Laine M, Salmelin R, Helenius P, Marttila R
University of Turku, Turku, Finland.
J Cogn Neurosci. 2000 Jul;12(4):622-34. doi: 10.1162/089892900562381.
Magnetoencephalographic (MEG) changes in cortical activity were studied in a chronic Finnish-speaking deep dyslexic patient during single-word and sentence reading. It has been hypothesized that in deep dyslexia, written word recognition and its lexical-semantic analysis are subserved by the intact right hemisphere. However, in our patient, as well as in most nonimpaired readers, lexical-semantic processing as measured by sentence-final semantic-incongruency detection was related to the left superior-temporal cortex activation. Activations around this same cortical area could be identified in single-word reading as well. Another factor relevant to deep dyslexic reading, the morphological complexity of the presented words, was also studied. The effect of morphology was observed only during the preparation for oral output. By performing repeated recordings 1 year apart, we were able to document significant variability in both the spontaneous activity and the evoked responses in the lesioned left hemisphere even though at the behavioural level, the patient's performance was stable. The observed variability emphasizes the importance of estimating consistency of brain activity both within and between measurements in brain-damaged individuals.
我们对一名患有慢性深度诵读困难的芬兰语患者在单字和句子阅读过程中的皮质活动磁脑图（MEG）变化进行了研究。此前有假说认为，在深度诵读困难中，书面文字识别及其词汇语义分析由完整的右半球负责。然而，在我们的患者以及大多数正常读者中，通过句末语义不一致检测所衡量的词汇语义处理与左侧颞上皮质激活有关。在单字阅读中也能识别出同一皮质区域周围的激活情况。我们还研究了与深度诵读困难阅读相关的另一个因素，即所呈现单词的形态复杂性。形态学效应仅在准备口语输出时被观察到。通过相隔1年进行重复记录，我们得以记录到受损左侧半球的自发活动和诱发反应中存在显著变异性，尽管在行为层面患者的表现是稳定的。观察到的变异性强调了在脑损伤个体中评估测量内部和测量之间脑活动一致性的重要性。
