Memory in the Brain
Have you ever wondered how memories are formed or where they are stored in the brain after formation? The following text consists of a discussion on the aforementioned topic. Six questions regarding how memories are formed and maintained in the brain through the actions of neural circuitry are addressed below.
The first question centers on the differences and similarities between working memory and long-term memory. Matlin (2009) defines working memory as the “brief, immediate memory for the limited amount of material that you are currently processing” (p. 99). Matlin (2009) then explains that long-term memory has a large capacity and it stores memories from throughout your lifetime. Working memory and long-term memory are similar as they are both a holding place for memories. Working memory differs, however, from long-term memory, as it does not have enough room to store as much material (Corbin & Camos, 2011). It has a limited capacity and it is constantly functioning (Corbin & Camos, 2011). Long-term memory on the other hand does not have a limit, as it has more room for storing experiences and information that has accumulated (Matlin, 2009).
Richard Mohs, a notable researcher, describes that memory is a process. It starts with encoding, then storage, and last is retrieval. In the process of encoding, perception is involved. In the hippocampus, perceptions are wrapped into one to form one specific memory. To encode memories in the brain, a neural circuit is needed. The points of action in the brain are synapses. A synapse is where nerve cells meet other cells. In the gaps between the cells, electrical pulses carrying messages leap to get from one to the next. When the pulses do this, it prompts the discharge of neurotransmitters. Neurotransmitters then diffuse across the gaps and attach themselves to other cells. “Each brain cell can form thousands of links like this, giving a typical brain about 100 trillion synapses” (Mohs, 2013, p. 2.4).
The connections between the brain cells are constantly changing every time new experiences are introduced. If a person repeats the same experience, such as dancing the same routine, then with each time the routine is done, the connections between the cells are getting stronger. The same cells are being fired repetitively, and that helps the brain to repeat this firing the recurring times (Mohs, 2013).
Just like the connections in a person’s brain, a person’s memory is constantly adapting and changing throughout that person’s lifetime. As new experiences are introduced, new memories are made. Take a baby for instance. When babies are born, they are new to the surrounding world. As they grow up, they see, learn, and experience new things. This occurs throughout their entire life and their memory is growing and adapting with them. Forgetting can also be adaptive. In negative situations, a person could choose to forget the things they saw and the experiences they had. Two examples of when this might happen are childhood abuse and war. In these cases, it could be adaptive to forget if the memory is too painful.
Memories can be accurate, but there are many factors that can influence memory. For instance, a study was done on misinformation being given to subjects. These studies demonstrate “that exposure to misinformation can lead to distortions in memory for genuinely experienced objects or people” (Morgan, 2013). Another factor that influences memory is stress. When stress hormones become over-secreted, it has a negative effect on brain function and memory (Franklin Institute, 2004). “Too much cortisol can prevent the brain from laying down a new memory, or from accessing already existing memories” (Franklin Institute, 2004, p. 3.1). Cortisol can interfere with neurotransmitters, and this has a negative effect on memory because as previously mentioned, neurotransmitters are what the brain uses to communicate. (Franklin Institute, 2004)
For individuals suffering from problems like poor memory or post-traumatic stress disorder, also known as PTSD, knowledge of the brain and memory systems can be beneficial. This is because the problem stems from the brain and memory systems. Knowledge regarding where the issue is coming from can direct efforts to help those individuals suffering from memory problems. Poor memory, for instance, is an issue that can be resolved with increased knowledge of how memory systems work. If a person has poor memory, he or she could employ a memory technique to help with remembering things.
A study was done on Vietnam veterans and veterans from the Gulf War regarding PTSD. The findings showed that extreme stress affects areas of the brain and arousal mechanisms (Vasterling, 2002). It was found that “weaknesses involving sustained attention, working memory and new learning may be attributed to disordered arousal and dysfunction of the prefrontal cortex, and possibly, to a lesser extent, the hippocampus” (Vasterling, 2002, p. 10). Knowing where the issue is resulting from, helps to get the issue addressed. Vasterling recommends preventative training that deals with coping skills for the veterans (Vasterling, 2002). Rehabilitation should focus on internal strengths and could employ the use of external memory aids such as calendars or notepads (Vasterling, 2002).
As learned above, environment can play a role in how memories are formed and maintained. For instance, a negative environment such as a traumatic childhood, some clinicians believe could lead to problems in the area of memory storage and retrieval (American Psychological Association, 2013). Clinicians have also proposed that sexual abuse in childhood can lead to problems in dissociation or delayed memory (American Psychological Association, 2013). A few studies have been done regarding how environment affects memory, but more specifically, what happens when lack of sleep is involved. Prehn-Kristensen and others did a study regarding visual memory and sleep and found that 10-13 year olds had improved visual memory after sleep (Potkin, Bunney, and Garcia, 2012). Katya Potkin also performed a sleep experiment and found that when it came to the paired-associate test, participants with sleep had higher performance results than those with no sleep (Potkin, Bunney, Garcia, 2012).
The brain is an intricate organ. It is responsible for many functions, and one of those functions is memory. Neural circuits are formed in the brain and these are what guide the brain to complete functions. The brain is not only responsible for the formation of these memories, but it then has to store the memories for later retrieval as well. To answer the question from earlier, the formation of memories is a process that neural circuits are responsible for, and once they are formed they are stored in working memory for a short period of time or long-term memory over a long period of time.
American Psychological Association. (2013).
Corbin, L., & Camos, V. (2011). Improvement of working memory performance by training is not transferable. Europe's Journal Of Psychology, 7(2), 279-294.
Matlin, M. W. (2009). Cognition (7th edition). Hoboken, NJ: John Wiley and Sons.
Mohs, R. (2013). How Human Memory Works.
Morgan III, C., Southwick, S., Steffian, G., Hazlett, G., Loftus, E. (2013). Misinformation Can Influence Memory for Recently Experienced, Highly Stressful Events. International Journal of Law and Psychiatry, Volume 36, Issue 1, January–February 2013, Pages 11-17
Potkin, K., Bunney Jr., W. E., & Garcia, A. (2012). Sleep Improves Memory: The Effect of Sleep on Long Term Memory in Early Adolescence. Plos ONE, 7(8), 1-4. doi:10.1371/journal.pone.0042191
The Franklin Institute. (2004). How Your Brain Responds to Stress.
Vasterling, J. (2002). Intellectual Resources may Help Soldiers Stave off Post-Traumatic Stress Disorder. American Psychological Association.
Dr Billy Kidd from Sydney, Australia on May 16, 2015:
Good summary about brain function and memory!