


Short-Term Memory

• Capacity of short term memory is 7+/−2 chunks of information

• Young adults can hold three to five items without strategy to retain information



Short-Term Memory

• Unfamiliar words, information result in further reductions– Digit-span test

Series of numbers is read to subjects Subjects are asked to recall the numbers

in order



Figure 5.3 Digit-Span TestInstructions for the digit-span test: Listen carefully as the instructor reads each string of numbers out loud. As soon as each string is ended (the instructor may say “go”), write down the numbers in the exact order in which they were given.


Short-Term Memory

• Unfamiliar words, information result in further reductions– Chunking

Combining information into meaningful units or chunks

More information can be held in STM



Short-Term Memory

• Maintenance rehearsal – information to be remembered is

repeated over and over mentally– maintains it in short-term memory

STMs tend to be encoded in auditory form



Short-Term Memory

• Duration of STM – 12 to 30 seconds without rehearsal

• STM is susceptible to interference – e.g. if counting is interrupted, count is

lost



It is very important for this pharmacist to count out the number of pills in the prescription accurately. Short-term memory allows her to remember the last number she counted, but if she is interrupted, she will have to start all over again. Short-term memory is very susceptible to interference.


Long-Term Memory

• System of memory into which information is placed to be kept permanently

• Physical change in brain takes place with LTM storage

• Elaborative rehearsal – Information transferred from STM

to LTM by making it meaningful– Deeper processing occurs with LTM

LO 5.4 Long-term memory


These students are rehearsing for a concert. They will use maintenance rehearsal (repeating the musical passages over and over) until they can play their parts perfectly. The movements of their fingers upon the strings of their instruments will be stored in long-term memory. How is this kind of long-term memory different from something like the memorized lines of one’s part in a play?


Types of LTM

• Procedural (nondeclarative) memory – Includes memory for skills, procedures,

habits, and conditioned responses– These memories are not conscious

Implied to exist because they affect conscious behavior

LO 5.5 Different types of long-term memory


Types of LTM

• Declarative memory – Contains information that is conscious

and known– Memory for facts



Procedural (Nondeclarative) LTM

• Includes emotional associations, habits, simple conditioned reflexes – May or may not be in conscious

awareness

• Anterograde amnesia – Damage to hippocampus– New memories cannot be made – Usually does NOT affect procedural LTM



Procedural knowledge, such as tying one’s shoes, often must be learned by doing, as it is difficult to put into words. Once this child learns how to tie shoes, the knowledge will always be there to retrieve.


Procedural (Nondeclarative) LTM

• Implicit memory – Memory not easily brought into

conscious awareness



Figure 5.4 Tower of HanoiThe Tower of Hanoi is a puzzle that is solved in a series of steps by moving one disk at a time. The goal is to move all of the disks from peg A to peg C; the rules are that a larger disk can not be moved on top of a smaller one and a disk can not be moved if there are other disks on top of it. Amnesia patients were able to learn the procedure for solving the puzzle but could not remember that they knew how to solve it.


Declarative LTM

• All the things that people know• Semantic memory

– General knowledge, such as language and information learned in formal education

• Episodic memory – Knowledge of personal information

Not readily available to others Includes daily activities and events



Declarative LTM

• Semantic and episodic memories are forms of explicit memory – Memory that is consciously known



Figure 5.5 Types of Long-Term MemoriesLong-term memory can be divided into declarative memories, which are factual and typically conscious (explicit) memories, and nondeclarative memories, which are skills, habits, and conditioned responses that are typically unconscious (implicit). Declarative memories are further divided into episodic memories (personal experiences) and semantic memories (general knowledge).


LTM Organization

• LTM organized in terms of related meanings and concepts.

• Semantic network model – Model of memory organization– Assumes information is stored in a

connected fashion– Related concepts are stored physically

closer to each other than those not related



Figure 5.6 An Example of a Semantic NetworkIn the semantic network model of memory, concepts that are related in meaning are thought to be stored physically near each other in the brain. In this example, canary and ostrich are stored near the concept node for “bird,” whereas shark and salmon are stored near “fish.” But the fact that a canary is yellow is stored directly with that concept.


Retrieval Cues

• A stimulus for remembering• Encoding specificity

– Retrieval of information is improved If related situation available when the

memory is first formed is available when the memory is being retrieved

– Example: Best room to take a test in is the room

the material was learned in

LO 5.6 Kinds of cues that help people remember


Retrieval Cues

• Encoding specificity – State-dependent learning

Easier to recall memories if in same physiological or psychological state as in when memory was made



When this bride and groom dance together later on in their marriage, they will be able to recall this moment at their wedding and the happiness they felt at that time. State-dependent learning makes it easier for people to recall information stored while in a particular emotional state (such as the happiness of this couple) if the recall occurs in a similar emotional state.


Recall

• Recall – Information to be retrieved must be

“pulled” from memory – Few external cues

• Retrieval failure – Recall has failed temporarily– Tip of the tongue phenomenon



Recall

• Serial position effect – Remember information at the beginning

and end more accurately than information in the middle

– Primacy effect Best remember information at the

beginning of a body of information

– Recency effect Best remember information at the end of

a body of information



These people are waiting to audition for a play. The person who auditioned first and the one who auditioned last have the greatest chance of being remembered when the time comes for the director to choose. The serial position effect will cause the impression made by the actors who come in the “middle” to be less memorable.


Figure 5.8 Serial Position EffectIn the serial position effect, information at the beginning of a list will be recalled at a higher rate than information in the middle of the list (primacy effect), because the beginning information receives more rehearsal and may enter LTM. Information at the end of a list is also retrieved at a higher rate (recency effect), because the end of the list is still in STM, with no information coming after it to interfere with retrieval.


Recognition

• The ability to match information or a stimulus to a stored image or fact

• Usually easier than recall• Tends to be very accurate for images• False positive

– Error of recognition – Recognize a stimulus not actually in

memory

LO 5.7 How recall and recognition differ


Eyewitness Testimony

• Elizabeth Loftus – Memory researcher also trained as a

lawyer– Information provided after event can

affect memory accuracy of initial event– Eyewitness testimony not always

reliable



Dr. Elizabeth Loftus is an internationally known expert on the accuracy of eyewitness testimony. She is often called on to testify in court cases.


Automatic Encoding and Flashbulb Memories

• Automatic encoding – Information enters long-term memory

with little or no effortful encoding

• Flashbulb memories – Automatic encoding – Unexpected event with strong emotional

associations– Emotions enhance formation of

long-term memories



Fans of entertainer Michael Jackson may remember the moment they heard of his death on June 25, 2009. Events like this are so emotional for many people that the memories for the event are stored automatically, as if the mind had taken a “flash” picture of that moment in time. Such “flashbulb” memories seem to be very accurate but are actually no more accurate than any other memory.


Constructive Processing of Memories

• Constructive processing – Retrieval of memories altered, revised,

or influenced by newer information

• Hindsight bias – Memories get revised to reflect new

information – Falsely believe, through revision of older

memories that one correctly predicted the outcome of an event

LO 5.8 How long-term memories are formed


These men may engage in “Monday morning quarterbacking” as they apply hindsight to their memories of this game. Their memories of the game may be altered by information they get afterward from the television, newspapers, or their friends.


Memory Retrieval Problems

• Misinformation effect – Misleading information that becomes

part of memory– Alters memory of the event itself– Even if information is provided in a

different format, it can be incorporated

LO 5.8 How long-term memories are formed


Reliability of Memory Retrieval

• False memory syndrome – Creation of inaccurate or false memories

through the suggestion of others– Often while the person is under hypnosis– False memories are established in the

brain in the same manner as real memories

– False memories must be plausible in order to hold

LO 5.9 False memory syndrome


Forgetting

• Curve of forgetting – Graph with distinct pattern – Forgetting is very fast immediately after

learning – Later tapers off gradually

• Distributed practice – Spacing of material to be remembered

with breaks– Much better recall than mass learning

LO 5.10 Different causes of forgetting


Figure 5.9 Curve of ForgettingEbbinghaus found that his recall of words from his memorized word lists was greatest immediately after learning the list but rapidly decreased within the first hour. After the first hour, forgetting leveled off.


Forgetting

• Encoding failure – Failure to have processed information

into memory– Information does not get past sensory

memory– See penny often but difficult to recall

details



Figure 5.10 Which Penny Is Real?Most people do not really look at the face of a penny. Which of these pennies represents an actual penny? The answer can be found on the next slide.


Figure 5.10 (continued) Which Penny Is Real?Most people do not really look at the face of a penny. Which of these pennies represents an actual penny? The answer is A.


Forgetting: Memory Trace Decay Theory

• Physical change in the brain that occurs when a memory is formed– Decay

Loss of memory Due to the passage of time Memory trace is not used



Forgetting: Memory Trace Decay Theory

• Physical change in the brain that occurs when a memory is formed• Disuse Another name for decay Memories not used will eventually decay

and disappear



The fact that this woman can remember the things shown in the pictures even after many years makes it unlikely that the memory trace decay theory can explain all forgetting in long-term memory.


Forgetting: Interference Theory

• Proactive interference – Older information prevents or interferes

with retrieval of newer information

• Retroactive interference – Newer information prevents or interferes

with the retrieval of older information



Figure 5.11 Proactive and Retroactive InterferenceIf a student were to study for a French exam and then a Spanish exam, interference could occur in two directions. When taking the Spanish exam, the French information studied first may proactively interfere with the learning of the new Spanish information. But when taking the French exam, the more recently studied Spanish information may retroactively interfere with the retrieval of the French information.


Table 5.1 Reasons for Forgetting


Neuroscience of Memory

• Procedural memories seem to be stored in the cerebellum

• PET scans suggest short-term memories are stored in the prefrontal cortex and temporal lobe

• Consolidation– Changes in structure and functioning of

neurons when a memory is formed

LO 5.11 How and where memories are formed in the brain


Amnesia

• Retrograde amnesia – Loss of memory for the past– Memory loss coincides with injury or

illness

LO 5.12 How does Amnesia occur


Amnesia

• Anterograde amnesia – Inability to form new long-term

memories Senile dementia

– Form of anterograde amnesia though retrograde amnesia may also be present

LO 5.12 How does Amnesia occur


Alzheimer’s Disease

• 5.3 million Americans have Alzheimer’s (Alzheimer’s Association, 2010)

• The most common type of dementia – 60 to 80 percent of all cases of

dementia

• Brain forms large number of beta-amyloid protein deposits (plaques)– Strands of protein become twisted

LO 5.13 What are the facts about Alzheimer’s disease


Alzheimer’s Disease

• Risk factors include diabetes, obesity, smoking, high cholesterol

• Treatments slow but do not stop the disease

• Involvement in new learning on daily basis stimulates brain derived neurotropic factors

LO 5.13 What are the facts about Alzheimer’s disease

memory

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