What theory suggests that new memories can impair the retrieval of older memories?

The theory that suggests new memories can impair the retrieval of older memories is retroactive interference. This phenomenon occurs when newly acquired information disrupts the recall of previously learned information. For instance, if you learn a new phone number, you may have difficulty remembering your old phone number due to the new information interfering with the retrieval process. Retroactive interference highlights the dynamic nature of memory, illustrating how ongoing learning can influence access to older memories.

In contrast, proactive interference refers to the difficulty in learning new information because of the influence of previously established memories. Memory suppression generally involves consciously trying to forget certain memories, while reconstructive interference relates to the process of remembering where existing knowledge impacts the way we recall information, leading to alterations in memory recall.