Education & Learning
How Memories Form – And Why You Should Care
Memory is one of the most important functions of the brain. Your memories define who you are, but they also enable you to function properly in day to day life. You probably have a number of outstanding memories from your childhood, perhaps a fishing trip you took with your father or maybe something unpleasant like the passing of a loved one. These long-term memories are deeply ingrained in your brain and you are unlikely to ever forget them.
Then you have the short-term memories, most of which blend into your daily routine and are soon forgotten, like the drive to work or what you had for lunch. Without the formation of both long and short-term memory, life would be extremely difficult to navigate.
You would not remember the meeting you had with a client or your new boss and, in the long-term, you would forget the important defining moments in your life that have helped to form your character.
Despite the fact that memories are so important to us human beings, research has shown that what you remember may not always be completely accurate. This is because the brain is highly susceptible to suggestion and, over time, whether days, months or years, your memory and perception of a particular event or happening tends to change.
Many people have what are known as flashbulb memories of momentous occasions in their lives or in the world around them.
If you have you ever discussed an important event with a friend or relative, you probably noticed that their memory of that event differs slightly (or maybe even quite dramatically) from yours. Many people have what are known as flashbulb memories of momentous occasions in their lives or in the world around them.
This can include things like what they were doing when they heard about the September 11 attacks or where they were when they received a call about the death of a loved one.
Although these memories are generally extremely detailed and tend to be remembered very clearly by the individual in question, psychologists have also been found them to be rather inaccurate when put to the test. Karim Nader, a neuroscientist at the McGill University in Montreal, has carried out numerous studies on this phenomenon and is of the opinion that the act of remembering may actually cause your memories to change.
According to Nader, it is virtually impossible for anyone to think of an event that happened in the past without changing it somehow. He also believes that flashbulb memories in particular are more likely to be altered dramatically.
This is because memories of monumental events are often replayed over and over in a person’s mind or during conversations with colleagues, family or friends, and each time the memory is replayed it might be slightly altered.
Not all scientists agree with Nader’s theory that memories are altered simply by remembering them, but, his theory may explain why certain types of therapy are extremely helpful for people who suffer from post traumatic stress disorder and wish to move on with their lives by putting painful memories behind them.
Researchers at the Stanford University in California carried out a study showing that both the frontal lobe and left and right temporal lobes dictate which scenes the brain will remember and store up as a memory. The researchers found that the verbal memories of an experience are encoded in the left frontal regions, while the spatial and visual aspects of the same experience are encoded in the right frontal regions.
Why the brain picks out certain pictures or words to remember is not entirely clear, but the researchers suspect that it may have to do with a person’s previous experiences and the time that it takes to process the information. For example, you are more likely to remember a picture of your hometown than a picture of a place you have never visited.
A study carried out by scientists at the Salk Institute for Biological Studies in California, showed that the brain, with the help of new brain cells that are generated every day, is able to establish when a particular event happened and then store up that information as a memory.
Although the brain does not give events a specific time stamp, such as February 15, 2011, events are remembered with the help of other memories that occurred around the same time. So, the brain will be able to establish whether a certain memory happened before or after another one.
According to neuroscientists, if the same neurons are active during two separate events, your brain may link these memories together, which causes you to associate them with each other when you think back on them.
For example, if you went to a friend’s birthday party on Monday morning and then went to see a movie with that same friend on Friday night, you might remember these separate events as occurring on the same day, although in actuality they were days apart.
You are more likely to remember a picture of your hometown than a picture of a place you have never visited…
This is because the same young neurons that were active during your friend’s birthday party were also active when you went to see a movie with the same friend, which links these events closely in your memory. According to researchers, even events that happened as far as several weeks apart may be remembered together.
Have you ever smelled a bar of soap in a bathroom or taken a bite of a freshly baked pie and suddenly been transported back to an event that took place in your childhood? This is because your brain cells link this smell or taste to the event that happened in your childhood, even if the event was completely unrelated to the pie or soap.
Although you may not have necessarily eaten a piece of cherry pie on your first day of school or washed your hands with lavender soap after winning your first soccer match, your neurons associate the taste or smell with that event because it happened around the same time.
Of course, the young brain cells only play a small part in the forming of memories, but scientists believe that this finding may help them in finding effective treatments for conditions where new brain cells don’t form as they should, such as Alzheimer’s, Parkinson’s and even depression.
Image by Ethan Hein