Department of Psychology, Rice University, Houston, TX, USA.
Department of Neurology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, USA.
Psychon Bull Rev. 2020 Aug;27(4):607-639. doi: 10.3758/s13423-019-01706-6.
Theories of semantic memory based on neuropsychological findings have posited a distinction between stored semantic representations and the mechanisms used to access and manipulate them (e.g., Lambon Ralph, Jefferies, Patterson, & Rogers, 2017; Warrington & Cipolotti, 1996). The most recent instantiation of this view, the controlled semantic cognition theory (Lambon Ralph et al., 2017), is supported by findings suggesting that multimodal (i.e., both verbal and nonverbal) semantic deficits may result from qualitatively different impairments: on the one hand, damage to a semantic access mechanism related to executive control, which is observed in semantic aphasia (SA), and on the other, damage to semantic representations, which is observed in semantic dementia (SD) (Jefferies & Lambon Ralph, 2006). In this study we compared SA and SD patients on several phenomena previously used to support these distinctions. Contrary to the prior results, we found that (1) overall, cross-task consistency was equivalent for the two groups; (2) neither patient group showed consistency driven by item identity across different semantic tasks; (3) correlations among task performance were not obviously driven by the semantic control demands of different tasks; (4) both groups showed executive function deficits; and (5) both groups showed strong effects of distractor interference in a synonym judgment task. Furthermore, we investigated the components of executive ability that could underlie semantic control deficits by correlating performance on updating, shifting, and inhibition tasks with performance on tasks testing semantic abilities. We found that updating was related to semantic processing generally, whereas shifting and inhibition were not. These results also suggest that complex executive function tasks relate to semantic tasks through their shared relationship with language abilities. Overall, evidence from SA and SD patients does not differentiate representations and access mechanisms in the semantic system, as has previously been suggested. Implications for the storage-access distinction are discussed.
基于神经心理学发现的语义记忆理论假设，存储的语义表示和用于访问和操作它们的机制之间存在区别（例如，Lambon Ralph 等人，2017 年；Warrington 和 Cipolotti，1996 年）。这一观点的最新体现是受控语义认知理论（Lambon Ralph 等人，2017 年），该理论得到了以下发现的支持：即多模态（即言语和非言语）语义缺陷可能是由不同性质的损伤引起的：一方面，与执行控制相关的语义访问机制受损，这在语义性失语症（SA）中观察到；另一方面，语义表示受损，这在语义性痴呆（SD）中观察到（Jefferies 和 Lambon Ralph，2006 年）。在这项研究中，我们比较了 SA 和 SD 患者在几个先前用于支持这些区别的现象上的表现。与之前的结果相反，我们发现：（1）总体而言，两组之间的跨任务一致性是相等的；（2）两组患者都没有表现出跨不同语义任务的项目身份一致性；（3）任务表现之间的相关性并非明显受到不同任务语义控制需求的驱动；（4）两组患者都表现出执行功能缺陷；（5）两组患者在同义词判断任务中都表现出明显的干扰抑制效应。此外，我们通过将更新、转移和抑制任务的表现与测试语义能力的任务的表现进行相关分析，研究了可能导致语义控制缺陷的执行能力的组成部分。我们发现，更新与一般的语义处理有关，而转移和抑制则不然。这些结果还表明，复杂的执行功能任务与语义任务相关，是通过与语言能力的共同关系。总的来说，来自 SA 和 SD 患者的证据并没有像以前那样区分语义系统中的表示和访问机制。讨论了存储-访问区别的含义。
