A Father's Memories

Imagine the world as a swirling mass of information—to grab hold of something elusive, you need to focus your attention on it, concentrate and make an effort to capture it. Your brain then takes several steps in order to form lasting memories.

1. Attention, Sensory Perception, and Emotional Stimulation
   Various nerve cells in different parts of the brain are activated in a specific circuit that combines all sorts of incoming information, from sensory perceptions of smell, sound and sight to emotional ones generated by the amygdala.


2. Short Term Memory
   These impressions last only up to 30 seconds, and won’t be retained unless you make a conscious effort to hold on to them. Without such targeted attention, they can easily be replaced by other impressions. In most cases, the amount of information available in short term memory is also limited; the average person can retain about four pieces of information at a time, or the equivalent of the seven digits in a phone number.


3. Consolidation
   While you sleep, your hippocampus and amygdala are still active, busily transferring what you’ve experienced while you were awake to other parts of the brain that regulate higher level thought.


4. Long Term Memory
   Once these cognitive areas of the brain are involved, the information becomes like a dossier, annotated with all the relevant information that came with the experience, from sensory details to location and emotional ones.


5. Access and Re-storage
   Every time you pull up a memory, this dossier is altered slightly, by the time and place in which it was recalled. So a memory gets altered slightly every time it’s accessed and replaced.

A Memory at Work
A memory is more of a process than a biological thing; and depending on the sensory or emotional information available at the time a memory is generated, a single memory can range across different parts of the brain.

Making a Memory Last
All of us can recall events or experiences that are months, even years old. Yet those memories aren’t dependent on the proper nerve cell circuits firing constantly to keep that recall alive. So researchers have proposed a process called long term potentiation (LTP) that may be responsible for reinforcing certain patterns of nerve cell activity that might be critical for forming long term memories.

How Long Term Potentiation Works

First Stimulus
This is the triggering event for a memory; it could be incoming information generated by sensory nerve cells in the eyes, ears, nose, tongue or skin.

Triggering a Response
Chemical changes in nerve cells register the event. But in LTP, the initial stimulus is enhanced by the constant firing or activation of several nerve cells at the same time. This boost in the signal amplitude can last for weeks, and results in changes in the way the chemicals that communicate between nerve cells work.

Strengthening the Pattern
The changes in chemical activity result in alterations in the structure of the nerve cell endings, and these modifications can lead to the formation of new ways for nerve cells to talk to one another. These alternative pathways could now form the basis for circuits that can remain active for longer periods of time, reinforcing memories.