National Key Laboratory of Cognitive Neuroscience and Learning and IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, China.
School of System Science, Beijing Normal University, Beijing, China.
Hum Brain Mapp. 2024 Jan;45(1):e26569. doi: 10.1002/hbm.26569.
Successful visual word recognition requires the integration of phonological and semantic information, which is supported by the dorsal and ventral pathways in the brain. However, the functional specialization or interaction of these pathways during phonological and semantic processing remains unclear. Previous research has been limited by its dependence on correlational functional magnetic resonance imaging (fMRI) results or causal validation using patient populations, which are susceptible to confounds such as plasticity and lesion characteristics. To address this, the present study employed continuous theta-burst stimulation combined with fMRI in a within-subject design to assess rapid adaptation in regional activity and functional connectivity of the dorsal and ventral pathways during phonological and semantic tasks. This assessment followed the precise inhibition of the left inferior parietal lobule and anterior temporal lobe in the dorsal and ventral pathways, respectively. Our results reveal that both the dorsal and ventral pathways were activated during phonological and semantic processing, while the adaptation activation and interactive network were modulated by the task type and inhibited region. The two pathways exhibited interconnectivity in phonological processing, and disruption of either pathway led to rapid adaptation across both pathways. In contrast, only the ventral pathway exhibited connectivity in semantic processing, and disruption of this pathway alone resulted in adaptive effects primarily in the ventral pathway. These findings provide essential evidence supporting the interactive theory, phonological information processing in particular, potentially providing meaningful implications for clinical populations.
成功的视觉单词识别需要整合语音和语义信息，这得到大脑中背侧和腹侧通路的支持。然而，这些通路在语音和语义处理过程中的功能特化或相互作用仍不清楚。以前的研究受到其对相关功能磁共振成像（fMRI）结果的依赖或使用患者群体进行因果验证的限制，这些结果容易受到可塑性和病变特征等混杂因素的影响。为了解决这个问题，本研究采用连续 theta 爆发刺激结合 fMRI 在一个被试内设计中，评估在语音和语义任务中，背侧和腹侧通路的区域活动和功能连接的快速适应。在分别精确抑制背侧和腹侧通路中的左侧顶下小叶和前颞叶后，进行了这种评估。我们的结果表明，在语音和语义处理过程中，背侧和腹侧通路都被激活，而适应激活和交互网络则受到任务类型和抑制区域的调节。这两个通路在语音处理中表现出相互连接性，破坏任何一个通路都会导致两个通路的快速适应。相比之下，只有腹侧通路在语义处理中表现出连接性，而单独破坏该通路会导致主要在腹侧通路中出现适应性效应。这些发现为交互理论提供了重要证据，特别是语音信息处理，这可能为临床人群提供有意义的启示。
