Froeliger Brett, Gilbert David G, McClernon F Joseph
Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC 27708, USA.
Psychopharmacology (Berl). 2009 Sep;205(4):625-33. doi: 10.1007/s00213-009-1571-y. Epub 2009 Jun 2.
Dependent smokers exhibit deficits in attentional and memory processes when smoking abstinent as compared to when satiated. While nicotine replacement therapy improves attention during abstinence, it is unclear whether this is due to the alleviation of withdrawal-related deficits or inherent beneficial effects of nicotine.
The primary aim of these studies was to test whether nicotine exerts a beneficial effect on novelty detection and whether such effects occur in nonsmokers as well as habitual smokers.
In two parallel, double-blind, placebo-controlled studies, 24 smokers (study 1) and 24 nonsmokers (study 2) were tested in two counterbalanced sessions: once while wearing a nicotine patch (smokers = 14 mg; nonsmokers = 7 mg) and once while wearing a placebo patch. On each day, participants performed three content-specific oddball tasks (perceptual, semantic, and emotional) that required them to press a button whenever they saw a novel target (20% of stimuli) embedded in a stream of common nontarget stimuli (80% of stimuli). Recognition memory for targets was subsequently tested. Reports of mood, smoking withdrawal, patch side effects, and blind success were collected in each session.
Among smokers, compared to placebo, nicotine decreased target reaction time during all oddball tasks. Among nonsmokers, nicotine increased target detection accuracy and subsequent memory recognition. Nicotine's enhancement on each respective measure was not task-content specific in either sample.
These data suggest that acute nicotine administration may exert direct beneficial effects on novelty detection and subsequent memory recognition in both smokers and nonsmokers. Moreover, these effects are not content-specific.
与处于饱腹状态时相比，依赖烟草的吸烟者在戒烟时表现出注意力和记忆过程方面的缺陷。虽然尼古丁替代疗法可改善戒烟期间的注意力，但尚不清楚这是由于缓解了与戒断相关的缺陷还是尼古丁本身的有益作用。
这些研究的主要目的是测试尼古丁是否对新奇刺激检测有有益影响，以及这种影响是否在非吸烟者和习惯性吸烟者中均会出现。
在两项平行、双盲、安慰剂对照研究中，24名吸烟者（研究1）和24名非吸烟者（研究2）在两个平衡的阶段接受测试：一次佩戴尼古丁贴片（吸烟者 = 14毫克；非吸烟者 = 7毫克），一次佩戴安慰剂贴片。每天，参与者执行三项特定内容的oddball任务（感知、语义和情感），要求他们每当在一串常见的非目标刺激（80%的刺激）中看到一个新奇目标（20%的刺激）时就按下按钮。随后测试对目标的识别记忆。在每个阶段收集情绪、戒烟反应、贴片副作用和盲法成功率的报告。
在吸烟者中，与安慰剂相比，尼古丁在所有oddball任务中均缩短了目标反应时间。在非吸烟者中，尼古丁提高了目标检测准确性和随后的记忆识别能力。在两个样本中，尼古丁对各项指标的增强作用均不具有任务内容特异性。
这些数据表明，急性给予尼古丁可能对吸烟者和非吸烟者的新奇刺激检测及随后的记忆识别产生直接有益影响。此外，这些影响不具有内容特异性。
