Chapter 7 – Forgetting

1. Unit 3 – Area of Study 2: Memory Pages 361-391 Chapter 7 – Forgetting

2. Study Design Content • strengths and limitations of psychological theories of forgetting: – retrieval failure theory including tip-of-the-tongue phenomenon – interference theory – motivated forgetting as informed by the work of Sigmund Freud including repression and suppression – decay theory • manipulation and improvement of memory: – forgetting curve as informed by the work of Hermann Ebbinghaus – measures of retention including the relative sensitivity of recall, recognition and relearning

3. Forgetting • Forgetting refers to the inability to retrieve previously stored information. • When you forget something it means that it is unavailable to you at the time you are trying to remember it, not that it is gone forever. • The information may be stored in your memory but for some reason you cannot retrieve it when you want to.

4. The Forgetting Curve • A forgetting curve shows the pattern (rate and amount) of forgetting that occurs over time. • Generally this curve shows that forgetting is rapid at first, then the rate of memory loss gradually declines as time passes. • More than half of the memory loss occurs within the first hour after learning.

5. The Forgetting Curve • You can see that over half of what is learnt is forgotten in the first hour • Most of what we forget (about 65% ) is lost in the first 8 hours

6. The Forgetting Curve • Virtually all the material that will be forgotten is lost in the first hour, but memory loss, although slow, still continues after the initial forgetting. • The pattern for forgetting tends to occur for a wide variety of materials under many conditions. • However, the more meaningful the material, the slower the rate of forgetting.

7. The Forgetting Curve • The amount and rate of forgetting are also influenced by the strength of the original learning – the better the original learning, the longer the material is likely to be retained. • Furthermore, when material is well learned, the rate of retention is about the same regardless the degree of difficulty of the material and the learning ability of the individual. • Learning Activity 7.1– Review Questions, pg. 363 • Box 7.1 – How Good is Your Memory, pg. 364

8. Measure of Retention: recall, recognition & relearning • How can you find out whether information has been retained in memory? • One way is to simply ask for its retrieval. • How many of the seven dwarfs can you name? • In order to correctly answer this you need to search through your LTM store and locate the information you require.

9. Measure of Retention: recall, recognition & relearning • This approach to measuring the amount of information retained in memory (measure of retention) involves a test of recall. • The recall method involves being asked to reproduce information with the fewest possible prompts or cues to aid retrieval. • Free recall is involved when participants are asked to remember as much as they can, in no particular order.

10. Measure of Retention: recall, recognition & relearning • If participants were asked to recall a list of words in the order in which it was presented, psychologists would be asking for serial recall. • Cued recall makes use of various cues to aid retrieval. • For example a cue to recall the names of the 7 dwarfs may be B, D, D, G, H, S & S.

11. Measure of Retention: recall, recognition & relearning • The recognition method involves identifying the correct information from among alternatives, such as a multiple choice question. • Generally we can retrieve more information when tested by the recognition method rather than the recall method, because the recognition method provides more cues for retrieving information from LTM. • Police line-ups make use of the recognition method of memory.

12. Measure of Retention: recall, recognition & relearning • The relearning or savings method involves participants relearning information they have previously memorised. • If they learn more quickly the second time, it is assumed they must be remembering something from the first experience, whether they realise it or not.

13. Measure of Retention: recall, recognition & relearning • You have probably discovered this yourself when studying for an exam. • You may feel that you have forgotten some or all of the material, yet with even a small amount of reviewing it comes back relatively quickly. • By restudying, a rather weak association regains its original strength in your memory. • It is as if the previous experience has prepared us for remembering the material better when we confront it again.

14. Ebbinghaus & Relearning • The pioneering memory researcher Hermann Ebbinghaus (1885) was among the first to investigate relearning. • In his experiments, he was able to develop a theory in regards to how much information is lost and then regained after undergoing a period of relearning.

15. Ebbinghaus & Relearning • Imagine you were a participant in an experiment and it took 10 trials to learn a list of 12 nonsense syllables. • If in a subsequent experiment, perhaps 6 months later, it took you 5 trials to learn the same syllables. • Using Ebbinghaus’ formula for Savings, you can calculate how much information you have saved.

16. Ebbinghaus & Relearning • Savings = (for original learning) – (trials of relearning) X 100 (trials for original learning) 1 • Savings = 10 – 5 X 100 10 1 • Savings = 50% • A savings score can also be calculated for the time taken to learn and relearn using the same formula. • Manual Activity 1 – Measures of retention in practice – An activity identifying recall, recognition and relearning, pg. 71

17. Relative Sensitivity of Measures of Retention • The sensitivity of a measure of retention refers to its ability to assess the amount of information that has been stored in memory • Research indicates that recall tends to be the least sensitive measure of retention, followed by recognition and relearning • Less sensitive • Recall • Recognition • Relearning • More sensitive

18. Measure of Retention: recall, recognition & relearning

19. Measure of Retention: recall, recognition & relearning • Learning Activity 7.3– Identifying Measures of Retention, pg. 370 • Learning Activity 7.4– Review Questions, pg. 370

20. Theories of Forgetting • Psychologists have developed a number of theories to explain why we forget. • Forgetting may occur because: • The right retrieval cue is not used. • There is interference from competing material. • There is some underlying motivation not to remember. • Memory fades through disuse.

21. Retrieval Failure Theory • Retrieval Failure Theory refers to when we forget because we lack or fail to use the right cues or prompts to retrieve what is stored in our memory. • This theory is often referred to as cue-dependent forgetting and is a useful explanation of why we sometimes fail to retrieve information even when we’re sure we know the information. • Learning Activity 7.6– Using retrieval cues, pg. 372

22. Tip of the Tongue Phenomenon • Have you ever tried to recall a fact – perhaps the name of an actor in a movie – that you’re sure you know and feel just on the verge of remembering? • You know that you know the answer but can not quite bring it forth. • Psychologists call this the tip-of-the-tongue phenomenon.

23. Tip of the Tongue Phenomenon • Tip-of-the-tongue (TOT) is a state, or ‘feeling’, that occurs when individuals are aware of knowing something, confident they will eventually remember it, but aren’t able to retrieve it from memory at that point in time. • When the sought after information is recalled, its recall tends to occur suddenly, often seeming to ‘pop’ out of memory.

24. Tip of the Tongue Phenomenon • The apparent gap in memory which occurs in a TOT state is particularly intriguing because even though we can’t say the word, we have some information about the word we want; • For example we can often tell how many syllables it has, the beginning and ending letters, or what it rhymes with. • We can also eliminate words that don’t sound right or are incorrect.

25. Tip of the Tongue Phenomenon • These observations suggest that TOT involves a partial retrieval process in which bits of information can act as retrieval cues for the required information, helping to ‘home in’ on this information. • Furthermore, the observation that specific bits or types of information assist in retrieval indicates information in LTM is stored in an organised way and in a variety of forms.

26. Tip of the Tongue Phenomenon • The TOT phenomenon is significant because it illustrates several aspects of the retrieval process. • First it shows that retrieving is not an all-or-nothing process. • Second, information is stored in LTM but it is not accessible without retrieval cues. • Third, TOT experiences indicate that information stored in LTM is organised and connected in relatively logical ways.

27. Interference Theory • Interference Theory proposes that forgetting in LTM occurs because other memories interfere with the retrieval of what we are trying to recall, particularly if the other memories are similar to the one we are trying to remember. • Telephone Number Exercise, pg. 375

28. Interference Theory • The telephone number exercise is an example of retroactive interference. • Retroactive interference occurs when new information interferes with the ability to remember old information. • The standard experimental design for investigating retroactive interference can be seen on the next slide:

29. Interference Theory

30. Interference Theory • Interference also works in the opposite direction. • Information learned previously can interfere with our ability to remember new information. This effect is called Proactive Interference.

31. Interference Theory

32. Interference Theory

33. Interference Theory • Learning Activity 7.9 – Review questions, pg. 378 • Learning Activity 7.10– Analysing proactive and retroactive interference, pg. 379 • Learning Activity 7.11– Data analysis, pg. 379

34. Motivated Forgetting • This theory is based on an observation by Austrian psychoanalyst Sigmund Freud that individuals sometimes block or hide a memory from conscious awareness because it is too painful or unpleasant to remember. • Freud used the term repression to describe this type of motivated forgetting – when an individual has a strong motive or desire to forget.

35. Motivated Forgetting • According to Freud, repression is a form of self-defence which occurs unconsciously. • This is because retrieval of a memory can bring back unpleasant thoughts and feelings associated with the experience, the individual avoids these by repressing the memory of the experience. • Repressed memory is not lost from memory, it is just not easily accessible during normal waking consciousness.

36. Motivated Forgetting • It seems that many psychologists believe that memory can be affected by an individual’s conscious or unconscious needs, fears, anxieties and desires. • Our motivational needs not only prevent retrieval of certain memories but even change the tone and content of memories that we do retrieve.

37. Decay Theory • Decay theory is based on an assumption that when something new is learned, a physical change or chemical trace of the experience which contains the stored information is formed in the brain. • This is called memory trace and is believed to gradually fade or disintegrate as time passes unless it is reactivated by being used again.

38. Decay Theory • According to decay theory, forgetting occurs because a memory fades through disuse as time passes. • Box 7.6– Pseudoforgetting: Encoding failure, pg. 385 • Manual Activity 6– Jaime’s unforgettable day, pg. 82 • Learning Activity 7.13– Review questions, pg. 386