Wednesday, December 1, 2010

Essay 2: Long and Short-Term Memory


Stebbing
Stephanie Stebbing
Professor Kerr
En 101-5
10/4/10
Long and Short-Term Memory
A person’s capacity for long-term and short-term memory depends heavily on their age. Seniors often have a shorter capacity for memory storage than children and adults do because of memory loss and cognitive and memory diseases such as Alzheimer’s. Long-term and short-term memory differ in that long-term is used to store memories about the world and life, and these memories can be retrieved at any given time, while short-term memory is the working memory that is used to store all the current information for use right now. Both types are essential for survival to humans and even some animals because we rely on it to help us understand how to do things, it helps us to obtain higher-level thinking skills and speech, and it defines our person by giving us individuality and identity. Long-term memory includes memory for skills, habits, procedures, and instinctive reflex responses. Short-term memory includes memory for selective attention and gaining new current information. Memory is stored the easiest in adults and children, because children have not yet developed a sense of the world or put meaning to much information, and adults have a healthy working memory based on all their previous knowledge of the world.
Scientists and researchers used to believe that a child possessed absolutely no memory skills until they were about eight or nine months old. Recent studies have proved that babies and young children do, in fact, possess some memory skills. A study called Total Recall, published an article in American Baby Magazine in 2000, which shows that at six weeks old, babies can hold information in their long-term memory for up to 24 hours (Hollowell). Memory capacity increases in children as they get older. Jerome Kagan, a Starch research professor of Psychology at Harvard University, conducted experiments with the help of one of his senior students, Conor Liston, to find out when humans start to develop their long-term memory. Their findings showed that children have a hard time recalling the past before age one. "We interpret this to mean that, at 9 months, the human brain is too immature to firmly register experiences, while at 17-21 months it has developed enough to record and retrieve memories of single distinctive experiences," Kagan says (Cromie). Kagan and Liston’s studies, as well as hundreds of other research experimenter’s studies on memory development in children prove that children begin developing their long-term memory after age one.
The average person can hold seven bits of information in their short-term memory at once (Saundra K. Ciccarelli and J. Noland White). However, adults often have short-term memory problems due to an inability to filter out surrounding distractions. An fMRI (functional magnetic resonance imaging) study done by researchers at the University of California, Berkley, show that adults’ short-term memory failure is an effect of interference from irrelevant information. Study leader, Dr. Adam Gazzaley, is the adjunct assistant professor of neuroscience at UC Berkley and newley appointed assistant professor of neurology physiology at UC San Francisco. Commenting on the subject, Gazzaley states, “These results reveal that efficiently focusing on relevant information is not enough to ensure successful memory. It is also necessary to filter distractions. Otherwise, our capacity-limited short-term memory system will be overloaded.” (Sanders)
Memory is classified by time (short-term and long-term) and type (what specific information you have to recall). Different types of information is stored in different parts of the brain, all of which are part of the nervous system. The hippocampus, a structure inside the brain, helps store your long-term memory. It is highly vulnerable to age-related deterioration and can have an effect on your ability to retain information. Neurons in the brain are lost, increasingly over time, which causes the activity of the neurotransmitters and their receptors to slow down. An older person usually processes nutrients that enhance brain activity less efficiently than a younger person. All of these are contributing factors to memory loss in senior citizens (Jaffe-Gill, and Kemp).
Long-term and short-term memory are both necessary to human survival. It defines us as individuals because we each have our own past and our own memories. It allows us to accomplish simple as well as complicated tasks, and allows us to remember processes in which we may need to remember for a job, writing a school paper, or even simple processes such as how to cook a meal. Memory capacity decreases with age, yet is close to nonexistent before the age of one. Children start developing long-term memories at twelve months of age. Adults can have a large capacity for long-term memories, but a small capacity for short-term memories due to distractions and stress. Seniors process information slower, so it takes longer to be stored in their long-term memory, and also fades quickly.

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