Department of Experimental Psychology, Ghent University, Ghent, Belgium.
Neuroscience Research Australia, Margarete Ainsworth Building, Barker Street, Randwick, 2031, Australia.
Brain Struct Funct. 2021 May;226(4):1007-1021. doi: 10.1007/s00429-021-02222-x. Epub 2021 Feb 4.
Humans can be motivated by the prospect of gaining a reward. However, the extent to which we are affected by reward information differs from person to person. A possible mechanism underlying these inter-individual differences may be alterations in white matter (WM) microstructure; however, the relationship between WM properties and reward-based behaviour in healthy participants has not yet been explored. Here, we used a fixel-based approach to investigate potential associations between WM tracts and performance in a reward-cuing task. We found that WM properties in the corpus callosum, right uncinate fasciculus, left ventral cingulum, and accumbofrontal tracts were inversely related to reward-triggered performance benefits (indexed by faster reaction times). Moreover, smaller WM property values in the corpus callosum, uncinate fasciculus, and accumbofrontal tracts were associated with higher scores on the Behavioral Inhibition System scale, reflecting greater sensitivity to potential punishment. Finally, we also observed associations between functional hemodynamic activity in the ventral striatum and WM microstructure. The finding that reward-based behavioural benefits are related to lower measures of WM tracts is in contrast to studies linking higher WM metrics to superior cognitive performance. We interpret the current pattern in terms of higher susceptibility to motivationally relevant stimuli, which is in line with the current and previous studies reporting inverse relationships between WM properties and motivational traits. Taking a broader perspective, such propensities may only be beneficial up to a certain point, at which these may become detrimental to performance and even manifest as impulsive and addictive behaviour.
人类可以通过获得奖励的前景来获得动力。然而，我们受到奖励信息的影响因人而异。这些个体差异的潜在机制可能是大脑白质（WM）微结构的改变；然而，健康参与者的 WM 属性与基于奖励的行为之间的关系尚未得到探索。在这里，我们使用基于固定效应的方法来研究 WM 束与奖励提示任务表现之间的潜在关联。我们发现，胼胝体、右侧钩束、左侧腹侧扣带和伏隔核额束的 WM 属性与奖励触发的表现收益呈负相关（表现为更快的反应时间）。此外，胼胝体、钩束和伏隔核额束的 WM 属性值越小，与行为抑制系统评分越高相关，反映出对潜在惩罚的敏感性越高。最后，我们还观察到腹侧纹状体的功能血液动力学活动与 WM 微观结构之间的关联。基于奖励的行为收益与 WM 束的较低指标相关的发现与将较高的 WM 指标与更高的认知表现联系起来的研究相反。我们根据更高的动机相关刺激的易感性来解释当前的模式，这与报告 WM 属性与动机特征之间的反比关系的当前和先前研究一致。从更广泛的角度来看，这种倾向可能仅在一定程度上是有益的，在这一点上，这些倾向可能对表现有害，甚至表现为冲动和成瘾行为。
