The ability of our brains to process, store and retrieve information has been the subject of much research and debate by cognitive psychologists for a long time. Over that period the terminology used and ideas about how our memory system works have changed as research uncovers new findings. But it’s now widely accepted that our memory system consists of three components – a sensory memory that receives information from our surroundings, a working memory to process this information and also to retrieve information from our storage area known as the long-term memory.
A Brief History
As far back as 1890, the human memory system was proposed by William James to be a dual-system comprising of a primary memory (or conscious awareness) and a secondary memory (containing lasting memories). However, it wasn’t until the late 1950’s that evidence and acceptance for the division of the memory into multiple systems began to emerge. Around this time, research by Peterson and Peterson found that unfamiliar information could only be held for a matter of seconds before being forgotten. This in turn led to the proposal that human memory be separated into short-term and long-term systems. These findings added to the earlier research of Miller (1956) who found that there were limitations to the capacity of information that can be processed by the human memory system, in this case he discovered that only about seven (plus or minus two) pieces of new information could be held at any time.
In the 1968, Atkinson and Shiffrin’s Modal model became the most influential depiction of the human memory system. This model assumes that information comes in from the environment through a parallel series of sensory memory systems into a limited-capacity short-term store (STS), which forms a crucial bottle-neck between perception and LTM.
Working Memory
As the name suggests our working memory actively processes information and this information enters the working memory from one of two sources, either from our sensory memory (our senses) due to our interaction with the world around us or it’s retrieved from our long-term memory. The ability of our working memory to hold information is very limited so it can be easily overloaded.
Long-term Memory
Whilst the working memory is responsible for the active processing of information, the long-term memory is the storage area of our memory system. According to Sweller, our long-term memory “consists of a large, relatively permanent store of information” (2004, p.11).
Information is stored in the long-term memory in knowledge structures known as schemas or mental models. Schemas “permit us to treat a large number of information elements as a single element” (Clark et. al, 2006). The number of schemas held in long-term memory is what differentiates experts from novices so the focus of any instruction should be the formation and construction of schemas in the long-term memory.
Implications for Learning and Instruction
The study of the human memory system and its components has provided extensive evidence about how we process and store new and existing pieces of information. This knowledge is essential when it comes to designing instructional activities and they should account for the processing and storage capabilities of the human memory system. When learning something new, there are three types of cognitive load: intrinsic which is the inherent level of complexity of the content, germane which allow cognitive resources to be put towards learning and extraneous which are irrelevant elements that actually impose extra mental processing. These forms of cognitive load are additive, therefore in order for instruction to be effective and permit transfer to long-term memory, they should not exceed working memory capacity.
Cognitive load theory is “a universal set of instructional principles and evidence-based guidelines that offer the most efficient methods to design and deliver instructional environments in ways that best utilise the limited capacity of working memory” (Clark et. al, 2006, p.342). Examples of these principles include: the worked example effect – giving novice learners worked solutions of unfamiliar problems to study, the split-attention effect – reducing the need to integrate multiple sources of information in order for it to be understood, the modality effect – presenting information via both the visual and auditory channels and the redundancy effect – not presenting the same information via both the visual and auditory channels. Applying these principles to instructional design will facilitate improved learning outcomes because they incorporate the findings of research into the functioning of the human memory system.
In my next post I’ll talk about Mayer’s Cognitive Theory of Multimedia Learning that draws upon knowledge of our memory system as well as Sweller’s Cognitive Load Theory and outline some strategies to incorporate into eLearning design.
References
Clark, R., Nguyen, F., & Sweller, J. (2006). Efficiency in Learning, San Francisco: John Wiley & Sons Inc.
Miller, G. A. (1956). The magical number seven, plus or minus two: Some limits on our capacity for processing information. The Psychological Review, 63(2), 81-97.
Sweller, J. (2004). Instructional design consequences of an analogy between evolution by natural selection and human cognitive architecture. Instructional Science, 32, 9-31.