Memory: The mental processes involved in registering, storing or retrieving information. This can include memory of factual information (semantic memory), of personal experiences (episodic memory) and of skills or abilities (procedural memory).
Types of memory:
1. Sensory memory: external stimuli from the environment first enters the sensory memory, where they can be registered for very brief periods of time (duration: 0.5-2 seconds, capacity: 9-12 pieces, encoding: multi-modal - Sperling) before decaying or if rehearsed it enters the STM
2. Short-term memory (STM): where information is initially stored and held for a short period of time. Information is encoded acoustically (Baddeley). According to Jacobs the capacity of the STM is 7+/-2 units. The duration is 15-30 seconds (Peterson and Peterson), can be lost through displacement or decay unless rehearsed it enters the LTM.
3. Long-term memory (LTM): Material that is rehearsed is passed on to the LTM, where it remains for a lifetime it's capacity is unlimited (Bahrick), although loss is possible through decay, retrieval failure or interference. It is encoded semantically (Baddeley)
Encoding: The process by which information received by the senses is changed by a form or code which can be registered and stored by the memory. Encoding can be visual, acoustic (sound) or semantic (meaning).
Duration: a measure of how long information can be held in memory without being lost or forgotten.
Capacity: The amount of information that can be held in memory at one time.