Delay Discounting Correlates with Proportional Lateral Frontal Cortex Volumes
Delay Discounting Correlates with Proportional Lateral Frontal Cortex Volumes
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DOI：
10.1016/j.biopsych.2008.11.023
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发表时间：
2009-04-15
影响因子：
10.6
通讯作者：
Hommer, Daniel W.
中科院分区：
文献类型：
--
作者：
Bjork, James M.;Momenan, Reza;Hommer, Daniel W.
背景：健康对照受试者的功能神经影像实验表明，在延迟贴现（DD）任务中，在小而即时的奖励与较大但延迟的奖励之间进行选择会招募中额叶和外侧额叶皮层。额皮质灰质形态的个体差异是否与对即时奖励的偏好有关？方法：我们将实验室决策任务中的 DD 与根据 29 名健康成年人的分段磁共振图像计算出的额皮质灰质 (GM) 体积比例相关联。结果：背外侧和下外侧额皮质 GM 体积（校正为整个大脑体积的比例）均与决策过程中对即时满足的偏好成反比，由 DD 常数 k 表示。相反，眶额或中额皮质 GM 体积比例、脑容量 (CBV) 或颅内总体积 (ICV；最大脑生长量) 均与 DD 的严重程度显着相关。 结论：延迟奖励折扣的严重程度与外侧额皮质 GM 形态比例相关，但与全脑测量无关。鉴于物质依赖和反社会行为中额皮质异常的证据，未来的研究可以评估额皮质体积减少本身是否是精神疾病中无法延迟满足的形态学标志或危险因素。
Background: Functional neuroimaging experiments in healthy control subjects have shown that choosing between small and immediate rewards versus larger but deferred rewards in delay discounting (DD) tasks recruits mesofrontal and lateral frontal cortex. Might individual differences in frontocortical gray matter morphology be related to preference for immediate reward?Methods: We related DD in a laboratory decision-making task to proportional frontocortical gray matter (GM) volumes calculated from segmented magnetic resonance images in 29 healthy adults.Results: Dorsolateral and inferolateral frontal cortex GM volumes (corrected as a proportion of whole cerebral brain volume) each correlated inversely with preference for immediate gratification during decision making, as indexed by DD constant k. Conversely, neither proportional orbitofrontal or mesofrontal cortex GM volume nor cerebral brain volume (CBV) or total intracranial volume (ICV; a measure of maximal brain growth) significantly correlated with severity of DD.Conclusions: Severity of discounting of delayed rewards correlates with proportional lateral frontocortical GM morphology but not with whole brain measures. In light of evidence of frontocortical abnormalities in substance dependence and sociopathy, future studies can assess whether reduced frontocortical volume itself is a morphological marker or risk factor for inability to delay gratification in psychiatric disorders.