Kaganovich Natalya, Schumaker Jennifer
Department of Speech, Language, and Hearing Sciences, Purdue University, 715 Clinic Drive, West Lafayette, IN 47907-2038, United States; Department of Psychological Sciences, Purdue University, 703 Third Street, West Lafayette, IN 47907-2038, United States.
Department of Speech, Language, and Hearing Sciences, Purdue University, 715 Clinic Drive, West Lafayette, IN 47907-2038, United States.
Neuropsychologia. 2016 Jun;86:119-30. doi: 10.1016/j.neuropsychologia.2016.04.015. Epub 2016 Apr 16.
Sensitivity to the temporal relationship between auditory and visual stimuli is key to efficient audiovisual integration. However, even adults vary greatly in their ability to detect audiovisual temporal asynchrony. What underlies this variability is currently unknown. We recorded event-related potentials (ERPs) while participants performed a simultaneity judgment task on a range of audiovisual (AV) and visual-auditory (VA) stimulus onset asynchronies (SOAs) and compared ERP responses in good and poor performers to the 200ms SOA, which showed the largest individual variability in the number of synchronous perceptions. Analysis of ERPs to the VA200 stimulus yielded no significant results. However, those individuals who were more sensitive to the AV200 SOA had significantly more positive voltage between 210 and 270ms following the sound onset. In a follow-up analysis, we showed that the mean voltage within this window predicted approximately 36% of variability in sensitivity to AV temporal asynchrony in a larger group of participants. The relationship between the ERP measure in the 210-270ms window and accuracy on the simultaneity judgment task also held for two other AV SOAs with significant individual variability -100 and 300ms. Because the identified window was time-locked to the onset of sound in the AV stimulus, we conclude that sensitivity to AV temporal asynchrony is shaped to a large extent by the efficiency in the neural encoding of sound onsets.
对听觉和视觉刺激之间时间关系的敏感性是高效视听整合的关键。然而，即使是成年人，他们检测视听时间异步的能力也存在很大差异。目前尚不清楚这种变异性的潜在原因。我们在参与者对一系列视听（AV）和视-听（VA）刺激起始异步（SOA）执行同步判断任务时记录了事件相关电位（ERP），并比较了表现好和表现差的参与者对200ms SOA的ERP反应，该SOA在同步感知数量上显示出最大的个体变异性。对VA200刺激的ERP分析没有得出显著结果。然而，那些对AV200 SOA更敏感的个体在声音开始后210至270ms之间的电压明显更正。在后续分析中，我们表明该窗口内的平均电压预测了更大一组参与者对AV时间异步敏感性变异性的约36%。在210 - 270ms窗口内的ERP测量与同步判断任务准确性之间的关系对于另外两个具有显著个体变异性的AV SOA（-100和300ms）也成立。由于识别出的窗口与AV刺激中声音的起始时间锁定，我们得出结论，对AV时间异步的敏感性在很大程度上由声音起始神经编码的效率所塑造。
