Department of Psychiatry and Psychotherapy, Charité-Universitätsmedizin Berlin, Campus Mitte, Berlin, Germany.
Hum Brain Mapp. 2010 Jul;31(7):958-69. doi: 10.1002/hbm.20909.
Increased responsiveness to appetitive and reduced responsiveness to aversive anticipatory cues may be associated with dysfunction of the brain reward system in mania. Here we studied neural correlates of gain and loss expectation in mania using functional magnetic resonance imaging (fMRI).
Fifteen manic patients and 26 matched healthy control individuals performed a monetary incentive delay task, during which subjects anticipated to win or lose a varying amount of money. Varying both magnitude and valence (win, loss) of anticipatory cues allowed us to isolate the effects of magnitude, valence and expected value (magnitude-by-valence interaction).
Response times and total gain amount did not differ significantly between groups. FMRI data indicated that the ventral striatum responded according to cued incentive magnitude in both groups, and this effect did not significantly differ between groups. However, a significant group difference was observed for expected value representation in the left lateral orbitofrontal cortex (OFC; BA 11 and 47). In this region, patients showed increasing BOLD responses during expectation of increasing gain and decreasing responses during expectation of increasing loss, while healthy subjects tended to show the inverse effect. In seven patients retested after remission OFC responses adapted to the response pattern of healthy controls.
The observed alterations are consistent with a state-related affective processing bias during the expectation of gains and losses which may contribute to clinical features of mania, such as the enhanced motivation for seeking rewards and the underestimation of risks and potential punishments.
对正性预期刺激的反应增强，对负性预期刺激的反应减弱，可能与人类躁狂症中大脑奖赏系统功能障碍有关。在此，我们使用功能磁共振成像（fMRI）研究了躁狂症中收益和损失预期的神经相关性。
15 名躁狂症患者和 26 名匹配的健康对照者进行了一项金钱激励延迟任务，在此任务中，被试者预期会赢得或损失不同数量的钱。通过改变预期线索的大小和效价（赢，输），我们可以分离出大小、效价和预期价值的影响（大小-效价交互作用）。
组间的反应时间和总收益量无显著差异。FMRI 数据表明，两组的腹侧纹状体均根据线索激励的大小做出反应，且组间无显著差异。然而，在左侧外侧眶额皮层（OFC；BA 11 和 47）中观察到了预期价值表示的显著组间差异。在该区域，患者在预期收益增加时表现出 BOLD 响应增加，而在预期损失增加时表现出响应减少，而健康受试者则倾向于表现出相反的效果。在七名缓解后的患者中，OFC 反应在重新测试时适应了健康对照组的反应模式。
观察到的改变与收益和损失预期中的状态相关的情感处理偏倚一致，这可能有助于躁狂症的临床特征，例如对寻求奖励的动机增强，以及对风险和潜在惩罚的低估。
