Iconic Memory

What is iconic memory?

Iconic memory refers to the brief availability of visual information after a display disappears. It is a form of sensory memory, usually discussed on the scale of fractions of a second. Its auditory counterpart is echoic memory. How long a visual trace remains available depends on the display, what comes next and how memory is tested.

Sperling’s iconic memory experiment

In Sperling’s experiments, a tone after a brief letter display told observers which row to report. Immediate partial reports showed that more information was initially available than people could give in a whole report. The advantage declined rapidly as the cue was delayed.

Changing the visual field after the display also affected reporting. This interference is known as masking. The picture analogy is useful, but only up to a point: an iconic memory is brief and vulnerable to interference, not a photograph you can inspect at leisure.

Iconic memory versus echoic memory

The main difference is the kind of sensory information: iconic memory concerns vision, while echoic memory concerns sound. Neither term means that the information has become a lasting memory.

Related forms of memory

This brief persistence differs from the active maintenance and use of information in working memory. The phonological loop concerns speech-based maintenance and is not simply another name for a visual sensory trace.