Sensory Memory

Context

We are constantly bombarded by stimuli in our environment.

• All this info (even if not consciously perceived) is temporarily retained in sensory memory for an extremely brief period of time

Entry Level of Memory

• Retained in original form and has not been encoded

• Enables perceptual continuity for the world around us

Acts as a filter

• So much is entering sensory memory that not all can be transferred to STM

• Filters out unimportant info which is lose

• Duration: 0.2 - 4 secs

• Capacity: Unlimited

• Duration is brief but long enough for us to determine whether the incoming sensory info is important enough to be transferred to STM (lady blocking out sensory info and focuses on her book)

• Sensory info remains in sensory memory long enough for us to attend to it and for it to be transferred to STM

Attended to

• Once info is selected from sensory memory and is attended to, it is transferred to STM

• If sensory info is not attended to, the neural imprint/memory trace simlpy decays and disappears forever

• Rapid decay allows use to perceive our world as smooth and ongoing, hear sounds long enough to understand them

Iconic Memory

Temporary store for info received from the visual system.

• Duration: 0.2 - 4 secs

• Each image is registered before the previous image fades, view world in continuous manner

Echoic Memory

From auditory system

• Holds info in a unprocessed form

• Duration: 3 -4 secs after stimulus ceases

Why is echoic longer then iconic?

• Echoic relatively longer is important for understanding speech, we perceive speech by blending successive spoken sounds we hear

• A word is individual sounds at one time, we cannot identify a word until you have heard all the sounds

• Auditory info must be long enough for you to receive all the sounds involved

• When we see something, we see the whole image at once and do not need to retain the info for long