Vidal Manuel, Barrès Victor
Laboratoire de Physiologie de la Perception et de l'Action, UMR7152 Collège de France, CNRS Paris, France ; Institut de Neurosciences de la Timone, UMR7289 Aix-Marseille Université, CNRS Marseille, France.
Laboratoire de Physiologie de la Perception et de l'Action, UMR7152 Collège de France, CNRS Paris, France.
Front Hum Neurosci. 2014 Sep 4;8:677. doi: 10.3389/fnhum.2014.00677. eCollection 2014.
In binocular rivalry (BR), sensory input remains the same yet subjective experience fluctuates irremediably between two mutually exclusive representations. We investigated the perceptual stabilization effect of an additional sound on the BR dynamics using speech stimuli known to involve robust audiovisual (AV) interactions at several cortical levels. Subjects sensitive to the McGurk effect were presented looping videos of rivaling faces uttering /aba/ and /aga/, respectively, while synchronously hearing the voice /aba/. They reported continuously the dominant percept, either observing passively or trying actively to promote one of the faces. The few studies that investigated the influence of information from an external modality on perceptual competition reported results that seem at first sight inconsistent. Since these differences could stem from how well the modalities matched, we addressed this by comparing two levels of AV congruence: real (/aba/ viseme) vs. illusory (/aga/ viseme producing the /ada/ McGurk fusion). First, adding the voice /aba/ stabilized both real and illusory congruent lips percept. Second, real congruence of the added voice improved volitional control whereas illusory congruence did not, suggesting a graded contribution to the top-down sensitivity control of selective attention. In conclusion, a congruent sound enhanced considerably attentional control over the perceptual outcome selection; however, differences between passive stabilization and active control according to AV congruency suggest these are governed by two distinct mechanisms. Based on existing theoretical models of BR, selective attention and AV interaction in speech perception, we provide a general interpretation of our findings.
在双眼竞争（BR）中，感觉输入保持不变，但主观体验在两种相互排斥的表征之间不可避免地波动。我们使用已知在多个皮层水平涉及强大视听（AV）相互作用的语音刺激，研究了额外声音对BR动态的感知稳定作用。对麦格克效应敏感的受试者观看分别说出/aba/和/aga/的竞争面孔的循环视频，同时同步听到/aba/的声音。他们持续报告占主导地位的感知，要么被动观察，要么积极尝试促进其中一张面孔的感知。少数研究外部模态信息对感知竞争影响的报告结果乍一看似乎不一致。由于这些差异可能源于模态匹配的程度，我们通过比较两种视听一致性水平来解决这个问题：真实（/aba/视位）与虚幻（/aga/视位产生/ada/麦格克融合）。首先，添加/aba/的声音稳定了真实和虚幻一致的嘴唇感知。其次，添加声音的真实一致性改善了意志控制，而虚幻一致性则没有，这表明对选择性注意的自上而下的敏感性控制有分级贡献。总之，一致的声音显著增强了对感知结果选择的注意力控制；然而，根据视听一致性，被动稳定和主动控制之间的差异表明它们受两种不同机制的支配。基于现有的BR理论模型、语音感知中的选择性注意和视听相互作用，我们对我们的发现提供了一个一般性解释。
