[Effectiveness of cigarette-pack warning labels in capturing the attention of smokers and nonsmokersEficácia das tarjas de advertência em maços de cigarro para atrair a atenção de fumantes e não fumantes].

Objective: To determine the ability of cigarette-pack warning labels, of the minimum size required by the World Health Organization, to capture the attention of smokers and nonsmokers.

Methods: In this study, 30 smokers and 30 nonsmokers completed a dot-probe task in which they simultaneously observed images of cigarette packs split in two: the top contained the cigarette brand and the bottom contained the warning label. During the task, brain activity was recorded through two event-related potentials of the negative-polarity type--the potential that occurs in the posterior-contralateral zone approximately 200 ms after a stimulus (N2pc) and the sustained posterior contralateral negativity (SPCN) response--which are indicators of early and sustained attention.

Results: In both groups, a greater amplitude of N2pc and SPCN potentials was found for the part of the pack containing the cigarette brand. However, during the dot-probe task, reaction times were shorter for the warning label.

Conclusions: These results suggest that, initially, attention is focused on the cigarette brand, and only then on the warning label. The inability of warning labels to capture early-phase attention decreases their effectiveness, especially in smokers. We suggest that warning labels be enlarged to facilitate increased attention response.