Bublak P, Schubert T, Matthes-von Cramon G, von Cramon Y
Department of Neurology, Max-Planck-Institute of Cognitive Neuroscience, Leipzig, Germany.
J Clin Exp Neuropsychol. 2000 Apr;22(2):176-90. doi: 10.1076/1380-3395(200004)22:2;1-1;FT176.
In the present study, a working memory paradigm was used to assess coordinative abilities required for the flexible control of a sequence of actions. Subjects had to maintain and recall a list of digits that functioned as an ensemble of activity cues used for guiding a sequence of forced-choice responses. In three task conditions, the demand on the selection of the activity cues was varied parametrically to manipulate the requirement of coordinating maintenance and processing operations of working memory for guiding the response sequences. A comparison between subjects suffering from severe closed head injury (CHI) and matched controls in a blocked presentation of task conditions revealed that patients, in contrast to controls, did not preplan the sequence by rearranging the ensemble of activity cues prior to execution of the action sequence. Patients' performance was more comparable to controls tested in a random presentation in which preplanning was not possible. Our results further suggest that patients are less efficient in selecting activity cues from working memory, especially in more demanding situations when activity cues have to be completely reordered for guiding a sequence of actions. These results point to an executive dysfunction in CHI subjects that may contribute to the deficits known as inflexible and rigid behavior.
在本研究中，采用工作记忆范式来评估灵活控制一系列动作所需的协调能力。受试者必须保持并回忆一串数字，这些数字作为一组活动线索，用于指导一系列强制选择反应。在三种任务条件下，对活动线索选择的要求进行参数化变化，以操纵指导反应序列时协调工作记忆的维持和加工操作的要求。在任务条件的分块呈现中，对重度闭合性颅脑损伤（CHI）患者和匹配的对照组进行比较，结果显示，与对照组相比，患者在执行动作序列之前，不会通过重新排列活动线索组来预先规划序列。患者的表现与在随机呈现中测试的对照组更具可比性，在随机呈现中无法进行预先规划。我们的结果进一步表明，患者从工作记忆中选择活动线索的效率较低，尤其是在要求更高的情况下，即必须完全重新排列活动线索以指导一系列动作时。这些结果表明CHI受试者存在执行功能障碍，这可能导致了被称为不灵活和僵化行为的缺陷。
