Chapter 8

Memory

Learning Objectives

By the end of this chapter, students should be able to:

  1. Define the basic activities of memory and describe two major models of memory.
  2. Describe how information is encoded and transferred among different memory stores, and what we can do to enhance encoding, storage, and retrieval.
  3. Describe how we organize and store information in working and long-term memory, and how we can enhance our long-term memories.
  4. Describe how we retrieve information from memory and how retrieval cues, priming, context, and emotions can affect retrieval.
  5. Summarize theories of why we forget information and sometimes distort or manufacture memories.
  6. Describe how the brain is involved in memory.
  7. Describe the kinds of memories and memory changes that characterize early life and later life.
  8. Describe physical and psychological disorders that disrupt memory.

Lecture Outline

  1. What is Memory?
  2. Memory is the faculty for recalling past events and past learning.
  3. Memory involves three basic processes:
  4. Encoding
  5. Storage
  6. Retrieval
  7. How do we encode, store, and retrieve information?
  8. Information-processing model
  9. Parallel distributed processing model or a constructivist model
  10. Information processing is a stage model that compares memory to operations of a computer. The model consists of three stages:
  11. Sensory memory
  12. Working memory
  13. Long-term memory
  14. The parallel distributed processing or constructivist model holds:
  15. Newly encountered information joins relevant, previously encountered information to form and grow networks of information.
  16. This build upon new knowledge about the biology of memory—that brain neurons form networks of associations as we respond to repeated learning experiences and life events.
  1. How Do We Encode Information Into Memory?

a. Using automatic processing

i. Automatic processing encodes information unconsciously.

ii. Example: encoding the number of stairs you climb up to your front door.

b. Using effortful processing

i. We actively seek to learn information

ii. Example: studying for a psychology exam

c. How do we encode information into working memory?

  1. Automatic or effortful encoding of information requires paying attention.
  2. Our brain stores a brief sensory memory of a new stimulus for seconds.
  3. If we don’t attend to it, like we treat most stimuli, the memory vanishes.
  4. If we pay attention, the memory enters working memory, the second system.
  5. If we then rehearse it, or use other techniques, it enters long-term memory.

d. How do we encode information into long-term memory?

  1. By transferring it from working memory into long-term memory
  2. Long-term memory holds all information we have ever encoded.
  3. Rehearsal moves information both into working and long-term memory.
  4. Long-term memories are solidified by studying and by sleep.

e. In what form is information encoded?

i. We encode information in many ways, depending on type of information.

ii. We use phonological codes if we repeat sound of to-be-remembered names.

iii.Visual codes hold an image of how words would look in written form.

iv. We may remember objects/things as eidetic memory, or like a photograph.

v. Semantic codes employ meaning to store information in long-term memory.

vi. More meaningful information is more readily encoded and remembered.

vii. We may use all codes for a single bit of information or one that makes the

most sense for a particular instance.

viii. Organization enhances encoding.

  1. How Do We Store Memories?
  2. Storage in Working Memory
  3. Working memory has limited duration and a limited capacity of 5-9 items.
  4. “Chunking” bundles smaller bits of information into larger units to enhance the capacity of working memory.
  5. Storage in Long-Term Memory
  6. Unlike working memory, long-term memory is potentially unlimited, but the capacity may differ greatly among different individuals.
  7. Even information successfully stored in long-term memory may disappear.
  8. What types of memories do we store in long-term memory?
  9. Two types of explicit memories or those we consciously bring to mind.
  10. Semantic memories – general knowledge
  11. Episodic memories – memories of your life
  12. Implicit memories we are not consciously aware of, as how to ride a bike.

d. How are long-term memories organized?

i. Information in long-term memory is linked in a network of associations.

  1. How do we retrieve memories?
  2. We know retrieval occurs in several ways.
  3. It may require a “Search” process, where we scan memories for answers.
  4. It may be an “activation” process, where questions to our self activate relevant information and that it spreads to other associated information.
  5. Failure to locate information may mean we are looking in the wrong place.
  6. Retrieval cues—words, sights, stimuli remind us of information we need.
  7. Priming and Retrieval
  8. Priming occurs when we use one bit of information to connect to other associated pieces of information we are looking for.
  9. More retrieval cues we have available enhance our retrieval of memory.
  10. Priming may also occur without conscious awareness.
  11. Context and Retrieval
  12. We may recall information if we return to the location where we encoded it.
  13. We may retrieve implicit memories this same way—something triggers some emotional event that we have encoded.
  14. Emotion and Retrieval
  15. State-dependent memory means we retrieve information better if we are in the same emotional state (happy, sad) as when it was first encoded.
  16. We may think about a particularly good or bad memory over and over making its retrieval easier. We may employ rehearsal, elaboration, and organization to remember it.
  17. Flashbulb memories encode locations and contents of particularly emotional events that were also significant to others, such as where we were when we heard about or saw on television collapse of the World Trade Center towers.
  18. Why Do We Forget and Misremember?
  19. Theories of Forgetting
  20. Decay theory holds that if neglected or unused for a long period of time memories fade away on its own.
  21. Interference theory says due to competition from similar information we forget information.
  22. Proactive interference is when prior learned information interferes with recall of new information. Thus, you can’t remember your new phone number because you keep recalling your old phone number.
  23. Retroactive interference is when newly learned information disrupts retrieval of old information. Thus, you cannot recall your old phone number because your new number interferes with the retrieval.
  24. Motivated forgetting
  25. We may forget information that is painful or upsetting.
  26. Sigmund Freud called this repression, in which our conscious minds hide upsetting information from conscious awareness.

b. Distorted or manufactured memories are due to three common factors:

i. Source misattribution is a failure to recall where we learned information

stored in long-term memory, rendering memories distorted or manufactured.

ii. Misinformation may cause distorted memory, as retroactive interference or new, inaccurate information interferes with memory for an event.

iii. Imagination distorts real memory and lead to misremembered information.

c. The effect of aging on memory

i. Aging makes us susceptible to forgetting, distortions, and misremembering.

ii. The hippocampus begins to shrink in our twenties leading to memory flaws.

  1. Memory: What Happens in the Brain
  2. What Is the Anatomy of Memory?
  3. There is no single place where memories are stored.
  4. Information is encoded across various neurons throughout the brain.
  5. Some brain areas are critical for formation and retrieval of memory.
  6. Prefrontal lobes are active in working memory.
  7. Temporal lobes (including the hippocampus and amygdala) and the diencephalon (including thalamus and hypothalamus) are central in transferring short-term working memories to long-term memories.
  8. What Is the Biochemistry of Memory?
  9. Biochemical, bioelectrical active neurons make up biochemistry of memory.
  10. Neural circuits or networks of neurons are active as we retrieve information.
  11. Neural circuits probably develop through a process of long-term potentiation (LTP), where repeated stimulation of certain neurons greatly increases the likelihood they will respond strongly to the same future stimulation.
  12. Neurons and neural circuits that use the neurotransmitter glutamate are particularly likely to exhibit LTP.
  13. As we acquire new information, proteins are produced in certain brain cells.
  14. Neurotransmitters acetylcholine and glutamate are central to receiving and carrying new information to brain neurons that are tied to the memory.
  15. When Things Go Wrong--Disorders of Memory
  16. Organic Memory Disorders
  17. Brain injury, medical conditions, substance abuse
  18. Head injuries and brain surgery can cause amnesic disorders.
  19. Amnesic disorders
  20. Retrograde amnesia – inability to remember things before an organic disorder or amnesia
  21. Anterograde amnesia – inability to form new memories after onset of a disorder
  22. Dementias involve severe memory problems along with losses in cognitive functions, such as abstract thinking or language.
  23. Alzheimer’s disease often occurs after age 65. It involves abnormal brain changes, mainly neurofibrillary tangles and senile plaques.
  24. Men and women are at-risk for dementia and Alzheimer’s, while older women more often suffer dementia than man.

b. Dissociative Disorders

i. Dissociative disorders are major memory losses lacking physical causes.

1. Dissociative disorders include dissociative amnesia, dissociative

fugue, dissociative identity disorder or multiple personality disorder.

2. Leading explanations for dissociative disorders are state-dependent

learning, hypnosis, and exposure to misinformation.

Lecture Starters and Extensions

1. Memory and Movies. Most students are fond of movies. Talk about how memory and

memory loss operate has always fascinated movie-makers. The opening paragraphs of Chapter 8 describe the plot of a 2000 film Memento (a play on the word “meme,” meaning). The main character has retrograde amnesia: he cannot make new memories. Other memory-related movies include The Bourne Identity (many sequels), a movie about anterograde memories, the inability to remember what happened before a traumatic event; 50 First Dates, who has no short-term working memory (cannot make new memories) and for whom every date, no matter how similar to the last, is new; Eternal Sunshine of the Spotless Mind, whose main characters try to wipe out their memories but can’t erase implicit memories; The Manchurian Candidate (original-remake), which deals with amnesia; The Man Without a Past (anterograde amnesia), and The Truman Show, just to name a handful. You may have your own favorites that you wish to add to the list.

Though movies may not accurately depict cognitive and biological process behind memory (and lack of it), the popularity of the topic is testimony to public fascination with the mystery of human memory. Even movie critics are fascinated by movies about memories. Critiques on memory in the movies include these articles:

"Only in the Movies: Living a Life Unencumbered by Memory" by James Gorman (New York Times, 04/20/04) distinguishes between older generation of amnesia movies, which focuses on retrograde amnesia, and a newer crop, focusing on anterograde amnesia.He argues anterograde amnesia is an implausible premise for a modern plot, because modern people have access to lots of other records of the past besides their own memories -- including newspapers, photographs, and computer disks. Also see articles: "An Accurate Movie About Amnesia? Forget About It" by Richard Perez-Pena (New York Times, 11/02/03) and "The Last Word in Alienation: I Just Don't Remember" by Terrence Rafferty (New York Times, 11/02/03).

2. Eyewitness Misidentification and Wrongful Convictions. Elizabeth Loftus a leader in research on false eyewitness memories often testifies in court as an expert witness on the vagaries of memory. Her work has taught attorneys/judges about the sources of false eyewitness testimony. She has conducted riveting research demonstrating her point (see print resources for articles). Initially, legal experts met her research with skepticism. Now, thanks to changes in law that allow convicts to challenge convictions based on DNA evidence, we are learning many convictions that at one time were based primarily on eyewitness testimony turned out false. This topic is more powerful if you first have the class engage in one or more of the memory demonstrations that show how poor memories are. Imagine, as most eyewitnesses to a crime, they saw something only briefly, and without even paying attention. Their testimony often means the difference between life and death, or life and life in prison for a defendant. See data of the Innocence Project website:

3. Eiditic Memory. Neurologist and author Oliver Sacks has written wonderful stories dealing with extraordinary strengths and deficits in memory and cognition. In his book, The Man Who Mistook His Wife for a Hat (Touchstone, 1998) is about a boy with autism who has a photographic memory for places and buildings. Get a copy of the book and show pictures to the class. Take them outside the classroom and put them in front of a scene (student lounge or library) and have them study it for 15 minutes, then come back into class and “sketch” what they remember. Assure them this is not an artistic test, but a “recall” test of what they just stared at for 15 minutes. Some might be surprised by what they remember. Most believe eidetic memory cannot be “learned.” It is just one of those unexplained phenomena related to the brain. Oliver Sacks has interesting comments on eidetic memory in the case of people with autism and you may wish to share some of his thoughts with the class. Eiditic memory computer games are available for purchase at online sources. See Oliver Sacks, “The Autistic Artist,” New York Review of Books, vol. 32, no. 7 (April 25, 1985) pp. 17-21. Sacks also writes about a painter who remembers, from long ago, landscape of his childhood. In the story, pictures of actual and “remembered” landscape are shown and compared. See also, Sacks’ “A Neurologist's Notebook: The Landscape of His Dreams.” The New Yorker, vol. 68, no. 23 (July 27, 1992) pp. 56-66. This story appears in Sacks, An Anthropologist on Mars. Artist and his pictures are discussed at this website:

Cut-Across Connections

  1. The Biology of Memory and Research: Smoking and Dementia. Evidence shows smoking lessens the chance a person gets Alzheimer’s disease. The connection is related to the neurotransmitter acetylcholine, necessary for making new memories. Acetylcholine-making cells become impaired by plaques and tangles described in the text. Does that mean people should smoke so they don’t get’s Alzheimer’s disease? (Smoking also decreases incidences of Parkinson’s). No. And reasons why is not just severe health ramifications for smoking, but that the research done are retrospective studies, meaning people who have/have not smoked are studied to see if they get dementia or not. This is a good opportunity to connect to Chapter X, relating to research. Discuss why it would be unethical to do a study in which people had to smoke in order to see if chances of Alzheimer’s disease would decrease years later. See: R.Doll, R.Peto, J.Boreham, I.Sutherland (2000). Smoking and dementia in male British doctors: prospective study. British Medical Journal, vol.320, pp.1097-1102.
  1. Memory and DSM Disorders.
  2. One unusual, and hard to understand, memory-related disorders is dissociative fugue. Victims typically leave their homes and go someplace to start an entire new life. They don’t recall who they are, where they are from, or anything about their past lives. Movie-makers like this disorder. The Bourne movies (above discussion on memory and movies) have this disorder at the heart of the plots.
  3. Another hard to understand disorder related to memory is dissociative identity disorder. Formerly multiple personality disorder, it is a disorder in which identity is split in various “selves” or alter-egos. Dissociative identity disorder is not always thought of as a memory disorder. Yet, it is. One theory of how it develops holds the alternative selves exist to escape memories of horrific, repeated childhood abuse. The multiple selves do not remember what the others did, said, nor remember the other “selves.” The memory component of the disorder is best explained in a legal context. Say one “alters” of an individual commits a crime. Other alters may claim rightly that they have no memory of the crime committed. If a criminal defendant claims that he/she is not guilty by reason of insanity, a successful defense will rest on proving to a jury that because a person has no control or memory of what an “alter” did, he/she cannot be held legally responsible for the crime. As you imagine, a defense based on this disorder is a hard sell for judges and juries, one reason is that it is easily faked. Los Angeles “Hillside Stranger” was proven by savvy forensic psychologists to have faked a dissociative disorder by masquerading several “alters” who had no memory of what the other did. See O. van der Hart, H. Bolt, & B. A. van der Kolk, (2005), Memory fragmentation in dissociative identity disorder. Journal of Trauma and Dissociation, 6, 55-70.
  4. Amnesia. Life without memory is impossible for us to imagine. Yet sufferers of retrograde amnesia have no memory of something that happened before a brain injury or traumatic event, while sufferers of anterograde amnesia, because of brain injury or illness, have lost the ability to make new memories. The horror of being unable to make new memories has been chronicled in The Mind video series (Video resources below) that tells the story of Clive Wearing. In Part II of the video, Wearing’s wife explains what it is like to interact with her husband who has lost the ability to make new memories as a result of viral encephalitis.
  5. Memory and Development. Memory is an important topic in developmental psychology. Most think children cannot remember much that happens before about the age of two years, as memory-making areas of the brain are undeveloped. As we suggested, horrible childhood abuse may in rare cases lead to the onset of dissociative identity disorder. As we become older, we may become more forgetful. Some may develop dementia, which impairs memories of the past and impede the ability to make new memories. See Peter Graf and Nobuo Ohta (2002), Lifespan Development of Human Memory. Cambridge, MA: MIT Press
  1. Ecological and Cultural Memories: Self-report, observational and experimental tests.Ask male and female students for written recall of what they believe are their very earliest memories. Compare similarities and differences in the contents of earliest memories for some male and female students. You will find much of the recall has an emotional tone, as well as personalized or self-references. Use responses to show how emotional tone and self-reference influence the strength of memories. Ask students why they believe these are their earliest memories. Ask which variable emotion or self-reference they believe contributed more to recall and why. Use the illustration to introduce problems with self-reports as a measure of memories. In this case, no independent accounts exist to verify the truth of self-reports of the earliest memories. Point out cultural and gender trends in recall of the earliest memories. Ask students what will constitute a valid independent measure of these self-reports of the earliest memories. Further ask them to design an experimental or observational test of the earliest memories. Point out how other methods of investigations differ from self-reported type. The exercise yields interesting and entertaining accounts of recall of personal memories, and may reveals cultural, ethnic, gender and method specific effects on recall of earliest memories.

Classroom Discussions and Activities