Iconic memory is a type of visual sensory memory that is how the brain remembers images. Iconic memory is a very brief form of the short-term memory, and can perhaps best be understood by looking at an object, closing one’s eyes, and then “seeing” that object in one’s mind. There are two main components to iconic memory: visible persistence and informational persistence.
Visible persistence can be described as the immediate mental picture stored in the brain from a viewed image. It is frequently considered to be a by-product of neural persistence. However, there is a inverse component to visible persistence, meaning that the longer the physical persistence of the object, the quicker that image decays in the short-term memory.
Informational persistence relates more to the data that is coded into the brain. This is the information that is perceived by the brain, as opposed to the physical representation. It is believed that this aspect of iconic memory is what becomes transferred into the visual short-term memory (VSTM).
Iconic memory allows the brain to integrate a continual stream of images, so that information is not forgotten, such as when watching a television program. Iconic memory develops from birth, and capacity at six months is approaching that of an adult’s, and is fully developed by the age of five. However, mild decreases in iconic memory have been observed by the age of sixty, as compared to when one was in their early twenties.