1. PSY 445: Learning & Memory Chapter 8: Short-Term Retention

2. Retention over short intervals of time Some History James (1890) Primary Memory Memories that have never left consciousness Secondary Memory Memories that have been absent form consciousness and therefore belong to the psychological past

3. Short-Term Retention Waugh & Norman (1965) Reintroduced the primary-secondary distinction Primary Memory Holds only a few items for only a few seconds; forgetting occurs rapidly if rehearsal is prevented Addition of new items requires displacement of some other item already stored Secondary Memory Information that is available for future recall These researchers proposed the following: The fact that you can recall something immediately after presentation does not mean it has entered secondary memory Recall can come from primary memory, secondary memory, or both

4. Two Memory Stores Atkinson & Shiffrin (1968, 1971) Dual-Store Theory (1968) renamed Modal Model (1971) Renamed because it became the prototype of other theories Short-Term Store (STS) Long-term Store (LTS)

5. Atkinson & Shiffrin’s (1971) Modal Model Sensory Registers Detect sensory input from the various modalities Visual, auditory, haptic, etc. Memories are held for only a few hundred milliseconds Short-Term Store Lasts a few seconds and is made up of: Temporary working memory Control processes: Rehearsal Coding Decisions Retrieval strategies Long-Term Store Permanent memory store

6. Two memory stores are not enough… Baddeley & Hitch (1974) Proposed a model of working memory – a system that supports complex cognitive activities like reasoning instead of just short-term storage

7. STM Tasks Brown-Peterson Distractor Task (Brown, 1958; Peterson & Peterson, 1959) Procedure Read three letters, then a number Begin counting backwards by 3’s Counting backwards prevented the rehearsal of the letters After a set time, recall three letters Results Recall drops dramatically after just a few seconds See next slide 

8. Brown-Peterson Distractor Task 3 sec delay  recall rate 80% 18 sec delay  recall rate 10% Peterson & Peterson (1959)

9. Brown-Peterson Distractor Task Why the quick forgetting? Memory trace vanished because of decay during the passage of time after hearing the letters Closely spaced trials lead to poorer recall; susceptibility to interference Proactive Interference seems to be a problem Cumulative memory seems to be occurring as memory form previous lists may be hampering recall Information learned previously interferes with learning new information: seems to build up across trials

10. Proactive Interference The disruptive effect of prior learning on the recall of new information (old materials increasing the forgetting of new materials) Retroactive Interference The disruptive effect of new information on the recall of previous information (new materials increasing the forgetting of old materials) Types of Interference Time 1 Time 2 Test Interference Study French Study Spanish Recall Spanish Proactive Study French Study Spanish Recall French Retroactive

11. Brown-Peterson Distractor Task Why the quick forgetting? Similarity of items causes additional interference with recall If the words come from the same semantic category, performance declines even more across trials HOWEVER, if after several trials the category of target words is changed, recall increases dramatically: Release From Proactive Interference When previously learned information no longer interferes with new information See next slide 

12. Wickens et al. (1976): Procedures 12

13. Wickens et al. (1976): Results 13 Trial 4: There is a release of Proactive Interference

14. Memory Span  The longest sequence of items that can be recalled after a single presentation  Recall is attempted immediately; no delay or distractors  Typically letters, numbers, or words are used Miller (1956): “The Magic Number” 7 +/- 2 items George Miller (1920-2012) His book

15. Memory Span Conrad (1958) Procedure Asked postal workers to listen to and then recall 7, 8, and 9 digits Results 80% recall with 7 digits 50% recall with 8 digits 25% recall with 9 digits Interpretation Successful replication of Miller’s basic research as average human memory is approximately 5 to 9 items

16. Memory Span: The Word-Length Effect Baddeley, Thomson, & Buchanan (1975) Memory for lists of words is better for short words than for long words It takes longer to rehearse long words and to produce them during recall

17. Characteristics of Verbal Short-Term Retention There are several objective features of STM that distinguishes it form LTM Acoustic Encoding Limited Capacity Limited Duration Susceptibility to Forgetting Transfer to LTM

18. Acoustic Encoding Short-term memory relies primarily on an acoustic rather than semantic or visual code Word are remembered as they sound – as if they were being verbally rehearsed If words are encoded by sound sound-alike substitutions (errors) are likely In serial-recall tasks errors occur when participants substitute letters that sounded like the correct letters (e.g. B for P)

19. Acoustic Encoding Conrad (1964) Showed participants letters on the screen to remember Errors made were close to the letter’s sound, not appearance Example: F was mistaken as S or X, not P 19

20. Limited Capacity Miller (1956) Posited that we could enlarge the “magic number” by increasing the amount of information contained within each item Not absolute digits or letters that you remember but groups (chunks) of things that you remember Chunking Organizing information into meaningful units so that it can better be remembered

21. Chunking Helps Increase Limited Capacity Chase & Simon (1973) Procedure Chess master vs. beginners Memorize chess pieces positioned for a real chess game for 5 seconds Reproduce the arrangement shortly after Garry Kasparov is best known as the world's greatest living chess player 

22. Chunking Helps Increase Limited Capacity Procedure You have 5 seconds to memorize as much as you can Then, draw an empty chess board and reproduce the arrangement of pieces Chase & Simon (1973)

23. Actual GameRandom Game Chase & Simon (1973) Procedure

24. (a) The chess master is better at reproducing actual game positions (b) Master’s performance drops to level of beginner when pieces are arranged randomly Chase & Simon (1973) Results

25. Chunking Helps Increase Limited Capacity Chase & Simon (1973) Results Chess master did much better than novices on actual game board The chess master’s advantage vanished when the board was arranged randomly – familiar patterns were destroyed Interpretation Chess master did not have a superior STM (as some had suggested); rather he had stored many of the patterns that occur in real chess games in LTM He saw the layout of chess pieces not in terms of individual pieces but in terms of 4-6 chunks, each made up of a group of pieces that formed familiar, meaningful patterns The chess master’s advantage vanished when the board was arranged randomly – familiar patterns were destroyed

26. Chunking Helps Increase Limited Capacity Ericcson et al. (1989) College student had an initial digit span of 7 After 230 one-hour training sessions for 2 years, he could remember up to 79 digits How did he do it? By combining the numbers with meaningful sets: 3 4 9 2  record for mile (3 min 49.2 sec) 8 1 1 0  almost emergency (9 1 1) 8 9 3  very old man, 89.3

27. Limited Duration Without maintenance rehearsal, something stays in STM for between 15-30 seconds

28. Forgetting: STM is Sensitive to Disruption Forgetting from STM is believed to be due to spontaneous fading of the memory trace over time or to the displacement of old items by new items Does not take much to disrupt STM See next slide 

29. Forgetting: STM is Sensitive to Disruption Crowder (1972) Procedure Hear list of nine items Final auditory stimulus as cue to recall “Suffix”: zero or buzzer Results Zero-suffix: 50% more errors on last item Interpretation Zero-suffix: Increases list length referred to it as the “suffix effect” Note: Other studies have seen the suffix effect take place among participants with hearing loss who are using sign language

30. Transfer to LTM STM appears to help in the transfer of information into LTM Several multistore theories suggest that retention in STM allows the opportunity for information to be transferred or copied into LTM – much consensus on this

31. Other Modalities of STM Most STM testing in auditory and verbal material Here are some other modalities used to test STM Visual STM Spatial STM STM for Actions STM for Odors STM in the Hearing Impaired

32. Visual STM To study visual STM: Typical Procedure Acquisition Phase Stimuli are presented as short lists of images (pictures, slides, etc.) Images may be meaningless or meaningful Typical Test Phase A test picture is presented and the participant decides whether it was in the previous list

33. Spatial STM To study Spatial STM: Procedure Typical Acquisition Phase Spatial positions illustrated by using computer screen Asterisk is presented in one square at a time (random sequence) Typical Test Phase Participants attempt to point to locations in the same order in which they appeared

34. STM for Actions To study STM for Actions: Procedure Typical Acquisition Phase Movement triplets are presented to participants Varying delays; varying distractors Typical Test Phase Participants attempt to recall in order the actions

35. STM for Odors To study STM for Odors: Procedure Acquisition Phase List of odorants is presented Test Phase Participants attempt to recognize test odorants

36. STM for the Hearing Impaired People sometimes recode from one modality to another Hearing impaired participants are used to test this Procedure Typical Acquisition Phase Hearing participants will be tested using words; hearing- impaired will be tested using signs Typical Test Phase Compare the two groups to determine differences Limitations: varying levels of hearing impairment; amount of training in oral speech; varying degrees of expertise in different types of sign language

37. Working Memory (WM) Refers to the system for temporarily maintaining mental representations that are relevant to the performance of a cognitive task in an activated state More than just a storage system Reading span measures the capacity of working memory when attention must be paid to comprehension of sentences and to remembering a list of words

38. Working Memory: Modern STM Baddeley & Hitch (1974) Updated the STM model Working Memory Limited capacity system for temporary storage and manipulation of information for complex tasks such as comprehension, learning, and reasoning 1. Working memory consists of a number of parts 2. Working memory helps us manipulate information to carry out complex tasks, not just store information 38

39. Models of Working Memory Baddeley & Hitch (1974) Original model proposed a phonological loop and a visual- spatial sketch pad coordinated by a central executive

40. Models of Working Memory Later Baddeley added a fourth component (episodic buffer) The phonological loop stores and rehearses verbal representations whereas the sketch pad does the same for visual/spatial representations. Central executive focuses and switches attention, supervises and coordinates the storage components, and retrieves representations from long-term memory Episodic buffer connects WM to LTM Baddeley (2001)

41. Phonological Loop Brief storage of verbal material Remember: STM primarily uses auditory coding Made of two parts: Storage Passive, holds information Decays in about 2 seconds without rehearsal Rehearsal Active Repeats information in storage to prevent decay 41

42. Visuospatial Sketch Pad Holds visual and spatial information Used in doing anything visual - puzzles, drawings, etc. 42

43. Central Executive Pulls information from LTM and coordinates tasks Uses information from the phonological loop and visuospatial sketchpad Focuses on specific parts of task Switches attention from one part to another 43

44. Episodic Buffer This integrates information across: 1. The phonological and visual stores 2. The operations of the central executive 3. Information entry and retrieval from LTM 44

45. Is there really a separate STM? Neuropsychological Dissociations Studies of individuals with impairment of auditory-verbal STM indicate they have different sites of brain injury than do patients without STM losses Mishkin & Appenzeller (1987) Found that damage to the combined hippocampus and amygdala impaired short-term retention of objects recently shown to a monkey, but did not prevent long-term learning of objects They gave food reward for correct response STM task – monkey could not remember which of two objects had just been shown LTM task – monkey could learn which of two objects was paired with food

46. A Single-Memory Approach? An alternative explanation to the two-store memory theories suggests that we have a single set of memories – but memories can differ between those that are currently active and those that are inactive This idea has not gained acceptance

47. Credits Some of the slides in this presentation prepared with the assistance of the following web sites:  www.csupomona.edu/.../PSY335%20PPTs/Baddeley/BChap3.... www.csupomona.edu/.../PSY335%20PPTs/Baddeley/BChap3