NEW YORK (AdAge.com) -- A marketing research system that studies the emotions expressed by facial muscles has been used to analyze presidential campaign ads. The system is the subject of the new book, "Face Time," by Dan Hill. Mr. Hill heads Sensory Logic, a consulting firm that has been using "facial coding" methods to study second-by-second consumer reaction to TV commercials. Its clients are normally large marketing corporations. But during the primaries, the company began analyzing audience reactions to the major candidates' ads.