Memory consolidation is the process involved in coding a memory so that it can be retrieved later. Without consolidation, there would be no way to store information in the brain, which is a necessary stage in forming and storing memories for later use. Consolidation can be observed in a wide range of animal species and animals appear to have varying capacities for forming and storing new memories. A number of things can interfere with memory consolidation.
The process of memory consolidation begins within minutes on a synaptic level as the brain encounters something and interacts with it. System consolidation happens in the long term over weeks and months as the brain develops pathways that can be used to access a memory. Research on the brain has demonstrated that rather than being filed away in one location, memories are actually spread across the brain. Consolidation is the process of making memories accessible, essentially creating a map or index to the brain so that memories can be retrieved when they are needed.
Once a memory has been stored, it can be recalled at will. Initially, people believed that memories were permanently stored. However, researchers have since learned that in fact, they may need to be reconsolidated each time they are recalled. Memories become “labile,” meaning that they are fragile and can potentially be disrupted, when they are recalled. Reconsolidation returns the recalled memory back to its proper place in the brain so it can be used again.
A number of functions are involved in memory consolidation. The hippocampus appears to play an important role in memory formation and storage. Other parts of the brain can have varying degrees of involvement, depending on the memory involved. Rapid eye movement (REM) sleep also appears to help with the process of memory consolidation, while sleep in general is believed to help the brain refresh.
Interesting phenomena have been observed with learning. While memory consolidation normally takes an extended period of time, studies of people involved in learning tasks have shown that the brain can consolidate a memory successfully in less than an hour in some cases. The methods used to present the information appear to be important, as does the level of repetitiveness. Repeating the same information over and over can cause synaptic changes that lead to rapid consolidation of memory, explaining the long role of recitation in learning, from the techniques used by ancient scholars to memorize epic poems, to those taught to modern students for memorizing things like the times tables and the periodic table of elements.