The knowledge stored in our LTM affects our perceptions of the world, and influences what information in the environment we act on. LTM provides the framework to attach new knowledge. It contrasts with short-term and perceptual memory in that information can be stored for extended periods of time.
Schemas are mental models of the world. Information in LTM is stored in interrelated networks of these schemas. These, in turn, form intricate knowledge structures. Related schemas are linked together, and information that activates one schema also activates others that are closely linked. This is how we recall relevant knowledge when similar information is presented. These schemas guide us by focusing our attention to relevant information and allow us to disregard what is unimportant.
Since LTM storage is organized into schemas, instructional designers should activate existing schemas before presenting new information. This can be done in a variety of ways, including graphic organizers, curiosity-arousing questions, movies, etc.
LTM has a strong influence on perception through top-down processing - our prior knowledge affects how we perceive sensory information. Our expectations regarding a particular sensory experience influence how we interpret it. This is how we develop bias. Most optical illusions take advantage of this fact.
An important factor for retention of learned information in LTM is rehearsal.