The Impact of Nicotine Dose and Instructed Dose on Smokers' Implicit Attitudes to Smoking Cues: An ERP Study

It is unclear whether nicotine and perceived nicotine exposure can influence automatic evaluations of cigarette stimuli. In the present study, we investigated the effects of nicotine dose and instructed dose on motivational responses to smoking cues. Forty overnight nicotine-deprived smokers completed an Implicit Association Test (IAT) at each of the four laboratory sessions in a balanced-placebo design that crossed nicotine dose (Given-NIC [given nicotine] vs. Given-DENIC [given denicotinized]) with instructed dose expectancy (Told-NIC [told-nicotine] vs. Told-DENIC. [told-denicotinized]). We measured participants' behavioral performance, including reaction time (RT) and accuracy rate, and the early posterior negativity (EPN) component using the event-related potential (ERP) technique to the target pictures. During congruent trials when the categorization condition was smoking or unpleasant, smokers had greater classification accuracy, shorter RT latency, and greater EPN amplitudes compared to the incongruent trials when the categorization condition was smoking or pleasant. The Given-NIC condition was associated with increased classification accuracy, longer RT latency, and decreased EPN amplitudes compared to the Given-DENIC condition. Similarly, the Told-NIC condition was associated with increased accuracy and decreased EPN amplitudes compared to the Told-DENIC condition, but with shorter RT latency. Cigarette-related pictures produced greater EPN amplitudes than neutral pictures. Both behavioral and ERP results suggest that smokers have negative implicit attitudes toward smoking. While both nicotine dose and expected dose facilitated stimulus categorization, there was no evidence that either factor altered smokers' negative attitudes toward smoking cues.