Metacognition of visuomotor decisions in conversion disorder
Metacognition of visuomotor decisions in conversion disorder
复制标题
DOI：
10.1016/j.neuropsychologia.2018.04.018
复制
发表时间：
2018-06-01
期刊：
影响因子：
2.6
通讯作者：
Vuilleumier, Patrik
中科院分区：
文献类型：
--
作者：
Begue, Indrit;Blakemore, Rebekah;Vuilleumier, Patrik
运动转换障碍（CD）是指尽管缺乏明显的神经损伤，但患者仍然认为自己无法执行运动功能的主观体验中存在真正的障碍。个体在任务执行过程中评估自己能力的能力被称为元认知能力，这种能力的明显损害可以在几种自我意识障碍中观察到，如盲视和病感失认症。在乳糜泻中，先前的研究主要集中在运动和情绪脑系统的招募，通常将症状与边缘-运动相互作用的改变联系起来；然而，据我们所知，元认知功能尚未得到研究。在这里，我们在视觉引导运动范式中测试了10名CD患者和10名年龄性别匹配的对照组，该范式先前在健康对照组（HC）中使用，使我们能够探索运动意识和元认知。参与者必须画出通往视觉目标的直线轨迹，而他们不知道的是，在屏幕上看到的到达轨迹偶尔会出现偏差。然后，参与者报告了对偏差的意识和对自己回答的信心。运动前皮层和扣带皮层的活动比对照组更好地区分有意识和无意识的运动纠正。关键的是，对照组在信心判断时使用左上楔前叶和颞叶中部区域，而CD患者则使用双侧海马旁区和杏仁核-海马区。这些结果揭示了不同的脑区对HC和CD的元认知监测，指出了不同的机制和信息来源用于监测和形成运动表现的信心判断。当涉及感觉-运动整合和视觉的大脑系统更多地参与控制时，乳糜泻患者可能优先依赖于记忆和上下文联想处理，这可能解释了影响和记忆如何在这些患者中灌输当前的运动体验。
Motor conversion disorder (CD) entails genuine disturbances in the subjective experience of patients who maintain they are unable to perform a motor function, despite lack of apparent neurological damage. Abilities by which individuals assess their own capacities during performance in a task are called metacognitive, and distinctive impairment of such abilities is observed in several disorders of self-awareness such as blindsight and anosognosia. In CD, previous research has focused on the recruitment of motor and emotional brain systems, generally linking symptoms to altered limbic-motor interactions; however, metacognitive function has not been studied to our knowledge. Here we tested ten CD patients and ten age-gender matched controls during a visually guided motor paradigm, previously employed in healthy controls (HC), allowing us to probe for motor awareness and metacognition. Participants had to draw straight trajectories towards a visual target while, unbeknownst to them, deviations were occasionally introduced in the reaching trajectory seen on the screen. Participants then reported both awareness of deviations and confidence in their response. Activity in premotor and cingulate cortex distinguished between conscious and unconscious movement corrections in controls better than patients. Critically, whereas controls engaged the left superior precuneus and middle temporal region during confidence judgments, CD patients recruited bilateral parahippocampal and amygdalo-hippocampal regions instead. These results reveal that distinct brain regions subserve metacognitive monitoring for HC and CD, pointing to different mechanisms and sources of information used to monitor and form confidence judgments of motor performance. While brain systems involved in sensory-motor integration and vision are more engaged in controls, CD patients may preferentially rely on memory and contextual associative processing, possibly accounting for how affect and memories can imbue current motor experience in these patients.