Longe Olivia, Senior Carl, Rippon Gina
Aston University, Birmingham, UK.
J Cogn Neurosci. 2009 Jan;21(1):141-54. doi: 10.1162/jocn.2009.21012.
Recent functional magnetic resonance imaging (fMRI) investigations of the interaction between cognition and reward processing have found that the lateral prefrontal cortex (PFC) areas are preferentially activated to both increasing cognitive demand and reward level. Conversely, ventromedial PFC (VMPFC) areas show decreased activation to the same conditions, indicating a possible reciprocal relationship between cognitive and emotional processing regions. We report an fMRI study of a rewarded working memory task, in which we further explore how the relationship between reward and cognitive processing is mediated. We not only assess the integrity of reciprocal neural connections between the lateral PFC and VMPFC brain regions in different experimental contexts but also test whether additional cortical and subcortical regions influence this relationship. Psychophysiological interaction analyses were used as a measure of functional connectivity in order to characterize the influence of both cognitive and motivational variables on connectivity between the lateral PFC and the VMPFC. Psychophysiological interactions revealed negative functional connectivity between the lateral PFC and the VMPFC in the context of high memory load, and high memory load in tandem with a highly motivating context, but not in the context of reward alone. Physiophysiological interactions further indicated that the dorsal anterior cingulate and the caudate nucleus modulate this pathway. These findings provide evidence for a dynamic interplay between lateral PFC and VMPFC regions and are consistent with an emotional gating role for the VMPFC during cognitively demanding tasks. Our findings also support neuropsychological theories of mood disorders, which have long emphasized a dysfunctional relationship between emotion/motivational and cognitive processes in depression.
近期关于认知与奖赏处理之间相互作用的功能磁共振成像（fMRI）研究发现，外侧前额叶皮质（PFC）区域在认知需求增加和奖赏水平提高时均优先被激活。相反，腹内侧前额叶皮质（VMPFC）区域在相同条件下激活减少，这表明认知和情感处理区域之间可能存在相互关系。我们报告了一项关于奖赏工作记忆任务的fMRI研究，其中我们进一步探讨了奖赏与认知处理之间的关系是如何被调节的。我们不仅评估了不同实验背景下外侧PFC和VMPFC脑区之间相互神经连接的完整性，还测试了额外的皮质和皮质下区域是否会影响这种关系。采用心理生理交互分析作为功能连接的一种测量方法，以表征认知和动机变量对外侧PFC与VMPFC之间连接性的影响。心理生理交互分析显示，在高记忆负荷以及高记忆负荷与高激励背景同时存在的情况下，外侧PFC与VMPFC之间存在负性功能连接，但仅在奖赏背景下不存在。心理生理交互分析进一步表明，背侧前扣带回和尾状核调节这一通路。这些发现为外侧PFC和VMPFC区域之间的动态相互作用提供了证据，并且与VMPFC在认知需求较高的任务中所起的情绪门控作用相一致。我们的发现还支持情绪障碍的神经心理学理论，该理论长期以来一直强调抑郁症中情绪/动机与认知过程之间存在功能失调的关系。
