langetermijnmemories

Long-term memory (LTM) is the system that stores information for extended periods, from days to a lifetime. It contrasts with working memory, which holds content briefly for current use. LTM provides the durable record of facts, knowledge, and experiences that underpins ongoing thought and behavior.

LTM is commonly divided into explicit (declarative) memory and implicit (nondeclarative) memory. Explicit memory includes episodic memory (personal events) and semantic memory (facts and concepts) and can be recalled consciously. Implicit memory includes procedural skills, conditioning, and priming, which influence actions without conscious retrieval.

Encoding and consolidation: forming LTM begins with attention and processing; over time traces stabilize through consolidation. The hippocampus and surrounding medial temporal structures are essential for forming new explicit memories, while the neocortex stores distributed representations. Sleep and rehearsal aid consolidation; memories can be updated during reconsolidation after retrieval.

Retrieval and limitations: retrieving LTM depends on cues, context, and the strength of encoding. Memory is constructive and prone to distortion. Forgetting can result from decay, interference, or retrieval failure. Emotional arousal can strengthen certain memories via the amygdala.

Impact and aging: aging often reduces episodic memory more than semantic memory, and some forms of LTM decline with neurodegenerative disease, notably Alzheimer’s disease. Practices such as spaced repetition, retrieval practice, and meaningful encoding support long-term retention.