Blini Elvio, D'Imperio Daniela, Romeo Zaira, De Filippo De Grazia Michele, Passarini Laura, Pilosio Cristina, Meneghello Francesca, Bonato Mario, Zorzi Marco
Department of General Psychology and Padova Neuroscience Center, University of Padova, Padua, Italy.
Department of Neurosciences, Psychology, Drug Research and Child Health, University of Firenze, Florence, Italy.
Commun Biol. 2025 May 12;8(1):734. doi: 10.1038/s42003-025-08074-z.
Cognitive impairment after stroke is heterogeneous: there is no strict correspondence between brain damage and magnitude of deficit or recovery. Protective factors such as cognitive or brain reserve have been invoked to explain the mismatch. Here, we consider the opposite point of view: the instances in which this protection is overturned. We leveraged on multitasking to stress the brain's processing limits and unveil deficits that may be missed by standard testing in a sample of 46 patients with unilateral subacute to chronic stroke and no sign of lateralized spatial-attentional disorders at neuropsychological paper-and-pencil tests. Multivariate analyses identified a phenotype of patients with high susceptibility to multitasking, showing stark contralesional spatial awareness deficit only when multitasking. Multivariate brain-behavior mapping based on lesions location and structural disconnections pointed to the Multiple-Demand System, a network of frontal and fronto-parietal areas subserving domain-general processes. Damage in this network may critically interact with domain-specific processes, resulting in subtle and yet invalidating deficits. Indeed, these patients (one-third of the sample) presented worse performance in tests evaluating activities of daily living and domain-general abilities. We conclude that the theoretical construct of susceptibility to multitasking helps understanding what marks the passage to clinically visible deficits after brain damage.
脑损伤与功能缺损或恢复程度之间不存在严格的对应关系。诸如认知或脑储备等保护因素已被用来解释这种不匹配。在此，我们考虑相反的观点：这种保护被推翻的情况。我们利用多任务处理来强调大脑的处理极限，并揭示在46例单侧亚急性至慢性中风患者样本中，标准测试可能遗漏的缺陷，这些患者在神经心理学纸笔测试中没有侧化空间注意障碍的迹象。多变量分析确定了一类对多任务处理高度敏感的患者表型，仅在进行多任务处理时表现出明显的对侧空间意识缺陷。基于病变位置和结构连接的多变量脑行为映射指向了多重需求系统，这是一个由额叶和额顶叶区域组成的网络，支持领域通用过程。该网络的损伤可能与领域特定过程发生关键相互作用，导致细微但却使功能失效的缺陷。事实上，这些患者（样本的三分之一）在评估日常生活活动和领域通用能力的测试中表现更差。我们得出结论，对多任务处理敏感的理论结构有助于理解是什么标志着脑损伤后向临床可见缺陷的转变。
