Memory - Your Life Story
Making a memory is a very complex procedure. To make a memory we need to capture a strong input signal that is able to make it through the barriers imposed by working memory (vulnerable to distraction, limited capacity and short duration) and the magic of the hippocampus in consolidating and embedding the memory input signal into long-term memory. This process makes you appreciate even more how our brains work. I want to expand on that base of knowledge about memory and help you understand how our lifestyle and aging can disrupt this whole process. More importantly, I want to give you some tips to assist your memory and make it stronger.
Let’s take a look at the types of memory through classification. First there is classification of memory by information. Declarative memory (explicit memory) requires conscious recall of past events. Then there is procedural memory (implicit memory) which includes the learning and memory of motor skills. This memory takes place in the cerebellum and basal ganglia of the brain. Actions through this memory path are automatically translated into actions.
Now let’s look at memory though the classification by temporal direction. That simply means that we are looking at past and future memory. Retrospective memory includes semantic, episodic, and autobiographical memory where context of the memory is in the past. Prospective memory encompasses future intentions, such as, ‘I need to remember to set the clock when I get home’.
Types of Memory Failure
Now it is time to look at the types of memory failure.
Transcience memory failure means that memories degrade as time goes by. This failure occurs in the storage phase of memory – after storage but before retrieval. It can happen in short-term and long-term memory. The general pattern is that information is rapidly forgotten during the first couple of days or years. Then that loss is followed by small losses which increase later in days or years. Every time a memory is recalled it gains strength. If there is no recall happens during these time periods the strength of the memory decreases resulting in lack of recall.
Absentmindedness is a memory failure due to lack of attention. Attention plays a role in the strength of the input signal and the storing of information into long-term memory. If no attention is given, the input signal isn’t strong enough to make it into long-term storage. You never made the memory so there is nothing to retrieve.
Now that you have all of the technical knowledge about memory (sort of takes the magic out of it), let’s see how our aging brains are affected. It is important to note that memory loss is different in normal aging as opposed to Alzheimer’s disease. That leap to dementia is one that we probably all worry about when we start experiencing memory difficulties. The truth is, memory performance occurs in the prefrontal cortex and that is an area of the brain that loses neurons as we age. It is a normal aging change even though knowing that might not be of much comfort. There are researchers that believe that memory lapses may be due to just simply having our brains be overwhelmed by the amount of information it takes in routinely. There is also evidence that the production of the neurotransmitter acetylcholine decreases as we get older. Acetylcholine is critical to learning and memory.
Memory and Sleep
It is time to talk about sleep and memory. Sleep is critical to memory because consolidation of memories from the day occurs while you are sleeping. During sleep the hippocampus plays the events from the day and decides which ones to keep. The neocortex then reviews and processes that information and then moves them on to long term memory. Sleep strengthens the neural connections and the opposite can happen when you don’t get enough sleep. If you don’t get enough sleep then it is more difficult to learn and the neural connections are not strengthened. If you are sleep- deprived you can actually experience false memories because they are properly transferred to long-term memory. It is critical to get enough shut-eye.
Emotions and Memory/Scent and Memory
There are two outside functions that assist with the memory process. Emotions can have a powerful impact on memory. When your emotions are heightened the amygdala get involved and allow stress hormones to strengthen the neural communication. Unfortunately, fear is the emotion that is most effective in kick-starting the amygdala. The strength and longevity of a memory is directly proportional to the amount of emotion experienced with the event. Odors are the other outside function that strengthens memory. When an event occurs in the presence of a scent the memory is encoded together. Scent and memory are primitive connections. You already experience this with holidays that have lots of scents – like Christmas and Thanksgiving. When you smell a scent associated with those holidays memories of past holidays come flooding back. You can intentionally embed memories by connecting a scent to the event. Take studying for an exam as an example. If you study with a scent, like lemon, and then take that scent with you for the exam you will recall more information. This is known as olfactory cueing.
Physical exercise is just good for the brain. Aerobic exercise can reverse some of the aging changes that occur in the brain. In fact, physical exercise stimulates the growth of new brain cells in the hippocampus, the center for learning and memory. This is cumulative however, so you need to be consistent in your exercising. Walk, swim, run or cycle at least 3-4 times per week for at least 30 minutes. You need to keep those new brain cells functional so you need to use them. Your brain loves a challenge, so find something mentally stimulating to do. It can range from taking a trip to playing a board game. Use your brain in activities you don’t normally do and your brain will reward you.
Good News about Memory and Older Adults
Now for some good news! Overall memory remains good for older adults throughout their seventies. You have to trust the research when it reports that seventy-year olds perform as well on cognitive tests as twenty-year olds. And, the older brain performs better on verbal intelligence than younger brains. There are some challenges with learning as you get older. But researchers have found that even though an older brain won’t learn as quickly as a younger brain, the older brain will learn and remember nearly as well. I am a testament to that belief. I was fifty-years old when I went back to graduate school. My colleagues were half my age. After the initial shock at the speed with which I had to learn, my brain adapted when I figured out my own way of studying. My brain loved my academic years. It isn’t a matter of not having the correct equipment to learn as you get older; the problem lies in not using our brain cells to capacity. The brain loves to trim cells and neural branches if they are not used.
I hope you create new memories on a daily basis. They all become our life story and that is worth protecting.
Now that you know how we lose memories it is important to capture your memories of your life. What you possess in your memory banks is a valuable resource to pass on to your family. Your story may be lost after you die because your memories died with you. Your life story can be your most important legacy that leave behind.
Mohs, R.C. (2015). How human memory works. Retrieved April 15, 2015 from, http://science.howstuffworks.com/life/inside-the-mind/human-brain/human-memory4.htm.
Memory. Retrieved April, 13, 2015 from, http://en.wikipedia.org/wiki/memory.
Memory and aging. Retrieved April 15, 2015 from, http://en.wikipedia.org/wiki/Memory_and_aging#Memory_decline_in_normal_aging.