Why Some Harrowing Memories Continuously Haunt Us

Source: public domain

After submitting my last Psychology Today post, “You Can’t Always Control Your Thoughts,” I began to think about memories, especially those that pop up more often than expected. What was said about thoughts carries over to what I can say about repeated memories. One of mine is about a moment when I saw two men electrocuted.

I was eleven years old, living in the Bronx. In my memory, it was a day of light rain, an afternoon of fast-moving, white cumulonimbus clouds when my mother had sent me to buy milk from a corner grocery store. Somehow, I wandered deep in thought, not bothered by the rain, when, from a distance, I saw a man frantically trying to free his car from a fallen power line. I fetched a policeman who was directing traffic at the busy intersection, trusting that he should know what to do. By the time he arrived, the man was fully entangled in the wire and nearly as blue as the policeman’s uniform. He tried to free the man, but the current ran through both bodies, overpowering nerve signals that should have told their fingers, but didn’t, to open and let go. My intuition of electricity told me, don’t touch them, even though I knew I would watch both men die.

For years afterward I felt responsible for that policeman’s death.

When I came home, I didn’t tell anyone about what I had witnessed. The neighborhood buzzed for the next few days with telephonic reports of the incident. I kept my role in that ghastly event a secret for more than thirty years, sometimes suppressing any recollection and other times dismayed. That repeating memory, over time, swerved from maladaptive guilt to a healthy feeling of blamelessness.

Of course, there are other memories, some difficult to process, some trivial, and some joyful. I wondered where they come from, why they pop up, and what makes them. The central questions for me were: What are memories? How do they emerge? How do they become lasting? They are philosophical neurologically stubborn questions surrounding the deepest investigations of consciousness that have been debated for centuries.

The basic and fundamental understanding is that recalling an event is not a full memory itself but rather a composite structure of an enormous array of neurons relaying electrochemical signals through dendrites making thousands of connections with other neurons down the line. Innumerable pathways connect, one to another, to form a sequential pattern for signaling and storing a distinctive memory. It’s as if memory is the pathway structure, not a coded image of something that was once thought, heard, or observed.

Irrelevant memories are filtered out.

All senses, everything that happens in our consciousness, are processed and stored as a connected matrix.

In a single day, the number of events that pass and get to temporary pigeonhole cells in the hippocampus is astounding. Most encounters and happenings are as uneventful as brushing teeth or commuting to work. Remembering a tragedy, the moment you fell in love, or being at the event of the birth of a child is different from recalling the name of an actor in a movie or what one had for breakfast. The brain has far more than enough storage space for any finite number of memories, but an overload just adds to retrieval confusion. So the brain has to filter out those memories that are irrelevant to the health of the body. But how?

Looping through sharp-wave ripples.

Neuroscientists don’t know, so how could I? Short of knowing anything about retrieval, I can say that the loops I talked about in my last PT blog play a role. Retrieval relies on the conscious-subconscious loops that filter episodic standouts that do not fade before being cataloged for access in the cellular niches of the hippocampus. Some events are episodically strong enough to have a robust charge. Losing a job is not the same as not getting the job applied for. Both, though, are not good news and both get pondered till memory puts them into the twists of conscious and unconscious mindfulness relays involving the cortex and other brain areas bringing on dreams connected to random daytime events temporarily stored in consciousness. All that goes into a loop of highlighted daytime mindfulness and the subconscious until it can be retrieved with little effort. Added are the sharp-wave ripples that happen when the brain is asleep, when electrical signals move through episodic memory circuits and consolidate them to form long-term memory.

Because of that loop, the memories are retrieved but with variations of accuracy. It seems that the subconscious recollection, which is merely an ambiguous collage of imprints, adds vagueness and loosely rational interpretation that consciousness accepts without the impossible fact-checking.

So, why is it that my feelings of responsibility for a policeman’s death continue to haunt me so many decades after the event? The memory has surely modulated, swerved, and faded, though I can still recall every footstep I took on that rainy day. I have other memories that directly affected my health and well-being. Those memories have almost vanished, and others have left me with falsely imagined interpretive depictions. I suppose the difference is that the policeman’s death happened when I was more impressionable and feeling—as a child would—that I caused someone to die. It was too big to handle, and so the neuronal connections weakened enough to confuse imagination with inventiveness.

My repeated image of the policeman is perceived as an emotion caught in a conscious-unconscious loop while the amygdala played with its perception to coordinate the experience with its significance. I suspect it is constantly repairing and calibrating the emotion in cognition for further episodic choice decisions. I suppose that’s healthy.