School of Psychological Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University.
Genes Brain Behav. 2014 Apr;13(4):385-93. doi: 10.1111/gbb.12122. Epub 2014 Mar 11.
This study examines implicit sequence learning impairments that may indicate at-risk cerebellar profiles proposed to underlie some aspects of subtle cognitive and affective dysfunctions found among female fragile X mental retardation 1 (FMR1) premutation (PM)-carriers. A total of 34 female PM-carriers and 33 age- and intelligence-matched controls completed an implicit symbolically primed serial reaction time task (SRTT) previously shown to be sensitive to cerebellar involvement. Implicit learning scores indicated a preservation of learning in both groups; however, PM-carriers demonstrated poorer learning through significantly elevated response latencies overall and at each specific block within the symbolic SRTT. Group comparisons also revealed a core deficit in response inhibition, alongside elevated inattentive symptoms in female PM-carriers. Finally, strong and significant associations were observed between poor symbolic SRTT performance and executive, visuospatial and affective deficits in the PM-carrier group. These associations remained strong even after controlling motor speed, and were not observed in age- and intelligence quotient-matched participants. The findings implicate cerebellar non-motor networks subserving the implicit sequencing of responses in cognitive-affective phenotypes previously observed in female PM-carriers. We contend that symbolic SRTT performance may offer clinical utility in future pharmaceutical interventions in female PM-carriers.
本研究考察了潜在的序列学习损伤，这些损伤可能表明小脑存在风险，小脑的某些功能异常可能与脆性 X 智力低下 1 型（FMR1）前突变（PM）携带者的某些认知和情感功能障碍有关。共有 34 名女性 PM 携带者和 33 名年龄和智力匹配的对照者完成了一项先前被证明与小脑有关的内隐符号启动序列反应时任务（SRTT）。内隐学习分数表明两组的学习都得到了保留；然而，PM 携带者的总体反应时显著升高，在符号 SRTT 的每个特定块中，学习能力也显著下降。组间比较还显示，女性 PM 携带者存在核心的反应抑制缺陷，以及注意力不集中的症状。最后，在 PM 携带者组中，符号 SRTT 表现差与执行功能、视空间和情感缺陷之间存在强烈而显著的关联。即使在控制了运动速度后，这些关联仍然很强，在年龄和智商匹配的参与者中没有观察到这些关联。这些发现表明，小脑的非运动网络在以前观察到的女性 PM 携带者的认知情感表型中，对反应的内隐序列起到了作用。我们认为，在未来针对女性 PM 携带者的药物干预中，符号 SRTT 的表现可能具有临床应用价值。
