Neural substrates of reliability-weighted visual-tactile multisensory integration
Neural substrates of reliability-weighted visual-tactile multisensory integration
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DOI：
10.3389/fnsys.2010.00025
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发表时间：
2010-01-01
影响因子：
3
通讯作者：
Ro, Tony
中科院分区：
文献类型：
--
作者：
Beauchamp, Michael S.;Pasalar, Siavash;Ro, Tony
随着感觉系统的老化或疾病的恶化，大脑必须重新学习适当的权重，以在多感觉整合过程中分配每一种模式。利用人体受试者的血氧水平依赖的功能磁共振成像，我们测试了一种被称为“加权连接”的感官加权神经机制模型。该模型认为，早期和晚期区域之间的连接权重取决于通道的可靠性，而与早期感觉皮质活动的水平无关。当受试者检测到看到并感觉到对手的触摸时，大脑区域的网络是活跃的，包括枕叶外侧皮质的视觉区域，顶下叶的躯体感觉区域，以及顶内沟(IPS)的多感觉区域。与加权连接模型一致，对于躯体感觉可靠刺激，结构方程模型测量的躯体感觉皮层与IPS之间的连接权重增加；对于视觉可靠刺激，用结构方程模型测量的视觉皮层与IPS之间的连接权重增加。这种连接强度的双重分离类似于不一致多感觉刺激时的行为反应模式，表明加权连接可能是行为可靠性加权的一种神经机制。
As sensory systems deteriorate in aging or disease, the brain must relearn the appropriate weights to assign each modality during multisensory integration. Using blood-oxygen level dependent functional magnetic resonance imaging of human subjects, we tested a model for the neural mechanisms of sensory weighting, termed "weighted connections." This model holds that the connection weights between early and late areas vary depending on the reliability of the modality, independent of the level of early sensory cortex activity. When subjects detected viewed and felt touches to the hand, a network of brain areas was active, including visual areas in lateral occipital cortex, somatosensory areas in inferior parietal lobe, and multisensory areas in the intraparietal sulcus (IPS). In agreement with the weighted connection model, the connection weight measured with structural equation modeling between somatosensory cortex and IPS increased for somatosensory-reliable stimuli, and the connection weight between visual cortex and IPS increased for visual-reliable stimuli. This double dissociation of connection strengths was similar to the pattern of behavioral responses during incongruent multisensory stimulation, suggesting that weighted connections may be a neural mechanism for behavioral reliability weighting.