Answer:
Consolidation
Explanation:
Consolidation: When short term memory change into long term memory or short memory turn into long term memory then consolidation happened. As we know that short term memories are stored for short time period about 30 seconds but we want to remember things for long time then short term memory moved to the long term memory. Consolidation is the cause of turning our short term memory into long term memories. There can be multiple reason for decaying of memories but when aging start our memories naturally decaying from the long term memories.
There are some way through that memories can be properly consolidated: