***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: The contribution of sensory factors to smoking satisfaction and nicotine withdrawal symptoms was assessed by evaluating responses to three types of cigarettes : a regular cigarette , a de-nicotinized cigarette ( de-nic ) , and a lettuce leaf cigarette . Doses were varied by requiring subjects to smoke cigarettes using a five-port cigarette manifold . The ratio of the regular or de-nic cigarettes to the lettuce cigarettes was varied across the following values : zero , one , two , and four of five . Seven male smokers were tobacco-deprived for 12 h before testing . On one test day they smoked the de-nic cigarettes , and on another day they smoked the regular cigarettes .  Ratings of satisfaction and cigarette linking were directly related to the number of regular or de-nic cigarettes , but were generally higher after the regular cigarette . The regular and de-nic cigarettes were equivalent in reducing acute withdrawal symptoms . Expired CO was similar on both experimental days . The regular cigarette dose-dependently increased plasma nicotine , but the de-nic cigarette did not increase plasma nicotine . These results indicate that sensory characteristics of cigarettes contribute to the abuse liability of smoke-delivered nicotine . The results suggest that smoking cigarettes that do not provide nicotine may temporarily suppress cigarette withdrawal symptoms The effect of smoking abstinence  on the dissociated components of a simple reaction-time response was investigated . 7 subjects completed two experimental sessions conducted one week apart . Each experimental session was comprised of two tests . The first test consisted of abstinent baseline measures , while the second test was administered after smoking either an investigator-supplied nicotinised or denicotinised cigarette . A within-subjects design was utilized which permitted each subject to be their own control . Interestingly , the smoking of either experimenter-controlled cigarette ( nicotinised or denicotinised ) reliably decreased the subjects ' desire to smoke . More importantly , however , was that only the nicotinised cigarette had any influence on simple reaction time . Moreover , this decrease in reaction time was isolated within the premotor or cognitive processes . In fact , there was no evidence that the smoking of a nicotinised cigarette had any effect on the motor-time component of this task . These findings are relevant for two reasons , ( 1 ) performance decrements due to smoking abstinence were independent of the urge or craving to smoke and ( 2 ) nicotine affects cognitive and motor processes of a simple reaction-time task differently The neural circuitry implicated in addictive drug use , which appears to be down-regulated in early abstinence , corresponds closely with brain reward pathways . A literature review suggests that responses to incentive stimuli and the ability to inhibit reflexive responses , both of which have been associated with normal functioning in these pathways , might be weakened during acute abstinence from chronic drug use . In an ongoing study , 82 smokers , abstinent overnight before two separate testing occasions , have been assessed after administration of nicotine and placebo lozenges ( order of sessions counterbalanced ) . Nicotine administration is associated with a significant reduction in anhedonia , a near-significant increase in response to financial incentive , enhanced ability to inhibit reflexive eye movements , and increased attentional bias to words with appetitive significance .  Fifty-nine participants then initiated a quit attempt and 19 reported relapsing within 7 days . Comparing their performance in the two prequit lozenge assessment sessions , relapsers showed a stronger effect of nicotine on enhancing their ability to inhibit reflexive eye movements and a near-significant trend towards greater nicotine-induced increases in attentional bias toward appetitive words AIMS Nicotine is known to enhance aspects of cognitive functioning in abstinent smokers , but the effects on specific areas of executive functions and in non-smokers are inconclusive . This may be due in part to the poor sensitivity of tests used to assess executive functions . This study used a new virtual reality assessment of executive functions known as JEF ( the Jansari assessment of Executive Functions ) to address this issue . DESIGN A 2 × 2 design manipulating group ( smokers and never-smokers ) and drug [ nicotine ( 4 mg for smokers ; 2 mg for never smokers ) versus placebo gum ] . SETTING School of Psychology ; University of East London . PARTICIPANTS Seventy-two participants ( aged 18 - 54 years ) : 36 minimally deprived ( 2 hours ) smokers and 36 never-smokers . MEASUREMENTS Components of executive function were measured using the virtual reality paradigm JEF , which assesses eight cognitive constructs simultaneously as well as providing an overall performance measure . FINDINGS Univariate analyses of variance revealed that nicotine improved overall JEF performance , time-based prospect i ve memory and event-based prospect i ve memory in smokers ( P < 0.01 ) , but not in never-smokers . Action-based prospect i ve memory was enhanced in both groups ( P < 0.01 ) and never-smokers out-performed smokers on selective thinking and adaptive thinking ( P < 0.01 ) . CONCLUSIONS Executive functioning and prospect i ve memory as aspects of cognitive performance can be enhanced by nicotine gum in smokers who have abstained for as little as 2 hours Schizophrenic patients have among the highest rates of smoking of any group of patients . Previous studies have identified psychophysiological and potential nicotinic receptor abnormalities which may be associated with this phenomenon . The effects of acute smoking or acute administration of nicotine nasal spray , after smoking abstinence , on negative symptoms and neurocognitive function have been less extensively studied in experimental design s. This study investigated the effects of smoking of high nicotine or denicotinized cigarettes , and receiving active or placebo nicotine nasal sprays , on positive and negative symptoms and cognitive functions in schizophrenic patients . The study utilized a placebo controlled crossover experimental design with pre- and post-drug evaluations on each experimental day . Smoking high nicotine cigarettes decreased negative symptoms more than denicotinized cigarettes , but smoking neither cigarette changed scores of positive symptoms , anxiety , or depression .  Active nicotine nasal spray did not differentially decrease negative symptoms compared with placebo , but did improve performance on a spatial organization task , and tended to improve some measures of verbal memory and two-choice reaction time in schizophrenic patients . Both high and denicotinized cigarettes improved performance on the spatial processing task , but there was no statistically significant differential drug ( Cigarette type ) effect . These results suggest that acute smoking of cigarettes may transiently decrease negative symptoms in patients with schizophrenia , but it is unclear whether this effect is attributable to nicotine , other components of cigarettes , or the act of smoking . Nicotine nasal spray may modestly improve some selected aspects of cognitive function in schizophrenia The effects of immediate post-learning smoking of low and medium nicotine delivery cigarettes were compared to those of smoking a denicotinised cigarette and a no-smoking control condition in a paired-associate learning task . Thirty-nine male smokers were tested for retention of the memorised material at 1 week post-learning . All subjects received all conditions in a repeated measures design . The low nicotine condition was associated with significantly fewer errors on first trial of recall and fewer total errors to criterion . There were no differences in performance reported between the no-smoking and zero nicotine conditions . The medium nicotine condition produced results part way between the no-smoking and low nicotine conditions . Results are discussed in terms of the effects of nicotine on long-term consolidation mechanisms As many as one-half of smokers relapse in the first week following a quit attempt , and subjective reports of cognitive deficits in early abstinence are associated with increased relapse risk . This study examined whether objective cognitive performance after 3 days of abstinence predicts smoking resumption in a 7-day simulated quit attempt . Sixty-seven treatment-seeking smokers received either varenicline or placebo ( r and omized double-blind ) for 21 days . Following medication run-up ( days 1 - 10 ) , there was a 3-day m and atory ( biochemically confirmed ) abstinence period ( days 11 - 13 ) during which working memory ( Letter-N-Back Task ) and sustained attention ( Continuous Performance Task ) were assessed ( day 13 ) . Participants were then exposed to a scheduled smoking lapse and instructed to try to remain abstinent for the next 7 days ( days 15 - 21 ) . Poorer cognitive performance ( slower correct reaction time on Letter-N-Back task ) during abstinence predicted more rapid smoking resumption among those receiving placebo ( p=0.038 ) but not among those receiving varenicline . These data lend further support for the growing recognition that cognitive deficits involving working memory are a core symptom of nicotine withdrawal and a potential target for the development of pharmacological and behavioral treatments Inattention and hyperactive-impulsive symptoms have been associated with nicotine dependence . In an open-label r and omized trial ( N = 454 ) of  transdermal nicotine versus nicotine nasal spray , we examined whether increases in inattention and hyperactive-impulsive symptoms measured by self-report in the first quit week predicted relapse at the end of 8 weeks of treatment ( EOT ) . During the first quit week , 166 ( 37 % ) participants reported an increase whereas 288 ( 63 % ) reported no change/decrease in total symptoms ; changes were not influenced by treatment type . In a logistic regression model of abstinence , an increase in total symptoms in the first quit week significantly reduced odds of abstinence at EOT ( continuous change score : OR = 0.94 , 95 % CI = 0.91 - 0.98 , p = .002 ; dichotomized change score : OR = 0.57 , 95 % CI = 0.37 - 0.87 , p = .009 ) . Early increases in inattention and hyperactive-impulsive symptoms following quit date during nicotine replacement therapy predicted relapse to smoking , suggesting that treatments targeting these symptoms in the first quit week may facilitate abstinence Background : Reduced nicotine content ( RNC ) cigarettes have led to smoking fewer cigarettes , withdrawal relief , and facilitation of cessation . The aim of this study is to examine the effects RNC cigarettes with and without nicotine patch and patch alone on smoking behavior , toxicant exposure , withdrawal discomfort , and as an exploratory analysis , on long-term abstinence . Methods : This study involved a r and omized , parallel arm design and six weeks of : ( i ) 0.05–0.09 mg nicotine yield cigarettes ( N = 79 ) ; ( ii ) 21 mg nicotine patch ( N = 80 ) , or ( iii ) 0.05–0.09 nicotine yield cigarettes with 21 mg nicotine patch ( N = 76 ) ; all groups received six weeks of additional behavioral treatment with follow-ups up to six months . Results : Combination approach led to lower rates of smoking assigned cigarettes and hence lower carbon monoxide levels than RNC cigarettes alone . In addition , the combination approach was associated with less withdrawal severity when switching from usual br and to assigned product , and less smoking of usual br and cigarettes during treatment , but not after treatment compared with the other approaches . Conclusion : Combining very low nicotine content cigarettes with nicotine patch may improve the acute effects result ing from switching to either of these products alone . Impact : These findings may have implication s for smoking cessation treatment or a policy measure to reduce nicotine content in cigarettes . Cancer Epidemiol Biomarkers Prev ; 22(6 ) ; 1015–24 . © 2013 AACR Our group recently reported that smoking a regular cigarette ( 1.2 - 1.4 mg nicotine ) result ed in 88 % occupancy of brain alpha4beta2 * nicotinic acetylcholine receptors ( nAChRs ) . However , this study did not determine whether nicotine inhalation or the many other pharmacological and behavioural factors that occur during smoking result ed in this receptor occupancy . If nicotine is solely responsible for alpha4beta2 * nAChR occupancy from smoking , then ( as estimated from our previous data ) smoking a denicotinized ( 0.05 mg nicotine ) or a low-nicotine ( 0.6 mg nicotine ) cigarette ( commonly used for research and clinical purpose s ) would result in substantial 23 % and 78 % alpha4beta2 * nAChR occupancies , respectively , and a plasma nicotine concentration of 0.87 ng/ml would result in 50 % alpha4beta2 * nAChR occupancy ( EC50 ) . Twenty-four positron emission tomography sessions  were performed on tobacco-dependent smokers , using 2-[F-18]fluoro-A-85380 ( 2-FA ) , a radiotracer that binds to alpha4beta2 * nAChRs . 2-FA displacement was determined from before to 3.1 hours after either : no smoking , smoking a denicotinized cigarette , or smoking a low-nicotine cigarette . Analysis of this PET data revealed that smoking a denicotinized and a low-nicotine cigarette result ed in 26 % and 79 % alpha4beta2 * nAChR occupancies , respectively , across three regions of interest . The EC50 determined from this data set was 0.75 ng/ml . Given the consistency of findings between our previous study with regular cigarettes and the present study , nicotine 
    Output:
    
Overall , VLNC cigarettes may not fully ameliorate withdrawal-induced disruptions in performance , although this varies by domain , with the strongest evidence for reaction time .
Importantly , combining VLNC cigarettes with NRT appears to ameliorate withdrawal that is not reduced by VLNC cigarettes alone .