Center for Mind/Brain Sciences (CIMeC), University of Trento, Trento, Italy.
Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands.
Sci Rep. 2021 Jan 13;11(1):942. doi: 10.1038/s41598-020-79957-w.
The world around us appears stable and continuous despite saccadic eye movements. This apparent visual stability is achieved by trans-saccadic perception leading at the behavioural level to preview effects: performance in processing a foveal stimulus is better if the stimulus remained unchanged (valid) compared to when it changed (invalid) during the saccade that brought it into focus. Trans-saccadic perception is known to predictively adapt to the statistics of the environment. Here, we asked whether the behavioural preview effect shows the same characteristics, employing a between-participants training design. Participants made saccades to faces which could change their orientation (upright/inverted) during the saccade. In addition, the post-saccadic face was slightly tilted and participants reported this tilt upon fixation. In a training phase, one group of participants conducted only invalid trials whereas another group conducted only valid trials. In a subsequent test phase with 50% valid and 50% invalid trials, we measured the preview effect. Invalid training reduced the preview effect. With a mixed-model analysis, we could show how this training effect gradually declines in the course of the test phase. These results show that the behavioural preview effect adapts to the statistics of the environment suggesting that it results from predictive processes.
尽管我们的眼睛会快速跳动，但我们周围的世界在我们眼中似乎是稳定且连续的。这种明显的视觉稳定性是通过眼跳后的感知实现的，这导致了行为层面的预视效应：如果在注视时刺激保持不变（有效），那么处理中央凹刺激的表现会更好，而如果在注视时刺激发生了变化（无效）。眼跳后的感知被认为可以对环境的统计数据进行预测性适应。在这里，我们通过参与者间的训练设计来询问行为预视效应是否具有相同的特征。参与者会注视面孔，这些面孔在眼跳过程中可能会改变朝向（直立/倒置）。此外，在眼跳后，面孔会略微倾斜，参与者在注视时报告这个倾斜度。在训练阶段，一组参与者只进行无效试验，而另一组参与者只进行有效试验。在随后的 50%有效和 50%无效试验的测试阶段，我们测量了预视效应。无效训练降低了预视效应。通过混合模型分析，我们可以显示这种训练效应如何在测试阶段逐渐下降。这些结果表明，行为预视效应适应了环境的统计数据，这表明它是由预测性过程产生的。
