Department of Psychology, University of RomeLa Sapienza, Rome, Italy.
Brain Cogn. 2010 Jun;73(1):28-34. doi: 10.1016/j.bandc.2010.01.008. Epub 2010 Feb 26.
Tourette syndrome (TS) is characterized by dysfunctional connectivity between prefrontal cortex and sub-cortical structures, and altered meso-cortical and/or meso-striatal dopamine release. Since time processing is also regulated by fronto-striatal circuits and modulated by dopaminergic transmission, we hypothesized that time processing is abnormal in TS.
We compared time processing abilities between nine children with TS-only (i.e. without major psychiatric comorbidities) and 10 age-matched healthy children, employing a time reproduction task in which subjects actively reproduce different temporal intervals, and a time comparison task in which subjects judge whether a test interval is longer or shorter than a reference interval. IQ, sustained and divided attention, and working memory were assessed in both groups using the Leiter International Performance Scale-Revised, and the Digit Span sub-test of the WISC-R.
Children with TS-only reproduced in an overestimated fashion over-second, but not sub-second, time intervals. The precision of over-second intervals reproduction correlated with tic severity, in that the lower the tic severity, the closer the reproduction of over-second time intervals to their real duration. Time reproduction performance did not significantly correlate with IQ, attention and working memory measures in both groups. No differences between groups were documented in the time comparison task.
The improvement of time processing in children with TS-only seems specific for the over-second range of intervals, consistent with an enhancement in the 'cognitively controlled' timing system, which mainly processes longer duration intervals, and depends upon dysfunctional connectivity between the basal ganglia and the dorso-lateral prefrontal cortex. The absence of between-group differences on time comparison, moreover, suggests that TS patients manifest a selective improvement of 'motor' timing abilities, rather than of perceptual time abilities. Our data also support an enhancement of cognitive control processes in TS children, probably facilitated by effortful tic suppression.
妥瑞氏综合征（TS）的特征是前额叶皮层和皮质下结构之间的功能连接障碍，以及中皮质和/或中纹状体多巴胺释放的改变。由于时间处理也受到额纹状体回路的调节，并受多巴胺传递的调制，我们假设 TS 患者的时间处理异常。
我们比较了九名仅患有 TS（即没有主要精神共病）的儿童和十名年龄匹配的健康儿童之间的时间处理能力，使用时间复制任务，其中受试者主动复制不同的时间间隔，以及时间比较任务，其中受试者判断测试间隔是否长于或短于参考间隔。使用 Leiter 国际表现量表修订版和 WISC-R 的数字跨度子测试，在两组中评估 IQ、持续和分散注意力以及工作记忆。
仅患有 TS 的儿童在超过 2 秒但不超过 2 秒的时间间隔内以高估的方式复制。超过 2 秒的时间间隔复制的精度与抽搐严重程度相关，即抽搐严重程度越低，超过 2 秒的时间间隔的复制越接近其实际持续时间。两组的时间复制表现与 IQ、注意力和工作记忆测量均无显著相关性。在时间比较任务中，两组之间没有差异。
仅患有 TS 的儿童的时间处理能力的提高似乎特定于超过 2 秒的时间间隔范围，这与“认知控制”计时系统的增强一致，该系统主要处理较长的持续时间间隔，并且依赖于基底节和背外侧前额叶皮层之间的功能连接障碍。此外，组间在时间比较上没有差异，这表明 TS 患者表现出对“运动”计时能力的选择性提高，而不是对感知时间能力的提高。我们的数据还支持 TS 儿童认知控制过程的增强，这可能是由于费力的抽搐抑制。
