2. Chapter 8: Memory 1

3. Memory - any indication that learning persists over time Involves ability to store and retrieve information Sensory memory - initial recording of information in the memory system Sensory memory - very fleeting, fraction of a second Known as sensory registers. 2

4. Information checks in (registers) in the sensory system, but usually immediately checks out (within a fraction of a second) Sperling - classic experiment Sperling’s experiment - flashed letters on a screen for one-twentieth of a second Subjects - write as many of the letters as they can recall 3

5. 4 K ZR Q BT S GN

6. 5 K ZR Q BT S GN

7. How many could they recall? About 50% Sperling - about to conclude that only 50% of the letters registered in sensory memory However, before doing so he did one other experiment. 6

8. This time after flashing letters he indicated to subjects which row of letters to reproduce He did this by sounding either a high, medium, or low tone immediately after flashing the letters 7 High tone - top line,Medium tone - middle line, Low tone - bottom line

9. 8 K ZR Q BT S GN

10. Could subjects reproduce the row? Remember, subjects were not told which row to remember until after they had seen the letters Results - subjects could almost always reproduce the row which they were asked to reproduce Now what does Sperling conclude? All nine letters registered in sensory memory 9

11. Sperling used the term iconic memory A fleeting photographic memory Goal is to take information from sensory memory and place it in longer term storage Short-term memory - the second level of memory 10

12. Short-Term Memory Capacity of STM: 7  2 (5 - 9) bits of information. Capacity still limited For about 3 - 20 seconds (thus, short-term) Number examples Can we take information from short-term memory and place it in long-term memory? 11

13. Long-Term Memory Relatively permanent Unlimited storage Task - to take information from STM and place it in LTM In order to understand this process, let’s look at encoding. 12

14. Encoding - the processing of information Automatic encoding - encoding that occurs without effort. Example Effortful processing - encoding which requires attention and conscious effort Hermann Ebbinghaus - experiments with nonsense syllables such as JIH, BAZ, YOX, SUJ, LEQ Ebbinghaus made long lists of these syllables, studied them for certain amounts of time, then checked recall. 13

15. Ebbinghaus’s conclusion: The amount remembered depends on... time spent learning Also, spacing effect - distributing or spacing out study or practice time enhances memory Serial position effect - our tendency to recall best the first and last items in a list However, if we are asked to recall the list much later, recall is good for only first items. 14

16. Other Types of Encoding: 1) Visual encoding - the encoding of picture images 2) Acoustic encoding - the encoding of sound, especially the sound of words 3) Semantic encoding - the encoding of meaning Two or more types are better than one An experiment. 15

17. What was the purpose of this experiment? To demonstrate the difference between acoustic and visual encoding Which type of encoding was best for retention purposes? Visual encoding However, semantic encoding, although, not a part of this experiment is usually superior. 16

18. Semantic Encoding Processing information in a meaningful way We do this in at least two ways: 1. Relate information to what we already know 2. Relate information to something about ourselves. This makes it meaningful An experiment. 17

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20. What was the purpose of this demonstration? To show value of semantic encoding Ebbinghaus estimated that compared with learning nonsense material, learning meaningful material only requires one-tenth the effort. 19

21. Wayne Wickelgren (textbook, page 358) states “The time you spend thinking about material you are reading and relating it to previously stored material is about the most useful thing you can do in learning any new subject matter.” Also, this experiment could be a demonstration for chunking Organizing information into manageable units 20

22. What you did - chunk this information into one unit and this unit was something you already knew Example of both chunking and semantic encoding Advertisers - telephone numbers A seven digit number is hard to remember, so make it into a word … 1 - 800 - HOLIDAY. 21

23. Mnemonic Devices Memory aids, especially those that use visual imagery and organizational devices Chunking is an example of a mnemonic Another mnemonic: learning Great Lakes by learning a retrieval cue HOMES 22 H - Huron S E M O - Erie - Superior. - Michigan - Ontario

24. Storing Memories in the Brain Where is memory? In what form is it stored? Lashley’s 1950 experiment with rats Lashley’s conclusion: Memories do not reside in single specific spots More recent research has focused on synaptic changes Sea snail classically conditioned (with electric shock) to reflexively withdraw gills when squirted with water. 23

25. Finding: the snail releases the neurotransmitter serotonin at certain synapses when learning occurs. (seen with powerful microscope) First glimpse of what actually happens in NS when learning occurred These synapses fire together more efficiently when learned response is repeated Long-Term Potentiation - an increase in the firing potential associated with neurons involved in the learning. 24

26. Stress Hormones and Memory Hormones produced when excited or stressed also increase learning and retention Emotion triggered hormonal changes help explain why we long remember exciting or shocking events - a first kiss, an earthquake experience, etc. Point to remember: strong emotional experiences make for strong reliable memories. 25

27. Implicit and Explicit Memories Implicit memory - retention without conscious recollection Explicit memory - memory of facts and experiences that one can consciously know and declare Hippocampus - a limbic system structure that serves as a way station for passing explicit memories to long-term storage. p. 342-343. 26

28. Retrieval: Getting Information Out Retrieval cues - along with learning, store a cue. Example: HOMES Context effects - putting yourself in the context (environment) in which you learned something may enhance recall State dependent memory - things we learn in one emotional state are sometimes more easily recalled when we are again in the same state (state dependent memory). (p. 374) 27

29. Mood congruent memory - tendency to recall experiences that are consistent with one’s current good or bad mood Example: depressed person Retrieval can be an encoding problem Look at the following picture and questions. 28

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32. Failure to correctly answer may be due to encoding failure - you never processed the information Failure to remember may be a failure in our ability to retrieve Example: name of a person. You know it is there, you just can’t retrieve it Perhaps, you need a retrieval cue. 31

33. 32 REVIEW

34. Memory Construction Can you reconstruct memory accurately? Assume you witnessed a bank robbery You would be interviewed about what you could recall How accurate would your memory be? Misinformation effect - incorporating misleading information into one’s memory Example Source amnesia - failure to remember correct source. 33

35. Improving Memory 34