Abstract
This study examined the influence of smoking on low-level sensory and higher-level visual cognitive abilities utilizing a common methodology to assess cross-task changes. Previous research with smokers has suggested that smoking actually enhances some low-level visual abilities. Research on higher-level visual cognitive abilities, namely visual attention, has produced more mixed results. Three groups (non-smokers, deprived smokers, and non-deprived smokers) with twenty-two observers per group were tested using a visual target discrimination task. To assess sensory and visual cognitive differences, a masking task developed by Enns and Di Lollo (1997) was used. In the task, the target was masked by either a contour mask (contour masking) or an object mask (attentional masking by object substitution) that only produces masking under conditions of divided attention. The strongest masking effects were found in the group of non-deprived smokers, for both sensory and attentional masking. Deprived smokers showed a reduction in attentional orienting. We interpreted the data using the Brietmeyer (1984) model of masking, in which masking is produced by both intrachannel and interchannel inhibitory interactions between sustained and transient channels. The current pattern of results from the non-deprived smokers, as well as results in the deprived smokers, indicated changes in transient visual processing channels were due to the acute actions of nicotine, not mediated by withdrawal relief. Smoking appeared to increase transient channel activity, resulting in increased inhibitory effects and thus masking. The data from the deprived smokers indicated that this effect was accompanied by an opponent process which, in the deprived smokers, resulted in less transient channel activity, producing decreased orienting to transient visual information (onsets) as well as less pronounced masking.