Neuroimaging Research Branch, National Institute on Drug Abuse-Intramural Research Program, 251 Bayview Blvd. Suite 200 (NIDA), Baltimore, MD, 21224, USA.
Psychopharmacology (Berl). 2010 May;209(4):291-302. doi: 10.1007/s00213-010-1788-9. Epub 2010 Mar 23.
Nicotine influences many cognitive processes, especially those requiring high attentional loads, yet the impact of nicotine on all aspects of information processing has not been well delineated.
The aim of the study was to determine the relative behavioral and functional effects of nicotine on dissociable aspects of information processing (i.e., selective attention and motor intention).
Adult smokers (N = 25) and healthy controls (N = 23) performed the intention/attention task (IAT) twice, during functional magnetic resonance imaging. The IAT assesses the relative differences in performance evoked by prime stimuli that provide information regarding either the correct hand with which to respond (i.e., intentional primes) or the likely location of a target stimulus (i.e., attentional primes). Smokers were scanned 2 h after nicotine (21 mg) or placebo patch placement. The order of nicotine and placebo sessions was randomized and counter-balanced. Controls were also scanned twice, with no patch placement in either session.
While drug condition had no significant effect on reaction time, smokers were overall more accurate than controls. Moreover, nicotine significantly increased the response to intentional primes in brain regions known to mediate response readiness, e.g., inferior parietal lobe, supramarginal gyrus, and striatum.
While limited to participant accuracy, these data suggest that the behavioral effects of nicotine in smokers are not only limited to information processing input (i.e., selective attention) but are also generalizable to output functions (i.e., motor intention). Moreover, nicotine's effects on intention appear to be mediated by a facilitation of function in brain regions associated with information processing output.
尼古丁会影响许多认知过程,尤其是那些需要高度注意力的过程,但尼古丁对信息处理各个方面的影响还没有得到很好的描述。
本研究旨在确定尼古丁对信息处理的可分离方面(即选择性注意和运动意图)的相对行为和功能影响。
成年吸烟者(N=25)和健康对照者(N=23)在功能磁共振成像期间两次完成意图/注意任务(IAT)。IAT 评估由提供有关正确反应手(即意向性启动)或目标刺激可能位置(即注意启动)信息的启动刺激引起的相对性能差异。吸烟者在尼古丁(21 毫克)或安慰剂贴片放置后 2 小时进行扫描。尼古丁和安慰剂的顺序是随机和平衡的。对照组也进行了两次扫描,两次扫描均未放置贴片。
尽管药物条件对反应时间没有显著影响,但吸烟者的整体准确性高于对照组。此外,尼古丁显著增加了对大脑中与介导反应准备有关的区域的意向性启动的反应,例如顶下小叶、缘上回和纹状体。
尽管仅限于参与者的准确性,但这些数据表明,尼古丁对吸烟者的行为影响不仅限于信息处理输入(即选择性注意),而且可推广到输出功能(即运动意图)。此外,尼古丁对意图的影响似乎是通过促进与信息处理输出相关的大脑区域的功能来介导的。