Memory Research

Put forward by Atkinson and Shiffrin in 1968

• Memory is seen as a flow of information
• Information flows through an information processing system
• The system is didvided into 3 stores
• There are restrictions at each store: capacity, duration and encoding

The Stores:

• Sensory Memory- stays for a very brief period of time before either decaying or passing on
• Short-Term Memory- has a very small capacity, information can be lost within a few seconds if not rehearsed, encoding is mainly through sound
• Long-Term Memory- has a limitless capacity, information can be stored for upto a lifetime, encoding is mainly through meaning

Put forward by Atkinson and Shiffrin in 1968

• Memory is seen as a flow of information
• Information flows through an information processing system
• The system is didvided into 3 stores
• There are restrictions at each store: capacity, duration and encoding

The Stores:

• Sensory Memory- stays for a very brief period of time before either decaying or passing on
• Short-Term Memory- has a very small capacity, information can be lost within a few seconds if not rehearsed, encoding is mainly through sound
• Long-Term Memory- has a limitless capacity, information can be stored for upto a lifetime, encoding is mainly through meaning

Evidence for Sensory Memory

Sperling showed a 4x3 chart of letters to his participants for 50 milliseconds

When asked to recall as many letters as possible participants could only recall 4 or 5 letters but they knew there were more

This is because:

• As participants are naming 4 or 5 letters the  image of the chart fades

This is a laboratory experiment so;

• it has a high degree of control
• it lacks ecological validity

Capacity in STM

Jacobs used memory span to see how much could be stored in STM at any one time

Procedure:

• Presented his participants with a random sequence of digits
• Participants were then asked to repeat them back in order

The memory span was the longest sequence of items recalled at least 50% of the time

Findings: 

• The average number of items recaled was between 5 and 9
• This is known as 7 plus or minus 2
• The span increased with age

Duration in STM

Aimed to study how long information remains in STM without rehearsal 

Procedure:

• Participants were presented with a trigram made up of 3 consonants
• Recall took place after 3,6,9,12,15 or 18 seconds
• Partcipants counted back in 3's from starting with a random number between the initial presentation of the trigram and the recall time
• Recall had to be 100% accurate and in the correct order

Findings:

• There was a rapid increase in forgetting from STM as the time delay increased
• After 6 seconds 50% were recalled
• After 18 seconds fewer than 10% were recalled