The Mechanism Research Of Smokers’ Craving To Cigarette And Impulsive Behavior

Cigarette smoking remains the single largest cause of preventable morbidity and mortality in the world, it has become the greatest threat of human’s health. According to the research of the World Health Organization, smoking is estimated to be annually responsible for5,000,000deaths worldwide. Beyond the physiology dimension, smoking is believed to be largely motivated by clinical or subclinical levels of nicotine dependence, which is smoking addiction. Apart from the addictive dominants in cigarette, there have many complicated factors of society and psychology which is implicated behind smoking dependence and addiction. As a consequence, understanding the factors that cause and maintain nicotine dependence may control the quantity of smokers and improve prevention and treatment.Drug-dependent individuals prefer immediate reward in exchange for larger long-term goals, and show worse ability of self regulation and impulsive behavior. So far, studies where impulsivity behavioral measures were used agreed to consider two broad categories of laboratory impulsivity paradigms. The first category refers to the degree to which immediate (rewarding) consequences have more control over an individual’s behavior than consequences that are delayed. The second category is related to behavioral inhibition and denotes an individual’s ability to appropriately inhibit thoughts or actions. Both are very important of smoking behavior. On the one hand, for the Delay Discounting paradigm, Compared to non-smokers, nicotine dependent individuals exhibit significantly more impulsive delay discounting. On the other hand, for the response inhibition paradigm, the worse ability of behavioral inhibition, more difficulty for smokers to contral smoking, which is easier to become somking addiction. So, response inhibition is refered to the important factor to resist addiction. In addition, a lot of researchs discuss the attentional bias and craving to drug related signals for smokers, and they have found that drug related signals(like smoking pictures)could activate and improve the smokers’craving to drug, but there has no research about craving that concerned with general impulsion in behavior.In order to explore the phychological mechanism behind the impulsive behavior of smoking individuals. Experiment I activates smoking and non-smoking individuals’craving to smok through explicit or implicit way, and try to explore whether there have diffidence of the degree of crving between two groups and can this craving influence individual’s ability of inhibitory control. In view of that individual’s attention to addictive substance signals may influence the inhibitory control, in other word the reduced inhibitory control could improve when exposed addictive related signals. So Experiment Ⅱ use smoking related pictures as the materials of Go-Nogo test, take the emotional valence(positive or negative) into account, try to explore the difference reaction of response inhibition between smoking and non-smoking individuals, and whether the attention to addictive substance signals could influence the inhibitory control. Combine the results of Experiment I and Experiment Ⅱ, we draw the following conclusions:(1) Smokers’craving to cigarette can be activated and improved through explicit and implicit ways, regardless of the activation methods.(2) there has no difference of baseline delay discounting degree between smoking and non-smoking individuals. But smokers discounted the value of delayed money more than did the comparison groups after activate their craving to cigarette. In addition, individuals’delay discounting level can be predicted by the craving level, which indicate that smokers’impulsion in behavior can improve afer the activation of craving to cigarette.(3) In Go-Nogo test using smoking related pictures as the materials, there has no difference of the reaction time in "go" response between smoking and non-smoking individuals. But in "nogo" response, the accuracy in smokers is more than comparison groups, suggest that when using addictive strengthen signals as the experimental material, smokers can make better than comparison groups.(4) In "go" response trials, individual’s reaction time and accuracy to positive pictures is better than to neutral and negative pictures, but in "nogo" response trials, their accuracy to inhibit positive pictures is worse than to neutral pictures, suggest the individual’s attention and response tendence to positive stimulative signals.