Trace decay theory
- Each rehearsal strengthens memory trace
- Trace decays over time
Interference theory
- Memories don’t just fade away
- Proactive and retroactive interference
Proactive interference
Something you learned can interfere with something you learned later
Retroactive interference
Something you learned can interfere with something you learned earlier
Reasons for interference theory
- Response competition
- Unlearning
- List differentiation
Response competition hypothesis
- Occurs when A is paried with B and then with C
- The more rehearsal with C lowers the chance of recalling B instead of C
Unlearning hypothesis
Original association of A = B is being unlearned
Problems of unlearning hypothesis
- No evidence of retroactive interference when using a recognition test
- Supports that A = B is not unlearned
List differentiation hypothesis
Interference occurs because of failing to discriminate which list has been learned
Impact of the interval between learning AB vs AC
As interval increases, less proactive interference occurs
Release from proactive interference
- Category of information impacts recall
- Group 1 remembering numbers
- Group 2 remember letters
- Test on letters
- Group one has no interference on group 1
Encoding specificity
- Information encoded includes the context
- Context provides cues which can influence retrieval
- Memory best when retrieval cues match encoded cues
Environmental context
Retrieve information better if you are at the same place as where you learned it
State-dependent learning
Retrieve information better if you’re in the same mood as when you learned it
Typical eyewitness study
- Witness event
- Series of questions to influence re-encoding
- Memory test
Conclusions from eye witness reports
- Memories of events are not perfect
- Memory can be easily altered (smashed vs hit)
- Slight changes caused by simple re-encoding can also alter other aspects of our memory for an event (see shattered glass?)
