Mirza N R, Stolerman I P
Section of Behavioural Pharmacology, Institute of Psychiatry, London, UK.
Psychopharmacology (Berl). 1998 Aug;138(3-4):266-74. doi: 10.1007/s002130050671.
Although nicotine has cognitive enhancing effects in both animals and humans, most studies in humans have only shown consistent improvements in sustained attention. Moreover, many studies with smokers have been criticised, since nicotine may simply be relieving withdrawal-induced deficits. The present study investigated the effect of nicotine on sustained attention in drug-naïve rats using a five-choice serial reaction time task. Initially, the task was demonstrated to satisfy some of the criteria for the construct validity of a vigilance task: reducing signal length and either increasing or decreasing the inter-trial interval significantly (P<0.05) impaired performance. Whether nicotine (0.05-0.4 mg/kg, SC) reversed the deficits induced by a signal length of 0.25 s (weak signal) or an inter-trial-interval of either 20 s (low event rate) or 1 s (high event rate) was assessed. Nicotine (0.15 mg/kg) improved accuracy and decreased omission errors under low event rate conditions only. However, nicotine (0.05/0.15 mg/kg) improved reaction time and increased anticipatory responses under both weak signal and low event rate conditions. There was no effect of nicotine on performance under high event rate conditions. Under the low event rate condition, nicotine enhanced the ability of rats to maintain attention (i.e. accuracy) throughout a session. These findings suggest (i) that nicotine's effect on attention depends upon task characteristics; (ii) these effects on attention may reflect self-reports by smokers that nicotine aids concentration, particularly in stressful situations, and (iii) nicotinic agonists may have therapeutic benefits in patient populations suffering from attentional deficits.
尽管尼古丁对动物和人类都有认知增强作用，但大多数针对人类的研究仅表明在持续注意力方面有持续改善。此外，许多针对吸烟者的研究受到了批评，因为尼古丁可能只是缓解了戒断引起的缺陷。本研究使用五选择连续反应时间任务，调查了尼古丁对未接触过药物的大鼠持续注意力的影响。最初，该任务被证明满足了警觉任务结构效度的一些标准：显著缩短信号长度以及增加或减少试验间隔（P<0.05）会损害表现。评估了尼古丁（0.05 - 0.4毫克/千克，皮下注射）是否能逆转由0.25秒的信号长度（弱信号）或20秒（低事件率）或1秒（高事件率）的试验间隔所诱导的缺陷。尼古丁（0.15毫克/千克）仅在低事件率条件下提高了准确性并减少了遗漏错误。然而，尼古丁（0.05/0.15毫克/千克）在弱信号和低事件率条件下均改善了反应时间并增加了预期反应。在高事件率条件下，尼古丁对表现没有影响。在低事件率条件下，尼古丁增强了大鼠在整个实验过程中保持注意力（即准确性）的能力。这些发现表明：（i）尼古丁对注意力的影响取决于任务特征；（ii）这些对注意力的影响可能反映了吸烟者的自我报告，即尼古丁有助于集中注意力，特别是在压力情况下；（iii）烟碱激动剂可能对患有注意力缺陷的患者群体具有治疗益处。
