Fiez J A, Raichle M E, Balota D A, Tallal P, Petersen S E
Department of Neurology, McDonnell Center for Higher Brain Function, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
Cereb Cortex. 1996 Jan-Feb;6(1):1-10. doi: 10.1093/cercor/6.1.1.
Previous studies using positron emission tomography (PET) report blood flow changes in superior and middle temple gyri associated with auditory and language tasks (Petersen et al., 1988, 1989; Wise et al., 1991; Demonet et al., 1992; Howard et al., 1992; Sergent et al., 1992; Zatorre et al., 1992; Petrides et al., 1993; Raichle et al., 1994; Fiez et al., 1995). An important issue is whether these changes reflect the activation of a single functional region or multiple regions with distinct functional contributions. In the present study, we examined this issue by focusing upon two tasks for which we have previously reported posterior temporal blood flow changes: listening to auditorily presented words (Petersen et al., 1988, 1989), and generation of a verb in response to a visually presented noun (Raichle et al., 1994); see also Wise et al. (1991). We began by further characterizing a left temporoparietal region of change previously associated with auditory word presentation. This previously reported response was replicated, and the results were extended by demonstrating presentation of pseudowords also produced activation. We next asked whether the activation associated with auditory word presentation could be distinguished from that associated with the generation of verbs in response to visually presented nouns. It was found that the activations associated with these two tasks could be both functionally and spatially dissociated. Thus, two posterior temporal areas associated with auditory word presentation and verb generation appear to represent distinct areas concerned with word processing. More generally, the results demonstrate an approach for assessing the independence of two activated areas.
以往使用正电子发射断层扫描（PET）的研究报告称，颞上回和颞中回的血流变化与听觉和语言任务相关（彼得森等人，1988年、1989年；怀斯等人，1991年；德莫内等人，1992年；霍华德等人，1992年；塞尔让等人，1992年；扎托雷等人，1992年；佩特里德斯等人，1993年；赖克尔等人，1994年；菲耶兹等人，1995年）。一个重要问题是，这些变化反映的是单个功能区域的激活，还是具有不同功能作用的多个区域的激活。在本研究中，我们通过关注两项任务来探讨这个问题，我们之前曾报告过这两项任务会引起颞叶后部血流变化：听听觉呈现的单词（彼得森等人，1988年、1989年），以及对视觉呈现的名词做出反应生成动词（赖克尔等人，1994年）；另见怀斯等人（1991年）。我们首先进一步描述了先前与听觉单词呈现相关的左颞顶叶变化区域。重复了先前报告的反应，并通过证明伪词呈现也会产生激活来扩展结果。接下来，我们询问与听觉单词呈现相关的激活是否可以与对视觉呈现的名词做出反应生成动词相关的激活区分开来。结果发现，与这两项任务相关的激活在功能和空间上都可以分离。因此，与听觉单词呈现和动词生成相关的两个颞叶后部区域似乎代表了与单词处理相关的不同区域。更一般地说，结果展示了一种评估两个激活区域独立性的方法。
