Would you like to enhance your memory? How to improve memory Memory has three stages: encoding, retention and recovery. The brain encodes information when it perceives it and registers it. This information can then be retained and later recovered. There is a memory failure when one of these stages breaks down. There are several types of memory, including sensory, short term and long term. Sensory is stimulated by means of the senses, such as smell, sight and touch. The short-term, also called working memory, holds small amounts of information for short periods.