(1) A defendant to a criminal charge shall be presumed competent to stand trial. He shall be determined incompetent to stand trial only if he is incapable because of his mental condition of understanding the nature and object of the proceedings against him or of assisting in his defense in a rational manner. The court shall determine the capacity of a defendant to assist in his defense by his ability to perform the tasks reasonably necessary for him to perform in the preparation of his defense and during his trial.

    (2) A defendant shall not be determined incompetent to stand trial because psychotropic drugs or other medication have been or are being administered under proper medical direction, and even though without such medication the defendant might be incompetent to stand trial. However, when the defendant is receiving such medication, the court may, prior to making its determination on the issue of incompetence to stand trial, require the filing of a statement by the treating physician that such medication will not adversely affect the defendant’s understanding of the proceedings or his ability to assist in his defense.