Fair warning to presidential candidates participating in upcoming presidential debates: your inappropriate nonverbal behavior is noticed, and it could overshadow the substance of what you say.

"When style obscures substance: Visual attention to display appropriateness in the 2012 presidential debates," recently published in the journal Communication Monographs, and highlighted in the National Communication Association's newly released research digest, Communication Currents, examines the consequences of appropriate versus inappropriate nonverbal behavior as displayed by candidates during presidential debates.

Communication researchers Zijian Harrison Gong of the University of Tampa and Erik P. Bucy of Texas Tech University describe inappropriate political nonverbal behavior as facial displays and gestures that are not compatible with the intended message or tone of the setting in which they occur. For example, during the 2012 debates between Mitt Romney and Barack Obama, viewers criticized the president's nonverbal behavior in the first debate, which focus group participants characterized as "unprofessional" and "unpresidential." Critics said he avoided eye contact and smirked at some of Romney's comments and that, while he occasionally winced when under verbal attack, he did not fire back.

How, exactly, do viewers react when they see these kinds of behaviors in televised presidential debates? Gong and Bucy analyzed reactions using measures of visual attention (an eye-tracking test) as well as focus groups.

In an eye-tracking experiment, they found that people tend to fixate on inappropriate nonverbal behavior more often and for longer periods of time than they spend focusing on appropriate behavior. The researchers also found that people remember the substance of candidate statements better when they perceive candidates as behaving appropriately but the inverse can be expected when candidates are perceived as behaving inappropriately.

Focus group comments supported the experimental eye-tracking results. One participant said he thought Obama deserved a dip in the polls following his first 2012 presidential debate performance, not because he appeared weak or incompetent but "because of his body language and his attitude."

Other participants agreed, saying they thought Obama appeared uninterested, dismissive, and even disrespectful toward Romney.

In responding to the third debate of the campaign, however, participants said they thought that Romney's behavior was inappropriate, noting his rapid blink rate (a sign of stress), the rehearsed quality of his answers, and hurried talking pace.

According to the researchers, understanding the influence of nonverbal communication on how citizens perceive candidates is important because voters rely heavily on television as a primary source of political information -- a timely warning for this year's candidates as the presidential race continues.