What is the test for determining whether a defendant is competent to stand trial?

p. 1032.) Competence to stand trial requires a defendant's sufficient present ability to consult with his or her lawyer with a reasonable degree of rational understanding or a rational and factual understanding of the proceedings. (Dusky v. United States (1960) 362 U.S. 402.) Proceedings must be suspended and a competency hearing held if a trial court is presented with substantial evidence the defendant is incompetent. (Mai, at p. 1032.)