Department of Experimental Psychology, Otto-von-Guericke-University Magdeburg, D-39016 Magdeburg, Germany.
J Neurosci. 2010 Jan 6;30(1):47-55. doi: 10.1523/JNEUROSCI.2205-09.2010.
The dopaminergic system is known to play a central role in reward-based learning (Schultz, 2006), yet it was also observed to be involved when only cognitive feedback is given (Aron et al., 2004). Within the domain of information-integration category learning, in which information from several stimulus dimensions has to be integrated predecisionally (Ashby and Maddox, 2005), the importance of contingent feedback is well established (Maddox et al., 2003). We examined the common neural correlates of reward anticipation and prediction error in this task. Sixteen subjects performed two parallel information-integration tasks within a single event-related functional magnetic resonance imaging session but received a monetary reward only for one of them. Similar functional areas including basal ganglia structures were activated in both task versions. In contrast, a single structure, the nucleus accumbens, showed higher activation during monetary reward anticipation compared with the anticipation of cognitive feedback in information-integration learning. Additionally, this activation was predicted by measures of intrinsic motivation in the cognitive feedback task and by measures of extrinsic motivation in the rewarded task. Our results indicate that, although all other structures implicated in category learning are not significantly affected by altering the type of reward, the nucleus accumbens responds to the positive incentive properties of an expected reward depending on the specific type of the reward.
多巴胺能系统被认为在基于奖励的学习中起着核心作用（Schultz，2006），但当仅提供认知反馈时，也观察到其参与（Aron 等人，2004）。在信息整合类别学习领域，需要在决策前整合来自几个刺激维度的信息（Ashby 和 Maddox，2005），因此认知反馈的重要性已经得到证实（Maddox 等人，2003）。在这项任务中，我们研究了奖励预期和预测误差的共同神经相关物。十六名受试者在单个事件相关功能磁共振成像会议内完成了两个并行的信息整合任务，但仅对其中一个任务给予了金钱奖励。在这两种任务版本中，相似的功能区域包括基底神经节结构都被激活。相比之下，在信息整合学习中，与认知反馈的预期相比，在金钱奖励的预期期间，单一结构——伏隔核——显示出更高的激活。此外，这种激活可以通过认知反馈任务中的内在动机测量和奖励任务中的外在动机测量来预测。我们的结果表明，尽管涉及类别学习的所有其他结构都不会因改变奖励类型而受到显著影响，但根据预期奖励的具体类型，伏隔核会对其积极激励特性做出反应。
