Department of Psychology, University of Wisconsin-Madison, Madison, 53703, USA.
Leiden Centre for Research in Linguistics and the Leiden Centre for Brain and Cognition, Leiden University, Leiden, 2300 RC, The Netherlands.
Sci Rep. 2018 Apr 26;8(1):6606. doi: 10.1038/s41598-018-25093-5.
Perceptual experience results from a complex interplay of bottom-up input and prior knowledge about the world, yet the extent to which knowledge affects perception, the neural mechanisms underlying these effects, and the stages of processing at which these two sources of information converge, are still unclear. In several experiments we show that language, in the form of verbal labels, both aids recognition of ambiguous "Mooney" images and improves objective visual discrimination performance in a match/non-match task. We then used electroencephalography (EEG) to better understand the mechanisms of this effect. The improved discrimination of images previously labeled was accompanied by a larger occipital-parietal P1 evoked response to the meaningful versus meaningless target stimuli. Time-frequency analysis of the interval between the cue and the target stimulus revealed increases in the power of posterior alpha-band (8-14 Hz) oscillations when the meaning of the stimuli to be compared was trained. The magnitude of the pre-target alpha difference and the P1 amplitude difference were positively correlated across individuals. These results suggest that prior knowledge prepares the brain for upcoming perception via the modulation of alpha-band oscillations, and that this preparatory state influences early (~120 ms) stages of visual processing.
知觉体验是由自下而上的输入和对世界的先验知识的复杂相互作用产生的，但知识对感知的影响程度、这些影响的神经机制以及这两个信息源在处理过程中的融合阶段仍不清楚。在几项实验中，我们表明，语言（以口头标签的形式）既有助于识别模棱两可的“Mooney”图像，也有助于提高匹配/不匹配任务中的客观视觉辨别性能。然后，我们使用脑电图（EEG）来更好地理解这种效应的机制。对先前标记的图像的辨别能力提高伴随着对有意义与无意义目标刺激的枕顶叶 P1 诱发反应增大。在比较刺激的意义被训练时，对目标刺激的间隔的时频分析显示出后alpha 波段（8-14 Hz）振荡的功率增加。在个体之间，前目标 alpha 差异和 P1 振幅差异呈正相关。这些结果表明，先验知识通过调节 alpha 波段振荡为即将到来的感知做准备，并且这种预备状态影响早期（约 120 毫秒）的视觉处理阶段。
