I am frequently asked what the difference is between memory changes associated with normal aging and that related to Alzheimer’s disease (AD). First, the memory changes associated with normal aging are not a disease. The typical pattern of memory change with advanced age is a deficit in retrieval. A healthy older brain can encode information because the hippocampus is relatively healthy. This permits new information to be encoded. The older adult has some difficulty retrieving that new information, but with cues and prompts they retrieve the information as well as those in their thirties.
In contrast, a brain with AD has a damaged hippocampus that prevents new information from being encoded. This means that new learning does not take place and that cures and prompts do not help because the information is not there to be prompted.
In general, a healthy older adult encodes new information, but needs some help in retrieving what has been encoded. A brain with AD does not encode new information and therefore cues and prompts will not help with retrieval.
Fore more information about Alzheimer’s Disease