In psychology, memory is an organismâ€™s ability to store, retain, and subsequently retrieve information.
Traditional studies of memory began in the realms of philosophy, including techniques of artificially enhancing the memory. The late nineteenth and early twentieth century put memory within the paradigms of cognitive psychology. In recent decades, it has become one of the principal pillars of a branch of science called cognitive neuroscience, an interdisciplinary link between cognitive psychology and neuroscience.There are several ways to classify memories, based on duration, nature and retrieval of information. From an information processing perspective there are three main stages in the formation and retrieval of memory:
Encoding or registration (processing and combining of received information) Storage (creation of a permanent record of the encoded information)
Retrieval or recall (calling back the stored information in response to some cue for use in a process or activity)Sensory memory corresponds approximately to the initial 200 – 500 milliseconds after an item is perceived. The ability to look at an item, and remember what it looked like with just a second of observation, or memorization, is an example of sensory memory. With very short presentations, participants often report that they seem to â€œseeâ€ more than they can actually report. The first experiments exploring this form of sensory memory were conducted by George Sperling using the â€œpartial report paradigm.â€ Subjects were presented with a grid of 12 letters, arranged into three rows of 4. After a brief presentation, subjects were then played either a high, medium or low tone, cuing them which of the rows to report. Based on these partial report experiments, Sperling was able to show that the capacity of sensory memory was approximately 12 items, but that it degraded very quickly (within a few hundred milliseconds). Because this form of memory degrades so quickly, participants would see the display, but be unable to report all of the items (12 in the â€œwhole reportâ€ procedure) before they decayed. This type of memory cannot be prolonged via rehearsal.