Clinical Neuroelectrophysiological and Cognitive Research Laboratory, University of Ottawa Institute of Mental Health Research, Royal Ottawa Mental Health Centre, Ottawa, ON, Canada.
J Psychopharmacol. 2011 Feb;25(2):239-48. doi: 10.1177/0269881109348158. Epub 2009 Nov 25.
Nicotine-enhanced attentional functions are purported to underlie improvements in behavioral performance in cognitive tasks but it is unclear as to whether these effects involve selective attention or attentional control under conditions of distraction. Behavioral and event-related potential measures were used to examine the effects of nicotine on distractibility in 21 non-smokers who were instructed to ignore task-irrelevant auditory stimuli while they performed a visual discrimination task. In a randomized, double-blind, placebo-controlled cross-over design, nicotine gum (6 mg) shortened overall reaction times but failed to prevent increased response slowing and errors caused by deviant sounds. Relative to placebo, nicotine did not modulate the early pre-attentive detection of deviants as reflected in the mismatch negativity but it attenuated the amplitude of the deviant-elicited P3a, an event-related potential component indexing the involuntary shifting of attention. Nicotine also enhanced attentional re-focusing back on to task-relevant stimuli following distraction as evidenced by an increased amplitude of the re-orienting negativity. These findings and the behavioral-electrophysiological dissociation seen with nicotine are discussed in relation to theories of attention and smoking motivation.
尼古丁增强注意力功能，被认为是改善认知任务中行为表现的基础，但尚不清楚这些影响是否涉及选择性注意或在分心条件下的注意力控制。本研究采用行为和事件相关电位测量来检查尼古丁对 21 名不吸烟者分散注意力的影响，这些人在进行视觉辨别任务时被指示忽略无关的听觉刺激。在一项随机、双盲、安慰剂对照的交叉设计中，尼古丁口香糖（6 毫克）缩短了整体反应时间，但未能防止因异常声音引起的反应速度减慢和错误增加。与安慰剂相比，尼古丁并没有调节异常声音的早期非注意检测，如失匹配负波所反映的，但它减弱了与注意力不自主转移相关的异常诱发 P3a 的振幅。尼古丁还通过增加重新定向负波的振幅，增强了注意力重新集中在与任务相关刺激上，这表明注意力重新集中。这些发现以及尼古丁引起的行为-电生理分离，与注意力和吸烟动机的理论有关。
