FIGURE 1.

Variability in effects of nicotine on cognitive performance

Nicotine’s effect on cognitive performance can be modeled as an inverted “U” shape dose-response relationship for each cognitive task. This figure illustrates two situations in which an equivalent degree of nAChR stimulation by extrinsic nicotine administration produces opposite effects depending on both the subject’s underlying nAChR activity and the level of cognitive effort required by the task itself. (1a) Illustrates an example of a Non-smoker who has healthy relatively high baseline nAChR activity and has improvement in cognitively difficult tasks, but worsening on easier tasks. (1b) Illustrates a different scenario of a smoker or individual with neuropsychiatric pathology that has relatively lower baseline nAChR activity and has improvement both in cognitively difficult and less difficult tasks. Figure adapted from Newhouse and colleagues (Newhouse et al., 2004).