Sensory Memory

Sensory memory is the very first stop for any incoming information. It has a large capacity — it can register information arriving from every one of our senses, and it does so with reasonable accuracy, essentially as an exact replica of the stimulus. Its major limitation is duration: information here decays automatically and is lost in well under a second unless it is picked up by the next stage. Because information from every sense is registered here, sensory memory is sometimes called a sensory register, and different senses have their own named registers. The visual register is called iconic memory, and the auditory register is called echoic memory. Two everyday experiences illustrate these registers directly: the trailing streak of light you briefly see after a bulb is switched off is an example of an iconic (visual) after-image, and the faint reverberation you seem to hear for an instant after a sound has actually stopped is an example of an echoic (auditory) trace. Since sensory memory holds on to a …