Sensory Memory

• The sensory register is not under cognitive control, but it is an automatic response to the information from our 5 senses.
• Coding in the Sensory store

  Information is stored in a raw, unprocessed from with separate sensory stores for different sensory inputs

  • The echoic store for auditory information
  • The iconic store for visual information
  • The haptic store for tactile information
  • The gustatory store for taste information
  • The olfactory store for smell information
• Information that is paid attention to is passed on to the STM while the remainder quickly fades away due to trace decay.
• Crowder (1993) found that the Sensory store retains visual information for 500 milliseconds whereas auditory information can be retained for 2-3 seconds.
• Capacity of the Sensory Store

  Sperling (1960) tested this using a tachyscope which flashed symbols to participants for one twentieth of a second. When shown a grid of 12 symbols, participants could only recall 3-4. However, they reported seeing more items which shows that all the information was originally there and indicates the actual capacity was high.

  
• Evaluation of Sperling (1960) and Sensory Store

  Calculating the capacity of the Sensory Memory often involves experiments which are artificial in nature and lack mundane realism, so we can't generalise to real life easily.

  Although, evidence exists that our iconic store can hold about 15-20 images, the capacity of the other sensory memory stores is less well studied as they last so briefly so it's difficult to draw conclusions about the actual capacity of each of the senses.
• Duration of the Sensory store

  Crowder (1993)

  Visual = 500 milliseconds

  Auditory = 2-3 seconds
• Evaluation of the duration of the Sensory store

  Brief duration of memory can be understood from an evolutionary perspective as people only needed to focus on perceptual important information with survival value.