Hartmann did a survey of 456 dreams and found zero instances of reading and writing, and only one instance of arithmetic. He also sent a questionnaire to 400 people interested in dreams, and about 90% of them said they "never" or "almost never" did any reading, writing or arithmetic in their dreams. This supports his theory that dreaming disrupts the sequential, logical processing of waking thought. > ... dreaming avoids tightly structured cognitive material such as reading, writing, typing, calculating. It deals with (makes connections in) the broader, looser and perhaps more emotionally important portions of our mental networks.^[Hartmann, Ernest. The Nature and Functions of Dreaming. Oxford University Press, 2010. https://doi.org/10.1093/acprof:oso/9780199751778.001.0001.] --- **Source** Hartmann, Ernest. “We Do Not Dream of the 3 R’s: Implications for the Nature of Dreaming Mentation.” Dreaming 10, no. 2 (June 2000): 103–10. https://doi.org/10.1023/A:1009400805830.