Psychology:
Memory
How Things Get Remembered
Long-Term Memory System
Memory Organization
Encoding and LTM
Remembering and Forgetting
Searching for Memory
A stimulus in an environment is held momentarily in the sensory register. Iconic storage is for visual sensory register, and echoic storage is for auditory sensory registration. Sensory registers hold information for a split second allowing a mental model or presentation to be formed for further processing. Many of the stimuli register briefly without further processing or storage. Therefore, these stimuli will not be remembered. Other information is passed along to short-term memory (STM), which stores information for roughly 20-30 seconds. Some information is further processed/encoded and passed on to long-term memory (LTM). The memory in LTM may last a lifetime. Not all information follows the path. Some information in sensory registers may enter long-term memory without passing short-term memory or without conscious processing/encoding.
For example, while you are walking, things entered in your visual field are held in the iconic storage (sensory register). If you recognize, say, a notice on the wall, the information is held in short-term memory. As you read and understand the information, as the encoding of the information occurs, the information is passed to long-term memory. The information can be retrieved at later time. Some things entered in your visual field may be implicitly held in long-term memory. For example, if you notice a strange shape for a split second, you may not think of it at all. However, later you may recognize a similar shape and wonder it looks familiar: the shape was passed to long-term memory without your conscious effort to encode the information.
Source(s): Drew Westen, Psychology: mind, brain,
& culture (NY 1996)