6.3. Information Processing Approach: The Stage Model

Initially, it was thought that memory is the capacity to store all information that we acquire through learning and experience. It was seen as a vast storehouse where all information that we knew was kept so that we could retrieve and use it as and when needed. But with the advent of the computer, human memory came to be seen as a system that processes information in the same way as a computer does.

The Stage Model of memory suggests that human memory functions similarly to a computer. It is not just a passive storehouse; instead, it actively processes information. When we acquire new knowledge or experiences, that information first enters our memory system where it gets processed before we can recall or utilize it. Just like a computer processes data through various stages, our memory system does the same, handling the information we receive from our environment.

Think of memory as a library. Initially, you gather information like books, but the library staff (our brain) needs to organize these books (information). The staff sorts them, categorizes them, and files them in a way that you can find them later, just like memory encodes, stores, and retrieves information.

According to the Stage Model, there are three memory systems: the Sensory Memory, the Short-term Memory, and the Long-term Memory. Each of these systems has different features and performs different functions with respect to the sensory inputs.

The Stage Model divides memory into three distinct systems:

1. Sensory Memory: This is the first stage where sensory information is received. It has a high capacity but lasts for a very short duration (less than a second).
2. Short-term Memory (STM): Information from sensory memory that we pay attention to transfers to short-term memory. STM can hold a small amount of information for about 30 seconds.
3. Long-term Memory (LTM): Information that survives STM moves to long-term memory, where it can be stored indefinitely and has an unlimited capacity.

Imagine walking into a crowded room (sensory memory) and noticing a friend across the room (attending to that information). You remember the friend's face for a moment (short-term memory), and if you engage in conversations or remember shared experiences, this information can be stored in long-term memory, allowing you to recall it even years later.

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. It is a memory system that registers information from each of the senses with reasonable accuracy.

Sensory memory is the initial stage of memory where brief impressions of sensory information are held. Different sensory modalities (like sight and sound) have their own types of sensory memory, known as iconic (visual) and echoic (auditory) memories. These memories only last a very short time but can provide us immediate awareness of our surroundings.

Consider seeing a flash of lightning during a storm. You see it for less than a second, but it makes a quick impression on you. That initial glimpse, before your brain has time to fully process it, is like the sensory memory of visual information.

Information that is attended to enters the short-term memory (abbreviated as STM), which holds small amounts of information for a brief period of time (usually for 30 seconds or less).

Short-term memory acts as a working space where active information is processed. The STM can only hold a limited amount of information—typically around 7 items, give or take 2. If we do not actively rehearse or manipulate this information, it will be forgotten relatively quickly.

When you're trying to remember a phone number while you dial it, that number resides in your short-term memory. If you don’t rehearse it (like writing it down), it can quickly fade away before you finish dialing.

Materials that survive the capacity and duration limitations of the STM finally enter the long-term memory (abbreviated as LTM), which has a vast capacity. It is a permanent storehouse of all information.

Long-term memory holds vast amounts of information for extended periods, potentially for a lifetime. Unlike short-term memory, long-term memory can store information semantically, meaning we remember based on the comprehension of the material rather than just its form. When information is stored in LTM, it can be recalled later, although retrieval can sometimes fail due to lack of appropriate cues.

Think of long-term memory like a storage garage filled with old but valuable belongings. Once you’ve stored your items, you can revisit them anytime; however, if you've forgotten where you placed something, it might take a while to find it again.

Atkinson and Shiffrin propose the notion of control processes which function to monitor the flow of information through various memory stores.

Control processes are strategies that manage the transfer of information between sensory memory, short-term memory, and long-term memory. Key control processes include selective attention (filtering information to focus on what’s important), maintenance rehearsal (repeating information to keep it in STM), and elaborative rehearsal (linking new information to what you already know for lasting storage).

When studying for a test, you might focus solely on the subject matter (selective attention), repeat notes to memorize them (maintenance rehearsal), and connect concepts to your personal experiences or previous knowledge (elaborative rehearsal).

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

The Stage Model conceptualizes memory as an information processing system, similar to a computer, where information is inputted, processed, and outputted. The model outlines the stages through which information passes, from sensory memory to short-term memory and finally to long-term memory, emphasizing the sequential nature of memory processing.

Visualize how you might install new software on your computer. The data first downloads (sensory memory), then it’s installed in a temporary folder (short-term memory) before being stored in a permanent location where you can access it anytime (long-term memory).

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