Interference theory
The battle of the Roaches
• There is a famous old experiment that
demonstrates interference in the laying
down of new memories. It’s always easy
to remember so I will mention it
It is Dallenbach (1924) the cockroach
experiment
• 2 cockroaches learn a maze one gets put
to bed all comfy in a matchbox with
cotton wool
• The other is left to roam
• Which one will negotiate the maze best
the next day?
Yes you were right the one that didn’t
go roaming around picking up new
confusing information!
Interference in the LTM
• In the long term memory interference theory best
explains the kind of forgetting that happens when we
mix things up
• The idea is that as new information is learnt the
cognitive connections can get confused especially if
the information is similar to old information that we
have .
• This will result in us giving a wrong answer or making
an incorrect motor response in the case of motor
skills such as sport, driving or playing an instrument
Pro active and retro active
interference
• There are 2 types of interference in the long
term memory:• Proactive interference (old confuses
new)
• Retroactive interference (opposite)
There is only one way you will get these the right
way around and that is by rote learning what
each means
• Pro-active is old interfering with
new
• A Pro golfer –swings club forward
• Retro-active is new interfering
with old
• A retro –designer adds a new twist to an old
classics
Say it over and over until you get it right
It is slightly counter-intuitive for some people
Proactive interference
• This is when previously learnt information
interferes with the new information you are
trying to store.
• E.g You go on holiday and on the first day get a white mark
where your watch was. As you are no longer 8 and don’t want
a white mark you move your watch to your right wrist.
For 2 days you keep looking at your left wrist
• This is proactive interference . Old learning is
interfering with new
Retroactive interference
This is when newly learnt information gets
mixed up with the old information
E.g.
The holidays over both wrists are nicely
browned and the watch is returned to the
traditional left wrist but now you keep looking
at the right wrist
this is retroactive interference
new info is interfering with old
Don’t do it
Don’t start thinking about this too much just
keep it simple and learn the example
otherwise you get into a bit of a perfectly valid
quandary regarding when new information
becomes the old information, but lets not
worry about that for now.
Strengths
• There is a lot of evidence that backs up the
idea that interference causes certain types of
forgetting e.g. Dallenbach (1924) and
Underwood & Postman (1960)
• It is a credible theory because it is backed up
by our own everyday experience e.g.
windscreen wipers if they are on a different
side to what you are used to, or the watch
example or trying to learn a 3rd language
Weaknesses
• It is hard to be specific that interference has
happened and not trace decay or
displacement which can also explain some of
the findings
• Most of the strongest evidence is provided by
laboratory experiments which lacks ecological
validity and may therefore not truly explain
the nature of memory in real life