Westerhausen René, Hugdahl Kenneth
Department of Biological and Medical Psychology, Cognitive NeuroScience Group, University of Bergen, Jonas Lies vei 91, N-5009 Bergen, Norway.
Neurosci Biobehav Rev. 2008 Jul;32(5):1044-54. doi: 10.1016/j.neubiorev.2008.04.005. Epub 2008 Apr 26.
The dichotic listening paradigm using verbal stimulus material typically yields a right ear advantage (REA) which indicates the left-hemisphere dominance for speech processing. Although this interpretation is widely accepted, the cerebral hemispheres also interact through the corpus callosum. Moreover, the two most influential theoretical models of dichotic listening, the structural and the attentional model, both refer to the functional integrity of the corpus callosum, when explaining the REA. However, the current review of the available data reveals several aspects that can not be explained by the dichotic listening models. For example, an individual's ability to direct attention to either ear is mediated by callosal fibers. Consequently, the corpus callosum not only has to be considered as a channel for the automatic exchange of information between the cerebral hemispheres, it rather allows for a dynamic and flexible interaction in supporting both bottom-up and top-down stimulus processing. The review has also revealed how inter-individual variability in callosal fiber structure affects both bottom-up and top-down performance on the dichotic listening task.
使用言语刺激材料的双耳分听范式通常会产生右耳优势（REA），这表明左半球在言语处理方面占主导地位。尽管这种解释已被广泛接受，但大脑半球也通过胼胝体相互作用。此外，双耳分听的两个最具影响力的理论模型，即结构模型和注意模型，在解释右耳优势时都提到了胼胝体的功能完整性。然而，目前对现有数据的综述揭示了一些双耳分听模型无法解释的方面。例如，个体将注意力导向任一只耳朵的能力是由胼胝体纤维介导的。因此，胼胝体不仅必须被视为大脑半球之间自动信息交换的通道，它更允许在支持自下而上和自上而下的刺激处理方面进行动态灵活的相互作用。该综述还揭示了胼胝体纤维结构的个体间差异如何影响双耳分听任务的自下而上和自上而下的表现。
