# Working memory limits
A working memory is a part of our cognitive system where we hold temporary information and process them. There are limits to our working memory:
- How long we can hold the information
- How many pieces of information we can hold and process
We can't hold the information in our working memory for more than 30 seconds. There are a couple of answers to how many information we can hold and process. Many references would refer to the number 7 (Miller). A more recent study points that our limit is more like a maximum of 4 (Cowan).
Ahrens, How to Take Smart Notes (p. 68).
Our short-term memory is also limited. We need strategies not to waste its capacity with thoughts we can better delegate to an external system. While the estimations of our long-term memory capacity are wildly diverse and rather speculative, psychologists used to tend to agree on a very specific number when it came to short-term memory: We can hold a maximum of seven things in our head at the same time, plus/minus two (Miller 1956).
Miller, George A. ‘The Magical Number Seven, plus or Minus Two: Some Limits on Our Capacity for Processing Information.’ Psychological Review, vol. 63, no. 2, 1956, pp. 81–97. DOI.org (Crossref), doi:10.1037/h0043158.
Cowan, Nelson. ‘The Magical Number 4 in Short-Term Memory: A Reconsideration of Mental Storage Capacity’. Behavioral and Brain Sciences, vol. 24, no. 1, Feb. 2001, pp. 87–114. DOI.org (Crossref), doi:10.1017/S0140525X01003922.
We have a short-term memory that is limited in size to something like seven digits, words, or other units. The only way to hang on to information for a longer time period is to create a more durable representation, either by writing it down or encoding a long-term memory of it.
- Writing makes thinking possible
- We need a good method to think because we have Working memory limits. If Effective tool circumvents human limits, we need to find a tool that circumvents our working memory limit. The tool, or method of thinking that has been proven by science is note-writing. Many would think that writing helps our thinking, but contemporary handbook of neuroscientists argues that writing is what makes thinking possible. Scientists with different specialisation, like psychologists, educators, or philosophers, may disagree on how our brain works, but most of them agree that real thinking will require a form of writing (Ahrens 95-96).
- Writing allows us to deliberately forget
- We have Working memory limits, therefore making sure that we can populate our working memory with what's relevant in the current circumstances is necessary for us to be effective. Unfortunately we don't really have a full control over what we have in our working memory, other irrelevant thoughts might linger (like open tasks) and will reduce our ability to focus. (See also: Zeigarnik Effect)
- Humans are constrained by biological limits
- To write is to rubber duck
- The limits of consciousness
- Mihaly seems to indicate that this is related to working memory, but I don’t really understand how consciousness is related to the concept of working memory. See Working memory limits.
- The prerequisites of flow are needed to flood working memory