Research Unit for Cognitive Psychology.
Department of Rehabilitation Sciences, Katholieke Universiteit Leuven.
Neuropsychology. 2013 Jan;27(1):28-36. doi: 10.1037/a0031278.
Freezing of gait (FOG) in Parkinson's disease (PD) may involve specific impairments in acquiring automaticity under working memory load. This study examined whether implicit sequence learning, with or without a secondary task, is impaired in patients with FOG.
Fourteen freezers (FRs), 14 nonfreezers (nFRs), and 14 matched healthy controls (HCs) performed a serial reaction time (SRT) task with a deterministic stimulus sequence under single-task (ST) and dual-task (DT) conditions. The increase in reaction times (RTs) for random compared with sequenced blocks was used as a measure of implicit sequence learning. Neuropsychological tests assessing global cognitive functioning and executive dysfunction were administered in order to investigate their relation to sequence learning.
nFRs and HCs showed significant implicit sequence learning effects (p < 0.001). FRs demonstrated a tendency to learn sequence-specific information in the SRT-ST task (p = 0.07) but not in the SRT-DT task (p = 0.69). Severity of FOG, however, correlated positively with SRT-DT task performance (r = -0.56; p < 0.05).
The present results suggest that PD patients suffering from FOG pathology exhibit a specific impairment in the acquisition of automaticity. When working memory capacity is supplementarily loaded by adding a DT, sequence learning in FRs becomes increasingly impaired. These findings indicate that therapies should focus on extensive training in acquiring novel motor activities and reducing working memory load to improve learning in FOG.
帕金森病（PD）冻结步态（FOG）可能涉及在工作记忆负荷下获得自动性的特定损伤。本研究旨在探讨在有 FOG 的患者中，是否存在隐式序列学习（无论是否存在次要任务）受损的情况。
14 名冻结者（FR）、14 名非冻结者（nFR）和 14 名匹配的健康对照者（HC）在单任务（ST）和双重任务（DT）条件下，进行了一系列反应时（SRT）任务，具有确定性刺激序列。随机块与序列块相比反应时间（RT）的增加，被用作隐式序列学习的衡量标准。进行了神经心理学测试，以评估其对序列学习的影响，评估的内容包括总体认知功能和执行功能障碍。
nFR 和 HC 显示出明显的隐式序列学习效应（p < 0.001）。FR 在 SRT-ST 任务中表现出对序列特异性信息的学习趋势（p = 0.07），但在 SRT-DT 任务中则没有（p = 0.69）。然而，FOG 的严重程度与 SRT-DT 任务的表现呈正相关（r = -0.56；p < 0.05）。
本研究结果表明，患有 FOG 病理的 PD 患者在获得自动性方面表现出特定的损伤。当通过添加 DT 来补充工作记忆容量时，FR 中的序列学习会受到越来越大的损害。这些发现表明，治疗方法应侧重于广泛的新运动活动的获取训练，以及降低工作记忆负荷，以提高 FOG 中的学习能力。
