Proactive and Retroactive Interference: Definition and Examples

Proactive interference happens when an individual is unable to learn new information because old information prevents its retrieval. In other words, old memories interfere with the retrieval of new memories. Older memories are often more strongly encoded in long-term memory because the individual has had more time to revisit and rehearse them. As a result, they are easier to recall than memories that were made more recently. 

Research has shown that one way to reduce proactive interference is to rehearse the new information through testing or recitation.

Retroactive interference happens when an individual is unable to recall old information because new information prevents its retrieval. In other words, new memories interfere with the retrieval of old memories.

Retroactive interference has been shown to disrupt learning.

There is a great deal of research backing up the effects of proactive and retroactive interference. However, there are some issues with the theory. Most studies on interference theory take place in a lab using word memory tasks that are presented fairly close together. In real life, people rarely perform word memory tasks, much less with only a little bit of time between them. As a result, many of the studies of proactive and retroactive interference may not be generalizable to the real world.