Page 2 - LN 1_Human Memory

▪ This analogy led development of the first model of memory, which was
proposed by
▪ Atkinson and Shiffrin in 1968. It is known as Stage Model.

MEMORY SYSTEMS

▪ According to the Stage Model, there are three memory systems :

1. the Sensory Memory,
2. The Short-term Memory and
3. the Long-term Memory
▪ Each of these systems have different features and perform different functions with
respect to the sensory inputs.
▪ SENSORY MEMORY
✓ The incoming information first enters the sensory memory.

✓ Sensory memory has a large capacity.

✓ However, it is of very short duration, i.e. less than a second.

✓ Often this system is referred to as “sensory memories” or “sensory registers”

because information from all the senses are registered here as exact replica of
the stimulus.

✓ EXAMPLE- The experience of visual after-images, i.e the trail of light that stays

after the bulb is switched off.

▪ THE SHORT-TERM MEMORY

✓ Information that is attended to enters the second memory store called the short-
term memory
✓ Holds small amount of information for a brief period of time (usually for 30
seconds or less).
✓ Atkinson and Shiffrin propose that information in STM is primarily encoded
acoustically, i.e. in terms of sound and
✓ Unless rehearsed continuously, it may get lost from the STM in less than 30
seconds.

✓ Note that the STM is fragile but not as fragile as sensory registers where the
information decays automatically in less than a second.

▪ THE LONG-TERM MEMORY
✓ Materials that survive the capacity and duration limitations of the STM finally
enter the long-term memory (abbreviated as LTM)

✓ Has a vast capacity.
✓ It is a permanent storehouse of all information.