Ikumi Nara, Soto-Faraco Salvador
Multisensory Research Group, Center for Brain and Cognition, Universitat Pompeu Fabra Barcelona, Spain.
Multisensory Research Group, Center for Brain and Cognition, Universitat Pompeu FabraBarcelona, Spain; Institució Catalana de Recerca i Estudis AvançatsBarcelona, Spain.
Front Integr Neurosci. 2017 Jan 19;10:44. doi: 10.3389/fnint.2016.00044. eCollection 2016.
Perception in multi-sensory environments involves both grouping and segregation of events across sensory modalities. Temporal coincidence between events is considered a strong cue to resolve multisensory perception. However, differences in physical transmission and neural processing times amongst modalities complicate this picture. This is illustrated by cross-modal recalibration, whereby adaptation to audio-visual asynchrony produces shifts in perceived simultaneity. Here, we examined whether voluntary actions might serve as a temporal anchor to cross-modal recalibration in time. Participants were tested on an audio-visual simultaneity judgment task after an adaptation phase where they had to synchronize voluntary actions with audio-visual pairs presented at a fixed asynchrony (vision leading or vision lagging). Our analysis focused on the magnitude of cross-modal recalibration to the adapted audio-visual asynchrony as a function of the nature of the actions during adaptation, putatively fostering cross-modal grouping or, segregation. We found larger temporal adjustments when actions promoted grouping than segregation of sensory events. However, a control experiment suggested that additional factors, such as attention to planning/execution of actions, could have an impact on recalibration effects. Contrary to the view that cross-modal temporal organization is mainly driven by external factors related to the stimulus or environment, our findings add supporting evidence for the idea that perceptual adjustments strongly depend on the observer's inner states induced by motor and cognitive demands.
在多感官环境中的感知涉及跨感官模态对事件的分组和分离。事件之间的时间一致性被认为是解决多感官感知的一个重要线索。然而，各模态之间物理传输和神经处理时间的差异使情况变得复杂。跨模态重新校准就说明了这一点，即对视听异步的适应会导致感知同步性的变化。在这里，我们研究了自愿行动是否可以作为跨模态重新校准时间的时间锚点。在适应阶段后，参与者接受了一项视听同步判断任务的测试，在该阶段他们必须将自愿行动与以固定异步呈现的视听对同步（视觉超前或视觉滞后）。我们的分析重点关注跨模态重新校准对适应的视听异步的幅度，作为适应期间行动性质的函数，假定这会促进跨模态分组或分离。我们发现，当行动促进分组而非分离时，时间调整更大。然而，一项对照实验表明，其他因素，如对行动规划/执行的关注，可能会对重新校准效果产生影响。与跨模态时间组织主要由与刺激或环境相关的外部因素驱动的观点相反，我们的研究结果为感知调整强烈依赖于由运动和认知需求引起的观察者内部状态这一观点提供了支持证据。
