Explanations for Forgetting
From our coverage of the Multi-Store Model, we already know that there are at least 4
reasons why we forget:
- Decay – happens in all 3 stores (sensory, STM, LTM) only the time scale varies
(milliseconds-years).
- Displacement – happens in STM due to its limited capacity (7+/-2). New
information from sensory memory displaces existing information (e.g. Glanzer and
Cunitz and the primary-recency effect).
However, the 2 types of forgetting you need to know for the exam happen in LTM:
- Interference
- Retrieval failure
Interference
Interference happens when one LTM memory interferes with our ability to recall
another one (available but not accessible). Interference is more likely if the two memories
are similar.
There are two types of interference:
- Proactive
- Retroactive
Proactive interference happens when an old memory interferes with a new one.
Retroactive interference happens when a new memory interferes with an old one.
Tip: Remember this by thinking that the prefix “pro” means “for” - proactive interference
happens when an old memory goes forwards and interferes with a new one.
The prefix “retro” means “back” - retroactive interference happens when a new memory
goes backwards and interferes with the attempt to retrieve an old one.
Interference theory:
Forgetting occurs when two pieces of information conflict with each other, resulting in the
forgetting of one or both, or in some distortion of memory.
Interference has been proposed mainly as an explanation for forgetting in long-term
memory: once information has reached LTM, it is more-or-less permanent. Therefore, any
forgetting of LTMs is most likely because we can’t get access to them even though they
, are available. Interference between memories makes it harder for us to locate them, and
this is experienced as ‘forgetting’.
A01 content:
Interference A form of forgetting in which one LTM interferes with
or blocks out our attempt to retrieve a different LTM.
Proactive interference When an old LTM comes forwards and interferes
with an attempt to retrieve a new LTM.
Example of proactive Calling someone by their older sibling’s name
interference
Retroactive interference When a new memory goes back and interferes with
the attempt to retrieve an old memory.
Example of retroactive Calling someone by their younger sibling’s name
interference
Effect of similarity The more similar the 2 memories are, the more likely
interference is to take place.
Available Means that the memory still exists in our LTM (it
hasn’t decayed)
Accessible The LTM can be accessed and retrieved
Available but not accessible With interference, LTM memories are available, but
we can’t access them because another LTM
interferes.
John McGeoch and William McDonald, 1931
Procedure: McGeoch and McDonald studied retroactive interference by changing the
amount of similarity between two sets of materials. Participants had to learn a list of 10
words until they could remember them with 100% accuracy. They then learned a new list.
There were six groups of participants who had to learn different types of lists:
Group 1: synonyms – words with the same meanings as the originals
Group 2: antonyms – words with the opposite meanings to the originals
Group 3: words unrelated to the original ones
Group 4: nonsense syllables
Group 5: three-digit numbers
Group 6: no new list – these participants just rested
From our coverage of the Multi-Store Model, we already know that there are at least 4
reasons why we forget:
- Decay – happens in all 3 stores (sensory, STM, LTM) only the time scale varies
(milliseconds-years).
- Displacement – happens in STM due to its limited capacity (7+/-2). New
information from sensory memory displaces existing information (e.g. Glanzer and
Cunitz and the primary-recency effect).
However, the 2 types of forgetting you need to know for the exam happen in LTM:
- Interference
- Retrieval failure
Interference
Interference happens when one LTM memory interferes with our ability to recall
another one (available but not accessible). Interference is more likely if the two memories
are similar.
There are two types of interference:
- Proactive
- Retroactive
Proactive interference happens when an old memory interferes with a new one.
Retroactive interference happens when a new memory interferes with an old one.
Tip: Remember this by thinking that the prefix “pro” means “for” - proactive interference
happens when an old memory goes forwards and interferes with a new one.
The prefix “retro” means “back” - retroactive interference happens when a new memory
goes backwards and interferes with the attempt to retrieve an old one.
Interference theory:
Forgetting occurs when two pieces of information conflict with each other, resulting in the
forgetting of one or both, or in some distortion of memory.
Interference has been proposed mainly as an explanation for forgetting in long-term
memory: once information has reached LTM, it is more-or-less permanent. Therefore, any
forgetting of LTMs is most likely because we can’t get access to them even though they
, are available. Interference between memories makes it harder for us to locate them, and
this is experienced as ‘forgetting’.
A01 content:
Interference A form of forgetting in which one LTM interferes with
or blocks out our attempt to retrieve a different LTM.
Proactive interference When an old LTM comes forwards and interferes
with an attempt to retrieve a new LTM.
Example of proactive Calling someone by their older sibling’s name
interference
Retroactive interference When a new memory goes back and interferes with
the attempt to retrieve an old memory.
Example of retroactive Calling someone by their younger sibling’s name
interference
Effect of similarity The more similar the 2 memories are, the more likely
interference is to take place.
Available Means that the memory still exists in our LTM (it
hasn’t decayed)
Accessible The LTM can be accessed and retrieved
Available but not accessible With interference, LTM memories are available, but
we can’t access them because another LTM
interferes.
John McGeoch and William McDonald, 1931
Procedure: McGeoch and McDonald studied retroactive interference by changing the
amount of similarity between two sets of materials. Participants had to learn a list of 10
words until they could remember them with 100% accuracy. They then learned a new list.
There were six groups of participants who had to learn different types of lists:
Group 1: synonyms – words with the same meanings as the originals
Group 2: antonyms – words with the opposite meanings to the originals
Group 3: words unrelated to the original ones
Group 4: nonsense syllables
Group 5: three-digit numbers
Group 6: no new list – these participants just rested
