Elliott R, Sahakian B J, Matthews K, Bannerjea A, Rimmer J, Robbins T W
Department of Experimental Psychology, University of Cambridge, UK.
Psychopharmacology (Berl). 1997 May;131(2):196-206. doi: 10.1007/s002130050284.
Previous studies of the effects of the psychomotor stimulant, methylphenidate, have concentrated on vigilance and reaction time tasks. In this study, the effects of methylphenidate on more complex aspects of cognition were studied using tasks from the CANTAB battery and related tests which have been shown to be sensitive to frontal lobe dysfunction. Twenty-eight young healthy men participated in a counterbalanced, double-blind, placebo-controlled study of the effects of methylphenidate. Cognitive assessment included tests of spatial working memory, planning, verbal fluency, attentional set-shifting and sustained attention. Methylphenidate had significant effects on performance of the tests of spatial working memory and planning but not on the attentional and fluency tests. When the drug was taken on the first test session, performance on the spatial tests was enhanced by the drug compared to placebo. However, when the drug was taken second, performance accuracy was impaired whereas response latencies were decreased. These results are consistent with a hypothesis that methylphenidate influences performance in two conflicting ways; enhancing executive aspects of spatial function on novel tasks but impairing previously established performance. This pattern of effects is discussed within the framework of dual, interacting arousal mechanisms.
以往关于精神运动兴奋剂哌醋甲酯作用的研究主要集中在警觉性和反应时间任务上。在本研究中，使用已被证明对额叶功能障碍敏感的剑桥神经心理测试自动化成套系统（CANTAB）中的任务及相关测试，研究了哌醋甲酯对更复杂认知方面的影响。28名年轻健康男性参与了一项关于哌醋甲酯作用的平衡、双盲、安慰剂对照研究。认知评估包括空间工作记忆、计划、言语流畅性、注意力转换和持续注意力测试。哌醋甲酯对空间工作记忆和计划测试的表现有显著影响，但对注意力和流畅性测试没有影响。当在第一个测试环节服用该药物时，与安慰剂相比，药物增强了空间测试的表现。然而，当在第二个测试环节服用该药物时，表现准确性受损，而反应潜伏期缩短。这些结果与一种假设一致，即哌醋甲酯以两种相互矛盾的方式影响表现；增强新任务中空间功能的执行方面，但损害先前已建立的表现。这种效应模式在双重相互作用的唤醒机制框架内进行了讨论。
