Effects of cigarette smoking and abstinence on stroop task performance

Rationale Smokers report enhanced concentration after cigarette smoking and difficulty concentrating when abstinent from smoking. These perceived effects may contribute to smoking cessation failures, and if so, clarification of their cognitive bases could inform treatment strategies. Selective attention may be important in this regard, but earlier literature presents inconsistent findings on how smoking abstinence and resumption of smoking influence this cognitive function. Objectives We aimed to compare smokers and nonsmokers on selective attention, and in smokers, to test the effects of overnight abstinence from smoking and of acute smoking on selective attention. Materials and methods Smokers and nonsmokers (n = 43) performed a Stroop test (two test days, two test blocks per day). Smokers participated after overnight abstinence and also within 1-h of ad libitum smoking. Smokers each smoked a cigarette between test blocks on each day; nonsmokers did not. Results Smokers demonstrated longer response latencies for both congruent and incongruent stimuli after overnight than brief abstinence, but no deficit specifically related to selective attention. Whereas nonsmokers showed no changes in performance in the second test block, smoking between blocks reduced the Stroop effect when smokers were abstinent overnight. Conclusions These data are consistent with the hypothesis that abstinence from smoking among nicotine-dependent individuals has deleterious effects on cognitive performance, but do not indicate that selective attention is adversely effected. Improvement in selective attention after terminating abstinence with one cigarette may also contribute to smokers’ perceived enhanced ability to concentrate after smoking.     

Improved incidental memory with nicotine after semantic processing, but not after phonological processing

RATIONALE: A number of lines of evidence suggest that a nicotinic cholinergic system is mediating attentional processing. However, the evidence is less clear for a nicotinic system being involved in mnemonic processing. OBJECTIVES: The present study investigated the effects of nicotine on memory using a depth of processing paradigm. METHODS: A double-blind design was used with participants (n = 40) smoking either a nicotine containing cigarette (n = 20) and a denicotinized cigarette (n = 20). After smoking, each set of these participants was further subdivided into two groups (n = 10 for each). One group were presented with a series of trials each beginning with the presentation of a "decision word" which they had to say whether it represented something which was living or non-living (semantic-orienting). The second group had to say whether the word had one syllable or two syllables (phonological or non-semantic orienting condition). This decision was followed by a word in coloured ink whose colour participants were required to name as quickly as possible. On completion of the whole task the participants were given an unexpected free recall test. RESULTS: The nicotine-containing cigarette reduced the latencies for decision-making and colour naming in comparison with the denicotinized cigarette. The free recall test showed that nicotine-containing cigarette increased the number of words remembered, but only for the semantic-orienting condition and not the non-semantic condition. CONCLUSIONS: There is a nicotinic cholinergic system that mediates effortful processing. It can be deployed for attentional processing, including the associative processing required for memory encoding.     

Effects of transdermal nicotine on attention and memory in healthy elderly non-smokers

RATIONALE: Nicotine has been found to improve cognitive functions in patients with Alzheimer's disease, but little is known about its effects in the healthy non-smoking elderly. OBJECTIVES: This study aimed to investigate the effects of nicotine on cognitive function in healthy non-smoking or nicotine-na?ve elderly subjects. METHODS: A transdermal patch containing either 5 mg nicotine or placebo was applied on the back of 63 healthy nicotine-na?ve or non-smoking elderly Koreans. Cognitive functions were evaluated with the Short Blessed Test, Rey-Kim Memory Test, and digit span test of the Korean-WAIS, both before and 5.5 h after nicotine administration. The plasma level of nicotine after testing was measured using gas chromatography. RESULTS: The subjects' memory functions in trial 5 of the Rey-Kim Memory Tests improved significantly. Furthermore, the effect on memory slope was significantly correlated with the higher plasma level of nicotine. However, the other tests did not reveal any correlation to a significant degree. CONCLUSIONS: These results suggest that nicotine of lower plasma level can improve short-term verbal memory functions in non-smoking or nicotine-na?ve healthy elderly people and that some effects are dependent on nicotine plasma levels.     

Influencing cigarette smoking with nicotine antagonists

Antagonists of nicotine have been used in an attempt to resolve the continuing controversy about the role of nicotine as the primary reinforcer in cigarette smoking. Mecamylamine, an antagonist which readily penetrates to the central nervous system, increased the rate of cigarette smoking by about 30% in laboratory tests; this was accompanied by reduced blood pressure, impaired performance of a digit symbol substitution test, improved hand steadiness, and by dysphoria. The increased smoking may be regarded as self-titration with nicotine, an interpretation which receives some support from results obtained with pentolinium, an antagonist with predominantly peripheral actions. In the doses used, pentolinium did not affect smoking rate, blood pressure, or hand steadiness, but it impaired digit symbol performance and induced dysphoria. The different results with mecamylamine and pentolinium support previous evidence that the action of nicotine in the central nervous system has a small but clearly demonstrable role as a primary reinforcer of the smoking habit.A preliminary account of this work has appeared previously (Jarvik, in press).     

Acute cigarette smoking reduces latencies on a Smoking Stroop test

Rationale

Sensitivity to addiction-related cues, a type of attentional bias, may interfere with executive functions that are important in sustaining abstinence from drug abuse. Assessments of attentional bias in research participants who smoke cigarettes have used Smoking Stroop tasks, which are variations of emotional Stroop tasks in which the stimuli are smoking-related and neutral words.

Objectives

We aimed to determine the effect of resumption of smoking by deprived cigarette smokers on attentional bias.

Methods

Testing occurred twice on each of two test days. One test day began after overnight abstinence (13–16 h) and the other after < 1 h of abstinence. The participants (n = 51) smoked a cigarette between the two test sessions on each test day.

Results

Smokers exhibited attentional bias for smoking-related words and had longer response times after overnight abstinence than after brief abstinence. Cigarette smoking between sessions reduced response times on both test days with no interaction by stimulus type.

Conclusions

Smoking-related cues have distracting effects in smokers, and smoking reduces response latency, with no specific effect on attentional bias. The increase in response speed may contribute to a smoker's impression that abstinence hinders performance and that smoking reverses impairment.     

Reaction time performance as a function of cigarette smoking procedure

Laboratory studies examining the effects of cigarette smoking on behavior have routinely employed a variety of standardized smoking procedures. This study examined whether reaction time performance after smoking varied as a function of the cigarette smoking procedure employed. Twelve regular smokers were tested on a reaction time task after smoking on three different occasions. In each session, they smoked by one of the three following procedures: (1) ad libitum smoking of their own cigarette; (2) ad libitum smoking of a standard cigarette; (3) smoking a standard cigarette with a prescribed puff pattern. The results show that reaction time performance was significantly faster after smoking under the latter two conditions relative to the subjects' performance after ad libitum smoking of their own cigarette. These findings illustrate that experimental requirements which are commonly imposed upon subjects may affect the results obtained.     

Naltrexone,smoking behaviour and cigarette withdrawal

In order to examine the role of endogenous opioids in the reinforcing effects of nicotine, a double-blind, placebo-controlled, cross-over design was used to study the effects of the opiate antagonist, naltrexone, on smoking behaviour and cigarette withdrawal in 12 heavy smokers. Although naltrexone (50 mg) appeared to reduce the perceived difficulty of abstaining during 24-h cigarette withdrawal, other withdrawal symptoms were unaffected. Naltrexone also had no effect on a variety of biochemical and behavioural measures of nicotine intake or on subjective satisfaction and enjoyment from the first cigarette smoked after 24-h abstinence. Similarly naltrexone (100 mg) had no effect on smoking behaviour, nicotine intake or satisfaction from smoking during a 48-h period of ad libitum smoking. However, during the ad libitum smoking period naltrexone caused mood changes of the kind that occur during tobacco withdrawal. Since nicotine intake and smoking behaviour were unaffected, the mood changes are unlikely to have been mediated by blockade or any other form of opioid interaction with nicotinic mechanisms. These findings provide evidence against the notion that the endogenous opioids are involved in mediating the reinforcing properties of nicotine in smokers under normal conditions.     

Effects of cigarette smoking on learning and retention

Verbal rote learning was studied on 10 habitual smokers in a smoking and non-smoking session. Smoking induced a significant decrease in the number of correct responses on the learning task as compared to non-smoking values. The impaired learning coincided in time by an increased arousal as measured by heart rate. A test of recall 45 min after the end of the learning period, when the presmoking arousal level had been restored, showed that retention was better in the smoking condition than in the nonsmoking condition. The results were interpreted in terms of Walker's theory (1958) postulating a relationship between arousal level and consolidation of memory.     

Electroencephalographic effects of cigarette smoking

The effects of cigarette smoking on the electroencephalogram (EEG) of smokers were examined in a study involving both task and no-task conditions. Nonsmoking subjects were employed as controls. In light inhaling smokers, (depth of inhalation inferred from preto post-smoking changes in tidal breath carbon monoxide), smoking was found to attenuate EEG activity in the delta, theta, and alpha frequency bands, as well as facilitate behavioral performance. For theta, the attenuation was lateralized over the right frontal cerebral hemisphere. In deep inhaling smokers, smoking produced a symmetrical central midline increase in beta2 magnitude, an EEG effect that in the benzodiazepine literature is associated with anxiety relief.A preliminary version of these data was presented during the symposium Psychophysiology of Nicotine, held at the Thirtieth Annual Convention of the Society for Psychophysiological Research, Boston, October, 1990     

Effects of post-learning smoking on memory consolidation

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.     

Can cigarette size and nicotine content influence smoking and puffing rates?

The stimuli controlling the rate at which people smoke cigarettes have not been clearly defined. On the hypothesis that smoking is basically nicotine-seeking behavior. nicotine available to the subject was experimentally manipulated through controlling cigarette size and nicotine content. In Experiment I, subjects given their own cigarettes in whole, half, quarter, and eighth lengths, increased the number of cigarettes smoked and number of puffs to compensate for reductions in size. Satisfaction was directly related to cigarette length. In Experiment II, subjects given special cigarettes delivering 0.2 or 2.0 mg nicotine/cigarette smoked significantly more of the low than of the high nicotine cigarettes and took significantly more puffs. As in Experiment I, significantly more quarter length than full length cigarettes were smoked, but total number of puffs did not differe. These results support the hypothesis that nicotine controls smoking behavior.     

Effects of abstinence and smoking on information processing in adolescent smokers

RATIONALE: Although adolescent smokers appear to display some of the hallmark features of dependence, the biological and behavioral effects of smoking in this population are poorly understood. OBJECTIVES: This study aimed to define empirically the effects of abstinence and smoking in adolescent smokers, using indices validated in adult smokers. METHODS: Subjects were 16 young novice smokers (five male, 11 female), ages 14-18 years. A modified Stroop task measured the ability to inhibit attention to smoking-related cues; the classic Stroop task measured the ability to inhibit a pre-potent response (i.e. reading a word); a rapid information processing (RIP) task measured vigilance. RESULTS: Abstinence increased and smoking decreased the intrusiveness of smoking cues. Parallel effects were seen in commission errors on the RIP task. These effects were restricted to heavier smokers (>11 cigarettes/day). Subjective withdrawal effects predicted the intrusiveness of smoking words during abstinence. The number of cigarettes smoked per day predicted the beneficial effect of smoking on the classic as well as modified Stroop tasks. The physiological effects of abstinence and smoking predicted RIP performance. CONCLUSIONS: Abstinence impairs and smoking improves inhibitory information processing in young novice smokers in a manner similar to adult smokers. Daily frequency of smoking is a critical moderator of these effects.     

Smoking,processing speed and attention in a choice reaction time task

Nineteen subjects performed a choice reaction time task in which two levels of choice (two and four stimuli), and two levels of spatial attention (narrow and wide) were manipulated under each of two smoking conditions: sham smoking (denicotinised cigarette) or regular smoking (0.8 mg nicotine cigarette). All three factors significantly affected reaction time, with the smallest reaction times being recorded to the two-choice narrow grouped stimuli recorded under the high nicotine condition. Nicotine appears to speed decision time for both complex and hard-to-attend tasks, which is compatible with a role for nicotinic receptors in systems jointly mediating attention, memory and processing speed.     

Effects of cigarette smoking and 12-h abstention on working memory during a serial-probe recognition task

Nicotine has been shown to affect attentional and mnemonic processes. However, whether these effects are due to changes in perceptual and/or motor aspects of the tasks is not at all clear. This study tested the hypothesis that nicotine from cigarette smoking has differential effects on perceptual and motor processes, as reflected by event-related potentials (ERPs) and reaction times (RTs), respectively, and that perceptual effects may be specific to changes in working memory. ERPs, RTs and performance accuracy were recorded from smokers and nonsmokers during a serial-probe recognition memory task in which lists of words or “memory sets” were followed by a probe word that was either in-set or out-of-set. Smokers were tested in a “smoking” and a 12-h “deprived” condition. Smoking-smokers and deprived-smokers exhibited fast RTs to in-set and out-of-set probes relative to a group of nonsmokers. They exhibited even faster RTs when the in-set probe word matched the first or last item in the memory set. Thus, smokers as a group showed enhanced primacy and recency effects suggesting that smoking specifically facilitates processes related to the motor output aspects of working memory. Different effects characterized the electrophysiology. Larger P300s were recorded to in-set compared to out-of-set probes by both subject groups. Smoking smokers exhibited enhanced P300s to both types of probes. When smokers abstained for 12 h (deprived smokers), the differences in P300 amplitude were reduced but not eliminated. Smoking smokers exhibited faster P300 latencies to in-set probes, while deprived smokers showed delayed latencies relative to nonsmokers. Primacy and recency P300 effects characterized nonsmokers and deprived smokers. However, this relationship was reversed in the Smoking condition. These results support the hypotheses that nicotine has distinct effects on memory-related perceptual and motor aspects of working memory. The increase in efficiency of the memory search with nicotine is consistent with the functional role of the cholinergic system in maintaining a state “appropriate for efficient information processing.” Received: 12 April 1997/Final version: 4 March 1998     

Manipulation of cigarette craving through rapid smoking: efficacy and effects on smoking behavior

Craving is thought to play an important role in maintaining regular smoking patterns in current smokers, and in leading to relapse in smokers attempting to quit. Within the scientific community however, the concept is surrounded by controversy. In an effort to 1) identify interventions that can reliably influence cigarette cravings, and 2) assess the relationship between cigarette craving and smoking behavior, effects of aversive rapid smoking (up to nine cigarettes with puffs taken every 6 s) on self-reported craving and subsequent smoking behavior were compared to effects of self-paced smoking or no smoking. Subjects (n = 14) engaged in a rapid, self-paced or no smoking procedure at the start of three separate sessions. Craving levels, measured repeatedly during the next 3 h of no smoking, were significantly lower after rapid smoking than after either self-paced or no smoking. Measures of subsequent smoking behavior (latency to first cigarette, number of cigarettes, number of puffs) did not differ systematically across conditions. Thus, craving was reliably suppressed by aversive rapid smoking, but craving scores did not predict actual smoking behavior. Received: 2 April 1998/Final version: 7 August 1998     

Individual differences in stress and arousal during cigarette smoking

Self-rated feelings of stress and arousal were monitored before and after each cigarette, over a day of normal smoking. Subjects comprised 105 unpaid volunteers (65 female, 40 male; mean age 30.4 years; mean consumption 12.4 cigarettes on test day). Feelings of arousal were significantly higher post-smoking than presmoking. The degree of arousal change was monotonically related to scores on the smoking motivation questionnaire (SMQ) stimulant subscale, with high stimulant smokers reporting the greatest arousal modulation. However stimulant smokers reported low arousal before smoking, rather than high arousal after smoking. Feelings of stress were significantly lower post-smoking than presmoking. The degree of stress change was monotonically related to scores on the SMQ sedative subscale, with high sedative smokers reporting the greatest stress change. This confirms the criterion validity of this second SMQ subscale. However, as with the arousal data, sedative smokers tended to report high stress before smoking, rather than low stress after smoking. Smoking did not therefore produce advantageous post-cigarette feeling states. Instead, mood modulation largely comprised the alleviation of poor psychological states prior to smoking. These stress and arousal changes often occurred simultaneously, against the predictions of the arousal modulation theory. Arousal modulation and stress modulation should therefore be seen as separate and independent processes. Lastly, feelings of stress and arousal fluctuated repeatedly over the day, with improved moods immediately after smoking, but impaired moods developing between cigarettes. These mood reversals provide a clear psychological rationale for the repetitive (addictive) nature of nicotine use.     

Changes in behavioral and physiological activation induced by cigarette smoking in habitual smokers

Performance in tasks on visual simple- and choice-reaction time was studied in six healthy habitual smokers. Results from a non-smoking condition, and a condition in which each subject smoked four cigarettes, indicated that smoking had a beneficial effect on performance efficiency in both tasks: (a) simple-reaction time increased over time in the non-smoking condition, but remained at the same level in the smoking condition, and (b) choice-reaction time increased slightly in the non-smoking condition, and decreased in the smoking condition. The difference between conditions was statistically significant for simple-reaction time. Hand steadiness was impaired by smoking. Heart rate and systolic pressure increased in the smoking condition, while catecholamine secretion remained relatively unaffected by smoking. Self-estimates of wakefulness and mood showed that smoking was judged to have favourable effects.Financial support was obtained from the Swedish Medical Research Council (Project No. 14X-997), and the Swedish Council for Social Science Research. A group of students participated in the data collection: Gunbritt Bülow, Ulla Hilldoff, Karin Lagerberg, Jan-Eric Olsson and Lena Wedin. The catecholamine analyses were performed by Birgitta Linell.     

Effects of cigarette smoking upon frequencies of EEG alpha rhythm and finger tapping

Under the influence of nicotine, an increase in EEG alpha frequency as well as finger tapping speed has been reported from separate experiments, and it has also been shown that tapping and alpha frequencies may correlate in defined experimental settings. The present study aimed at the analysis of smoking effects using parallel recordings of both EEG and finger tapping. Twelve healthy subjects were tested in two sessions (smoking deprivation versus smoking). After smoking, both dominant alpha frequency (P<0.05) and tapping performance (P<0.001) were higher than during deprivation. In most subjects, the increase of both parameters developed in parallel, and during phases of very stable tapping the ratio of alpha and tapping frequencies was close to 2:1. Both frequencies correlated during the deprived (r=0.6108,P=0.035) as well as the smoking (r=0.7009,P=0.011) conditions. Results confirm earlier findings regarding the effect of smoking upon EEG and tapping, and the parallel changes of both parameters may be attributed to the pharmacological properties of nicotine. Besides possible peripheral and spinal effects of nicotine, the increase of tapping performance parallels the increased frequency of central nervous pacemakers.     

Naltrexone reduces the relative reinforcing value of nicotine in a cigarette smoking choice paradigm

Rationale Human behavioral pharmacology studies can examine how medications that target different neurotransmitter systems influence different aspects of smoking. Naltrexone and bupropion have been shown to alter ad lib smoking behavior; however, medication effects on nicotine reward in a cigarette choice paradigm have yet to be investigated.Objective This study explored the effects of an acute dose of naltrexone, bupropion, or placebo on the relative reinforcing value of nicotine from cigarette smoking using new nicotine and de-nicotinized (Quest, 0.6 and 0.05 mg = denicotinized) cigarettes.Methods In a double-blind, within-subjects design, 26 dependent smokers participated in three experimental cigarette smoking sessions following pretreatment with either naltrexone (50 mg), bupropion (300 mg), or placebo. After medication administration and 2 h of monitored deprivation from cigarettes and food, participants rated their responses to the initial exposure to the cigarettes and then participated in four choice sessions over a 2-h period during which they could take four puffs from either cigarette.Results The relative reinforcing value of nicotine, as measured by the number of nicotine puffs chosen out of 16, was significantly lower following naltrexone compared to placebo. There were no effects of an acute dose of bupropion on nicotine choices.Conclusions These results suggest that naltrexone may reduce the relative reinforcing effects of nicotine via cigarette smoking and support ongoing investigation of opioid antagonists as potential smoking cessation pharmacotherapies.     

Does noise stress modulate effects of smoking/nicotine? Mood, vigilance, and EEG responses

Effects of smoking multiple cigarettes on EEG, vigilance, and subjective state were assessed in a repeated measures design where noise level (high versus minimal) was crossed with nicotine dose (quasi-ad lib own versus 1.0 mg FTC nicotine machine-delivered dose versus 0.05 mg FTC nicotine machine-delivered dose). Vigilance was increased by nicotine, but not by noise and there was no noise by dose interaction. Effects of nicotine on EEG varied as a function of dose, noise, hemisphere, time, and eyes-open versus eyes-closed condition. Smoking normal nicotine delivery (0.9–1.1 mg FTC-estimated) cigarettes resulted in decreases in percentages of delta and theta EEG magnitude and increased percentage beta-1 EEG magnitude across conditions and time. Changes in alpha and theta magnitude were dependent on eyes being open versus closed. Hemispheric asymmetries varied as a function of noise and time. Consistent with inverted “U” models, effects of nicotine on EEG were clearly stimulant during the quiet conditions while there were minimal to no differences between nicotine doses during the high-noise conditions. The failure of nicotine to modify mood is interpreted in terms of bioinformational models of nicotine’s subjective effects. Received: 19 July 1996/Final version: 8 September 1996