Section 1 - The Foundations of Memory
MAIN IDEA QUESTIONS
What is memory?
Are there different kinds of memory?
What are the biological bases of memory?
VOCABULARY
memory - the process by which we encode, store, and retrieve information
sensory memory - The initial, momentary storage of information, lasting only an instant
short-term memory - memory that holds information for 15 to 25 seconds
long-term memory - Memory that stores information on a relatively permanent basis, although it may be difficult to retrieve
chunk - a meaningful grouping of stimuli that can be stored as a unit in short-term memory
rehearsal - the repetition of information that has entered short-term memory
working memory - a set of active, temporary memory stores that actively manipulate and rehearse information
declarative memory - memory for factual information: names, faces, dates, and the like
procedural memory - memory for skills and habits, such as riding a bike or hitting a baseball; sometimes referred to as nondeclarative memory
semantic memory - memory for general knowledge and facts about the world, as well as memory for the rules of logic that are used to deduce other facts
episodic memory - memory for events that occur in a particular time, place, or context
semantic networks - mental representations of clusters of interconnected information
Memory is the process by which we encode, store, and retrieve information. Memory involves 3 stages;
Encoding - the first stage in remembering something in which information is recorded in a form usable to memory
Storage - the maintenance of material saved in memory
Retrieval - material in memory storage is located and brought into awareness to be useful
EX: You are playing a game of trivial pursuit and are posed with the following question to win the game; 'On what body of water is Mumbai located?'
1. You may have never been exposed to information regarding Mumbai's location - or, if you have, it may not have registered in a meaningful way. Either way, this demonstrates the process (or lack thereof) of encoding (registering information).
2. Even if you have been exposed to the information previously and knew the name of the body of water, you may still be unable to retrieve the information because of a failure to retain it. If material is not stored adequately, it cannot be retained later.
3. Material in storage must be located and brought into awareness. Not recalling Mumbai's location may rest on your inability to to retrieve information that you learned earlier.
The three-system memory theory proposes the existence of three separate memory stores; sensory memory, short-term memory, and long-term memory.
SENSORY MEMORY
Sensory memory can store information for only a very short time. If the information does not pass into short-term memory, it is lost for good. EX: Consider the letter test on the projector during class. Sensory memory acts as a snapshot that stores information - which may be of a visual, auditory, or other sensory nature - for a brief moment in time. Representation of information, however brief, is clear and detailed. EX: Consider lightning.
SHORT-TERM MEMORY
The information received in sensory memory is of raw sensory stimuli and is not meaningful to us. If we are to make sense of it and retain it, it must be transferred to the next stage of memory - short-term memory. This is the memory store in which information first has meaning, although the maximum length of retention is short. Unlike sensory memory, this storage has incomplete representational capabilities. Information instead is stored in "chunks." A chunk is a meaningful grouping of stimuli that can be stored as a unit in short-term memory. Chunks can be individual numbers or letters... like the following phone number (226-4610). Chunks may also be of larger categories. EX: The TV stations in the power point.
The specific nature of what constitutes a chunk varies according to one's past experience. EX: Viewing a chess board. Short-term memory is lost after 15 to 25 seconds.
Rehearsal
Rehearsal is the repetition of short-term memory and can allow us to transfer it to long-term memory.
Repetitve rehearsal - EX: Memorizing a phone number which is forgotten after the number has been dialed
Elaborate rehearsal - this occurs when information is considered and organized in some fashion. The organization includes different strategies; expanding the information to make it fit in a logical framework, linking it to another memory, turning it into an image, or transforming it in some way. EX: You are remembering which vegetables you need to purchase at the store;
1. The list could be woven together with the items you use to prepare an elaborate salad
2. The list could be linked to items you bought on an earlier shopping trip
3. You think of an image of a farm with the different vegetables in rows
These organizational strategies are called mnemonics, which are techniques for organizing information in a way that makes it more likely to be remembered.
WORKING MEMORY
Short-term memory is also considered as working memory since it actively rehearses and manipulates information. It is the central processor in reasoning and decision-making. It coordinates material into three stores (or storage units)...
Visual store - visual and spatial material
Verbal store - speech, words, numbers
Episodic buffer - episodes or occurences
~Working memory permits us to keep information in an active state briefly so that we can do something with the information, EX: Solving a math problem or figuring out a tip in a restaurant
~Working memory uses a significant amount of cognitive resources, which can make us less aware of our surroundings. EX: Police situations, driving while on a cell phone, or being stresses during a test
LONG-TERM MEMORY
Information that is transferred to long-term memory enters a storehouse of almost unlimited capacity. The memory is filed and coded so we can retrieve it... just like a hard drive. Similar to working memory, long-term memory contains differing memory modules...
Long-Term Memory Modules
Declarative memory - names, faces, dates, facts, etc. (EX: a bike has two wheels)
Procedural memory - skills and habits (EX: riding a bike, hitting a baseball)
Semantic memory - general knowledge about facts of the world, rules of logic (EX: Zip code for Beverly Hills, location of Mumbai, correct spelling of words) (Semantic memory is like a mental almanac, permitting us to dredge up tens of thousands of facts).
Episodic memory - events that occur in a particular time, place, or context (EX: First kiss, 21st birthday party, when and how you learned 2 X 2 = 4)
Consider the following question... 'how were you doing on Monday afternoon in the second week of August two years ago?' Your episodic memory will be at work and can provide information about events that happened long in the past.
Semantic Networks
The Neuroscience Of Memory
-Memory at the Level of Neurons.
Section 2 - Recalling Long-Term Memories
MAIN IDEA QUESTION
What causes difficulties and failures in remembering?
VOCABULARY
tip-of-the-tongue phenomenon - the inability to recall information that one realizes one knows - a result of difficulty of retrieving information from long-term memory
recall - memory task in which specific information must be retrieved
recognition - memory task in which individuals are presented with a stimulus and asked whether they have been exposed to it in the past or to identify it from a list of alternatives
levels-of-processing theory - the theory of memory that emphasizes the degree to which new material is mentally analyzed
explicit memory - intentional or conscious recollection of information
implicit memory - memories of which people are not consciously aware but that can affect subsequent performance and behavior
priming - a phenomenon in which exposure to a word or concept (called a prime) later makes it easier to recall related information, even when there is no conscious memory of the word or concept
flashbulb memories - memories centered on a specific, important, or surprising event that are so vivid it is as if they represented a snapshot of the event
constructive processes - processes in which memories are influenced by the meaning we give to events
schemas - organized bodies of information stored in memory that bias the way new information is interpreted, stored, and recalled
autobiographical memories - our recollections of circumstances and episodes from our own lives
Trying to remember someone's name - convinced that you know it - but being unable to recall it is known as the tip-of-the-tongue phenomenon, which exemplifies how difficult it can be to retrieve long-term memory.
RETRIEVAL CLUES
The average college student has a vocabulary containing 50,000 words and knows hundreds of mathematical "facts." Simply cataloging all your memories would take years of work. How do we sort through this vast array of material to retrieve information?
~Retrieval cue - a stimulus which allows us to recall more easily information that is in long-term memory. (Smell of a roasting turkey may evoke memories of Thanksgiving).
Retrieval cues help us to recall information. In recall, a specific piece of information must be retrieved. In contrast, recognition occurs when people are presented with a stimulus and are asked whether they have been exposed to it previously or are asked to identify it from a list of alternatives. Recognition is much easier than recall.
(EX: Consider a multiple choice question [recognition] vs. a short answer question [recall]).
LEVELS OF PROCESSING
The levels-of-processing theory emphasizes the degree to which new material is mentally analyzed. This theory suggests that the depth of information processing during exposure to material - meaning the degree to which it is analyzed and considered - is critical; the greater the intensity of the initial processing, the more likely we are to remember it.
Because we do not pay close attention to much of the information to which we are exposed, very little mental processing typically takes place, and we forget new material almost immediately.
The theory suggests that there are considerable differences in the ways in which information is processed at the various levels of memory. At shallow levels, it is processed merely in terms of physical and sensory aspects (EX: the word 'dog'). At the intermediate level, shapes are translated into meaningful units (letters of the alphabet).
At the deepest level of processing, information is analyzed in terms of its meaning. We see it in a wider context and draw associations between the meaning of information and broader networks of knowledge. The deeper level of processing, the greater the likelihood of long-term retention.
EXPLICIT AND IMPLICIT MEMORY
Two forms of long term memory exist; explicit memory and implicit memory.
Explicit - remembering a name or date we have learned about or encountered previously
Implicit - memories which people are not consciously aware of but can affect subsequent performance and behavior (EX: Jumping out of the path of a moving vehicle)
One way to study implicit memory is through priming - a phenomenon in which exposure to a word or concept (called a prime) later makes it easier to recall related information. (EX: Remembering the planet Phobos from a documentary)
FLASHBULB MEMORIES
Memories tied to a specific, important, or surprising event that are so vivid they represent a virtual snapshot. (EX: Where were you on 9/11?) Other examples may include; involvement in a car accident, meeting a roomate for the first time, high school graduation, senior prom, early romantic experience, public speaking, receiving college admissions letter, first date, first airplane flight, or moment you opened SAT scores.
CONSTRUCTIVE PROCESSES IN MEMORY: REBUILDING THE PAST
Memories are processed based on the meaning we give to events. People tend to remember in terms of schemas - organized bodies of information stored in memory that bias the way new information is interpreted, stored, and recalled.
Memory in the Courtroom: The Eyewitness of Trial
In cases where an innocent person is incorrectly identified as the perpetrator, one reason for this mishap is the impact of weapons in crimes. When a perpetrator displays a gun or knife, it acts like a perceptual magnet, attracting the eyes of the witness. Because of this, the witness pays less attention to other details of the crime and are less able to recall what actually occurred.
-Children's Reliability.
-Repressed and False Memories: Separating Truth from Fiction. There is much controversy about repressed memory - recollections of events which are so shocking that the mind responds by pushing them into the unconscious. Some maintain that repressed memories may be inaccurate or wholly false, representing false memory, as a result of people being unable to recall the source of a memory or event about which they have only vague recollections. People become confused about whether they actually experienced the event or it was imagined.
Autobiographical Memory: Where Past Meets Present
These memories encompass the episodic memories we hold about ourselves. We tend to forget information about our past which is incompatible with the way in which we currently see ourselves. Often times in late adulthood, people remember transitional points in their life - such as beginning college or a first job - better than they remember their middle age years.
Section 3 - Forgetting: When Memory Fails
MAIN IDEA QUESTIONS
Why do we forget information?
What are the major memory impairments?
VOCABULARY
decay - the loss of information in memory through its nonuse
interference - the phenomenon by which information in memory disrupts the recall of other information
cue-dependent forgetting - forgetting that occurs when there are insufficient retrieval cues to rekindle information that is in a memory
proactive interference - interference in which information learned earlier disrupts the recall of newer material
retroactive interference - interference in which there is difficulty in the recall of information learned earlier because of later exposure to different material
Alzheimer's disease - an illness characterized in part by severe memory problems
amnesia - memory loss that occurs without other mental difficulties
retrograde amnesia - amnesia in which memory is lost for occurences prior to a certain event
anterograde amnesia - amnesia in which memory is lost for events that follow an injury
Korsakoff's syndrome - a disease that afflicts long-term alcoholics, leaving some abilities intact but including hallucinations and a tendency to repeat the same story
Memory failure is essential to remembering important information. For example, the reason our friends consistently look familiar to us is because we're able to forget their clothing, facial blemishes, and other transient features that change from one occasion to the next... instead our memories are based on a summary of various critical features (a far more economical use of our memory capabilities).
WHY WE FORGET
First, we may not have paid attention to the material - a failure of encoding. But what about material that was encoded? Several processes account for memory failures.
decay - the loss of information through nonuse... memory traces simply fade away over time as new material is learned
interference - information in memory disrupts the recall of other information (EX: Library books)
cue-dependent forgetting - insufficient retrieval cues to rekindle information in memory (EX: Retracing your path when you lose your phone or keys - the 'library' may be your cue to remembering you set them on a desk there.)
PROACTIVE AND RETROACTIVE INTERFERENCE: THE BEFORE AND AFTER OF FORGETTING
There are two parts of interference; proactive and retroactive.
proactive - information learned earlier disrupts the learning of new material (EX: French in 10th, Spanish in 11th)
retroactive - difficulty in the recall of information because of exposure to later material (EX: See above, in reverse)
MEMORY DYSFUNCTIONS: AFFLICTIONS OF FORGETTING
~Alzheimer's Disease is the fourth leading cause of death among adults in the U.S., affecting nearly 5 million people. In the beginning, symptoms appear to be simple forgetfulness of things such as appointments and birthdays... but as the disease progresses, the memory loss becomes more profound. Simple tasks, such as using the telephone are forgotten. Victims can also lose their ability to speak and comprehend language, followed by physical deterioration and then death.
Causes of the disease are not fully understood. Increasing evidence suggests an inherited susceptibility to a defect in the production of the protein beta amyloid - necessary for the maintenance of nerve cell connections. When the synthesis of this protein goes awry, large clumps of cells form, triggering inflammation and the deterioration of nerve cells in the brain.
~Amnesia - memory loss which occurs without other mental difficulties
~Retrograde amnesia - memory is lost for occurences prior to a certain event (EX: A football player receives a blow to the head and can't remember anything prior to)... lost memories often gradually reappear, although full restoration can take years.
~Anterograde amnesia - Loss of memory for events following an injury (EX: See above, in reverse)
~Amnesia is a result of Korsakoff's syndrome - a disease afflciting long-term alcoholics which can create memory loss, hallucinations, and a tendency to repeat the same story over and over