Biology 202
2004 Second Web Paper
On Serendip

Do remember the series finale for the television sitcom, Full House, in which the youngest daughter, Michelle fell off her horse while trying to jump a log and developed symptoms of amnesia? Luckily, for Michelle, her memory was restored and she returned to a full functioning state. We would all like for this happy conclusion to occur in the lives of those we know who are suffering from the memory loss deficit known as amnesia. However, we all know that images on television are sometimes false and are methods for producers to draw viewers away from the melancholy of their life and into the arena of happiness and goodness. Though Michelle's accident did make us aware of amnesia, some of us may not understand how one gets amnesia, its various types, and how it is cured. This will be explained in this paper. So sit back, relax and enjoy the show.

The brain performs main functions such as storing, processing and drawing on memory. "Amnesia is a profound memory loss which is usually caused either by physical injury to the brain or by the ingestion of a toxic substance which affects the brain...memory loss can be caused by a traumatic, emotional event."(1). Memory loss may result from bilateral damage to the limbic system and the hippocampus in the medial temporal lobe, which are parts of the brain that are vital for memory storage, processing, or recall. When someone has amnesia, tissues in the temporal lobes of the brain are destroyed along the medial borders. Amnesia is a symptom of various neurodegenerative diseases. Individuals having lost his or her memory are described as amnesiacs. Syndromes and diseases such as Wernicke-Korsakoff syndrome and herpes can cause amnesia by damaging the brain's memory centers from the use of substances such as alcohol or by infections in the brain tissue. Some medical treatments such as Magnetic Resonance imaging (MRI) and Psychological testing called neuropsychological testing can be very helpful in determining the presence of amnesia.

Amnesia is an inability to form or retrieve memories and is a defect in declarative memory. Declarative memory is known as cognitive system, stores facts and events that are accessible to conscious recollection. It is located inside the medial temporal lobe, medial thalamus, and orbital prefrontal lobe of the brain. The hippocampal system, which "contributes to (1) the temporary maintenance of memories and (2) the processing of a particular type of memory representation,"(2). is what is first affected during memory loss. It also plays a vital role in memory and learning because it secures the link between immediate memory and the long-term storage. Although amnesia results from medial temporal lobe damage, there have been cases in which severe amnesia can occur without the hippocampus being damaged. That is only if the cortical areas surrounding the hippocampus are infected.

When someone has amnesia, he or she has difficulties recalling old and/or new information. The three main types of amnesia are anterograde, retrograde and transient global amnesia. Anterograde is the inability to remember events that occurred after an incident. Though their short term memory many disappear, "victims can recall events prior to the trauma with clarity."(3). Common causes of this type of memory loss are Alzheimer's disease, stroke, and trauma. The patient cannot create new memories and can only recall what they know from the past. However, how is it that new memories of the present cannot be stored again by the brain? Anterograde is also called post-traumatic amnesia (PTA) because it usually follows a traumatic injury to the brain. When short-term memories are in the process of becoming long term, they go through consolidation. During consolidation, short-term memory is repeated and rooted for long-term admission. When one has anterograde amnesia, their short-term memory cannot be restored for access.

Retrograde amnesia is opposite from anterograde because it is the inability to remember events that happen before the incidence of trauma, "but cannot remember previously familiar information of the events preceding the trauma."(4). In other words, one cannot recall memories of the past. "A person who experiences physical trauma to the brain or an electroconvulsive shock may forget his past while retaining the ability to create new materials." (5). It can also encode memory for one's emotional behavior such as being happy, sad and ecstatic. If the hippocampus is damaged, the amnesiac will not be able to recall new memories but can recollect older memories. "Usually, when a person has a brain injury resulting in a memory disorder, there is some degree of both anterograde and retrograde amnesia. Often, the anterograde amnesia is more severe and more difficult to deal with." (6). The last type for amnesia is transient global amnesia, which is a brief cereval ischemia that produces sudden loss of memory that can last from minutes to days. Usually middle-aged to elderly people suffer from this. In severe cases, a person can be extremely confused and may experience retrograde amnesia that can last for several years.

What Michelle suffered from was retrograde amnesia; she was not able to remember events that happened before the accident. However, what was significant about her case as that she had a concussion after she fell off her "wild stallion". Concussion is a head injury that results in temporary loss of consciousness. Most often amnesia is usually caused by concussion. Michelle got amnesia because she only forgot what happened to her before her head injury. Therefore, if she had an argument with her father the night before, she would not have been able to remember it unless her father reminds her about it. When she was released from the hospital, Michelle's doctor did not diagnose her because the best way for her to recall her memories was being her family familiarizing her with the things she loves and having he go through her daily routine. This method works for some people but for other depending on the severity of their case, may be prescribed a drug called Amytal (sodium amorbarbital). Amytal helps them recover some lost memories. "Cognitive rehabilitation may be helpful in learning strategies to cope with memory impairment."(7). In addition, psychotherapy can be used for people who amnesia is caused by emotion trauma.

Memory is the persistence of learning over time. Memory impairment occurs with a variety of neurological conditions and is associated with symptoms such as cognitive and motor impairments, brain trauma and Parkinson's disease. Nevertheless, once one has amnesia, they have to try to relearn the things that they have forgotten and learn new information. "In the medical field, amnesia means a disturbance of long-term memory and a loss of memory caused by brain damage."(8). There are various prognoses for amnesia, depending on the type of amnesia and the severity of the case. The next time you get the rare opportunity to watch the last two episodes of Full House, you will be able to make links between what I have stated in this paper and how Michelle's behavioral pattern changes before, after, and during the memory loss.

1)Blueprint for Health: Amnesia, A Good Web Source

2)Two Component Functions of the Hippocampal Memory System, A Good Web Source

3)Amnesia., A Good Web Source

4)Blueprint for Health: Amnesia, A Good Web Source

5)Kinder, Annette and Shanks, David R. "Amnesia and the declarative/ nondeclarative distinction: A recurrent network model of classification, recognition, and repetition priming". Journal of Cognitive Neuroscience, July 1, 2001, v13 i5., A Good Book

6)What is amnesia? , A Good Web Source

7)What is amnesia? , A Good Web Source

8)Amnesia, A Good Web Source

Additional Sources:
9), A Good Book

10) Long. Charles J. PH. D. Physiological Psychology, 24. Memory., A Good Web Source

11)What is amnesia?, A Good Web Source

12)Cohen, Neal J. and Howard Eichenbaum. Memory, Amnesia, and the Hippocampal System. MIT Press: Cambridge, 1993, A Good Book

13)Memory., A Good Web Source


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