1. Short-Term Memory Kimberley Clow kclow2@uwo.ca http://instruct.uwo.ca/psychology/130/

2. Outline What is Memory? Structure STM vs. LTM Capacity of STM Forgetting Decay vs. Interference Structure of STM

3. What Is Memory? Two different types of memory Short-Term Memory Long-Term Memory Important Terms Structure Encoding Retrieval Forgetting

4. What is the Structure? Atkinson & Shiffrin Modal Model or Multi-Store Model Modal Model or Multi-Store Model

5. What Words? 1. drum 2. curtain 3. bell 4. coffee 5. school 6. parent 7. moon 8. garden 9. hat 10.farmer 11.nose 12. turkey 13. colour 14. house 15. river quite good recall bad recall best recall

6. Serial Position Curve % recalled position of word in list 5 th 10 th 15 th 100 Primacy Effect (quite good recall) Recency Effect (best recall) Asymptote (bad recall)

7. Primacy & Recency IQ Word frequency Delay Distraction Low frequencyLow IQdistracter task10 sec delay

8. Neurological Evidence CW Problems with short-term memory Anterograde amnesia HM Short-term memory was good Problems with long-term memory KF Short-term memory impaired Span of apprehension was 1 item

9. Short-Term Memory What is Short-Term Memory? The information that is in consciousness right now The limited-capacity memory component for temporary information storage and manipulation The mental workplace for retrieval and use of already known information

10. The Magical Number 7 (± 2) “My problem is that I have been persecuted by an integer. For seven years this number has followed me around, has intruded in my most private data, and has assaulted me from the pages of our most public journals. This number assumes a variety of disguises, being sometimes a little larger and sometimes a little smaller than usual, but never changing so much as to be unrecognizable… Either there really is something unusual about the number or else I am suffering from delusions of persecution.”

11. Capacity of STM How can we function on such a small short-term memory capacity? Techniques that aid memory Rehearsal Eases transfer to LTM Mnemonic Devices Strategies for increasing STM capacity

12. Chunking IFYOUGROUPTOGETHERYOUREMEMBERBETTER

13. Which is Easier? CHJ MLK ODW

14. Which is Easier? FBI PHD IBM

15. Which is Easier? AFGHANISTAN VENEZUELA NICARAGUA

16. Which is Easier? CUBA MALTA GREECE

17. Individual Differences Mnemonic Differences Novice vs. Expert

18. What About Forgetting?

19. The Brown-Peterson Task Forget the letters very quickly 70% accuracy after 3 s 10% accuracy after 15 s Concluded that items decay out of short term memory very quickly

20. Decay vs. Interference Two reasons why we may forget things Decay Information fades from memory Not influenced by other information Interference Other information disrupts learning Proactive Interference Retroactive Interference

21. Probe Digit Task

22. Release From PI Probe Digit Task Results due to # of items, not time Interference NOT decay Brown-Peterson results probably due to proactive interference of past trials Is there a way to eliminate proactive interference?

23. Searching STM Sternberg Shown a string of characters (1-6) 53427 Then a single character appears (probe) 7 Was the probe in the string? Measure speed of response depending upon… How many characters were presented The sequential position of the probed character Whether the answer was yes or no

24. 3 Possible Search Patterns

28. What Info Is in Memory? Verbal Confuse E with D (auditory information) Not E with F (visual information) Semantic Release from proactive interference (PI) Changing categories is semantic info Visual Mental rotation tasks

29. Mental Rotation Task Which of the three objects below matches the standard?

30. Baddeley’s Working-Memory

31. Evidence Remember a string of 6 numbers or letters Simultaneously do a reasoning task Shown stimuli like “AB” Then asked a true or false question A precedes B B precedes A B is preceded by A A is preceded by B B does not precede A A does not precede B A is not preceded by B B is not preceded by A

33. Evidence Test for limited resources & visual memory Verbal task or spatial task Verbal response or spatial response Yes No Yes

34. Visual response competes with resources of visuo- spatial sketchpad

35. Summary Short-term memory is limited in capacity Decay vs. Interference Short-term memory is where information is consciously manipulated Rehearse to maintain information temporarily or to transfer to long-term memory Workbench for manipulating current conscious information Short-term memory specializes in verbal and visuo-spatial information