Vetter Petra, Grosbras Marie-Helene, Muckli Lars
Centre for Cognitive Neuroimaging, Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QB, UK Current address: Department of Neuroscience, Laboratory for Behavioral Neurology and Imaging of Cognition, Medical School and Swiss Center for Affective Sciences, University of Geneva, Geneva 1205, Switzerland.
Centre for Cognitive Neuroimaging, Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QB, UK.
Cereb Cortex. 2015 Apr;25(4):1052-9. doi: 10.1093/cercor/bht297. Epub 2013 Oct 23.
Given the vast amount of sensory information the brain has to deal with, predicting some of this information based on the current context is a resource-efficient strategy. The framework of predictive coding states that higher-level brain areas generate a predictive model to be communicated via feedback connections to early sensory areas. Here, we directly tested the necessity of a higher-level visual area, V5, in this predictive processing in the context of an apparent motion paradigm. We flashed targets on the apparent motion trace in-time or out-of-time with the predicted illusory motion token. As in previous studies, we found that predictable in-time targets were better detected than unpredictable out-of-time targets. However, when we applied functional magnetic resonance imaging-guided, double-pulse transcranial magnetic stimulation (TMS) over left V5 at 13-53 ms before target onset, the detection advantage of in-time targets was eliminated; this was not the case when TMS was applied over the vertex. Our results are causal evidence that V5 is necessary for a prediction effect, which has been shown to modulate V1 activity (Alink et al. 2010). Thus, our findings suggest that information processing between V5 and V1 is crucial for visual motion prediction, providing experimental support for the predictive coding framework.
鉴于大脑必须处理大量的感官信息,基于当前情境预测其中一些信息是一种资源高效的策略。预测编码框架表明,大脑的高级区域会生成一个预测模型,并通过反馈连接传递到早期感官区域。在此,我们在视错觉运动范式的背景下,直接测试了高级视觉区域V5在这种预测处理中的必要性。我们在预测的错觉运动标记的时间或非时间点,在视错觉运动轨迹上闪现目标。与之前的研究一样,我们发现可预测的及时目标比不可预测的非及时目标更容易被检测到。然而,当我们在目标出现前13 - 53毫秒对左侧V5区域施加功能磁共振成像引导的双脉冲经颅磁刺激(TMS)时,及时目标的检测优势消失了;而在头顶施加TMS时则没有这种情况。我们的结果是因果证据,表明V5对于预测效应是必要的,这已被证明可调节V1的活动(阿林克等人,2010年)。因此,我们的研究结果表明,V5和V1之间的信息处理对于视觉运动预测至关重要,为预测编码框架提供了实验支持。