***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: This study examined the effects of abstinence from smoking , of smoking history , and of nicotine administration on visual attention ( 2-Letter Search Task ) , verbal information processing ( Logical Reasoning Task ) , and working memory ( N-Back Tasks ) .  Fourteen smokers , 15 ex-smokers , and 9 never-smokers took part . All subjects participated in a training session ( when smokers had been smoking ad libitum ) and in two subsequent test sessions after administration of 4 mg nicotine gum or placebo , respectively . Smokers were 12-h abstinent when they received gum . An effect of acute nicotine administration ( independent of smoking history ) was seen only with respect to reaction time on the 2-Letter Search Task . Working memory performance was related to smoking history ( smokers performed most poorly and never-smokers best ) . The Logical Reasoning Task showed no effects of either acute or chronic nicotine exposure . The findings indicate that nicotine may influence focusing of attention in smokers as well as nonsmokers , and that trait-like differences in some cognitive domains , such as working memory , may be either long-term effects or etiological factors related to smoking In the elderly , cigarette smoking has been related to reduced cognitive performance and moderate alcohol consumption to increased cognitive performance . It is not clear whether these associations also exist in middle age . The authors examined these relations in a population -based cohort study of 1,927 r and omly selected , predominantly middle-aged subjects aged 45 - 70 years at the time of cognitive testing and living in the Netherl and s. From 1995 until 2000 , an extensive cognitive battery was administered , and compound scores were calculated . Risk factors had been assessed approximately 5 years previously . Multiple linear regression analyses ( in which one unit of the cognitive score = one st and ard deviation ) showed that , after the authors adjusted for age , sex , education , alcohol consumption , and cardiovascular risk factors , current smokers had reduced psychomotor speed ( beta = -0.159 , 95 % confidence interval : -0.071 , -0.244 ; p = 0.0003 ) and reduced cognitive flexibility ( beta = -0.133 , 95 % confidence interval : -0.035 , -0.230 ; p = 0.008 ) compared with never smokers . This effect was similar to that of being approximately 4 years older . Alcohol consumption was related to increased speed and better flexibility , especially among women who drank 1 - 4 alcoholic beverages a day . In conclusion , among middle-aged subjects , current smoking was inversely and alcohol consumption positively related to psychomotor speed and cognitive flexibility . This finding suggests that actions to prevent cognitive decline can be taken in middle age Auditory P300 latency prolongation or amplitude reduction has been reported in patients affected by bipolar disorder and in schizophrenia . The purpose of this study was to test whether the auditory P300 and earlier event-related potential ( ERP ) components elicited during an auditory discrimination task could differentiate between these two disorders . Thirteen patients with manic or mixed bipolar disorder , 12 patients with schizophrenia , and 24 control subjects were evaluated . None of the subjects had a history of alcohol or substance abuse or dependence .  ERPs were elicited during an auditory discrimination task in which a subject pressed a key to infrequent 1500 Hz tones interspersed amid a series of 1000 Hz tones . The amplitude and latency of N100 and P200 were measured from ERPs to non-target tones , and N200 and P300 were measured from ERPs to target tones . N100 , P200 and N200 amplitudes were reduced in schizophrenia patients , but not in bipolar patients . Both bipolar disorder and schizophrenia patients showed reduced P300 amplitude and prolonged P300 latency . Amplitude reduction in the early ERP components implicates auditory processing deficits in schizophrenia . Both groups showed reductions in P300 amplitude , suggesting a disturbance of the temporal-parietal generators of this component . Prolonged P300 latency is consistent with impaired attentional processing in schizophrenia and symptomatic bipolar disorder patients Numerous studies have evaluated  event-related potentials ( ERPs ) as biological indicators of the liability for alcoholism . This study extends that approach by investigating ERPs in boys at risk for other substance use disorders . Prepubertal ( 10 - 12 years ) sons of fathers diagnosed with psychoactive substance dependence ( n = 28 ) were compared to matched sons of nonaffected fathers ( n = 26 ) on an auditory ERP oddball task . Multivariate analyses of variance applied to peak amplitude and latency measures indicated small to moderate between-groups differences at midline or parietal sites : N2 and P3 amplitude ; P2 , N2 , P3 , and Nc latency . This replicated P3 amplitude findings in alcoholism-risk studies , though the effect size was moderate . Analysis of event-related alpha power indicated significantly longer latency of alpha synchronization and oscillations of desynchronization in boys at risk . The alpha power findings were statistically the more robust of the measures applied . The role of neurocognitive factors in determining liability for substance use disorders is discussed A 21-mg dose of nicotine was administered transdermally to 16 overnight smoking-deprived smokers in a double-blind , placebo-controlled design . Mood ratings , electroencephalography ( EEG ) , behavioral performance and event-related potential ( ERP : P300 ) indices of attention and information processing speed were assessed before and 4 h after placebo/nicotine treatment . Although nicotine , relative to placebo , failed to alter mood , it increased absolute and relative power indices of EEG arousal , shortened reaction times , and increased P300 amplitudes . The results are discussed in relation to nicotine 's actions on cholinergic transmission and its role in smoking behavior BACKGROUND Previous studies suggested a protective effect of smoking on Alzheimer 's disease , but most were case-control studies based on prevalent cases . The findings of prospect i ve studies on the association between smoking and the risk of dementia are inconclusive . METHODS We did a population -based follow-up study of elderly people who were initially free of dementia . 6870 people aged 55 years and older agreed to take part .  Smoking history was taken at baseline and participants were classified as never smokers , former smokers , and current smokers . During follow-up , we recorded all incident cases of dementia . We used never smokers as the reference category to calculate relative risks of dementia and Alzheimer 's disease by Cox proportional hazards regression , after adjustment for age , sex , education , and alcohol intake . We also examined modification of risk by age , sex , and the apolipoprotein E ( APOE ) genotype . FINDINGS During mean follow-up of 2.1 ( range 1.5 - 3.4 ) years , 146 incident cases of dementia were detected , of which 105 were Alzheimer 's disease . Compared with never smokers , smokers had an increased risk of dementia ( relative risk 2.2 [ 95 % CI 1.3 - 3.6 ] ) and Alzheimer 's disease ( 2.3 [ 1.3 - 4.1 ] ) . Smoking was a strong risk factor for Alzheimer 's disease in individuals without the APOEepsilon4 allele ( 4.6 [ 1.5 - 14.2 ] ) , but had no effect in participants with this allele ( 0.6 [ 0.1 - 4.8 ] ) . INTERPRETATION Smoking was associated with a doubling of the risk of dementia and Alzheimer 's disease . Our finding that carriers of the APOEepsilon4 had no increased risk of dementia suggests an interaction between smoking and the APOEepsilon4 genotype in the aetiology of Alzheimer 's disease OBJECTIVES Early diagnosis and monitoring of disease progression have become vital in clinical practice as disease modifying treatments for Alzheimer 's disease ( AD ) become available . This one-year prospect i ve study aim ed to clarify the usefulness of  event-related potentials  ( ERPs ) in cognitive decline and eluci date their cognitive significance in AD . METHODS Using the Cognitive Abilities Screening Instrument ( CASI ) and ERPs , probable AD patients , mild cognitive impairment ( MCI ) patients , and normal controls were recruited . RESULTS The AD and MCI patients had significantly decreased cognitive function and manifested a delay of P300 latency . The P300 latencies demonstrated significantly more prolongation than their baseline values in probable AD and MCI patients , although their CASI scores showed no statistically significant decline . Whereas N100 , P200 , and N200 components did not reach statistical differences between groups either in the baseline or follow-up assessment s and did not show significant change on follow-up . CONCLUSION The combination of neuropsychological tests and P300 measurements proved useful in improving reliability and increasing sensitivity to early cognitive decline or disease progression in AD patients . SIGNIFICANCE The P300 latency may reflect cognitive decline more sensitively than neuropsychological tests in the longitudinal follow-up of AD patients OBJECTIVE Previous studies indicate that people respond defensively to threatening health information , especially when the information challenges self-relevant goals . The authors investigated whether reduced acceptance of self-relevant health risk information is already visible in early attention processes , that is , attention disengagement processes . DESIGN In a r and omized , controlled trial with 29 smoking and nonsmoking students , a variant of Posner 's cueing task was used in combination with the high-temporal resolution method of event-related brain potentials ( ERPs ) . MAIN OUTCOME MEASURES Reaction times and P300 ERP . RESULTS Smokers showed lower P300 amplitudes in response to high- as opposed to low-threat invalid trials when moving their attention to a target in the opposite visual field , indicating more efficient attention disengagement processes . Furthermore , both smokers and nonsmokers showed increased P300 amplitudes in response to the presentation of high- as opposed to low-threat valid trials , indicating threat-induced attention-capturing processes . Reaction time measures did not support the ERP data , indicating that the ERP measure can be extremely informative to measure low-level attention biases in health communication . CONCLUSION The findings provide the first neuroscientific support for the hypothesis that threatening health information causes more efficient disengagement among those for whom the health threat is self-relevant Event-related  potentials ( ERPs )  can eluci date aspects of sensory and cognitive processing that have been compromised due to closed head injury . We present the results of two investigations , one previously unreported , in which we used ERPs to evaluate information processing in head-injury survivors . In the first study , we used visual and auditory reaction time tasks differing in attentional dem and s to assess processing after head trauma . We found numerous changes in auditory processing in survivors : longer reaction times ( but normal accuracy ) , longer N200 and P300 latencies , and reduced N100 and N200 amplitudes . In contrast , on visual tasks , only reduced N200 amplitude distinguished survivors and controls . To increase attentional dem and s , in a second study , we administered the continuous performance test ( CPT ) . Survivors performed with lower accuracy than controls on visual and auditory tasks , and their ERPs were characterized by smaller visual and auditory N200s and P300s and smaller auditory N100s . We also present a synthesis , derived from a review of the literature , of closed head-injury effects on ERPs . Our own findings are in agreement with that synthesis . Namely , cognitive ERP components are more sensitive than sensory components to the effects of trauma . Specifically , in survivors , the amplitudes of N200 and P300 are often reduced , and their latencies prolonged . In general , as compared with visual ERPs , auditory ERPs may be more susceptible to the effects of closed head injury , suggesting that the auditory processing system is more vulnerable than the visual system . We conclude by discussing the potential use of  ERPs  to monitor clinical course and recovery in survivors of closed head injury The aim of this study was to eluci date the chronic effects of tobacco smoking on the P300 , a neurophysiological index of cognitive function . Prospect i ve study participants were recruited from a family medicine polyclinic . We selected 32 right-h and ed smokers who had smoked more than 15 cigarettes per day , by inhalation , for more than 2 years . The control population consisted of 32 right-h and ed , age-matched healthy individuals who had never smoked .  Event-related potentials ( ERPs ) were recorded with the auditory " oddball " two-tone discrimination task . The data from the central ( Cz ) and frontal ( Fz ) electrodes were analyzed . The P300 and N1 amplitudes at Fz were lower in the study population compared to the control group . The early component of ERP , the measure of mental speed ( N1 ) latency at Fz was prolonged in the study group compared to the controls , possibly because early cognitive processes such as sensory input or initial encoding of sensory information were delayed in this group . For those who smoke , a decreased N1 amplitude might indicate delayed information processing and possibly short-term memory disturbance . Thus , chronic tobacco smoking may produce prefrontal cognitive dysfunction BACKGROUND P300 event-related brain potential ( ERP ) amplitude is reduced in patients with schizophrenia . Little attention has been paid to gender differences underlying this abnormality , despite clinical differences between male and female schizophrenics . Studies have also largely ignored the fact that the P300 represents the activity of multiple neural generators and have not 
    Output:
    
CONCLUSIONS P300 amplitude was smaller in cigarette smokers than in nonsmoking controls , and a possible dose-response relationship was apparent .
Findings indicate a possible association between cigarette smoking and decreased P300 amplitude