The higher thresholds of sensory stimulation required by some older adults in order to be able to perceive new information may result in memory impairment. Generally, among healthy subjects, short-term recall is unaffected by age. However, if individuals are asked to manipulate this information in some way, such as recalling the digits in reverse order, younger subjects appear to outperform older subjects. One explanation is that information in short-term memory is more fragile in the minds of older adults, and decays more rapidly if not attended to or rehearsed. Short-term memory may remain effective and efficient with age but may require more conscious effort to do so.
Age appears to have no effect on the capacity of long-term memory.
What age does seem to affect is the ability to encode and store information, and to retrieve it. Older adults seem less efficient in encoding material and retrieving this material once it has been stored. There are so many problems with this research that it is impossible to say with certainty that age-associated memory problems are centered in encoding, storage or retrieval. The Effort to Remember If memory were truly effortless, our brains would be crowded with every detail of every event we have ever experienced. Instead, the memory system is made for remembering and forgetting.