Subjects in the three guilty groups watched a videotape depicting the burglary of an apartment through the eyes of the thief. Each subject was asked to imagine that it was he who was committing the crime and was given instructions to encourage his becoming absorbed in the videotape. Afterwards, the subject received either diazepam, methylphenidate, or a placebo. Subjects in the fourth group, the innocent control condition, viewed a videotape depicting scenes from the interior of another apartment, this time with no crime committed. All subjects were given a guilty knowledge test by an examiner who was blind to both their guilt or innocence and drug status. The results indicated that drug status did not affect the validity of the polygraph examination, which had an overall accuracy of 94%. A significant relationship between the ability to recall facts about the crime and detectability was found. The effects of habituation and personality attributes on detectability were also examined. (Author abstract)