Centre de Neuroscience Système et Cognition, Institut de Recherche en Sciences Psychologiques, Université catholique de Louvain, Louvain-la-Neuve, Belgium.
Neuropsychologia. 2012 Jul;50(9):2365-70. doi: 10.1016/j.neuropsychologia.2012.06.006. Epub 2012 Jun 21.
Numerosity and duration processing have been shown to be underlain by a single representational mechanism, namely an accumulator, and to rely on a common cerebral network located principally in areas around the right intraparietal sulcus. However, recent neuropsychological findings reveal a dissociation between numerosity and duration processing, which suggests the existence of partially distinct mechanisms. In this study, we tested the idea of partially common and distinct mechanisms by investigating, for the first time, both numerical and temporal processing abilities in non-demented Parkinson's disease (PD) patients known to suffer from duration impairment and in healthy elderly adults known to have impaired performance in duration tasks. The aim was to assess whether this impaired duration processing would extend to numerosity processing. The participants had to compare either the numerosity of flashed dot sequences or the duration of single dot displays. The results demonstrate an effect of aging on duration comparison, healthy elderly participants making significantly more errors than healthy young participants. Importantly, the performance of PD patients on the duration task was worse than that of the healthy young and elderly groups, whereas no difference was found for numerosity comparison. This dissociation supports the idea that partly independent systems underlie the processing of numerosity and duration.
数量和时长处理被证明是由单个表示机制（即累加器）所支撑的，并且依赖于主要位于右顶内沟周围区域的共同大脑网络。然而，最近的神经心理学研究结果揭示了数量和时长处理之间的分离，这表明存在部分不同的机制。在这项研究中，我们通过首次测试非痴呆帕金森病（PD）患者的数量和时间处理能力来检验部分共同和不同机制的想法，这些患者已知存在时长损伤，而健康老年人则已知在时长任务中表现不佳。目的是评估这种受损的时长处理是否会扩展到数量处理。参与者必须比较闪烁点序列的数量或单个点显示的时长。结果表明，年龄对时长比较有影响，健康的老年参与者比健康的年轻参与者犯的错误明显更多。重要的是，PD 患者在时长任务上的表现比健康的年轻和老年组差，而在数量比较上没有发现差异。这种分离支持了数量和时长处理是由部分独立的系统支撑的观点。
