 - Many cigarette smokers claim that smoking improves their ability to think and concentrate, and have reported problems in thinking and concentration after quitting smoking. Some research has indicated that nicotine can enhance certain aspects of attention and memory in humans. However, more research is needed to determine how nicotine affects different elements of the brain s ability to think, pay attention, respond to rewards, and make decisions. Researchers are interested in using functional magnetic resonance imaging fMRI to study the effects of nicotine on brain function and activity. 