Sensory Memory
The world is filled with sights, sounds, and many other kinds of sensory stimulation, but you don’t remember all of them. When you first receive a particular stimulus, it is held for only a fraction of second in what is known as the sensory memory.
What Is Sensory Memory?
Sensory memory is a repository that makes able to store sensory experiences temporarily as they are produced. It refers to an initial process that holds environmental information in its raw form for a brief period of time, from an instant to several seconds.
Sensory memory is the stage of memory Opens in new window first encountered by a stimulus. Sensory memory holds impressions briefly, but long enough so that series of perceptions are psychologically continuous.
The purpose of sensory memory is to maintain the representation of a stimulus long enough so that it can be recognized.
For example, you hear the sound of a lone saxophone player. When these sounds first reach your ears, they are held in sensory memory for a second or two. During that brief time, you recognize the sounds as music and next decide whether or not to listen further.
Sensory memory uses a short-term storage area called the sensory register Opens in new window (otherwise known as sensory store).
If you do not listen or pay attention to the sounds in sensory memory, they automatically disappear without a trace. If you do listen or pay attention, however, the auditory information is transferred into its sensory store—another memory process called short-term memory Opens in new window.
Sensory memory operates automatically, and if we quickly switch our attention to our sensory store, we may be able to interpret what is in it.
Types of Sensory Memory
There are different forms of sensory memory—there is one for each of the five senses.
Each of these forms has different characteristics, however, the two commonly researched that each represent visual– and auditory sense are briefly discussed below.
- Iconic Memory
Iconic memory Opens in new window is a visual sensory memory. It holds a brief “snapshot” of what you have just looked at. Iconic memory has a very short duration; it lasts only about 250 to 300 milliseconds (Averbach & Sperling, 1961; Sperling, 1960).
- Echoic Memory
Echoic memory Opens in new window is an auditory sensory store. You can think of it as an “echo” of what you have just heard. It lasts considerably longer than iconic memory, on the order of several seconds longer (Darwin, Turvey & Crowder, 1972).
The coding or representation of information in sensory memory thus varies with the modality. Iconic memory stores visual representations; echoic memory, auditory ones.
See also:
- M. W. Eysenck (1994) Perspectives on psychology (Hove, UK: Psychology Press).
- A. E. Wadeley, A. Birch, and A. Malim (1997) Perspectives in psychology (2nd Edn.) (Basingstoke, UK: Macmillan).
- J.C. Berryman, D.J. Hargreaves, C.R. Hollin, and K. Howells (1978) Psychology and you (Leicester, UK: BPS Books).
- C. Tavris and C. Wade (1997) Psychology in perspective (New York: Longman).
- W.E. Glassman (1995) Approaches to psychology (Milton Keynes, UK: Open University Press).
