Memory

In psychology there are two major classes of memory:
- short-term memory
- long-term memory

Short-term memory

It's know as the memory of the just present. The information can be easily retained and retrieved without much effort. The amount of information that can be retained this way is very limited (usually between 5 - 7 items).

"Short-term memory is invaluable in the performance of everyday tasks, in letting us remember words, names, phrases, and parts of tasks.
It acts as a working or temporary memory. But the memory is quite fragile. Get distracted by some other activity and poof, the stuff in short-term memory disappears."
Don Norman

Long-term memory

It's the memory for the past. It takes much more effort to retain and retrieve it.
These is how our experiences are recorded. How well those experiences can be recalled depends on how well it was interpreted in the first place.
When it comes to storage, no one really knows it's limits, but it's around billions of items.

The size it's so large that does not impose any practical limitations.

"The difficulty with LTM is in organization - in getting material in and in figuring out how to retrieve it - not in capacity. Storage and retrieval are easier when the material makes sense, when it fits into what is already known. When the material makes no sense, it will have to be worked on, structured, and interpreted, until finally it can be retained."
Don Norman

The multi-store memory model

This model was proposed by Richard Atkinson and Richard Shiffrin (1968).

The human brain processes images between three different types of memories (sensory memory, short-term memory and long-term memory).
Iconic memory (belongs to Sensory memory), which is responsible for the first visual impact where it extracts the main details of the image, such as shapes, background and appealing elements.
Then, this information is sent to the visual working memory, where it will make a comparison of common patterns or elements that the iconic memory sent you with those that the long-term memory has stored.
After identifying a positive result, object identification proceeds. In other words, iconic memory takes visual information that has stood out and sends it to visual working memory. Visual working memory takes information from iconic memory and from long-term memory, comparing the two until you get a result. This is a more simplified model, due to the complexity of the human brain. The process is quite complex and still unknown in its entirety.

The brain normally interprets a sketch faster than a photography.

Although photography is something more realistic, it contains elements such as textures, shadows and details, which need a greater amount of memory to be processed.
In the sign industry, this is taken into account. It is not by fortunate that in most cases the emergency signals or even the emergency instructions that the aeronautical industry uses on airplanes are simple illustrations and not photographs.

Cognitive load memory

It refers to how much new information the working memory, temporarily stores and how many tasks it can process.

The designer's main objective is to make the user transfer this information, from the working memory as quickly as possible to the long-term memory, so that it is easy and quick to remember the actions of the interface or interactivity.

It is necessary to pay attention to the initial amount of information, so that it does not lead the user to give up because it is too dense. It shouldn't have a feeling of “overwhelming information”.