Institute of Biological Psychology, Otto-von-Guericke University, 39120 Magdeburg, Germany.
Neuroimage. 2013 Jan 15;65:13-22. doi: 10.1016/j.neuroimage.2012.09.056. Epub 2012 Sep 29.
Approaching or looming signals are often related to extremely relevant environmental events (e.g. threats or collisions) making these signals critical for survival. However, the neural network underlying multisensory looming processing is not yet fully understood. Using functional magnetic resonance imaging (fMRI) we identified the neural correlates of audiovisual looming processing in humans: audiovisual looming (vs. receding) signals enhance fMRI-responses in low-level visual and auditory areas plus multisensory cortex (superior temporal sulcus; plus parietal and frontal structures). When characterizing the fMRI-response profiles for multisensory looming stimuli, we found significant enhancements relative to the mean and maximum of unisensory responses in looming-sensitive visual and auditory cortex plus STS. Superadditive enhancements were observed in visual cortex. Subject-specific region-of-interest analyses further revealed superadditive response profiles within all sensory-specific looming-sensitive structures plus bilateral STS for audiovisual looming vs. summed unisensory looming conditions. Finally, we observed enhanced connectivity of bilateral STS with low-level visual areas in the context of looming processing. This enhanced coupling of STS with unisensory regions might potentially serve to enhance the salience of unisensory stimulus features and is accompanied by superadditive fMRI-responses. We suggest that this preference in neural signaling for looming stimuli effectively informs animals to avoid potential threats or collisions.
逼近或逼近的信号通常与极其相关的环境事件（例如威胁或碰撞）有关，这使得这些信号对生存至关重要。然而，多感觉逼近处理的神经网络基础尚不完全清楚。使用功能磁共振成像（fMRI），我们确定了人类视听逼近处理的神经相关性：视听逼近（与后退）信号增强了低水平视觉和听觉区域以及多感觉皮层（颞上沟；加上顶叶和额叶结构）的 fMRI 反应。在对多感觉逼近刺激的 fMRI 反应特征进行描述时，我们发现与视觉和听觉皮层中敏感的单感觉反应的平均值和最大值相比，多感觉敏感的视觉和听觉皮层以及 STS 中存在显着增强。在视觉皮层中观察到超加性增强。基于受试者的感兴趣区域分析进一步显示，在视听逼近与总和单感觉逼近条件下，所有感觉特定的逼近敏感结构以及双侧 STS 内均存在超加性反应谱。最后，我们观察到在逼近处理过程中，双侧 STS 与低水平视觉区域的连接增强。STS 与单感觉区域的这种增强耦合可能有助于增强单感觉刺激特征的显着性，并伴随着 fMRI 反应的超加性。我们认为，这种对逼近刺激的神经信号的偏好有效地告知动物要避免潜在的威胁或碰撞。
