7.5 Atkinson & Shiffrin’s Modal Model of Memory
Introduction to the Model
Lisa is a psychologist interested in memory. More specifically, Lisa would like to know how memories are formed. During her studies, Lisa comes across the Atkinson-Shiffrin model of memory. So what exactly does this model propose?
The Atkinson-Shiffrin modal model of memory was first developed by Richard Atkinson and Richard Shiffrin in 1968. Atkinson and Shiffrin believed that once information enters the brain, it must be either stored or maintained and that the information which is stored goes into three distinct memory systems: the sensory register, short-term memory, and long-term memory. Let’s look at each of these components more carefully.
The sensory register is the first memory system that information passes through. The sensory register perceives and retains information that is received via the five senses for a very short amount of time, i.e. a few seconds. Though we have sensory registers for all five senses, only two have been well-studied. Research has primarily focused on iconic memory, (visual memory) and echoic memory, (auditory memory). It’s estimated that we can hold information in iconic memory for less than one second, while we can keep information in echoic memory for up to five seconds. We can think of sensory registry as a holding bin that keeps information until we decide which items we want to pay attention to. Most information that is not attended to is forgotten. Paying attention allows us to move information from sensory register to short-term memory.
Short-term memory is where we keep the content of our current thought. We can think of short-term memory as where we store information that we can actively work with and use. It’s estimated that we can hold information in short-term memory between 18 and 20 seconds, though there are techniques that we can use to increase this. For example, many people remember phone numbers by repeating them over and over in their heads until they can write them down or dial them. By continually repeating the numbers, you are rehearsing, which extends the length of time that you can recall the numbers. This brings up another point: the more that we repeat or use information, the more likely it is to move into long-term memory.
There are limitations to how much information we can keep in short -erm memory. In 1956, a cognitive psychologist named George Miller published a paper called ‘The Magical Number Seven, Plus or Minus Two,’ in which he claimed that we can only hold between 5 and 9 items in short-term memory at any given time. There are different techniques that we can use in order to increase this capacity. For example, instead of remembering a phone number as 10 separate digits (i.e. 5-5-5-3-1-4-7-8-8-9), we could break the numbers into chunks (i.e. 555-314-7889), which would allow us to remember the number as three items instead of ten.
Information transfers from short-term memory to long-term memory through rehearsal. Similarly to sensory register, information in short-term memory can be forgotten if not attended to.
Think about the fondest memories you have of your childhood. This information is stored in long-term memory. Long-term memory is where we store memories for an extended period of time, even in instances where we are no longer attending to it. Information can last in long-term memory anywhere from a few hours to the rest of our lives. While we can potentially store an unlimited amount of information in long-term memory, our memories can fade over time.
In order to retrieve information that is stored in long -erm memory and actively use it, we have to first move it to short-term memory. For example, recalling your childhood memories required you to access this information in your long-term memory and move it back to short-term memory so that you could work with it. It is possible for information to be lost when trying to retrieve it from long-term memory.
Atkinson & Shiffrin’s modal model of memory was first formed by Richard Atkinson and Richard Shiffrin in 1968. According to Atkinson and Shiffrin, memories are created and stored using three separate memory systems:
1. Sensory registry is the first memory system, which holds sensory information for up to a few seconds until we decide which information to pay attention to. It includes iconic (visual) and echoic (auditory) memory, which are the only two senses that have been extensively studied, despite there being sensory registers for all five senses.
2. The second memory system is short-term memory, which holds information for 18 to 20 seconds and, based on a 1956 paper by psychologist George Miller, is good for holding between only 5 and 9 items at a time.
3. The information that we rehearse gets move to the third memory system called long-term memory, which is limitless and can hold information for up to a lifetime. To access long-term memory, we need to move it to our short-term memory, though during this process, the information can be lost.