The memory system is, of course, located in the brain. It exists through the cortex and in what is called the brain stem, which is at the top of the spinal cord. As with the other parts of the brain, the memory system receives information from the senses and sends signals to our muscles, so we can respond with speech or movement. Different types of memory are located in different parts of the brain. People who have received brain damage in a certain area, such as might result from a motor accident, may lose memory abilities. If the left side of the brain is damaged, the person may have difficulty in remembering abstract concepts and yet may be able to remember motor skills. If the right side of the brain is damaged the person may have difficulty in recognising what is seen or heard. Although many memory functions reside in the brain, the precise location in the brain of many memory functions has yet to be discovered.
One kind of memory helper is the teaching machine. These devices are intended to facilitate learning, and modern variations of teaching machines involve devices that attempt to stimulate job experience, flying a plane, navigating a ship, air traffic control and many other occupations. Computer stores stock shelf after shelf with instructional schemes and programs that are intended to help learning, including, of course, microcomputers.
Currently there are no products available that can test your memory in the same way that a thermometer can test your temperature. Nevertheless, there are some products that can be used in a variety of ways, such as hand-held automated games that rely on memory performance, The Simon Game, for example, are marketed as a tester of memory. People who are concerned about their memory can test themselves periodically with the game. Some people find spelling difficult and the use of a pocket speller useful in the same way. Solving cross-word puzzles is another way of reviving the meaning and correct conventional way of spelling words.
Perhaps the oldest aid to memory is art in the form of drawings, maps and paintings. Sketches and cartoons were used to stimulate the artist's mind of the structure and form of a particular subject. One of the most famous of these was Leonardo da Vinci; his notebooks are full of designs and drawings of the myriad things that interested him.
Research has shown that it is beneficial for some people to remember their past lives, and a good way to stay in touch with your past is to keep a diary. It provides a back-up record of events and it also fosters a better memory because making a record makes you review what has happened. Another way to stimulate the feeling of connection with one's past is to collect mementoes, particularly photographs, sound recordings, and more akin to modern times, video tape recordings. These not only please and offer feelings of nostalgia, but also are also useful to the ones you love, children and families. Family trees were often written down in the large Bible that many people kept. This practice has grown into an industry in modern times with lost of people seeking their roots. Especially where families have emigrated to other countries.