In a field study, heart rate and motor activity were continuously assessed during two days in smokers, abstinent smokers and non-smokers. Smoking abstinence reduced heart rates by about 10 bpm to the non-smoker level without affecting motor activity. Averaging heart rate and activity using lighting of the cigarettes as the triggering event revealed the characteristic profiles described previously. Both variables increased during the last five minutes before lighting the cigarettes and decreased immediately upon fighting to near or even below the prelighting levels. This lighting response was maintained in a similar fashion when the subjects marked the time points of the desire for smoking but omitted lighting the cigarettes and it remained highly similar for the first and last five cigarettes of the day. In non-smokers a similar pattern was also obtained using the first sip of coffee as triggering event.
In smoking smokers, this lighting response was followed by an increase of heart rate without changes in activity. In contrast to the lighting response, this smoking related increase of heart rate disappeared for the last five as opposed to the first five cigarettes of the day, and it was also absent for 'imaginary' smoking without lighting.