Memory

Memory

Book author:

R.H. Ettinger

Chapter 7

Slide authors:

Larry D. Thomas

Landon O. Thomas

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Copyright 2007 Horizon Textbook Publishing

Remembering

 Psychologists think of memory as involving three processes

– Encoding

 Transforming information into a form that can be stored in short-term or long-term memory

– Storage

 The act of maintaining information in memory

 Consolidation

– A physiological change in the brain that must take place for encoded information to be stored in memory

– Retrieval

 The act of bringing to mind material that has been stored in memory

Copyright © 2007 Horizon Textbook Publishing All rights reserved

Remembering

 Atkinson-Shiffrin model

– Consists of three different, interacting memory systems known as sensory, short-term, and longterm memory


Remembering


Remembering



Sensory Memory

– The memory system that holds information coming in through the senses for a period ranging from a fraction of a second to several seconds

– Visual sensory memory lasts just long enough to keep whatever you are viewing from disappearing when you blink your eyes

– Auditory sensory memory lasts about 2 seconds, and is experienced when the last few words someone has spoken seem to echo briefly in your head


Remembering

 Sensory memory (continued)

– George Sperling

 Flashed 12 items of letters to participants

 Signaled the participants to report only the top, middle, or bottom row of items by sounding a high, medium, or low tone

 Found that participants could view the letters for 15/1000 to

½ second, they could report correctly all the items in any row nearly 100% of the time

 But the items fade from sensory memory so quickly that during the time it takes to report three or four of the items, the other eight or nine have already disappeared


Remembering

 Short-term memory

– The second stage of memory, which holds about seven items for less than 30 seconds without rehearsal

– Includes working memory; the mental workspace a person uses to keep in mind tasks being though about at any given moment

– Displacement

 The event that occurs when short-term memory is holding its maximum and each new item entering short-term memory pushes out an existing item


Remembering

 George A. Miller

– Capacity of short-term memory

 Miller’s “Magical Number”

 Capacity is limited to 7 +/- 2 items

– Duration of short-term memory

 items in short-term memory are lost in less than

30 seconds unless you repeat them over and over to yourself

 Developed the technique “chunking”

 Grouping information to make it easier to remember


Remembering

 Rehearsal

– The act of purposely repeating information to maintain it in short-term memory or to transfer it to long-term memory

– Increasing the time in short-term memory makes it more likely the information will be transferred to long-term memory

– An interruption to rehearsal can cause information to be lost in just a few seconds


Remembering

 Short-term memory as working memory

– Allan Baddeley

 Suggested that “working memory” is a more fitting term than short-term memory

– One of the most important working memory processes is the application of memory strategies to information

– Memory strategy involves manipulating information in ways that make it easier to remember

 Elaborative rehearsal

– A technique used to encode information into long-term memory by considering its meaning and associating it with other information already stored in long-term memory


Read this list of words aloud at a rate of about one word per second. Then click the mouse to have the words covered, and write down all the words you can remember. Click the mouse again when you are done writing down all the words you can remember bed awake dream snooze nap snore rest tired wake doze yawn slumber

Now check your list. Did you “remember” the word sleep?

Many people do, even though it is not one of the words on the list

(Deese, 1959)

Remembering

 Long-term memory

– The relatively permanent memory system with a virtually unlimited capacity

– Some experts believe that there a two main subsystems within long-term memory

 Declarative memory

 Nondeclarative memory


Remembering

 Declarative memory

– also called explicit memory

– The subsystem within long-term memory that stores facts, information, and personal life experiences

– Two types of declarative memory

 Episodic memory

– The subpart of declarative memory that contains memories of personally experienced events

 Semantic memory

– The subpart of declarative memory that stores general knowledge; a mental encyclopedia or dictionary


Remembering

 Declarative memory (continued)

– Two types of declarative memory (continued)

 Semantic memory (continued)

– Brain-imaging studies show that the range of activity for semantic memory is larger in the left than in the right hemisphere

– Researchers have demonstrated that some people who have suffered selective damage to their long-term semantic memory can still learn and remember using episodic memory


Remembering

 Nondeclarative memory

– Also called implicit memory

– The subsystem within long-term memory that consists of skills acquired through repetitive practice, habits, and simple classically conditioned responses

– Priming

 The phenomenon by which an earlier encounter with a stimulus increases the speed or accuracy with which that stimulus or a related stimulus can be named at a later time

 Can influence not only performance, but preferences and behavior as well


Remembering

 Levels-of-processing model

– A model of memory as a single system in which retention depends on how deeply information is processed

– Proposed by Craik and Lockhart

– With the shallowest levels of processing, a person is merely aware of the incoming sensory information

– Deeper processing takes place only when the person does something more with the information, such as forming relationships, making associations, attaching meaning to a sensory impression, or engaging in active elaboration on new material


Remembering

 Levels-of-processing model (continued)

– Craik and Tulving

 Tested the levels-of-processing model

 Had participants answer yes or no to questions asked about words just before the words were flashed to them for

1/5 of a second

 Participants had to process the words visually, acoustically, or semantically

 The test required shallow processing for the first question, deeper processing for the second question, and still deeper processing for the third question

 Later retention tests showed that the deeper the level of processing, the higher the accuracy rate of memory


Remembering

 Three kinds of memory tasks

– Recall

– Recognition

– Relearning

 Recall

– A measure of retention that requires a person to remember material with few or no retrieval cues, as in an essay test

– Trying to remember someone’s name, recalling items on a shopping list, memorizing a speech or a poem word for word, and remembering


Remembering

 Which of the following test questions is more difficult?

1. What are the three basic memory processes?

2. Which of the following is NOT one of the three basic memory processes?

A. encoding

B. retrieval

C. storage

D. relearning

 Most people think the second question is easier because it requires only recognition memory


Remembering

 Three kinds of memory tasks (continued)

– Recall (continued)

 May be made a little easier if cues are provided to jog memory

 Sometimes serial recall is required; that is, information must be recalled in a specific order

 In serial recall, each letter, word, or task may serve as a cue for the one that follows

 Research suggests that, in free recall tasks, order associations are more resistant to distractions than meaningful associations


Remembering


– Recognition

 A measure of retention that requires a person to identify material as familiar, or as having been encountered before

 Multiple-choice, matching, and true/false questions are examples of recognition test items

 Main difference between recall and recognition is that a recognition task does not require you to supply the information but only to recognize it when you see it

 Recent brain-imaging studies have discovered that the hippocampus plays an extensive role in memory tasks involving recognition, and the degree of hippocampal activity varies with the exact nature of the task


Remembering


– Relearning

 Measuring retention in terms of the percentage of time or learning trials saved in relearning material compared with the time required to learn it originally; also called the savings method

 Savings score

– The percentage of time or learning trials saved in relearning material over the amount of time or number of learning trials required for the original learning

 College students demonstrate the relearning method each semester when the study for comprehensive final exams


Nature of Remembering

 Memory as a reconstruction

– Elizabeth Loftus

 Believes recal is not an exact replica of an event

 Rather a memory is a reconstruction

 Reconstruction

– A memory that is not an exact replica of an event but has been pieced together from a few highlights, using information that may or may not be accurate



 Sir Frederick Bartlett

– Studied memory using rich and meaningful material learned and remembered under more lifelike conditions

 Gave participants stories to read and drawings to study, and at varying time intervals he had them reproduce the original material

 Accurate reports were rare

 The participants seemed to reconstruct the material they had learned, rather than actually remember it

 Errors in memory increased with elapse of time

 The parts his participants had created were often the very parts that they most adamantly believed to have remembered



 Sir Frederick Bartlett (continued)

– Concluded that people systematically distort the facts and the circumstances of experiences

– Information already stored in long-term memory exerts a strong influence on how people remember new information and experiences



 Schemas and memory

– Schemas

 The integrated frameworks of knowledge and assumptions a person has about people, objects, and events, which affect how the person encodes and recalls information

 Schemas influence what people notice and how they encode and recall information

 When we encounter new information or have a new experience related to an existing schema, we try to make it fit or be consistent with that schema

 To do this, we may have to distort some aspects of the information and ignore or forget other aspects



 Distortion in memory

– Occurs when people alter the memory of an event or an experience in order to fit their beliefs, expectations, logic, or prejudices

– The tendency to distort makes the world more understandable and enables people to organize their experiences into their existing systems of beliefs and expectations

– Bahrick and others

 Found that 89% of college students accurately remember the A’s they earned in high school, but only 29% accurately recalled the D’s





 Eyewitness testimony

– Studies on the accuracy of human memory suggest that eyewitness testimony is highly subject to error

– Research suggests that it is better to have an eyewitness first describe the perpetrator and then search for photos matching that description than to have the eyewitness start by looking through photos and making judgments as to their similarity to the perpetrator

– In lineups, subjects must resemble the suspect in age, body build, and certainly in race



 Eyewitness testimony (continued)

– Some police officers and researchers prefer a “show up”- presenting only one suspect and having the witness indicate whether that person is the perpetrator

– Eyewitnesses are more likely to identify the wrong person if the person’s race is different from their own

– Egeth

 Misidentifications are approximately 15% higher in crossrace than in same-race identifications



 Eyewitness testimony (continued)

– Questioning witnesses after a crime can influence what they later remember

– Misinformation effect

 A phenomenon that happens when misleading information is supplied after an event and causes erroneous recollections of the actual event

– Eyewitnesses who perceive themselves to be more objective have more confidence in their testimony, regardless of its accuracy, and are more likely to include incorrect information in their verbal descriptions



 Recovering repressed memories

– Bass and Davis

 Not only sought to help survivors who remember having suffered sexual abuse; they reached out as well to other people who have no memory of any sexual abuse and tried to help them determine whether they might have been abused

 They suggested that “if you are unable to remember any specific instances . . . but still have a feeling that something abusive happened to you, it probably did”

– Many psychologists are skeptical, claiming that the recovered memories are actually false memories created by the suggestions of therapists



 Recovering repressed memories (continued)

– Loftus

 Believes that “the therapist convinces that patient with no memories that abuse is likely, and the patient obligingly uses reconstructive strategies to generate memories that would support that conviction”

– Many research participants who are instructed to imagine that a fictitious event happened do in fact develop a false memory of the imagined event




– Garry and Loftus

 Were able to implant a false memory of being lost in a shopping mall at 5 years of age in 25% of participants aged

18 to 53, after verification of the fictitious experience by a relative

– Infantile amnesia

 The relative inability of older children and adults to recall event from the first few years of life




– Widom and Morris

 Found that 64% of a group of women who had been sexually abused as children reported no memory of the abuse in a 2-hour interview 20 years later

– Williams

 Found that 38% of women who had documented histories of sexual victimization did not report remember the sexual abuse some 17 years later




– The American Psychological Association, the

American Psychiatric Association, and the American

Medical Association hold the position that current evidence supports the possibility that repressed memories exist as well as that false memories can be constructed in response to suggestion of abuse



 Flashbulb memories: extremely vivid memories

– Flashbulb memory

 An extremely vivid memory of the conditions surrounding one’s first hearing the news of a surprising, shocking, or highly emotional event

– Pillemer

 Argues that flashbulb memories do not constitute a different type of memory altogether

 He suggests that all memories can vary on the dimensions of emotion, consequentiality, and rehearsal



 Flashbulb memories: extremely vivid memories

(continued)

– Neiser and Harsch

 Questioned university freshmen about the Challenger disaster the following morning

 When the same students were questioned again 3 years later, one-third gave accounts that differed markedly from those given initially, even though they were extremely confident of their recollections



 Eidetic imagery

– The ability to retain the image of a visual stimulus several minutes after it has been removed from view

– Some studies show that about 5% of children apparently have something akin to photographic memory

– Children with eidetic imagery generally have not better long-term memory than others their age

– Virtually all children with eidetic imagery lose it before adulthood



 Memory and culture

– Sir Frederick Bartlett

 Believed that some impressive memory abilities operate within a social or cultural context and cannot be understood as a pure process

 Described that amazing ability of the Swazi people of Africa to remember the slight differences in individual characteristics of their cows

 This is less surprising when you consider that the Swazi people tend and depend on the cattle for their living

 He asked young Swazi men and young European men to recall a message consisting of 25 words and neither group had a better ability to recall



 Memory and culture (continued)

– Barbara Rogoff

 Maintains that such phenomenal, prodigious memory feats are best explained and understood in their cultural context

– Some studies where conducted on a tribal group in

India, the Asur to test memory for location

 Researcher hypothesized that members of this group would perform better on tests of memory for location than on conventional tasks used by memory researchers because, without artificial light, they have to remember where things are in order to be able to move around in the dark without bumping into things



 Memory and culture (continued)

– Cognitive psychologists have also found that we more easily remember stories set in our own cultures than those set in others

– In one study, researchers told women in the United

States and Aboriginal women in Australia a story about a sick child

 Participants were randomly assigned to groups for whom story outcomes were varied

 Aboriginal participants better recalled the story with the native healer, while U.S. women were more accurate in their recall of the story in which a physician treated the girl


Factors Influencing Retrieval

 Serial position effect

– The tendency to remember the beginning and ending items of a sequence or list better than the middle items

– Primacy effect

 The tendency to recall the first items on a list more readily than the middle items

– Recency effect

 The tendency to recall the last items on a list more readily than those in the middle of the list



 Environmental context and memory

– Tulving and Thompson

 Suggest the elements of the physical setting in which a person learns information are encoded along with the information and become part of the memory trace

– Godden and Baddeley

 Conducted one of the early studies of context and memory with members of a university diving club

 Participants memorized a list of words when they were either 10 feet underwater or on land

 They were later tested for recall of the words in the same or in a different environment

 Words were better recalled in the environment they were learned




(continued)

– In a study, participants viewed videotapes and then were tested on their memory of the videos in two separate interviews conducted two days apart

– Half the participants were questioned by different interviewers, whereas the other half were questioned by the same interviewer in both sessions

– The participants who were questioned twice by the same interviewer performed better than the other participants on the memory task




(continued)

– Study by Morgan

 Participants were placed in isolated cubicles and exposed to a list of 40 words

 They were instructed to perform a cognitive task using the words but were not asked to remember them

 Experimental participants who experienced a pleasant odor during learning and again when tested 5 days later had significantly higher recall than control participants who did not experience the odor during both learning and recall



 State-dependent effect

– The tendency to recall information better if one is in the same pharmacological or psychological (mood) state as when the information was encoded

– Participants learned (encoded) material while sober or intoxicated, and later where tested in either the sober or intoxicated state

– Recall was found to be best when the participants were in the same state for both learning and testing



 State-dependent effect (continued)

– Evidence does suggest that anxiety and fear influence memory

– Adults who are clinically depressed tend to recall more negative life experiences and are likely to recall their patents as unloving and rejecting

– A meta-analysis of 48 studies revealed a significant relationship between depression and memory impairment


Biology and Memory

 Hippocampus and hippocampal region

– Hippocampal region

 A part of the limbic system, which includes the hippocampus itself and its underlying cortical areas

– Case of H. M.

 A man who suffered from severe epilepsy agreed to a surgical procedure

 The surgeon removed the part of the brain believed to be causing H. M.’s seizures, the medial portions of both temporal lobes-the amygdala and the hippocampal region

 After his surgery, H. M. remained intelligent and psychologically stable, and his seizures were drastically reduced




(continued)

– Case of H. M. (continued)

 But the tissue cut from H. M.’s brain also contained his ability to use working memory to store new information in long-term memory

 H. M. suffers from anterograde amnesia

– The inability to form long-term memories of events occurring after a brain injury or brain surgery, although memories formed before the trauma are usually intact

 Though H. M. could still form nondeclarative memories; that is, he could still acquire skills through repetitive practice although he could not remember having done so




(continued)

– Research has established that the hippocampus is critically important for storing and using mental maps to navigate in the environment

– The observed reorganization of neural circuits in the hippocampus of the London taxi drivers confirms that brain plasticity in response to environmental demands can continue into adulthood



 Neuronal changes in memory

– Eric Kandel and his colleagues

 Provided the first close look at the nature of memory in single neurons

 Traced the effects of learning and memory in sea snail

 Using tiny electrodes implanted in several single neurons in the sea snail, the researchers mapped the neural circuits that are formed and maintained as the animal learns and remembers

 Also discovered the different types of protein synthesis that facilitate short-term and long-term memory

 Kandel won a Nobel Prize in 2000 for his work



 Neuronal changes in memory (continued)

– Donald O. Hebb

 Argued that the necessary neural ingredients for learning and memory must involve the enhancement of transmission at the synapses

– Long-term potentiation (LTP)

 A long-lasting increase in the efficiency of neural transmission at the synapses

 LTP is important because it appears to be the basis for learning and memory at the level of the neurons

 Does not take place unless both the sending and receiving neurons are activated at the same time by intense highfrequency stimulation; the receiving neuron must also be depolarized when the stimulation arrives



 Neuronal changes in memory (continued)

– Davis and others

 Gave rats a drug that blocks certain receptors in sufficient doses to interfere with a maze-running task

 Discovered that LTP in the hippocampus was also disrupted

– Riedel

 Found that LTP is enhanced and memory is improved when a drug that excites those same receptors is administered shortly after maze training



 Hormones and memory

– McGaugh and Cahill

 Suggests that there may be two pathways for forming memories-one for ordinary information and another for memories that are fired by emotion

 When a person is emotionally aroused, the adrenal glands release the hormones adrenalin and noradrenaline into the bloodstream

– Excessive levels of stress hormone cortisol, has been shown to interfere with memory in patients who suffer from diseases of the adrenal glands

– Estrogen, the female sex hormone, appears to improve working memory efficiency


Forgetting

 Ebbinghaus and the first experimental studies on forgetting

– Hermann Ebbinghaus

 Conducted the first experimental studies on learning and memory

 Invented the nonsense syllable

– A consonant-vowel-consonant combination that does not spell a word

 Conducted his studies on memory using 2,300 nonsense syllables as his material and himself as the only participant

 Carried out all his experiments at about the same time of day in the same surroundings

 Memorized lists of nonsense syllables by repeating them over and over at a constant rate of 2.5 syllables per second


Forgetting

 Ebbinghaus and the first experimental studies on forgetting (continued)

– Hermann Ebbinghaus (continued)

 He repeated a list until he could recall it twice without error, a point he called “mastery”

 He recorded the amount of time or the number of trials it took to memorize his lists to mastery

 After different periods of time had passed and forgetting had occurred, he recorded the amount of time or number of trials needed to relearn the same list to mastery

 The percentage of savings represented the percentage of the original learning that remained in memory


Forgetting


Forgetting

 Causes of forgetting

– Encoding failure

 A cause of forgetting resulting from material never having been put into long-term memory

– Decay theory

 A theory of forgetting that holds that the memory trace, if not used, disappears with the passage of time

 Harry Bahrick and others

– Found that after 35 years, participants could recognize

90% of their high school classmates’ names and photographs-the same percentage as for recent graduates


Forgetting

 Causes of forgetting (continued)

– Interference

 Memory loss that occurs because information or associations stored either before or after a given memory hinder the ability to remember it

 Proactive interference

– Occurs when information or experiences already stored in long-term memory hinder the ability to remember newer information

 Retroactive interference

– Happens when new learning interferes with the ability to remember previously learned information


Forgetting


– Consolidation failure

 Any disruption in the consolidation process that prevents a permanent memory from forming

 Retrograde amnesia

– A loss of memory affecting experiences that occurred shortly before a loss of consciousness

 Nader and others

– Demonstrated that conditioned fears in rats can be erased by infusing into the rats’ brains a drug that prevents protein synthesis


Forgetting


– Sigmund Freud

 Motivated forgetting

– Forgetting through suppression or repression in order to protect oneself from material that is too painful, anxiety- or guilt-producing, or otherwise unpleasant

 Repression

– Removing from one’s consciousness disturbing, guiltprovoking, or otherwise unpleasant memories so that one is no longer aware that a painful event occurred


Forgetting


– Amnesia

 A partial or complete loss of memory resulting form brain trauma or psychological trauma

– Prospective forgetting

 Forgetting to carry out some action, such as mailing a letter


Forgetting


– Retrieval failure

 When someone is certain that they know something, but they are not able to retrieve the information when they need it

 Endel Tulving

– Claims that much of what people call forgetting is really an inability to locate the needed information

– Found that participants could recall a large number of items they seemed to have forgotten if he provided retrieval cues to jog their memory


Improving Memory

 How information is organized strongly influences your ability to remember it

 Overlearning

– Practicing or studying material beyond the point where it can be repeated once without error

– Research suggests that people remember material better and longer if they overlearn it

– Krueger

 Showed very substantial long-term gains for participants who engaged in 50% and 100% overlearning



 Spacing study over several different sessions generally is more effective than massed practice

– Massed practice

 Learning in one long practice session as opposed to spacing the learning in shorter practice sessions over an extended period

 Long periods of memorizing make material particularly subject to interference and often result in fatigue and lowered concentration



 Recent research suggests that significant improvement in learning results when spaced study sessions are accompanied by short, frequent tests of the material being studied

 The spacing effect applies to learning motor skills as well as to learning facts and information



 A. I. Gates

– Tested groups of students who spent the same amount of time in study, but who spent different percentages of that time in recitation and rereading

– Participants recalled two to three times more if they increased their recitation time up to 80% and spent only 20% of their study time rereading


Memory - Blinn College

Chapter 7

Sensory Memory

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Sensory Memory

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