Explanations for forgetting

• Interference


  Forgetting because one memory blocks another
• Types of interference


  • Proactive interference
  • Retroactive interference
• Proactive interference


  Forgetting due to older memories disrupting recall of newer memories. Degree of forgetting greater when memories are similar.
• Retroactive interference

  Newer memories disrupting recall of older memories. Degree of forgetting greater when memories are similar.
• Underwood & Postman (1960)


  Aim: to find out if new learning interferes with previous learning
• Procedure


  1. Participants were divided into two groups

  2. Group A were asked to learn a list of word pairs, then learn a second list with different second words

  3. Group B were asked to learn only the first list of word pairs

  4. Both groups were asked to recall the first list of word pairs
• Baddeley & Hitch (1977)


  They asked rugby players to recall the names of teams recently played. They found that recall for the last game was equally good whether that game was played some time ago or last week, showing that incorrect recall was not due to decay (the passage of time) but was related to the number of intervening games.
• U + P Findings & Conclusions

  Grp B recall of list better than recall of list A

  Learning item in 2nd list interfered with ps ability to recall the list e.g. of retroactive interference
• Evidence supporting the theory

  • Most of the evidence comes from lab studies i.e. Underwood and Postman
  • The extraneous variables can be controlled and these experiments can be replicated so reliability can be tested
  • They use artificial material (i.e. word lists) which are meaningless to the participants so they do not represent every day situations when we have to remember things which have meaning to us i.e. a shopping list
• Participants' motivation to remember the stimuli

  Less accurate recall and stronger effects of interference than in real life
• Baddeley (1990) states that the tasks given to participants are too close to each other and, in real life, these kinds of events are more spaced out so the effect might be different
• The research does not investigate whether the information has "disappeared" or can be recovered later
• Ceraso (1967) showed that if tested again after 24 hours there is significant recovery so the effect of interference might be temporary
• Cue-dependent forgetting


  Theory that explains forgetting in the LTM as a retrieval failure: the information is stored in the LTM but cannot be accessed due to lack of cues
• Types of cues


  • Cues which are linked meaningfully to the information to be remembered
  • Cues which are linked to the environment in which the information was learned
• Context-dependent forgetting


  1. Occurs when the environment during recall is different from the environment you were in when you were learning

  2. Godden and Baddeley (1975) investigated the effect of environment on recall
• Conditions in Godden and Baddeley (1975) study


  • Learn on beach recall on beach
  • Learn on beach recall under water
  • Learn under water recall on beach
  • Learn under water recall under water
• The results show that the context acted as a cue to recall as the participants recalled more words when they learnt and recalled the words in the same environment than when they learnt and recalled the words in different environments
• Further support for the influence of contextual cues: Abernathy (1940) found that students performed better in tests if the tests took place in the same room as the learning of the material had taken place, and were administered by the same instructor who had taught the information
• Real-life application: Context-dependent forgetting is used as a strategy to improve recall in eye-witness memory when the witnesses are asked to describe the context in which the incident they have witnessed took place during cognitive interviews
• State-dependent forgetting


  Occurs when your mood or physiological state during recall is different from the mood you were in when you were learning
• Goodwin et al. (1969) study


  1. Forty-eight male medical students participated on day 1 in a training session and on day 2 in a testing

  2. They were randomly assigned to four groups: SS (sober on both days), AA (intoxicated both days), AS (intoxicated on day 1 and sober on day 2), SA (sober on day 1 and intoxicated on day 2)

  3. Participants had to perform 4 tests: an avoidance task, a verbal rote-learning task, a word-association test, and a picture recognition task
• More errors were made on day 2 in the AS and SA condition than in the AA or SS conditions, however this was not the case for the picture recognition test. The SS participants performed best in all tasks.
• This supports the state-dependent memory theory as the performance was best in the participants who were sober or intoxicated on both days.
• Further support for the influence of state-dependent cues: Overton (1964) experimented on two groups of rats, one group was given a mild barbiturate the other group did not get the drug. They were then placed in a simple maze and taught to escape an electrical shock. When the group with the drug were placed back in the maze without the drug they could not remember how to escape the shock but if they were given the drug again they could recall how to escape the shocks.
• This theory is difficult to disprove as if recall does not occur it could be because the information is not stored or because the right cue is not provided (circular argument)
• Real-life application: State-dependent forgetting is used as a strategy to improve recall in eye-witness memory when the witnesses are asked to describe their mood/emotional state when the incident they have witnessed took place (cognitive interview)