THEORIES OF FORGETTING

• Interference


  When two pieces of information conflict with each other this leads to one memory disrupting the ability to recall another. 
• Two types of interference (1)

  Proactive – when an older memory interferes with a newer memory 

  Old memories E.G. rearranging your room and going to the old places of items  
• Two types of interference (2)

  Retroactive – when a newer memory interferes with an older memory 

  New memories E.G. new facts about the WMM alters what you know about the MSM 
• Research on the effects of similarity


  McGeoch and McDonald - They studied retroactive interference by changing the amount of similarity between two sets of material. Participants had to learn a list of 10 words until 100% accuracy.  
• Research on the effects of similarity

  They then had to learn a new list. There were six groups who had to learn different lists: 

  • Group 1 – synonyms – same meanings as the originals 
  • Group 2 – antonyms – opposite meanings to the originals 
  • Group 3 – words unrelated to the originals 
  • Group 4 – consonant syllables 
  • Group 5 – 3-digit numbers 
  • Group 6 – no new list – rested (control condition) 
• Research on the effects of similarity

  Conclusion – when participants were asked to recall the original list of words the synonyms produced the worst recall, so the interference is strongest. 

  Explanation – proactive or retroactive interference 
• Evaluation of interference

  ✅ Evidence of interference in everyday life (Baddeley and Hitch – rugby) which increases validity of the theory. However, the conditions necessary for interference are rare and interference as a cause of forgetting is unusual. Two memories must be fairly similar to interfere with each other – forgetting may be better explained by other theories such as retrieval failure due to lack of cues. 
• Evaluation of interference

  ❌ Interference and cues – interference is temporary and can be overcome with cues. TULVING and PSOTKA gave participants lists of words organised into categories, one list at a time (not told categories). Recall averaged 70% for the first list but became worse with each additional list (PI). At the end participants were given a cued recall test (told the categories). Recall rose again to about 70%. Therefore, interference causes a temporary loss of accessibility to material still in the LTM. 
• Evaluation of interference

  ✅Support from drug studies – retrograde facilitation. COENEN and LUIJTELAAR conducted a study where they gave participants a list of words to recall later. They found that recall of the words was poorer when the words were learnt under the influence of diazepam than when the list was learnt before taking diazepam, so the drug improved the recall of information learnt beforehand.
• Retrieval cue failure


  The memory is available it is just not accessible – if cues are unavailable during learning and recall, we will forget. 
• Encoding specificity principle – TULVING (1933) 

  The principle states that if a cue is to help us to recall information it must be present at the time of encoding (when we learn the material) and at retrieval (when we recall it) 
• Two types of cues

  Context dependant cues – external cues usually found in the environment 

  State dependant cues – internal cues e.g. mood 
• Research on context dependant forgetting

  Procedure - GODDDEN AND BADDELEY studied deep sea divers who work underwater to see if training on land helped or hindered them.

  1. The divers learned a list of words either underwater or on land and then asked to recall them on the opposite. 
  2. There were 4 conditions: 

  • Learn on land – recall on land 
  • Learn on land – recall underwater 
  • Learn underwater – recall on land 
  • Learn underwater – recall underwater 
• Context dependant forgetting


  Findings and conclusions: accurate recall was 40% lower in the non-matching conditions. External cues available at learning were different to the ones at recall, leading to retrieval failure. 
• Research on state dependant forgetting

  Procedure – CARTER AND CASSADAY (1998) gave antihistamine drugs to participants – mild sedative effect (drowsy) 

  1. The participants had to learn lists of words and passages of prose and recall the information. 
  2. There were 4 conditions: 

  • Learn on drug – recall on drug 
  • Learn on drug – recall not on drug 
  • Learn not on drug – recall on drug 
  • Learn not on drug – recall not on drug 
• State dependant forgetting


  Findings – in the conditions where there was a mismatch between internal state at learning and recall performance was significantly worse when the cues are absent (alertness/drowsiness) there is more forgetting. 
• Strength (1)


  ✅ Real world application – can help overcome forgetting in everyday life. Although cues may not have a very strong effect, BADDELEY believes they have some significance. For example, forgetting why you entered a room but when you return to the place prior it is remembered. This shows how research can remind us of strategies we use in the real world to improve our recall. 
• Strength (2)


  ✅Impressive range of research supporting retrieval failure - GODDEN and BADDELEY + CARTER and CASSADAY. Retrieval failure occurring in real life not just in the highly controlled lab conditions. HOWEVER, BADDELEY argues that context effects are not very strong unless the environments are completely different (land and underwater). In contrast two different rooms are not that different. This means that retrieval failure due to lack of contextual cues may not actually explain everyday forgetting. 
• Limitation (1)


  ❌ Recall vs recognition – context effects depend on the type of memory being tested. GODDEN and BADDELEY replicated their underwater experiment using recognition rather than recall. When recognition was tested there was no context dependant effects, performance was the same in all four conditions. This suggests that retrieval failure is a limited explanation for forgetting – only applies to recall not recognition.