Problem solving, according to prominent cognitive psychologists, is fundamental to learning. It resides as an important research topic in educational psychology. A student is thought to interpret a problem by assigning it to a schema retrieved from long-term memory. A problem students run into while reading is called "activation." This is when the student's representations of the text are present during working memory. This causes the student to read through the material without absorbing the information and being able to retain it. When working memory is absent from the reader's representations of the working memory they experience something called "deactivation." When deactivation occurs, the student has an understanding of the material and is able to retain information. If deactivation occurs during the first reading, the reader does not need to undergo deactivation in the second reading. The reader will only need to reread to get a "gist" of the text to spark their memory. When the problem is assigned to the wrong schema, the student's attention is subsequently directed away from features of the problem that are inconsistent with the assigned schema. The critical step of finding a mapping between the problem and a pre-existing schema is often cited as supporting the centrality of analogical thinking to problem solving.