This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The purpose of this study is to measure the effect of the menstrual cycle phase on the responses to cigarette smoking cues (cigarettes and a lighter) and neutral cues (pencil and eraser) and to determine if men and women have different responses to these cues. Responses measured will include heart rate, skin conductance (a measure of the amount of sweat on the hands), and questionnaires.