Amyotrophic lateral sclerosis

Memories make up the ongoing experience of your life . Your collective set of memories is what makes you who you are . Encoding is the first step in creating a memory, it’s a biological phenomenon that begins with perception . Each memory is a set of multiple sensations that travel to the hippocampus in the brain which combines these perceptions into a single experience. The hippocampus and the frontal cortex are responsible for analyzing these various sensory inputs and deciding if they are worth remembering.If they are, they may become part of your long-term memory. Although a memory being with perception it is encoded and stored using electricity and chemicals.
Nerve cells connect with other cells at point called synapse. Electrical pulses carry messages between nerve cells in the brain. Brain cells work together in a network ,organizing themselves in groups ,that specialize in different kinds of information processing. The more signales sent between them , the stronger the connection grows. Your brain rewires its physical structure with each new experience. Once a memory is created, it must be stored (no matter how briefly).
Memories get stored in three ways :

first in the sensory stage then in short term memory; and ultimately, in long term memory. Because there is no need for us to maintain everything in our brain, the different stages of human memory function as a sort of filter that helps in protecting us from the flood of information on a daily basis.
When you want to remember something you retrieve the information on an unconscious level. Bringing it into your conscious mind at will. When you start forgetting random things, like a name of the colleague you are simply experiencing a breakdown of the assembly process of memory, a breakdown that many of us begin to experience in our 20's and that tends to get worse as we reach our 50's. This age dependent loss of function appears in many animals and it begins with the onset of sextual maturity. As you begin to age, these synapses begin to falter which begins to affect how easily you can retrieve memories.

But how do some memories get lost?

Age is one factor. As we get older, synapses begin to falter and weaken, affecting how easily we can retrieve memories. Scientists have several theories about what's behind this deterioration, from actual brain shrinkage, the hippocampus loses 5% of its neurons every decade for a total loss of 20% by the time you're 80 years old to the drop in the production of neurotransmitters, like acetylcholine, which is vital to learning and memory. These changes seem to affect how people retrieve stored information.
Age also affects our memory-making abilities. Memories are encoded most strongly when we're paying attention, when we're deeply engaged, and when information is meaningful to us. Mental and physical health problems, which tend to increase as we age, interfere with our ability to pay attention, and thus act as memory thieves. Another leading cause of memory problems is chronic stress. When we're constantly overloaded with work and personal responsibilites, our bodies are on hyperalert. This response has evolved from the physiological mechanism designed to make sure we can survive in a crisis. Stress chemicals help mobilize energy and increase alertness. However, with chronic stress our bodies become flooded with these chemicals, resulting in a loss of brain cells and an inability to form new ones, which affects our ability to retain new information.
 Depression is another culprit. People who are depressed are 40% more likely to develop memory problems. Low levels of serotonin, a neurotransmitter connected to arousal, may make depressed individuals less attentive to new information. Dwelling on sad events in the past, another symptom of depression, makes it difficult to pay attention to the present, affecting the ability to store short-term memories. Isolation, which is tied to depression, is another memory thief. A study by the Harvard School of Public Health found that older people with high levels of social integration had a slower rate of memory decline over a six-year period.
The exact reason remains unclear, but experts suspect that social interaction gives our brain a mental workout. Just like muscle strength, we have to use our brain or risk losing it. But don't despair.
There are several steps you can take to aid your brain in preserving your memories. Make sure you keep physically active. Increased blood flow to the brain is helpful. And eat well. Your brain needs all the right nutrients to keep functioning correctly. And finally, give your brain a workout. Exposing your brain to challenges, like learning a new language, is one of the best defenses for keeping your memories intact.

written by:Rashida El-bohy

References

1) https://lesley.edu/article/stages-of-memory
2) https://bokcenter.harvard.edu/how-memory-works