Memories: Learning, remembering, (not) forgetting
For 30 years, I have talked to people about their memories and, as a neuropsychologist interested in amnesia, I am very interested in brain areas that mediate learning and forgetting.
How memories work
A core brain structure for memory is the hippocampus. The hippocampus (the Greek word for seahorse) is shaped like its namesake. It plays a key role in the consolidation of new memories and in associating a new event with its context (e.g., where it took place, when it happened). For example, you might hear the name Princess Diana. The hippocampus may activate verbal associations (e.g., she was part of the Royal Family), as well as memories of particular images or experiences. When I hear the name Princess Diana, I recall my brother telling me of her death as I descended the stairs of his home on Cape Cod. I can picture that moment in my “mind’s eye.” Despite my age, my (relatively) intact hippocampus allows me to retrieve a complex set of images and ideas that remind me where I was and who I was with when I heard the sad news of Princess Di’s death.
Memories that last
Some memories seem to age well. Recall of specific “flashbulb” events, such as the death of John F. Kennedy, or where you were on September 11th, 2001, seems unblemished and unchanged over time. However, in reality all memories, even flashbulb events, are malleable; they change as a result of the passage of time. They shift each time you call a memory to mind, as they are affected by other memories that have overlapping elements. As a student of memory, I am just as interested in long-term forgetting as I am in remembering. I am particularly intrigued by changes that take place with regard to autobiographical memory. Autobiographical memory is the foundation on which we derive a sense of who we are, what we find rewarding, and how we define our world. It is integral to how we construct meaning and purpose in our lives.
Autobiographical memory as we grow older
As we age our personal memories become fragile. They become less accurate and lose context. People with neurodegenerative conditions such as Alzheimer’s disease are particularly vulnerable to the loss of personal memories, due to the combined effects of their neurological condition and the aging process. They no longer have the same access to important milestones that helped define them. The importance of autobiographical memory is often overlooked. People come to me to ask for assistance with memory skills. I teach them all I know about mnemonic techniques to enhance face–name associations. I review cognitive strategies for new learning. I rarely talk about old memories… their first day of school, their first kiss, music from teenage years.
Tending to autobiographical memory
More recently I shifted my focus in conversations with people who want to talk about memory. Together with a therapist colleague, I started the “memoir project.” Why? I want to help highlight the important role of personal memories in maintaining a strong sense of self. People, even those with mild dementia, are encouraged to review important life events by using personal timelines to identify, for example, key events, food, music, and people who contributed to their sense of self. They may contact childhood friends, college roommates, and family members to remind them of shared experiences and to augment past memories. They often receive memory “gifts” as a result of these conversations — filling in the gaps in a memory that was beginning to fade. And of course, documentation and journaling are critical strategies. The stories people have shared with me have been fascinating. More important is the joy of reminiscence they experience.