Overview of Memory

1. Overview of Memory • Atkinson-Shiffrin Model RETRIEVAL ATTENTION Sensory Memory Short-Term Memory Long-Term Memory Sensory Signals REHEARSAL

2. “Types” of Memory • Sensory Memory • brief ( < 1 second) • preattentive / parallel processing (very large capacity)

3. Sensory Memory

4. Capacity • Describe a simple experiment that could measure the capacity of “memory”

5. Capacity • Describe a simple experiment that could measure the capacity of “memory” • Briefly present some letters or digits and then ask the subject to report them • Called “whole report”

6. Capacity F S F E G S A U T O C G

7. Capacity “Recall as many letters as you can”

8. Capacity • George Sperling - Systematic investigation of memory capacity • Result: subjects accurately recall 3 or 4 items • What can you conclude from this result?

9. Capacity • What if subjects forget as they are recalling?

10. Capacity • What if subjects forget as they are recalling? • How could you modify the experiment to measure the instantaneous capacity, before any forgetting can occur?

11. Capacity • Partial Report - briefly present letters or digits and ask subject to report only some of them “Report the letters in the row indicated by the arrow”

12. Capacity U E S B O D W A I B V S

13. Capacity

14. Capacity Which Letters?

15. Capacity • Partial Report • Result: subjects can recall any 3 or 4 letters that are indicated by the arrow !

16. Capacity • Partial Report • Result: subjects can recall any 3 or 4 letters that are indicated by the arrow ! • What does this mean about the capacity of memory?

17. Capacity • There is some part of the perception system that stores huge amounts of information…

18. Duration • But for how long? How would you design an experiment to measure the duration of this high-capacity memory system?

19. Duration • But for how long? How would you design an experiment to measure the duration of this high-capacity memory system? • Vary the onset of the probe

20. Duration • Partial Report 10 # of letters potentially recalled 4 0 0 ms 500 ms never Probe Delay

21. Duration • Partial Report 10 # of letters potentially recalled 4 0 0 ms 500 ms never Delay Interpretation: Information dwells in a brief storage “buffer” duration of storage lasts about 1/2 of one second

22. Iconic Memory • a brief storage of “raw data” in the visual system

23. Echoic Memory • Auditory information is stored in a similar sensory “buffer” • Echoic memory seems to last for several seconds

24. Properties of Sensory Memory • Brief (iconic ~500ms; echoic ~2 seconds)

25. Properties of Sensory Memory • Brief (iconic ~500ms; echoic ~2 seconds) • unlimited capacity

26. Properties of Sensory Memory • Brief (iconic ~500ms; echoic ~2 seconds) • unlimited capacity • pre-attentive

27. Next Time: • Short-term memory