Chapter 8: Memory

Memory: Some Key Terms Memory: Active system that stores, organizes, alters, and recovers (retrieves) information Encoding: Converting information into a useable form Storage: Holding information in memory for later use Retrieval: Taking memories out of storage

Figure 8.4 A hypothetical network of facts about animals shows what is meant by the structure of memory. Small networks of ideas such as this are probably organized into larger and larger units and higher levels of meaning. (Adapted from Collins & Quillian, 1969.) Figure 8.4

Sensory Memory Stores an exact copy of incoming information for a few seconds; the first stage of memory Icon: A fleeting mental image or visual representation Echo: After a sound is heard, a brief continuation of the sensory activity in the auditory system

Short-Term Memory (STM) Holds small amounts of information briefly Working Memory: Part of STM; like a mental “scratchpad” Selective Attention: Focusing (voluntarily) on a selected portion of sensory input (e.g., selective hearing) Phonetically: Storing information by sound; how most things are stored in STM Very sensitive to interruption or interference

Long-Term Memory (LTM) Stores information relatively permanently Stored on basis of meaning and importance

Figure 8. 2 Remembering involves at least three steps Figure 8.2 Remembering involves at least three steps. Incoming information is first held for a second or two by sensory memory. Information selected by attention is then transferred to temporary storage in short-term memory. If new information is not rapidly encoded, or rehearsed, it is forgotten. If it is transferred to long-term memory, it becomes relatively permanent, although retrieving it may be a problem. The preceding is a useful model of memory; it may not be literally true of what happens in the brain (Eysenck & Keane, 1995). Figure 8.2

Figure 8.6 In the model shown here, long-term memory is divided into procedural memory (learned actions and skills) and declarative memory (stored facts). Declarative memories can be either semantic (impersonal knowledge) or episodic (personal experiences associated with specific times and places). Figure 8.6

Short-Term Memory Concepts Digit Span: Test of attention and short-term memory; string of numbers is recalled forward or backward Typically part of intelligence tests Magic Number 7 (Plus or Minus 2): STM is limited to holding seven (plus or minus two) information bits at once Information Bits: Meaningful units of information

More Short-Term Memory Concepts Recoding: Reorganizing or modifying information in STM Information Chunks: Bits of information that are grouped into larger units Maintenance Rehearsal: Repeating information silently to prolong its presence in STM

More Short-Term Memory Concepts Elaborative Rehearsal: Links new information with existing memories and knowledge in LTM Good way to transfer STM information into LTM

Long-Term Memory Concepts Constructive Processing: Updating long-term memories on basis of logic, guessing, or new information Pseudo-Memories: False long-term memories that a person believes are true or accurate Network Model: LTM is organized as a network of linked ideas

Redintegrative Memory Memories that are reconstructed or expanded by starting with one memory and then following chains of association to related memories

Types of Long-Term Memories Procedural: Long-term memories of conditioned responses and learned skills, e.g., driving Declarative: Part of LTM that contains factual information

More Types of Long-Term Memories Semantic Memory: Impersonal facts and everyday knowledge Subset of declarative memory Episodic: Personal experiences linked with specific times and places

Figure 8. 5 The tower puzzle Figure 8.5 The tower puzzle. In this puzzle, all the colored disks must be moved to another post, without ever placing a larger disk on a smaller one. Only one disk may be moved at a time, and a disk must always be moved from one post to another (it cannot be held aside). An amnesic patient learned to solve the puzzle in 31 moves, the minimum possible. Even so, each time he began, he protested that he did not remember ever solving the puzzle before and that he did not know how to begin. Evidence like this suggests that skill memory is distinct from fact memory. Figure 8.5

Measuring Memory Tip-of-the Tongue (TOT): Feeling that a memory is available but not quite retrievable Recall: To supply or reproduce memorized information with a minimum of external cues Hardest to recall items in the middle of a list; known as Serial Position Effect Usually easiest to remember last items in a list because they are still in STM

Figure 8. 7 The serial position effect Figure 8.7 The serial position effect. The graph shows the percentage of subjects correctly recalling each item in a 15-item list. Recall is best for the first and last items. (Data from Craik, 1970.) Figure 8.7

Measuring Memory (cont.) Recognition Memory: Ability to correctly identify previously learned material Usually superior to recall Distractors: False items included with a correct item Wrong choices on multiple-choice tests False Positive: False sense of recognition

Relearning Learning again something that was previously learned Used to measure memory of prior learning

Measuring Memory Concluded Savings Score: Amount of time saved when relearning information Explicit Memory: Past experiences that are consciously brought to mind Implicit Memory: A memory not known to exist; memory that is unconsciously retrieved Priming: When cues are used to activate hidden memories Internal Images: Mental pictures

Eidetic Imagery (Somewhat Like Photographic Memory) Occurs when a person (usually a child) has visual images clear enough to be scanned or retained for at least 30 seconds Usually projected onto a “plain” surface, like a blank piece of paper Usually disappears during adolescence and is rare by adulthood

Figure 8.8 (a) “Treasure map” similar to the one used by Kosslyn, Ball, and Reiser (1978) to study images in memory. (b) This graph shows how long it took subjects to move a visualized spot various distances on their mental images of the map. (See text for explanation.) Figure 8.8

Figure 8.9 Test picture like that used to identify children with eidetic imagery. To test your eidetic imagery, look at the picture for 30 seconds. Then look at a blank surface and try to “project” the picture on it. If you have good eidetic imagery, you will be able to see the picture in detail. Return now to the text and try to answer the questions there. (Redrawn from an illustration in Lewis Carroll’s Alice’s Adventures in Wonderland.) Figure 8.9

Forgetting Nonsense Syllables: Meaningless three-letter words (fej, quf) that test learning and forgetting Curve of Forgetting: Graph that shows amount of information remembered after varying lengths of time Encoding Failure: When a memory was never formed in the first place

More on Forgetting Memory Traces: Physical changes in nerve cells or brain activity that occur when memories are stored Memory Decay: When memory traces become weaker; fading or weakening of memories Disuse: Theory that memory traces weaken when memories are not used or retrieved

Memory Cues Any stimulus associated with a memory; usually enhance retrieval of a memory A person will forget if cues are missing at retrieval time

State-Dependent Learning When memory retrieval is influenced by body state; if your body state is the same at the time of learning AND the time of retrieval, retrievals will be improved If Robert is drunk and forgets where his car is parked, it will be easier to recall the location if he gets drunk again!

Even More Theories of Forgetting Interference: Tendency for new memories to impair retrieval of older memories, and vice versa Retroactive Interference: Tendency for new memories to interfere with retrieval of old memories Proactive Interference: Old memories inhibit (interfere with) recall of new memories

Figure 8. 16 Effects of interference on memory Figure 8.16 Effects of interference on memory. A graph of the approximate relationship between percentage recalled and number of different word lists memorized. (Adapted from Underwood, 1957.) Figure 8.16

Figure 8. 17 Retroactive and proactive interference Figure 8.17 Retroactive and proactive interference. The order of learning and testing shows whether interference is retroactive (backward) or proactive (forward). Figure 8.17

Figure 8. 10 The curve of forgetting Figure 8.10 The curve of forgetting. This graph shows the amount remembered (measured by relearning) after varying lengths of time. Notice how rapidly forgetting occurs. The material learned was nonsense syllables. Forgetting curves for meaningful information also show early losses followed by a long gradual decline, but overall, forgetting occurs much more slowly. (After Ebbinghaus, 1885.) Figure 8.10

More on Forgetting Repression: Unconsciously pushing painful, embarrassing, or threatening memories out of awareness/consciousness Motivated forgetting, according to some theories Suppression: Consciously putting something painful or threatening out of mind or trying to keep it from entering awareness

Flashbulb Memories Memories created during times of personal tragedy, accident, or other emotionally significant events Where were you when you heard that terrorists attacked the USA on September 11th, 2001? Includes both positive and negative events Great confidence is placed in them even though they may be inaccurate

Memory Formation Retrograde Amnesia: Forgetting events that occurred before an injury or trauma Anterograde Amnesia: Forgetting events that follow an injury or trauma Consolidation: Process by which relatively permanent memories are formed in the brain

Memory Structures Hippocampus: Brain structure associated with information passing from short-term memory into long-term memory If damaged, person can no longer “create” long-term memories and thus will always live in the present Memories prior to damage will remain intact Also associated with emotion

Engram Memory trace in the brain

Ways to Improve Memory Knowledge of Results: Feedback allowing you to check your progress Recitation: Summarizing aloud while you are learning Rehearsal: Reviewing information mentally (silently) Selection: Selecting most important concepts to memorize Organization: Organizing difficult items into chunks; a type of reordering

Ways to Improve Memory (cont.) Whole Learning: Studying an entire package of information at once, like a poem Part Learning: Studying subparts of a larger body of information (like text chapters) Progressive Part Learning: Breaking learning task into a series of short sections Serial Position Effect: Making most errors while remembering the middle of the list Overlearning: Studying is continued beyond initial mastery

Figure 8. 14 The effect of mood on memory Figure 8.14 The effect of mood on memory. Subjects best remembered a list of words when their mood during testing was the same as their mood was when they learned the list. (Adapted from Bower, 1981.) Figure 8.14

Figure 8.15 The amount of forgetting after a period of sleep or of being awake. Notice that sleep causes less memory loss than activity that occurs while one is awake. (After Jenkins & Dallenbach, 1924.) Figure 8.15

Ways to Improve Memory Concluded Spaced Practice: Alternating study sessions with brief rest periods Massed Practice: Studying for long periods without rest periods Lack of sleep decreases retention; sleep aids consolidation Hunger decreases retention Cognitive Interview: Technique used to jog memories of eyewitnesses

Figure 8.11 Figure 8.11

Figure 8.12 Figure 8.12

Figure 8.13 Some of the distractor items used in a study of recognition memory and encoding failure. Penny A is correct but was seldom recognized. Pennies G and J were popular wrong answers. (Adapted from Nickerson & Adams, 1979.) Figure 8.13

Mnemonics: Memory “Tricks” Any kind of memory system or aid Using mental pictures Making things meaningful Making information familiar Forming bizarre, unusual, or exaggerated mental associations Keyword Method: Familiar word or image is used to link two other words or items

Using Mnemonics to Remember Things in Order Form a Chain: Remember lists in order, forming an exaggerated association connecting item one to two, and so on Take a Mental Walk: Mentally walk along a familiar path, placing objects or ideas along the path Use a system

Using Mnemonics