Having done work with traumatic brain injury clients, I have come to understand memory in a different light then I ever thought I would. Growing up, I can’t say i actually spent any significant time thinking about memory, but given how significant memory actually is in our lives, I think it deserves more respect than most people give it. Memory is the foundation of our personality, the glue that holds together all of our relationships with family and friends, and determines a portion of our overall level of intelligence.
Development of memory is not independent and requires other cognitive abilities. The process starts with our attention. If we can not attend to the pen in front of us, then there is little hope that our brains will ever remember the pen. This is why people who have attention disorders will likely have poor memories. It is also why people with emotional distress (anxiety/depression) have poor memory. When you are anxious or depressed, your thoughts are often turned inward and are focused on thoughts/emotions. If attention is preoccupied with emotional distress then it is not free to attend to the environment. When attention focuses on something the information is collected by our senses (eyes, ears, skin etc).
Our senses receive the visual and auditory information from our environment and transform the information to neural signals that move into the brain. This information goes into our working memory, where we hold it temporarily. When I describe the working memory, I often refer to it as a juggler. This is the part of the memory process where we are actively using information. An example is when you are reciting a phone number over and over in your mind, or repeating a name that you are trying not to forget. The working memory brings in information from the sensory systems, holds it while the brain pulls from previous memories to identify what the sensory system is experiencing. This combines bottom up and top down processing1. So if we see a pen, our senses bring in information (color, size, lack of sound, texture, etc) and the working memory takes all these bits of information and holds them while our brain scans previous stored memories until it finds a match, thus being able to identify the object as a pen.
Once information is identified, the process of memory formation begins. The first stage is encoding of the information. Some people with awesome encoding skills are capable of seeing something once and it sticks. If your encoding abilities are not intact, then you need numerous exposures to something for the information to stick. This is why repetition and exposure to something will likely lead to remembering it. For example, people who struggle with encoding will need many encounters with Sally before they are able to remember her name. After the information is encoded it is stored in the brain. The next stage is retrieval. This is the ability to pull information out of the memory. When someone has difficulty with retrieval the information is there and stored but they are unable to recall it. Think of a time when you knew something, it was on the tip of your tongue but you were unable to recall it until someone gave you a hint or triggered the memory. Then the whole memory was accessible to you. This is the recall process.
Typically, when someone thinks of memory they think of episodic and semantic memory. Episodic memory2 is our memory of personal events. These memories are our history, our life story. They recount childhood birthday parties, first kisses, the birth of your child and more. They are autobiographical in nature and are made up of long term and short term memories. Without going into too much psychology, memories of our past also have a significant impact on the development of our personality and moods. Memories of traumatic events can stay with us, impacting how we act and feel. Also, fond memories about childhood friendships can significantly impact how we make/maintain current friendships. Memory also allows us to form relationships. It’s very hard to develop a relationship with someone if you can’t remember previous times with them. Ever see the movie “50 First Dates”?
Semantic memory3 is comprised of factual information. Examples of semantic memory are things that you learn in school, and things that you read in the newspaper. It is factual knowledge about the world around you. I have been lucky to work with a wide range of intellectual abilities and have noticed that people who are generally considered to be very intelligent alway have magnificent memories. These individual have an amazing attention and the ability to process information very quick, multitask without missing a beat, and retain important or subtle information which they can accurately recall after only one exposure. This helps them remember much more information that they have learned over the years, increasing their crystalized intelligence4 levels. There are other attributes that are common among geniuses but I feel that memory is possibly one of the most significant.
Given the significance of memory, it is important to work on improving our memory when ever possible. Cognitive games are a great way to work on this, assuming that they are constantly challenging your limits. You want to work at a level that is not too easy because this is not helping develop your abilities and not too hard because you wont learn from that if you can never complete the task. There are memory techniques such as chunking or mnemonic devices that can help with retaining and retrieving information. Chunking5 information reduces the number of things you need to remember. For example, instead of remembering a 10 digit phone number (1234567891) you can chunk the information into five numbers (12, 34, 56, 78, 91). Mnemonic devices6 are ways to organize information so that you are able to trigger the information that you are struggling to recall. For example in school we learned the sentence “My Very Energetic Mother Just Served Us Nine Pickles” to help remember the planets (yes I know Pluto has since been reclassified but this is the one I learned). The first letter of each word represents a planet (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto). You can also use HOMES to remember the Great Lakes with each letter representing a lake (Huron, Ontario, Michigan, Erie, Superior). When working with children, try games that require memory such as go fish, or the card game memory. Gradually increasing the number of information pieces being used will lead to an effective and challenging level to work at.
This barely touches on all the wonderful ways memory makes our lives better, and is by no means meant to encompass all aspects. I hope it helps to break it down into understandable parts.