Whether potentially interfering information precedes (proactive interference, PI) or follows (retroactive interference, RI) the target information, memory performance appears almost always to be impaired. But does this mean that the target information is forgotten? The alternative to this storage failure (or unlearning/erasing) hypothesis view cites retrieval failure (e.g., via inhibition) as the key mechanism.
It is easy to demonstrate that memory for an event can be affected if misleading information is subsequently received.
For instance, in many eyewitness testimony experiments (e.g., Loftus, Miller, & Burns) participants have been shown a sequence of slides depicting, say, a car accident at a junction where there is a Stop sign. If participants subsequently read a description of the accident which refers to a Yield sign, they will be misled into believing that the sign was indeed a
Yield sign. On a final recognition memory test misled participants are much less likely to select the correct slide than non-misled participants. Takarangi, Parker, and Garry developed video materials for demonstrating a similar misinformation effect.
Loftus has suggested that this arises because of overwriting or unlearning of the original memory trace (that is, storage failure). However, McCloskey and Zaragoza have questioned whether the data point to genuine forgetting (via RI) of the original memory. They showed participants a sequence of 79 slides depicting a theft by a workman in which at a critical moment a hammer was present. Half of the participants were then misled into believing the tool had been a screwdriver. On a recognition memory test comparing the hammer and screwdriver (the “original” test), misled participants were overall less likely to pick the hammer (37% correct choices) than were control participants not given the misleading