REMEMBER: The Science of Memory and the Art of Forgetting (2021)
Lisa Genova has written a book that isn’t too scientific, for the layperson. She approaches the subject of remembering and forgetting, by first explaining how we make memories, sprinkled with examples of memory lapses or senior moments. I laughed when I read and could identify with some of them. There are a few different parts of the brain that are involved in creating and saving memories.
In case it’s been a few decades since you went to school, maybe one of your kids brought home the knowledge of the parts of the brain and their jobs: the hippocampus collects the perceptions, the language and the Who What When Where Why (W5) and How of an event; the prefrontal cortex keeps what you see and hear, plus emotions and language, for less than 30 seconds, making sense of it (pun intended), before passing it to the hippocampus; the amygdala regulates emotions and emotional memory, especially related to stress and fear. Those are quick and easy descriptions.
Lisa Genova writes mostly about the hippocampus, where long-term memories are found. Here are more quick and easy descriptions of how the hippocampus creates a memory in four steps (p.16):
- Encoding: the brain collects the sights, sounds, information, emotion and meaning that you perceived;
- Consolidation: the brain links the collection of neural activity into a single pattern of associations;
- Storage: the pattern of activity is maintained over time through persistent changes in those neurons;
- Retrieval: you activate the connections and revisit, recall, know and recognize what you experienced.
What makes this book so interesting is the storytelling. Lisa refers to studies that show that what we think we remember perfectly, as if it were the day it happened, is often ‘wrong’ because our memories change over time, each time we retrieve them.
“We omit bits, reinterpret parts, and distort others in light of new information, context and perspective that are available now but weren’t back then …then we reconsolidate and restore this changed, 2.0 version of the memory and not the original …like hitting ‘SAVE’ in Microsoft Word.” (p.101–2)
There are three kinds of long-term memories: semantic, for information; episodic, for what happened; and muscle memory, for how to do things. (p.51) The hippocampus saves semantic and episodic memories. The basal ganglia, which is separate from the hippocampus, saves the muscle memories.
I have an episodic memory of my young daughter talking to me about a ‘depot’ (said /de-pott/). I distinctly remember joking with her that it was said /dē-pō/, as it occurred to me that she had probably only seen the word in print. (She was a voracious reader.) For many years, I couldn’t recall the actual word that she had mispronounced. Until this week when I was talking to a neighbour and—POP!—the word came to mind. Just like that! Lisa would say that I “bumped into a retrieval cue that was strong enough to trigger the activation of the word.” (p.120) God (and science?) only knows.
Fiona