Muckli Lars, Kohler Axel, Kriegeskorte Nikolaus, Singer Wolf
Department of Neurophysiology, Max Planck Institute for Brain Research, Frankfurt am Main, Germany.
PLoS Biol. 2005 Aug;3(8):e265. doi: 10.1371/journal.pbio.0030265. Epub 2005 Jul 19.
The illusion of apparent motion can be induced when visual stimuli are successively presented at different locations. It has been shown in previous studies that motion-sensitive regions in extrastriate cortex are relevant for the processing of apparent motion, but it is unclear whether primary visual cortex (V1) is also involved in the representation of the illusory motion path. We investigated, in human subjects, apparent-motion-related activity in patches of V1 representing locations along the path of illusory stimulus motion using functional magnetic resonance imaging. Here we show that apparent motion caused a blood-oxygenation-level-dependent response along the V1 representations of the apparent-motion path, including regions that were not directly activated by the apparent-motion-inducing stimuli. This response was unaltered when participants had to perform an attention-demanding task that diverted their attention away from the stimulus. With a bistable motion quartet, we confirmed that the activity was related to the conscious perception of movement. Our data suggest that V1 is part of the network that represents the illusory path of apparent motion. The activation in V1 can be explained either by lateral interactions within V1 or by feedback mechanisms from higher visual areas, especially the motion-sensitive human MT/V5 complex.
当视觉刺激在不同位置相继呈现时，可诱发似动错觉。先前的研究表明，纹外皮层中的运动敏感区域与似动的处理有关，但尚不清楚初级视觉皮层（V1）是否也参与虚幻运动路径的表征。我们利用功能磁共振成像，在人类受试者中研究了V1中代表虚幻刺激运动路径上各位置的区域内与似动相关的活动。在这里，我们表明，似动沿着虚幻运动路径的V1表征引发了血氧水平依赖反应，包括那些未被似动诱发刺激直接激活的区域。当参与者必须执行一项需要注意力的任务，从而将他们的注意力从刺激上转移开时，这种反应并未改变。利用一个双稳态运动四重奏，我们证实该活动与运动的有意识感知有关。我们的数据表明，V1是代表似动虚幻路径的网络的一部分。V1中的激活可以通过V1内的侧向相互作用或来自更高视觉区域，特别是运动敏感的人类MT/V5复合体的反馈机制来解释。
