Similar Stroop paradigm studies have concluded that attentional bias is not dependent on smoking itself, but rather the person who is the smoker displays attentional bias. A recent study required one group of smokers to refrain from smoking the night before and another less than an hour before. Abstinence from smoking created slower reaction time, but a smoke break between study sessions showed increased reaction time. Researchers say this shows that nicotine dependence intensifies attention, but does not directly depend on smoking itself due to lack of evidence. The longer reaction time suggests smokers craving a cigarette linger on smoking related words. Smokers and smokers attempting to quit displayed the same slower reaction time for smoking related words, which supports research that implies attentional bias is a behavioral mechanism versus a dependency mechanism, due to the fact that the smokers were slowed down by smoking related words and negative words, but not slowed down by positive and neutral words.