A dynamic interplay exists between Internally-Based (IBT) and Externally-Cued (ECT) time processing. While IBT processes support the self-generation of context-independent temporal representations, ECT mechanisms allow constructing temporal representations primarily derived from the structure of the sensory environment. We performed an activation likelihood estimation (ALE) meta-analysis on 177 fMRI experiments, from 79 articles, to identify brain areas involved in timing; two individual ALEs tested the hypothesis of a neural segregation between IBT and ECT. The general ALE highlighted a network involving supplementary motor area (SMA), intraparietal sulcus, inferior frontal gyrus (IFG), insula (INS) and basal ganglia. We found evidence of a partial dissociation between IBT and ECT. IBT relies on a subset of areas also involved in ECT, however ECT tasks activate SMA, right IFG, left precentral gyrus and INS in a significantly stronger way. Present results suggest that ECT involves the detection of environmental temporal regularities and their integration with the output of the IBT processing, to generate a representation of time which reflects the temporal metric of the environment.

基于内部的（IBT）时间和基于外部提示（ECT）的时间处理之间存在动态的相互作用。虽然IBT过程支持上下文无关时间表示的自生成，但ECT机制允许构造主要从感觉环境的结构派生的时间表示。我们对来自79篇文章的177项fMRI实验进行了激活可能性估计（ALE）荟萃分析，以识别参与计时的大脑区域；两个个体ALE检验了IBT和ECT之间存在神经隔离的假说。普通ALE强调了一个由辅助运动区（SMA），顶壁内沟，额下回（IFG），岛状（INS）和基底神经节组成的网络。我们发现IBT和ECT之间部分解离的证据。IBT依赖于ECT也涉及的部分领域，然而，ECT任务以明显更强的方式激活SMA，右IFG，左中前回和INS。目前的结果表明，ECT涉及环境时间规律的检测及其与IBT处理输出的集成，以生成反映环境时间指标的时间表示。