Department of Psychology, University of Bath, United Kingdom; Department of Psychology, University of Konstanz, Germany.
Department of Psychology, University of Konstanz, Germany; Zentralinstitut fuer Seelische Gesundheit, Mannheim, Germany.
Mult Scler Relat Disord. 2020 Jan;37:101433. doi: 10.1016/j.msard.2019.101433. Epub 2019 Oct 5.
Impairments in long-term and working memory are widespread in Multiple Sclerosis (MS), setting on in early disease stages. These memory impairments may limit patients' ability to take informed and competent medical decisions, too. In healthy populations, memory abilities predict decision quality across a wide range of tasks. These studies suggest that higher working memory capacity supports decisions in cognitively taxing tasks, whereas better semantic memory facilitates decisions in tasks requiring knowledge retrieval. In individuals with MS, previous studies have linked less accurate decisions to memory deficits and reduced executive functioning, too. However, these studies focussed on decisions under risk and did not broadly assess decision making skills. We aimed to fill this gap in a cross-sectional study.
Hundred thirty-seven participants with MS were recruited during their stay in an MS specialized rehabilitation centre. In a first test session, participants completed a standardized test battery for working memory and semantic memory, the inventory for memory diagnostics. In a second test session, participants filled out the Adult Decision Making Competence battery (A-DMC). This version of the A-DMC measured decision making competence on five subscales: Resistance to Framing Effects, Under/Overconfidence, Applying Decision Rules, Consistency in Risk Perception, and Resistance to Sunk Cost Effects. In addition, participants were screened for depression and cognitive fatigue.
Working memory was impaired in most participants, whereas semantic memory was not impaired. To understand which memory abilities underlie distinct components of decision making in people with MS, we used structural equation modelling. Replicating previous findings in a healthy sample, working memory capacity was associated with the ability to recall semantic knowledge. Participants with lower working memory capacity were less resistant to framing effects and adhered to decision rules less. In contrast, participants with worse semantic memory assessed their own knowledge less accurately, perceived risks less consistently, and made more errors in applying decision rules. Cognitive fatigue and depression unlikely explain these relationships.
Taken together, our study suggests that the memory problems, frequently reported in MS patients, may reach out to higher-order cognitive functions, such as decision making skills. Supporting shared decision-making and patient autonomy within MS thus requires to take memory impairments into account and to match the information provided to the patient's memory abilities.
在多发性硬化症（MS）中，长期和工作记忆受损是普遍存在的，并且在疾病早期就已经出现了。这些记忆损伤可能会限制患者做出明智和有能力的医疗决策的能力。在健康人群中，记忆能力可以预测广泛任务中的决策质量。这些研究表明，较高的工作记忆能力支持认知负荷高的任务中的决策，而更好的语义记忆则有利于需要知识检索的任务中的决策。在多发性硬化症患者中，之前的研究也将不太准确的决策与记忆缺陷和执行功能下降联系起来。然而，这些研究侧重于风险下的决策，并没有广泛评估决策能力。我们旨在通过一项横断面研究来填补这一空白。
我们招募了 137 名在多发性硬化症专门康复中心的患者。在第一次测试中，参与者完成了一个用于工作记忆和语义记忆的标准化测试组合，即记忆诊断测试。在第二次测试中，参与者填写了成人决策能力测试（A-DMC）。该版本的 A-DMC 通过五个子量表来衡量决策能力：抵制框架效应、过度自信/自信不足、应用决策规则、风险感知的一致性和抵制沉没成本效应。此外，参与者还接受了抑郁和认知疲劳的筛查。
大多数参与者的工作记忆受损，而语义记忆未受损。为了了解在多发性硬化症患者中哪些记忆能力与决策的不同成分相关，我们使用了结构方程模型。在健康样本中复制了之前的发现，工作记忆容量与回忆语义知识的能力相关。工作记忆容量较低的参与者对框架效应的抵抗力较低，对决策规则的遵守程度也较低。相比之下，语义记忆较差的参与者对自己的知识评估不准确，风险感知不一致，在应用决策规则时犯的错误更多。认知疲劳和抑郁不太可能解释这些关系。
综上所述，我们的研究表明，多发性硬化症患者经常报告的记忆问题可能会涉及到更高阶的认知功能，如决策技能。因此，在多发性硬化症患者中支持共同决策和患者自主性需要考虑记忆损伤，并根据患者的记忆能力匹配提供的信息。
