Patterson K, Lambon Ralph M A, Hodges J R, McClelland J L
MRC Cognition and Brain Sciences Unit, 15 Chaucer Road, Cambridge CB2 2EF, UK.
Neuropsychologia. 2001;39(7):709-24. doi: 10.1016/s0028-3932(01)00008-2.
Two distinct mechanisms are often considered necessary to account for generation of the past-tense of English verbs: a lexical associative process for irregular forms like speak-->spoke, and a rule-governed process ("add -ed") for regular and novel forms like talk-->talked and wug-->wugged. An alternative account based on a parallel-distributed processing approach proposes that one complex procedure processes all past-tense types. In this alternative view, neuropsychological dissociations are explained by reduced input from word meaning that plays a greater role in successful generation of the past-tense for lower frequency irregular verbs, and by phonological deficits that disproportionately affect regular and novel forms. Only limited evidence has been available concerning the relationship between knowledge of word meaning and verb-tense processing. The study reported here evaluated the past-tense verb abilities of 11 patients with semantic dementia, a neurodegenerative condition characterised by degraded semantic knowledge. We predicted and confirmed that the patients would have essentially normal ability to generate and recognise regular (and novel) past-tense forms, but a marked and frequency-modulated deficit on irregular verbs. Across the set of 11 patients, the degree of impairment for the irregular past-tense was significantly correlated with the degree of comprehension impairment as measured by verb synonym judgements. These results, plus other features of the data such as the nature of the errors to irregular verbs, are discussed in relation to currently developing theories of the language system.
通常认为，要解释英语动词过去式的生成，需要两种不同的机制：一种是针对不规则形式（如speak→spoke）的词汇联想过程，另一种是针对规则形式和新造形式（如talk→talked和wug→wugged）的规则支配过程（“加 -ed”）。基于并行分布式处理方法的另一种解释则提出，一个复杂的程序可以处理所有过去式类型。在这种另一种观点中，神经心理学上的分离现象可以这样解释：对于低频不规则动词，词义输入的减少在过去式的成功生成中起更大作用，而语音缺陷则对规则形式和新造形式产生不成比例的影响。关于词义知识与动词时态处理之间的关系，目前只有有限的证据。本文报道的这项研究评估了11名语义性痴呆患者的过去式动词能力，这是一种以语义知识退化特征的神经退行性疾病。我们预测并证实，这些患者生成和识别规则（及新造）过去式形式的能力基本正常，但在不规则动词方面存在明显的、受频率调制的缺陷。在这11名患者中，不规则过去式的受损程度与通过动词同义词判断所测量的理解受损程度显著相关。本文结合当前正在发展的语言系统理论，对这些结果以及数据的其他特征（如对不规则动词的错误性质）进行了讨论。
