Memory

Memory refers to the mental systems and processes involved in storing and recalling information about stimuli that are no longer present, as well as to all of the information that is stored. Memory is essential to healthy human functioning, and it can be said that every mental process involves some aspect of memory. Indeed, the ancient Greek philosopher Cicero once described memory as "the treasury and guardian of all things." The human brain has evolved an enormous capacity for remembering, and in the course of life, people gather and store vast amounts of information. Memories of past experiences are necessary to understand new experiences, and to decide how to behave in unfamiliar situations. Without memory every person or situation we encountered would be strange and unfamiliar, and we could never learn from past experience. In fact, we would not be able to learn anything at all, since all learning requires remembering the material learned. Memory is also essential to a sense of self or identity, as memories of our past experiences, thoughts, and feelings inform us as to what we have done, who we have been, and who we are now. Memory can hold information ranging from how to put pants on, to the composition of the stars.

Procedural memory

Procedural memory is, as its name implies, knowledge of the steps necessary to perform certain procedures or activities. It is the knowledge of how to ride a bike or swim, how to cook spaghetti and meatballs, and even how to walk and run. Procedural learning is the acquisition of skills, such as learning how to operate a computer. How well something is learned is reflected in improved performance of the skill. It seems well-learned knowledge stored in the procedural memory system can be used without conscious awareness of the steps being performed. For instance, once a behavior is mastered—such as walking or driving a car—one rarely has to stop and think about what step comes next, and attention can be paid to other activities.

Often the information stored in procedural memory is difficult for the individual to articulate even though it is obvious from their smooth performance of the activity that they know it well. Procedural memories seem to last for a very long time, if not for a lifetime, and they are often very hard to change. Thus if one learns how to do something in a certain way, such as swim or play tennis, it can be very hard to change one's technique later.