Proactive Interference

Proactive interference is a memory phenomenon in which information learned earlier hinders a person's ability to encode or later retrieve information learned more recently. The effect arises because previously formed memory associations, especially ones learned in similar contexts, can obstruct access to newer, related memories, since the brain must distinguish between competing memory traces during retrieval. Proactive interference is often illustrated with motor skill learning, where a person's established proficiency in one skill can interfere with their ability to learn a new but related skill, as earlier motor habits intrude on the newly forming ones. It is documented as the less common and generally less problematic form of interference compared with retroactive interference, in which newer learning instead disrupts memory for older material, though proactive interference still measurably affects working memory performance, particularly across lists of items that share conceptual similarity. Its effects have been shown to lessen when a memory test is given immediately after new learning or when the new material differs substantially in content from what was learned before.