Department of Psychology, The University of Oklahoma Norman, OK, USA.
Front Psychol. 2011 Sep 26;2:238. doi: 10.3389/fpsyg.2011.00238. eCollection 2011.
Research has shown that visual speech perception can assist accuracy in identification of spoken words. However, little is known about the dynamics of the processing mechanisms involved in audiovisual integration. In particular, architecture and capacity, measured using response time methodologies, have not been investigated. An issue related to architecture concerns whether the auditory and visual sources of the speech signal are integrated "early" or "late." We propose that "early" integration most naturally corresponds to coactive processing whereas "late" integration corresponds to separate decisions parallel processing. We implemented the double factorial paradigm in two studies. First, we carried out a pilot study using a two-alternative forced-choice discrimination task to assess architecture, decision rule, and provide a preliminary assessment of capacity (integration efficiency). Next, Experiment 1 was designed to specifically assess audiovisual integration efficiency in an ecologically valid way by including lower auditory S/N ratios and a larger response set size. Results from the pilot study support a separate decisions parallel, late integration model. Results from both studies showed that capacity was severely limited for high auditory signal-to-noise ratios. However, Experiment 1 demonstrated that capacity improved as the auditory signal became more degraded. This evidence strongly suggests that integration efficiency is vitally affected by the S/N ratio.
研究表明，视觉言语感知可以帮助提高口语单词识别的准确性。然而，对于涉及视听整合的处理机制的动态，我们知之甚少。特别是，使用反应时间方法测量的架构和容量尚未得到研究。与架构相关的一个问题是，言语信号的听觉和视觉源是“早期”还是“晚期”整合。我们提出，“早期”整合最自然地对应于共同激活处理，而“晚期”整合对应于单独决策并行处理。我们在两项研究中实施了双因子范式。首先，我们进行了一项试点研究，使用二选一强制选择辨别任务来评估架构、决策规则，并对容量（集成效率）进行初步评估。接下来，实验 1 旨在通过包括更低的听觉信噪比和更大的响应集大小，以更具生态效度的方式专门评估视听整合效率。试点研究的结果支持单独决策并行、晚期整合模型。两项研究的结果均表明，在高听觉信噪比下，容量受到严重限制。然而，实验 1 表明，随着听觉信号的恶化，容量会提高。这一证据强烈表明，整合效率受到信噪比的极大影响。
