Caffaratti Hugo, Navajas Joaquin, Rey Hernan G, Quian Quiroga Rodrigo
Centre for Systems Neuroscience, University of Leicester, Leicester, UK.
Institute of Cognitive Neuroscience, University College London, London, UK.
Psychophysiology. 2016 Sep;53(9):1441-8. doi: 10.1111/psyp.12691. Epub 2016 Jun 30.
We present results from two experiments, in which subjects watched continuous videos of a professional magician repeatedly performing a maneuver in which a ball could "magically" appear under a cup. In all cases, subjects were asked to predict whether the ball would appear under the cup or not, while scalp EEG recordings were performed. Both experiments elicited strong and consistent behavioral and neural responses. In the first experiment, we used two blocks of videos with different probabilities of the ball appearing in the cup and found that, first, based on the behavioral responses, the subjects could track this probability change; and second, the different probabilities modulated the neural responses. In the second experiment, we introduced a control condition in which the magician performed the maneuver under the table, out of subjects' view. Comparing the two conditions (i.e., performing the maneuver within or out of the subjects' view), we found that, first, the magic trick dramatically biased the subjects' behavioral responses; and second, the two conditions led to differential neural responses, in spite of the fact that the stimulus triggering the evoked responses (seeing the ball in the cup) was exactly the same. Altogether, our results show how new insights into sensory and cognitive processing can be obtained using adapted magic tricks. Moreover, the approach of analyzing responses to continuous video presentations offers a more ecological setting compared to classic evoked potential paradigms, which are typically based on presenting static images flashed at the center of the screen.
我们展示了两项实验的结果。在实验中，受试者观看一名职业魔术师反复表演一个动作的连续视频，在这个动作中，一个球能“神奇地”出现在杯子下面。在所有情况下，受试者被要求预测球是否会出现在杯子下面，同时进行头皮脑电图记录。两项实验都引发了强烈且一致的行为和神经反应。在第一个实验中，我们使用了两个视频块，球出现在杯子里的概率不同，结果发现，首先，基于行为反应，受试者能够追踪这种概率变化；其次，不同的概率调节了神经反应。在第二个实验中，我们引入了一个对照条件，即魔术师在桌子下面进行这个动作，受试者看不到。比较这两种情况（即在受试者视线内或视线外进行动作），我们发现，首先，魔术极大地影响了受试者的行为反应；其次，尽管引发诱发反应的刺激（看到球在杯子里）完全相同，但这两种情况导致了不同的神经反应。总之，我们的结果表明，如何通过改编魔术来获得对感觉和认知加工的新见解。此外，与典型基于在屏幕中心闪现静态图像的经典诱发电位范式相比，分析对连续视频呈现的反应的方法提供了一个更贴近实际的环境。
