Memory and its Classification - Essay Example

The present research has identified that usually memory is classified as sensory memory, short-term memory, and long-term memory. Sensory memory matches approximately to the initial 200 - 500 milliseconds after an object is perceived. The ability to look at an object, and remember what it looked like with just an instant of observation, or memorization, is an illustration of sensory memory. With extremely brief presentations, observers often report that they appear to "see" more than they can in fact report.

The earliest experiments exploring this form of sensory memory were performed by George Sperling using the "partial report paradigm." Participants were presented with a grid of 12 letters, prearranged into three rows of 4. After a short presentation, participants were then played either a high, medium or low tone, telling them which of the rows to report. Founded on these partial report experiments, Sperling was able to demonstrate that the capacity of sensory memory was around 12 items, but that it diminished very quickly (within a few hundred milliseconds).

Because this form of memory diminishes so quickly, participants would see the rows, but be incapable to recall all of the items (12 in the "whole report" procedure) before they decayed. This type of memory cannot be extended via rehearsal. Some of the information in sensory memory is then transmitted to short-term memory. Short-term memory lets one recall something from more than a few seconds to as long as a minute without practice. Its capacity is also very restricted.Estimates of the capacity of short-term memory are on the order of 4-5 items, and we know that memory capacity can be amplified through a process called chunking.

Short-term memory is believed to rely mostly on an auditory code for storing information and to a smaller extent a visual code. Conrad found that participants had more trouble recalling groups of words that were acoustically alike e.g. dog, fog, bog, log.