Fillmore Mark T, Rush Craig R, Marczinski Cecile A
Department of Psychology, University of Kentucky, Lexington, KY 40506-0044, USA.
Drug Alcohol Depend. 2003 Aug 20;71(2):143-52. doi: 10.1016/s0376-8716(03)00089-9.
The present study examined the effects of d-amphetamine on the ability to execute and inhibit behavior in a context where preliminary information signaled the likelihood that a response should be executed or suppressed. Eight adults (5 men and 3 women) with a history of stimulant abuse performed a cued go no-go task that required quick responses to go targets and suppression of responses to no-go targets. Performance was tested under four oral doses of d-amphetamine, 0 (placebo), 5, 10 and 20 mg, administered double-blind and in mixed order. d-Amphetamine produced a dose-dependent increase in inhibitory failures following invalid go cues and had no effect on inhibitory failures following valid no-go cues. d-Amphetamine had little effect on response execution as measured by reaction time. Subjective and physiological effects of d-amphetamine were also observed. The findings demonstrate that stimulant effects on fundamental aspects of behavioral control can be mediated by environmental cues that alter response tendencies. Identification of environmental conditions in which stimulants are likely to disinhibit behavior could provide insight into mechanisms that underlie the association between long-term stimulant use and poor impulse control.
本研究考察了在初步信息表明应执行或抑制反应的可能性的情境下，右旋苯丙胺对行为执行和抑制能力的影响。八名有兴奋剂滥用史的成年人（5名男性和3名女性）进行了一项线索化的“去/不去”任务，该任务要求对“去”目标快速做出反应，并抑制对“不去”目标的反应。在四种口服剂量的右旋苯丙胺（0[安慰剂]、5、10和20毫克）下进行测试，采用双盲法且给药顺序混合。右旋苯丙胺在无效“去”线索后导致抑制失败呈剂量依赖性增加，而对有效“不去”线索后的抑制失败没有影响。右旋苯丙胺对以反应时间衡量的反应执行几乎没有影响。还观察到了右旋苯丙胺的主观和生理效应。研究结果表明，兴奋剂对行为控制基本方面的影响可由改变反应倾向的环境线索介导。确定兴奋剂可能导致行为去抑制的环境条件，有助于深入了解长期使用兴奋剂与冲动控制不良之间关联的潜在机制。
