Redintegration refers to the restoration of the whole of something from a part of it. The everyday phenomenon is that a small part of a memory can remind a person of the entire memory, for example, “recalling an entire song when a few notes are played.” In cognitive psychology the word is used in reference to phenomena in the field of memory, where it is defined as "the use of long-term knowledge to facilitate recall." The process is hypothesised to be working as "pattern completion", where previous knowledge is used to facilitate the completion of the partially degraded memory trace.