Performance Effects of Nicotine during Selective Attention, Divided Attention, and Simple Stimulus Detection: An fMRI Study
Performance Effects of Nicotine during Selective Attention, Divided Attention, and Simple Stimulus Detection: An fMRI Study
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DOI：
10.1093/cercor/bhn226
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发表时间：
2009-09-01
期刊：
影响因子：
3.7
通讯作者：
Stein, Elliot A.
中科院分区：
文献类型：
--
作者：
Hahn, Britta;Ross, Thomas J.;Stein, Elliot A.
尼古丁的注意力增强作用似乎取决于注意力功能的性质。潜在的神经解剖学机制也可能因调节的功能不同而不同。这项功能磁共振成像研究记录了轻度剥夺吸烟者在简单刺激检测、选择性注意或在单盲应用尼古丁透皮贴片(21毫克)或安慰剂贴片后分散注意力的任务中的血氧水平依赖(BOLD)活动。与匹配的非吸烟者相比，吸烟者在安慰剂条件下的表现没有受到损害。尼古丁缩短了刺激检测和选择性注意条件下的反应时(RT)，但不影响分散注意。在所有的任务条件下，尼古丁减少了额叶、颞叶、丘脑和视觉区域的激活，并增强了所谓的“默认”区域的失活。丘脑效应在刺激检测过程中选择性地与RT减少相关。在额叶中上回观察到了与任务条件的交互作用，其中尼古丁只在刺激检测时降低了激活。一项视觉运动控制实验为尼古丁的非特异性影响提供了证据。总而言之，尽管前额叶活动部分表现出尼古丁的差异性调制，但大多数BOLD效应在不同任务中是相同的，尽管表现出不同的影响，这表明共同的神经元机制可以选择性地使不同的注意功能受益。总体而言，尼古丁的作用可以通过提高功能效率和下调独立于任务的“默认”功能来解释。
Attention-enhancing effects of nicotine appear to depend on the nature of the attentional function. Underlying neuroanatomical mechanisms, too, may vary depending on the function modulated. This functional magnetic resonance imaging study recorded blood oxygen level-dependent (BOLD) activity in minimally deprived smokers during tasks of simple stimulus detection, selective attention, or divided attention after single-blind application of a transdermal nicotine (21 mg) or placebo patch. Smokers' performance in the placebo condition was unimpaired as compared with matched nonsmokers. Nicotine reduced reaction time (RT) in the stimulus detection and selective attention but not divided attention condition. Across all task conditions, nicotine reduced activation in frontal, temporal, thalamic, and visual regions and enhanced deactivation in so-called "default" regions. Thalamic effects correlated with RT reduction selectively during stimulus detection. An interaction with task condition was observed in middle and superior frontal gyri, where nicotine reduced activation only during stimulus detection. A visuomotor control experiment provided evidence against nonspecific effects of nicotine. In conclusion, although prefrontal activity partly displayed differential modulation by nicotine, most BOLD effects were identical across tasks, despite differential performance effects, suggesting that common neuronal mechanisms can selectively benefit different attentional functions. Overall, the effects of nicotine may be explained by increased functional efficiency and downregulated task-independent "default" functions.