Tomasino Barbara, Marin Dario, Maieron Marta, D'Agostini Serena, Fabbro Franco, Skrap Miran, Luzzatti Claudio
IRCCS "E. Medea", Polo FVG, San Vito al Tagliamento (PN), Italy.
IRCCS "E. Medea", Polo FVG, San Vito al Tagliamento (PN), Italy.
Cortex. 2015 Dec;73:112-30. doi: 10.1016/j.cortex.2015.08.010. Epub 2015 Aug 19.
Neuropsychological data about acquired impairments in reading and writing provide a strong basis for the theoretical framework of the dual-route models. The present study explored the functional neuroanatomy of the reading and spelling processing system. We describe the reading and writing performance of patient CF, an Italian native speaker who developed an extremely selective reading and spelling deficit (his spontaneous speech, oral comprehension, repetition and oral picture naming were almost unimpaired) in processing double letters associated with surface dyslexia and dysgraphia, following a tumor in the left temporal lobe. In particular, the majority of CF's errors in spelling were phonologically plausible substitutions, errors concerning letter numerosity of consonants, and syllabic phoneme-to-grapheme conversion (PGC) errors. A similar pattern of impairment also emerged in his reading behavior, with a majority of lexical stress errors (the only possible type of surface reading errors in the Italian language, due the extreme regularity of print-to-sound correspondence). CF's neuropsychological profile was combined with structural neuroimaging data, fiber tracking, and functional maps and compared to that of healthy control participants. We related CF's deficit to a dissociation between impaired ventral/lexical route (as evidenced by a fractional anisotropy - FA decrease along the inferior fronto-occipital fasciculus - IFOF) and relatively preserved dorsal/phonological route (as evidenced by a rather full integrity of the superior longitudinal fasciculus - SLF). In terms of functional processing, the lexical-semantic ventral route network was more activated in controls than in CF, while the network supporting the dorsal route was shared by CF and the control participants. Our results are discussed within the theoretical framework of dual-route models of reading and spelling, emphasize the importance of the IFOF both in lexical reading and spelling, and offer a better comprehension of the neurological and functional substrates involved in written language and, in particular, in surface dyslexia and dysgraphia and in doubling/de-doubling consonant sounds and letters.
关于后天性读写障碍的神经心理学数据为双通路模型的理论框架提供了有力依据。本研究探讨了读写加工系统的功能神经解剖学。我们描述了患者CF的读写表现，CF是一位以意大利语为母语的人，在左颞叶肿瘤后，在处理与表层失读症和失写症相关的双字母时出现了极其选择性的读写缺陷（他的自发言语、口语理解、复述和口语图片命名几乎未受损害）。特别是，CF在拼写中的大多数错误是语音上合理的替换、关于辅音字母数量的错误以及音节音素到字素转换（PGC）错误。类似的损伤模式也出现在他的阅读行为中，大多数是词汇重音错误（由于意大利语中印刷与发音对应关系的极端规律性，这是意大利语中唯一可能的表层阅读错误类型）。CF的神经心理学特征与结构神经影像学数据、纤维追踪和功能图谱相结合，并与健康对照参与者进行比较。我们将CF的缺陷与受损的腹侧/词汇通路（表现为沿额枕下束 - IFOF的分数各向异性 - FA降低）和相对保留的背侧/语音通路（表现为上纵束 - SLF相当完整）之间的分离联系起来。在功能加工方面，词汇语义腹侧通路网络在对照组中比在CF中更活跃，而支持背侧通路的网络由CF和对照参与者共享。我们在读写双通路模型的理论框架内讨论了我们的结果，强调了IFOF在词汇阅读和拼写中的重要性，并更好地理解了书面语言，特别是表层失读症和失写症以及辅音加倍/去加倍音和字母所涉及的神经学和功能基础。
