De Renzi E, di Pellegrino G
Department of Neurology, University of Modena.
Cortex. 1995 Dec;31(4):619-36. doi: 10.1016/s0010-9452(13)80016-0.
We report a patient who, following a left fronto-temporal lesion, showed a complete sparing of the semantic store and a deficit of word production characterized by two types of dissociations. First, oral and written output was severely disrupted in naming and partially impaired in repetition, writing to dictation and oral spelling, with the exception of verbs, which were normally produced in every modality and condition of stimulation. Second, reading was normal for all type of words as well as non-words. This pattern of deficits suggests two functional lesions, one affecting the connections between the semantic store and the phonological lexicon and the other damaging the sublexical route that converts sound to sound and sound to print. It also implies that words are independently organized in the phonological lexicon, based on their grammatical class and have discrete connections with the semantic store. However, CT scan evidence does not support the hypothesis that this functional dissociation finds its anatomical correlate in the specialization of the frontal premotor cortex for verbs and the antero-medial temporal cortex for nouns. In spite of his normal reading performance, both in terms of comprehension and of accuracy and speed in word production, the patient complained that he met with great difficulty in reading newspapers and books, to the point that he had to renounce to this previously favourite activity. It was found that it took him time and effort to grasp the meaning of complex sentences and passages and it was speculated that, contrary to single words and elementary sentences, comprehension of this type of material cannot be achieved by the mere access of orthographic stimuli to semantics, but requires the retrieval of word-forms. It would appear that a patient, whose lexical route is blocked, can only read passages, by first converting print to sound via the sublexical route and then re-entering the semantic store with oral input.
我们报告了一名患者，该患者在左侧额颞叶病变后，语义存储完全保留，但存在单词生成缺陷，其特征为两种类型的分离。首先，口语和书面输出在命名时严重受损，在复述、听写和口头拼写时部分受损，但动词除外，动词在每种刺激方式和条件下都能正常生成。其次，所有类型的单词和非单词的阅读均正常。这种缺陷模式表明存在两种功能性损伤，一种影响语义存储与语音词汇之间的连接，另一种损害将声音转换为声音以及将声音转换为印刷体的次词汇通路。这也意味着单词在语音词汇中是根据其语法类别独立组织的，并且与语义存储有离散的连接。然而，CT扫描证据并不支持这样的假设，即这种功能分离在额叶运动前区皮质对动词的专门化以及颞叶前内侧皮质对名词的专门化中找到其解剖学对应物。尽管患者在阅读理解以及单词生成的准确性和速度方面表现正常，但他抱怨在阅读报纸和书籍时遇到了很大困难，以至于不得不放弃这项以前喜欢的活动。研究发现，他需要花费时间和精力来理解复杂的句子和段落，据推测，与单个单词和基本句子不同，理解这类材料不能仅仅通过正字法刺激直接通达语义来实现，而是需要检索单词形式。看起来，一名词汇通路受阻的患者只能通过先通过次词汇通路将印刷体转换为声音，然后通过口头输入重新进入语义存储来阅读段落。
