Max Planck Institut für Psycholinguistik, The Netherlands.
J Cogn Neurosci. 1989 Summer;1(3):262-72. doi: 10.1162/jocn.1989.1.3.262.
This study tests the hypothesis that agrammatic comprehension is due to a computational rather than a structural language deficit. It is claimed that grammatic Broca's aphasics do not meet the temporal constraints in the activation of different types of linguistic information necessary for normal parsing. These temporal constraints are investigated in two experiments using a crossmodal syntactic priming paradigm. Each experiment tests the effect on recognition of grammatical versus ungrammatical links between an auditory sentence fragment (the prime) and a visually presented word (the target). The experiments differ in the interstimulus interval (ISI i.e., the amount of time provided between the offset of the auditory prime and the onset of the visuai target. Experiment 1, with an ISI of 0 msec, reveals that Broca patients - much like the control groups - show a grammaticality effect. In contrast to normal students and age matched controls, however, these patients are in general much slower in making lexical decisions when auditory context is present as compared to when visual targets are presented in isolation. Experiment 2 with an ISI of 200 msec demonstrates that when additional time is given to process the syntactic context, Broca's aphasics in contrast to age matched controls show faster decision times on the target than when the ISI is 0 msec. The results are in accord with the view that agrammatic Broca's aphasics have not lost their syntactic knowledge, but that their a grammatic comprehension behavior is due to the inability to process the linguistic information within a given time frame. More generally, the findings suggest that language processing can break down once activation of different types of linguistic information does not follow the normal time pattern.
本研究检验了这样一个假设，即语法性理解障碍是由于计算而非结构语言缺陷所致。有人声称，语法性布洛卡失语症患者不符合正常解析所需的不同类型语言信息激活的时间限制。这两个实验使用跨模态句法启动范式来研究这些时间限制。每个实验都测试了在听觉句子片段（启动）和视觉呈现的单词（目标）之间的语法与不合语法的链接对识别的影响。实验在刺激间间隔（ISI，即听觉启动结束与视觉目标开始之间提供的时间量）方面有所不同。实验 1 的 ISI 为 0 毫秒，结果表明，布洛卡患者——与对照组非常相似——表现出语法效应。然而，与正常学生和年龄匹配的对照组相比，这些患者在听觉语境存在时，与视觉目标单独呈现时相比，做出词汇决策通常要慢得多。实验 2 的 ISI 为 200 毫秒，结果表明，当有更多时间来处理句法语境时，与年龄匹配的对照组相比，布洛卡失语症患者在目标上的决策时间更快，而当 ISI 为 0 毫秒时则较慢。这些结果与以下观点一致，即语法性布洛卡失语症患者并未失去其句法知识，而是他们的语法性理解行为是由于无法在给定时间内处理语言信息所致。更一般地说，这些发现表明，一旦不同类型的语言信息的激活不符合正常时间模式，语言处理就可能会中断。
