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Chapter 6: Memory Processes. Memory Processes. Encoding Processes. Creating an acoustic code What it sounds like Creating a semantic code What it means Creating a visual code What it looks like. Encoding Types and STM. Type of code may rely on type of task
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Encoding Processes • Creating an acoustic code • What it sounds like • Creating a semantic code • What it means • Creating a visual code • What it looks like
Encoding Types and STM • Type of code may rely on type of task • STM refers to memory that is held temporarily • Evidence exists for a variety of encoding types in STM
Evidence for Acoustic Encoding in STM • Conrad (1964) • Visually present a series of letters briefly • Immediately write the letters viewed once series is complete (Try it - Starts on next click) Write down letters B C F M P S T V
Conrad (1964) • You Viewed B C F M N P N S T V • What errors did you make? • F for S • B for V • P for B • Not visual errors (e.g., E for F, O for Q, R for P) • Thus, items acoustically even though stimuli were presented visually
Shulman (1970) • Evidence for semantic encoding in STM • Participants viewed 10-word lists • Given a recognition test using visually represented "probe words" which were either: • Homonyms - e.g. "bawl" for "ball" • Synonyms - e.g. "talk" for "speak" or • Identical to the original word
Shulman (1970) Results • The Homonym and Synonym probes produced similar error rates - suggesting that an equal amount of acoustic and semantic processing must be taking place • Homonyms - e.g. "bawl" for "ball" • Synonyms - e.g. "talk" for "speak" • Identical to the original word
Posner & Keele (1967) • Evidence for visual encoding in STM • Letter matching task • Two letters separated by brief interval • Participant had to indicate if same letter • A-a Yes • A-A Yes • A-M No • Measure reaction time
Posner & Keele (1967) Results • If letters were the same visually (a-a) participants were faster than if the letters were not the same visually (A-a) • Results indicate that visual code was also present for STM
Encoding Types & LTM • Type of code may rely on type of task • LTM refers to memory that may be held permanently • Evidence exists for a variety of encoding types for LTM
Semantic Encoding in LTM • Grossman & Eagle (1970) • Study 41 different words • Given recognition test after delay • 9 of the distractors were semantically related to words on list • 9 of the distractors were not • False alarms for each type: 1.83 of synonyms, but only 1.05 of unrelated
Visual Encoding in LTM • Frost (1972) • Participants studied 16 drawings • Manipulated visual orientation and semantic category • After a delay, participants were asked if they had studied an object with the same name as the test object • Reaction time was measured • Participants responded faster to identical drawings than drawings in a different orientation • This result indicates visual encoding occurred
Acoustic Encoding in LTM • Evidence of very long-term memory for songs • Rubin (1977) • Participants recall more of the text when provided with the melody of a well-learned song ("Star Spangled Banner") than when given no cue
Transfer from STM to LTM • Consolidation • Integrating new information into stored information • Disruption of consolidation is studied in amnesiacs • ECT patients (Squire)
Metamemory • Knowing what you know • Knowing how your memory works • Being able to assess your own memory • Young children lack metamemory skills
Principles to Strengthen Memory • Elaborative rehearsal is better than maintenance rehearsal • Distributed practice is better than massed practice • “Spacing effect” • Organizing information enhances memory
What causes the spacing effect? • Multiple encoding contexts theory • Multiple study sessions lead to multiple types of encoding, thus more possibility of matching during test conditions • REM Theory • The more REM sessions following study sessions, the more consolidation that occurs
Mnemonic Devices to Aid Memory • Categorical clustering • Interactive images • Pegword system • Method of loci • Acronyms • Acrostics • Keyword system
Which Mnemonic is the Best? • Roediger (1980) [Insert Table 6.2]
Prospective Memory • The ability to remember a future intention • Buying bread on your way home from work • Going to the dentist on Wednesday • Retrospective memory is memory of the past
Retrieval Processes • Getting information back out • Multiple processes can be used to enhance retrieval • Different strategies are used for short term storage and long term storage • Matching the type of processes done during encoding with the type of processes done at retrieval increases success
Retrieval from STM • Is the search serial or parallel? • Serial indicates one by one search • Parallel means all items are processed at once • Is the search exhaustive or self-terminating? • Exhaustive indicates that all items in the set are examined • Self-terminating means that after target is found the search stops
0 Studying Searching in STM • Saul Sternberg (1967) • Memorize a set of numbers (6,3,8,2,7) • Shown a probe digit • Participant must indicate if the probe was in the set • Time to respond is measured 2 6,5,8,2,7 Yes
0 Sternberg (1967) • 3 critical factors manipulated • How many items were in the set the participants had to memorize • Whether the probe was in the list • The probe’s location in the set
Sternberg (1967) • Possible Result Patterns • A represents parallel processing • B illustrates serial processing • C illustrates exhaustive serial processing • D illustrates self-terminating serial processing
Sternberg’s Conclusion • A serial exhaustive model • But…. • Corcoran (1971) proposed that a parallel model could also explain the pattern found • Townsend (1971) stated it was mathematically impossible to distinguish parallel from serial • Thus, both models still exist
Retrieval from LTM • The types of cues you use to retrieve may affect what you can retrieve… • Free recall vs Categorized recall • Study random list or an organized list • What is the impact on memory?
Bower, Clark, Lesgold, and Winzenz (1969) Randomized list Organized list World Europe Americas England Italy USA Canada London Rome Washington Ottowa Liverpool Florence Dallas Montreal Bristol Naples Orlando Winnipeg Naples World Italy Americas Montreal Bristol Washington Ottowa Orlando England Europe Dallas Liverpool Winnipeg Rome USA London Florence Canada
Bower & Associates (1969) • Participants remembered 65% of the organized list, only 19% of the random list • Thus, Organization helps memory retrieval
Chechile (2004) • Manipulated time to retrieve and probablility of retrieval • Little time, fewer words recalled • More time, more words recalled
If You Cannot Retrieve from LTM… • Has the memory disappeared? • Is the memory available but not accessible?
Paired associate List 43-house 67-dog 38-dress 77-sissors Cued recall test 43- ________ 67- ________ Two week delay Subjects recalled 75% of items on list But focus was on 25% they forgot. Evidence Supporting “Still There” Theory Nelson (1971)
Nelson (1971) Critical Manipulation If participants forgot “38-dress” and “77-sissors” then participants relearned either same pairs or changed pairs 78% 43% The better performance of participants in the same condition indicate that there was some memory left for “forgotten” items. Otherwise both groups would remember the same amount.
Theories about Forgetting • Decay theory • Memory is weakened with disuse • Simply passage of time… • Interference theory • Proactive: old memories interfere with recall of new information • Retroactive: new memories interfere with recall of old information
Interference versus Decay in STM • Brown-Peterson Paradigm • Participants were given 3 consonants to try to remember (e.g., FRL) • Participants were then given a 3 digit number (294) & asked to count backwards by threes (e.g., 291, 288, 285) • After varying delays (3-18 seconds) participants were asked to recall the 3 letters
Brown-Peterson results (1959) Trigrams were forgotten by 18 seconds due to retroactive interference of counting backwards
0 Proactive Interference in STM • Keppel & Underwood (1962) • Replicated the Peterson & Peterson Task varying the time delay to recall • Analysis was done by trial number (1st trial, 2nd trial, 3rd trial, etc.) • Found support for proactive interference
0 Retroactive Interference from LTM The experimental group will remember less material from the tested list A compared to the control group Information learned afterwards interferes with retrieval of List A.
Proactive Interference from LTM The experimental group remembers less material from the tested list B than the control group Information previously learned (list A) interferes with retrieval of List B
Let’s Test Your LTM! • You will see several words, one at a time • Do whatever you can to try and remember as many of the words as you can • At the end of the list, try to recall as many words as you can
