Ware, Information Visualization, Chapter 3. Note that this book is free to access on campus (the above link will not work off campus).
Attention and Visual Memory in Visualization and Computer Graphics. Christopher G. Healey, James T. Enns. IEEE Trans. Vis. Comput. Graph. 18(7): 1170-1188 (2012)
Gestalt principles (Part 1) Bang Wong. Nature Methods 7, pp. 863, Nov 2010.
Gestalt principles (Part 2) Bang Wong. Nature Methods 7, pp. 941, Dec 2010.