Memory is the retention of information over time. It is a crucial aspect of cognition, as it provides the basis for all cognitive processes. The term ‘memory’ has been derived from the Latin word, ‘memoria’, which means historical account or long remembrance.
Modern approach to memory has gone far beyond the simple yet significant beginnings made by Hermann Ebbinghaus (1885). The contemporary psychologists take an information processing view of memory, which relies on the computer as a model.
Like computers, the human mind receives information from the external world, stores it in some form for a period of time, and recalls it, when needed. Memory may be defined as a process by which we encode, store, and retrieve information. There are three distinct memory systems, which carry out the basic functions of encoding, storage, and retrieval. These three interrelated components of memory are discussed below.
Encoding refers to the processes through which information is converted to a form that can get an entry into memory system. The information from the external world is received in the form of physical energies, and transformed into a neural code that the brain can access.
At the time of reception, certain strategies are used for efficient encoding. These strategies consist of rehears; or practicing the information, organizing it into different groups or chunkini and relating it to the already stored information. The nature of storing the information and its retrieval for later use depend to a large extent on how the information was coded in the first place. Encoding, thus, may be considered as an active process of representing information in the memory system.
Storage refers to retaining the encoded information in memory over period of time. If the information were not stored, it would not be available for later use. The storing takes place in the form of neural traces. The encode information tends to be lost, when it cannot be linked to already store information.
The stored information is to be periodically practiced or used for retaining it for a longer period of time. Depending on the utility of the information some are only stored for a short period of time. Thus, storage refers to the holding of the information in the memory system for future use.
Retrieval refers to the process of recovering the stored information from memory. Even if information were stored in memory, it would be of little use, if it cannot be accessed at the time of need. Whether or not the stored information can be easily accessed depends on how the information was encoded and stored. When you meet a friend of yours after a long gap and are able to recognize him and remember his name, you are retrieving information from your long-term memory.
The two most common methods of testing retrieval are recall and recognition. Recall means reproducing the information already in memory, while recognition means identifying the present stimuli as having been learned earlier. The encoding and storage would be of little help, if we were not able to recover information from memory storage at the time of our need.