Kirsch Peter, Schienle Anne, Stark Rudolf, Sammer Gebhard, Blecker Carlo, Walter Bertram, Ott Ulrich, Burkart Jessica, Vaitl Dieter
Bender Institute of Neuroimaging and Department of Clinical and Physiological Psychology, Justus-Liebig-University, Giessen, Germany.
Neuroimage. 2003 Oct;20(2):1086-95. doi: 10.1016/S1053-8119(03)00381-1.
Findings from animal as well as human neuroimaging studies suggest that reward delivery is associated with the activation of subcortical limbic and prefrontal brain regions, including the thalamus, the striatum, the anterior cingulate and the prefrontal cortex. The aim of the present study was to explore if these reward-sensitive regions are also activated during the anticipation of reinforcers that vary with regard to their motivational value. A differential conditioning paradigm was performed, with the presentation of a rewarded reaction time task serving as the unconditioned stimulus (US). Depending on their reaction time, subjects were given (or not given) a monetary reward, or were presented with a verbal feedback consisting of being fast or slow. In a third control condition no task needed to be executed. Each of the three conditions was introduced by a different visual cue (CS). Brain activation of 27 subjects was recorded using event-related functional magnetic resonance imaging. The results showed significant activation of the substantia nigra, thalamic, striatal, and orbitofrontal brain regions as well as of the insula and the anterior cingulate during the presentation of a CS signalling a rewarded task. The anticipation of a monetary reward produced stronger activation in these regions than the anticipation of positive verbal feedback. The results are interpreted as reflecting the motivation-dependent reactivity of the brain reward system with highly motivating stimuli (monetary reward) leading to a stronger activation than those less motivating ones (verbal reward).
来自动物以及人类神经影像学研究的结果表明，奖励的给予与包括丘脑、纹状体、前扣带回和前额叶皮质在内的皮质下边缘和前额脑区的激活有关。本研究的目的是探讨在预期具有不同动机价值的强化物时，这些对奖励敏感的区域是否也会被激活。进行了一种差异条件作用范式，将呈现一个有奖励的反应时任务作为无条件刺激（US）。根据他们的反应时，受试者会得到（或未得到）金钱奖励，或者会收到关于反应快或慢的言语反馈。在第三个对照条件下，无需执行任何任务。三种条件中的每一种都由不同的视觉线索（CS）引入。使用事件相关功能磁共振成像记录了27名受试者的大脑激活情况。结果显示，在呈现预示有奖励任务的CS期间，黑质、丘脑、纹状体和眶额叶脑区以及岛叶和前扣带回有显著激活。预期金钱奖励在这些区域产生的激活比预期积极言语反馈更强烈。这些结果被解释为反映了大脑奖励系统对动机的依赖性反应，高动机刺激（金钱奖励）比低动机刺激（言语奖励）导致更强的激活。
