Who am I? An Examination of Memory and Identity

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Liz Frontino                                                                                                                                                           2/23/10                                                                                                                                                         

 

Who am I? An Examination of Memory and Identity

In addition to the connections between our neurons, what makes each one of us unique? What makes us who we are? Our experiences and memories help to shape us as individuals. In particular, our memories provide a foundation for our own unique individuality. 

Memory is the ability of humans to recall and conjure long-ago specific events from our lives (4). There are three main subdivisions of memory: the working memory which is stored in the prefrontal cortex, Long-term memory which is stored in the hippocampus and skill memory in the cerebellum (7).  All of these types of memory have some contribution to our identity, as we build on them when creating new memories. In addition to providing us with information on how to act or respond to situations and how to behave socially, the process of remembering has extreme identity-related abilities (4). 

In clinical terms, Amnesia, False Memory Syndrome and Alzheimer’s give perspective on memory’s importance. Global or generalized amnesia is defined as the total loss of a person's identity as a result of some sort of trauma, affecting personal memory but no loss in terms of general knowledge (5). Those suffering from amnesia are at a loss of identity, having no memories to draw back on. In addition, False Memory Syndrome (FMS) is a condition in which a person's identity and relationships with those around them are centered on memory of a traumatic experience. This memory is actually fictitious and never occurred in reality, but the individual is firmly convinced of its truth. The existence and impact of FMS gives another example of how deeply our own personalities and identities are affected by our individual memories (2). Regardless of the actuality of the event, memory can become the center of an individual’s personality. Alzheimer’s patients show another trend toward identity loss and loss of personal knowledge. The disease itself appears to attack the hippocampus, where long term memory is stored. Because only long term memory is the only one affected, Alzheimer victims can still perform the daily tasks associated with working memory (1). However, long-term memory is still affected in an extreme way. Those suffering from Alzheimer’s have to be told about their interests, hobbies, and favorite people (1). They are not aware of who they are as individuals because they do not have the memories of their life to draw back on. Comparisons with healthy older individuals shows that affected persons may also have a weaker sense of self as well as a “more abstract, more vague, and less definite sense of self” than their healthy counterparts (1). In addition, studies on Dementia have found a link between progression of the illness and the deterioration of finding a self-identity (1). 

Extremely intense events that occur in a person’s lifetime can create a sort of post-traumatic stress reaction in which a person’s life and identity is fixated on one specific event. For example are the case of post-holocaust identities. Individuals who have experienced the holocaust are considered to have suffered extreme trauma. The memory of this trauma has continued to haunt and shape the identities of holocaust victims, showing that their identities are not only centered around their memories, but especially one memory in particular (6). The intense nature of the memory creates an identity that is completely shaped around one particular occurrence. 

One can be conscious in each passing moment, but what does that mean if each moment has no memory attached to it? The fact is that memory is not equivalent to consciousness, it is the base from which we decide to act. We mentally refer each impulse to act to connected memory, which then leads to a decision between whether to act based upon what memory advises or select a devious impulse. Without memory either the strongest impulse would simply win out, or no impulse would be stronger than the others and there would be no action. The nervous system is constantly changing and adapting as a result of new knowledge, which eventually all becomes memory. The advance of the nervous system’s adaptability allows each individual to further progress and learn from previous experiences, mistakes, and knowledge. 

Another strong suggestion for contributions to identity involves the brain’s default mode network. If evidence for memory and identity shows a strong correlation, how might the default network fit into this? The default mode network, the portion of the brain that is active while the rest of the brain is particularly un-active, is responsible for life simulations, maintaining the crucial connections among and between brain cells and providing individuals with a sense of self and identity (9). Might there be a connection between the default network and memory? If stimulus-independent thought is considered, some memories which are not triggered by any outside force could indeed be a part of this default network. 

Some new data may show that there is indeed a connection between memory and the default network. These data suggest that the activity in the default network is sustained and less disrupted when an implicit memory task is performed, but is suspended when explicit retrieval is required. These results provide evidence that the default mode network is associated with unconscious processing when human subjects perform an implicit memory task. (8). Alzheimer’s research shows a connection between episodic memory processing and the default mode network. Default mode network in Alzheimer’s patients show a specific relationship between the hippocampus and the default network in addition to a faulty default network in these individuals (3). Indeed, our memory may play a greater part in our personalities and identities than we are able to know at this given time. 

 

References: 

 

1) Caddell, Lisa S., and Linda Clare. "The impact of dementia on self and identity." Clinical Psychology Review 30 (2009): 113-26. Web. 

2) Flannery, Kathleen. "False Memory Syndrome And The Brain." Serendip's Exchange. Web. <http://serendip.brynmawr.edu/bb/neuro/neuro03/web2/kflannery.html>. 

3) Greicius, Michael D., Gaurav Srivastava, Allan L. Reiss, and Vinod Menon. "Default-mode network activity distinguishes Alzheimer's disease from healthy aging: Evidence from functional." Proceedings of the National Academy of Sciences of the United States of America 101.13 (2004): 4637-642. Web. <http://www.pnas.org/content/101/13/4637.full>. 

4) "Memory." Stanford Encyclopedia of Philosophy. Web. <http://plato.stanford.edu/entries/memory/>. 

5) Miller, MD, John L. "Amnesia." At Health Mental Health. Web. <http://www.athealth.com/consumer/Disorders/Amnesia.html>.

6) "Post-Holocaust Identity." University of Toronto. Web. <http://www.utoronto.ca/wjudaism/journal/spring2002/abramovich.html>. 

7) "Sheep Brain Dissection: The Anatomy of Memory." Exploratorium: the museum of science, art and human perception. Web. <http://www.exploratorium.edu/memory/braindissection/index.html>. 

8) Yang, Jiongjiong, and Et al. "Sustained activity within the default mode network during an implicit memory task." Cortex 46.3 (2010): 354-66. Science Direct. Web. <http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B8JH1-4W9XF1P-5&_user=400777&_coverDate=03%2F31%2F2010&_alid=1215696450&_rdoc=1&_fmt=high&_orig=search&_cdi=43685&_sort=r&_docanchor=&view=c&_ct=234&_acct=C000018819&_version=1&_urlVersion=0&_userid=400777&md5=087f85435cce77baccac1eb2b3517996>. 

9) "You Are Who You Are By Default -." Science News. Web. <http://www.sciencenews.org/view/feature/id/45178/title/You_Are_Who_You_Are_by_Default>.

 

 

 

 

 

 

 

 

 

Comments

Paul Grobstein's picture

memory, identity, and neurons

"In addition to the connections between our neurons, what makes each one of us unique?"

Is memory, the default network, and identity "in addition to" our neurons and connections between them?  Or are there all different expressions of neurons/connections?   Can one memory without consciousness?  Maybe memory is actually constructed by the brain, part of the brain's actions rather than the  "base from which we act"?  For some additional recent discussion, see Manipulations of memories and forum discussion there.   See also Behavior without memory and my comment following. 

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