Fillmore Mark T, Rush Craig R, Hays Lon
Department of Psychology, University of Kentucky, Lexington, KY 40506-0044, USA.
Drug Alcohol Depend. 2002 Jul 1;67(2):157-67. doi: 10.1016/s0376-8716(02)00062-5.
Studies of humans show that individuals with histories of cocaine abuse display reduced inhibitory control over behavioral impulses. The present study tested the effects of oral cocaine on the ability to inhibit behavior in humans. Eight adult volunteers (seven men and one woman) with a history of cocaine abuse participated as in-patient volunteers. Response inhibition and response execution were measured by a stop-signal paradigm using a choice reaction time task that engaged subjects in responding to go-signals when stop-signals occasionally informed them to inhibit the response. Subjects' performance on the task was tested just before and 1 h after a randomized, double-blind administration of 0 mg (placebo), 50, 100, and 150 mg of oral cocaine HCl. Cocaine reduced subjects' ability to inhibit responses to stop-signals. By contrast, no effect of cocaine was observed on the ability to execute responses in terms of their speed and accuracy. Subjective and physiological effects of cocaine were also observed. Together, the findings indicate that acute administration of cocaine can impair the ability to inhibit behavioral responses at doses that do not affect the ability to respond. These findings are important because they identify a specific disinhibiting effect of cocaine that could help explain the documented association between long-term cocaine use and poor impulse control.
对人类的研究表明，有可卡因滥用史的个体对行为冲动的抑制控制能力降低。本研究测试了口服可卡因对人类抑制行为能力的影响。八名有可卡因滥用史的成年志愿者（七名男性和一名女性）作为住院志愿者参与了研究。通过停止信号范式测量反应抑制和反应执行，该范式使用选择反应时间任务，当停止信号偶尔告知受试者抑制反应时，让受试者对启动信号做出反应。在随机、双盲给予0毫克（安慰剂）、50、100和150毫克口服盐酸可卡因之前和之后1小时，测试受试者在该任务上的表现。可卡因降低了受试者抑制对停止信号反应的能力。相比之下，未观察到可卡因对反应执行的速度和准确性有影响。还观察到了可卡因的主观和生理效应。总之，研究结果表明，急性给予可卡因会在不影响反应能力的剂量下损害抑制行为反应的能力。这些发现很重要，因为它们确定了可卡因一种特定的去抑制作用，这有助于解释长期使用可卡因与冲动控制不良之间已记录的关联。
