ABSTRACT
Cognition is defined as the various thinking processes through which knowledge is gained, stored, manipulated, and expressed. Although many cognitive skills decline with age, the extent and pattern of decline vary both at individual level and with the type of function. Some individuals age successfully and maintain a similar cognitive function to that of the young, and some functions may even improve with aging. Other individuals may have some intact cognition functions (e.g. long-term memory, complex motor skills) while there is a decline in other areas of cognition (e.g. learning new information).
