Visual Neuroscience Laboratory, IBILI, Faculty of Medicine, University of Coimbra, Portugal.
J Int Neuropsychol Soc. 2012 Jul;18(4):689-96. doi: 10.1017/S1355617712000288. Epub 2012 May 29.
Huntington's disease (HD) is a genetic neurodegenerative disorder affecting the basal ganglia. These subcortical structures are particularly important for motor functions, response selection and implicit learning. In the current study, we have assessed prodromal and symptomatic HD participants with an implicit contextual learning task that is not based on motor learning, but on a purely visual implicit learning mechanism. We used an implicit contextual learning task in which subjects need to locate a target among several distractors. In half of the trials, the positions of the distractors and target stimuli were repeated. By memorizing this contextual information, attention can be guided faster to the target stimulus. Nine symptomatic HD participants, 16 prodromal HD participants and 22 control subjects were included. We found that the responses of the control subjects were faster for the repeated trials than for the new trials, indicating that their visual search was facilitated when repeated contextual information was present. In contrast, no difference in response times between the repeated and new trials was found for the symptomatic and prodromal HD participants. The results of the current study indicate that both prodromal and symptomatic HD participants are impaired on an implicit contextual learning task.
亨廷顿病（HD）是一种影响基底神经节的遗传性神经退行性疾病。这些皮质下结构对运动功能、反应选择和内隐学习尤为重要。在目前的研究中，我们使用了一种基于内隐视觉学习机制、而非运动学习的内隐语境学习任务，对前驱期和有症状的 HD 参与者进行了评估。在该任务中，参与者需要在几个干扰项中定位目标。在一半的试验中，干扰项和目标刺激的位置是重复的。通过记忆这种语境信息，可以更快地将注意力引导至目标刺激。共有 9 名有症状的 HD 参与者、16 名前驱期 HD 参与者和 22 名对照组参与者参与了研究。我们发现，对照组参与者在重复试验中的反应比在新试验中的反应更快，这表明当存在重复的语境信息时，他们的视觉搜索会得到促进。相比之下，有症状和前驱期 HD 参与者在重复试验和新试验中的反应时间没有差异。目前的研究结果表明，前驱期和有症状的 HD 参与者在一种内隐语境学习任务中都存在障碍。
