Interference of warnings on the manipulation of cigarette packs.

<p>(A) The participant grabs a holder with his/her dominant hand. Unseen by the participant, the experimenter places a cigarette pack on the holder, exposing either the brand face or the warning face. Upon illumination, the participant quickly flexes the arm. The latency between illumination and action (reaction time) is measured. (B) Reaction times for smokers. Reaction time when the warning face is exposed (left column of the graph) is significantly longer compared to when the brand face is exposed (right column). The results reveal that warnings impose a significant cost to the manipulation of the pack.</p