Lecture: Forgetting

L9- Forgetting
What is forgetting?
 To be unable to remember (something)

 To treat with thoughtless inattention- neglect

 To leave behind unintentionally

 To fail to mention (intentionally)

Aspects of forgetting
 Loss of information

 Loss of access

 Intentional or incidental

 Temporary or permanent

 Graded

Forgetting studied in the lab (Ebbinghaus)
 1st experimental study of forgetting

 Use of unrelated material- nonsense syllables

 Time course of forgetting- forgetting curve

Ebbinghaus’ experiment
 Lists of meaningless pronounceable
syllables
baf tay bef nid
- Consonant-vowel-consonant num ven hab kol
 Study list + re-learn after variable
saq pim wuk sap
time intervals 21 mins- 31 days rol sah zol dur
 How much forgotten as a function
juv pec kip qaw
of time?




Ebbinghaus’ forgetting curve

,  Forgetting= rapid at first but gradually slows down




What causes forgetting?
 Consolidation theory

 Decay

 Interference

 (If we know what causes forgetting- we learn something about how not to forget)

Consolidation
 Consolidation= memory traces consolidate (‘grow stronger’) over time as a function of
frequency of retrieval + ‘deep processing’

 Less consolidated traces are more likely to ‘fade’ + hence to be forgotten

 Older memory traces are more consolidated + thus less sensitive to forgetting

Decay or interference?
 BOTH can lead to forgetting

 Decay= memory traces spontaneously fade over time
- Time itself causes forgetting

 Interference= it is cognitive events during a retention interval that determine forgetting
- Not time per se BUT what you do during the interval
- Interference is more important in forgetting than decay

Types of interference
 Proactive (PI): old items interfere with retrieval of new items

 Retroactive (RI): new interfere with retrieval of old items

Proactive interference