Attentional and evaluative biases for smoking cues in nicotine dependence: component processes of biases in visual orienting.

The present study investigated attentional and evaluative biases for smoking-related cues in cigarette smokers and non-smokers. Using a visual probe task, we manipulated the presentation conditions of the stimuli to examine: (1). whether smokers have a bias to allocate attention towards smoking-related pictures that appear below the threshold of conscious awareness; and (2). whether attentional biases for smoking-related pictures that appear above the threshold of awareness operate both in initial orienting and in the maintenance of attention. We also obtained explicit and implicit measures of the valence of the smoking-related pictures from pleasantness ratings and from behavioural responses on a stimulus-response compatibility (SRC) task. Results showed that smokers, but not non-smokers, had an attentional bias for smoking-related pictures which had been presented at two exposure durations (200 and 2000 ms). The bias was not found in a brief (17 ms) masked exposure condition, so there was no evidence that it operated preconsciously. Smokers also showed greater preferences for smoking-related than control cues, compared with non-smokers, on both the explicit and implicit indices of stimulus valence. Results are discussed with reference to incentive and cognitive models of addiction.