Motivation is a hallmark of healthy aging, but the motivation to engage in effortful behavior diminishes with increasing age. Most neurobiological accounts of altered motivation in older adults assume that these deficits are caused by a gradual decline in brain tissue, while some psychological theories posit a switch from gain orientation to loss avoidance in motivational goals. Here, we contribute to reconcile the psychological and neural perspectives by providing evidence that the frontopolar cortex (FPC), a brain region involved in cost–benefit weighting, increasingly underpins effort avoidance rather than engagement with age. Using anodal transcranial direct current stimulation together with effort–reward trade-offs, we find that the FPC’s function in effort-based decisions remains focused on cost–benefit calculations but appears to switch from reward-seeking to cost avoidance with increasing age. This is further evidenced by the exploratory, independent analysis of structural brain changes, showing that the relationship between the density of the frontopolar neural tissue and the willingness to exert effort differs in young vs older adults. Our results inform aging-related models of decision-making by providing preliminary evidence that, in addition to cortical thinning, changes in goal orientation need to be considered in order to understand alterations in decision-making over the life span.

中文翻译：

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协调心理学和神经科学对衰老过程中动机减弱的解释


动力是健康老龄化的标志，但努力行为的动力会随着年龄的增长而减弱。大多数关于老年人动机改变的神经生物学解释都认为这些缺陷是由脑组织逐渐衰退引起的，而一些心理学理论则认为动机目标从获得导向转向避免损失。在这里，我们通过提供证据证明额极皮层（FPC）（一个涉及成本效益权重的大脑区域）越来越支持努力避免而不是与年龄相关，从而有助于调和心理和神经观点。使用阳极经颅直流电刺激和努力-回报权衡，我们发现 FPC 在基于努力的决策中的功能仍然集中在成本-效益计算上，但随着年龄的增长，似乎从寻求回报转向成本规避。对大脑结构变化的探索性独立分析进一步证明了这一点，表明年轻人和老年人的额极神经组织密度与努力意愿之间的关系不同。我们的研究结果通过提供初步证据来为与衰老相关的决策模型提供信息，这些证据表明，除了皮质变薄之外，还需要考虑目标取向的变化，以便了解整个生命周期决策的变化。