Department of Psychology, Vanderbilt University, Nashville, Tennessee 37240-7817, USA.
J Neurosci. 2012 Apr 11;32(15):5333-7. doi: 10.1523/JNEUROSCI.5756-11.2012.
Frontostriatal circuits have been implicated in reward learning, and emerging findings suggest that frontal white matter structural integrity and probabilistic reward learning are reduced in older age. This cross-sectional study examined whether age differences in frontostriatal white matter integrity could account for age differences in reward learning in a community life span sample of human adults. By combining diffusion tensor imaging with a probabilistic reward learning task, we found that older age was associated with decreased reward learning and decreased white matter integrity in specific pathways running from the thalamus to the medial prefrontal cortex and from the medial prefrontal cortex to the ventral striatum. Further, white matter integrity in these thalamocorticostriatal paths could statistically account for age differences in learning. These findings suggest that the integrity of frontostriatal white matter pathways critically supports reward learning. The findings also raise the possibility that interventions that bolster frontostriatal integrity might improve reward learning and decision making.
额-纹状体回路与奖励学习有关，新的研究结果表明，随着年龄的增长，额叶白质结构的完整性和概率性奖励学习能力会降低。本横断面研究在一个人类成年人的社区全生命周期样本中，检验了额-纹状体白质完整性的年龄差异是否可以解释奖励学习的年龄差异。通过将弥散张量成像与概率性奖励学习任务相结合，我们发现，与较年轻的成年人相比，年龄较大的成年人的奖励学习能力较差，并且连接丘脑至内侧前额叶皮质以及连接内侧前额叶皮质至腹侧纹状体的特定路径的白质完整性降低。此外，这些丘脑-皮质-纹状体路径中的白质完整性可以在统计学上解释学习中的年龄差异。这些发现表明，额-纹状体白质通路的完整性对奖励学习至关重要。这些发现还提出了一种可能性，即增强额-纹状体完整性的干预措施可能会改善奖励学习和决策制定。
