There are 3 types of memory, which are controlled by different brain areas.

Working Memory resides in the frontal part of the brain and typically lasts less than 30 seconds, allowing you to pay attention to your surroundings. Working memory declines with normal aging. If the information you are attending to attracts your interest, it is passed on to your short-term memory, which can store the information for up to two weeks.

Short-Term Memory allows you to recall information learned within the last two weeks. It takes about two minutes to transfer information from working memory to short-term memory. Brain areas called the entorhinal cortex and hippocampus control short-term memory function, and are the first areas affected by Alzheimer's disease (AD). Examples of short-term memory include recalling part of a recent movie, radio or TV show, book, article or conversation.

Long-Term Memory can last a lifetime. Information retained for more than two weeks is transferred from short term memory to long term memory, and is probably stored throughout the brain. Long-term memories, such as your children's names, your wedding date, the schools you attended, the jobs you held, etc., are not affected until the later stages of AD.