Bonnelle Valerie, Manohar Sanjay, Behrens Tim, Husain Masud
Department of Experimental Psychology, University of Oxford, Oxford OX1 3UD, UK.
Institute of cognitive neuroscience, University College London, London WC1N 3AR, UK.
Cereb Cortex. 2016 Feb;26(2):807-819. doi: 10.1093/cercor/bhv247. Epub 2015 Nov 12.
Lack of physical engagement, productivity, and initiative-so-called "behavioral apathy"--is a common problem with significant impact, both personal and economic. Here, we investigate whether there might be a biological basis to such lack of motivation using a new effort and reward-based decision-making paradigm, combined with functional and diffusion-weighted imaging. We hypothesized that behavioral apathy in otherwise healthy people might be associated with differences in brain systems underlying either motivation to act (specifically in effort and reward-based decision-making) or in action processing (transformation of an intention into action). The results demonstrate that behavioral apathy is associated with increased effort sensitivity as well as greater recruitment of neural systems involved in action anticipation: supplementary motor area (SMA) and cingulate motor zones. In addition, decreased structural and functional connectivity between anterior cingulate cortex (ACC) and SMA were associated with increased behavioral apathy. These findings reveal that effort sensitivity and translation of intentions into actions might make a critical contribution to behavioral apathy. We propose a mechanism whereby inefficient communication between ACC and SMA might lead to increased physiological cost--and greater effort sensitivity--for action initiation in more apathetic people.
缺乏身体参与度、生产力和主动性——即所谓的“行为冷漠”——是一个普遍存在的问题，会对个人和经济产生重大影响。在此，我们使用一种基于努力和奖励的新型决策范式，并结合功能成像和扩散加权成像，来研究这种缺乏动力的现象是否可能存在生物学基础。我们假设，在其他方面健康的人群中，行为冷漠可能与驱动行动的大脑系统差异有关（具体而言是基于努力和奖励的决策过程中），或者与行动处理过程（将意图转化为行动）的差异有关。结果表明，行为冷漠与努力敏感性增加以及参与行动预期的神经系统更多地被激活有关：辅助运动区（SMA）和扣带运动区。此外，前扣带回皮质（ACC）和SMA之间结构和功能连接性的降低与行为冷漠的增加有关。这些发现揭示了努力敏感性以及将意图转化为行动的过程可能对行为冷漠起着关键作用。我们提出了一种机制，即ACC和SMA之间低效的沟通可能会导致更冷漠的人在行动启动时生理成本增加——以及更高的努力敏感性。
