Short-term memory

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Short term memory is the ability to keep information in mind for a short amount time, such as remembering a phone number long enough to find a piece of paper. The mind is able to store memory that is learned recently for a small period of time for use again. The amount of time the mind is able to do this is usually within seconds. The opposite of short-term memory is long-term memory, which is where things can be stored in the mind for a long time to be recalled later.

Memory[change | change source]

Memory is what goes on in the brain in storing and retrieving past experiences. These processes do what we call remembering. Memory is the foundation of intelligence and the ability to adapt from learning.[1]

Information about a needle being sharp and hurtful when touched by bare hands is processed to make a response of survival and self-preservation. This leads to us (and other animals) to change what we do when we met needles a second time. Memory, which starts out as short-term memory allows for learning, and helps intelligent behavior.

Basis of memory[change | change source]

Donald Hebb (1904-1985) was the first to come up with a way to tell the difference between short-term and long-term memory. When the brain receives an input, like something that is seen or heard, a sensory memory keeps a copy of what is seen or heard, but this memory lasts for only about a few seconds. Anything that is retained in the brain longer depends on our selective attention, things that we "notice" are kept in short-term memory for up to a few minutes. This memory is thought to be dependent on electrical activity in the brain and is easily destroyed by interruption or interference. [2] Short-term memory includes iconic memory as well, which holds visual images; acoustic memory, to hold sounds; and working memory, which is an active process to keep a memory until it is put to use.

Memories which are stored for longer than this are called long-term memory. Hebb had a theory of long-term memory as a change in the strength of connections between the neurons. Long-term memory is relatively permanent storage and the process involves the creation of new proteins.

Whether or not the information is stored in long-term memory depends on its importance. Usually for animals memories that are made during times of stress and discomfort are important for adaptive values. In the future they help avoid anything that will bring them stress. This is among the many other reason a memory may become a long-term memory simply due to the nature of the mammal and what the memory itself relates to.

Duration[change | change source]

Short-term memory has a limited duration, and the contents decay over time.[3] The decay idea is usually paired by the idea of repeating the memory over and over. In order to overcome the limitation of short-term memory, and retain information for a longer amount of time, it has to be repeated either by saying it out loud of by saying it mentally repeatedly.[4] By doing this the information will re-enter the short-term process and be kept for a further period.

Capacity[change | change source]

Forgetting greatly limits the information that can be kept over a short period of time. The capacity of short-term memory is finite, but there is no clear unit of measurement for what that is. Memory span is the term used to describe this, where there is only a certain amount of information that can be memorized over a short period until it is lost.[5]

Factors affecting[change | change source]

The capacity of short-term memory leads to the question of the capacity of short-term memory as a whole. At present there is no way of telling whether a piece of information will be stored as short-term memory or not. In an experiment done to determine the capacity of short-term memory individuals had to memory a list of items and recall it, and it was suggested that the span of their short-term memory was reached when they could no longer remember the list in order.[6]

There are many conditions that can impact short-term memory they can range from simple distractions to serious disorders. The loss of memory is natural and is expected with aging. By the age of 55 it is found experimentally that the loss of memory starts to occur which usually occurs more often with long-term memory loss, age very much affects the short-term memory as well.

There are many other facts, which affect memory loss beside advanced age, many disorders such as Alzheimer’s disease, Aphasia, Schizophrenia, Advanced age, and Posttraumatic stress disorder are linked to the loss of memory.[7] [8]

References[change | change source]

  1. Baddeley, Alan D.; Thomson, Neil; Buchanan, Mary (1975). "Word length and the structure of short-term memory". Journal of Verbal Learning and Verbal Behavior 14 (6): 575–589. doi:10.1016/S0022-5371(75)80045-4. 
  2. Poirier, Marie; Saint-Aubin, Jean (1996). "Immediate serial recall, word frequency, item identity and item position". Canadian Journal of Experimental Psychology/Revue canadienne de psychologie expérimentale 50 (4): 408–412. doi:10.1037/1196-1961.50.4.408. 
  3. Baddeley, Alan (2000). "The episodic buffer: a new component of working memory?". Trends in Cognitive Sciences 4 (11): 417–423. doi:10.1016/S1364-6613(00)01538-2. 
  4. Davelaar, Eddy J. et al (2005). "The demise of short-term memory revisited: empirical and computational investigations of recency effects". Psychological Review 112 (1): 3–42. doi:10.1037/0033-295X.112.1.3. 
  5. Miller, George A. (1956). "The magical number seven, plus or minus two: some limits on our capacity for processing information". Psychological Review 63 (2): 81–97. doi:10.1037/h0043158. 
  6. Heuer, Friderike; Reisberg, Daniel. "Vivid memories of emotional events: The accuracy of remembered minutiae". Memory & Cognition 18 (5): 496–506. doi:10.3758/BF03198482. 
  7. Miller, George A. (1956). "The magical number seven, plus or minus two: some limits on our capacity for processing information.". Psychological Review 63 (2): 81–97. doi:10.1037/h0043158. 
  8. Fournet, Nathalie et al (2012). "Evaluating short-term and working memory in older adults: French normative data". Aging & Mental Health 16 (7): 922–930. doi:10.1080/13607863.2012.674487.