PS251 - Types of Memory

Sensory memory

Sensory memory is the brief initial stage of memory that holds raw sensory information for a fraction of a second before it fades or enters short-term memory

Sensory memory: Sperling (1960)

• Showed participants a grid of letters for 50 milliseconds. In the whole report condition, they recalled about 4–5 letters, but in the partial report (where a tone cued one row), they could recall almost all letters from that row.

• This showed that the sensory store has a large capacity but extremely short duration, supporting the existence of a fleeting visual store known as iconic memory.

Short-term memory

STM holds a limited amount of information for a short time while it’s being used. It mainly uses acoustic coding, as shown by Conrad (1964), who found that errors often involved similar-sounding letters.

STM: Peterson and Peterson (1959)

Found STM lasts about 15–30 seconds without rehearsal — recall of trigrams dropped from 80% after 3 seconds to 10% after 18 seconds

Long-term memory

Long-term memory is the store for information retained over time, with a potentially unlimited capacity and duration that can last a lifetime. It primarily uses semantic coding (Baddeley, 1966).

Main types of LTM

Tulving (1972) identified three types of long-term memory: episodic memory, semantic memory and procedural memory

Autobiographical memory

Autobiographical memory stores information about personal life events and integrates sensory, emotional, and contextual detail

Flashbulb memory

Flashbulb memories are vivid, detailed recollections of the moment one learned about a shocking or emotional event

Prospective memory

Prospective memory is remembering to perform future intentions, such as attending appointments or taking medication. It includes time-based (remembering at a certain time) and event-based (triggered by a cue) types.

Priming

Priming occurs when prior exposure to a stimulus unconsciously influences later behaviour or perception.