(a) Memory

• Memory involves storage, retention and retrieval of information.
• Memories include past experiences, knowledge and thoughts.
• All information entering the brain passes through sensory memory and enters short- term memory.
• Information is then transferred to long-term memory (LTM) or discarded.

(b) Sensory memory (SM)

• Sensory memory retains all the visual and auditory input received for a few seconds.
• Only selected images and sounds are encoded into short-term memory.

(c) Short-term memory (STM)

• STM has a limited capacity and holds information for a short time.
• The capacity of STM can be improved by ‘chunking’.
• A chunk is a meaningful unit of information made up of several smaller units.
• The serial position effect is where items at the start and end of a list are better remembered than those in the middle.
• STM can also process data, to a limited extent, as well as store it.
• This ‘working memory model’ explains why the STM can perform simple cognitive tasks.
• Memory span is, on average, about 7 items at a time.
• Items can be maintained by rehearsal (recital of information).
• Loss of items by displacement (info ‘pushed out’ by new info) and decay (breakdown of memory traces).

(d) Long-term memory (LTM)

• LTM has an unlimited capacity and holds information for a long time.
• Information is transferred from STM to LTM due to:
  • rehearsal (regularly reciting short pieces of information)
  • organisation (information put into logical categories)
  • elaboration (involves analysing the meaning of the item to be memorised and taking note of its various features and properties, so additional/meaningful information is provided)
• Rehearsal is regarded as a shallow form of encoding information into LTM.
• Elaboration is regarded as a deeper form of encoding which leads to improved information retention.
• Retrieval is aided by the use of contextual cues.
• A contextual cue is any other stimulus present at the time of memory formation. For example, a sight or smell or strong emotion, or even a song/music.
• Contextual cues relate to the time and place when the information was initially encoded into LTM.