cognitive psychology refers to the amount of working memory resources used
amount of effort that is exerted or required while reasoning and thinking.
Any mental process, from memory to perception to language, creates a cognitive load because it requires energy and effort.
heavy cognitive load can cause errors or interference can also lead to stereotyping because heavy cognitive load pushes excess info to subconscious processing where schemas are used.
Effects
Experts have more knowledge, therefore usually encounter less cognitive load compared to beginners in their field. This is due to the difference in processing capacities.
When many cognitive resources are available, a person is more likely to switch between tasks which causes a higher cognitive load.