Fujisaki Waka, Koene Ansgar, Arnold Derek, Johnston Alan, Nishida Shin'ya
NTT Communication Science Laboratories, NTT Corporation, Atsugi, Kanagawa 243-0198, Japan.
Proc Biol Sci. 2006 Apr 7;273(1588):865-74. doi: 10.1098/rspb.2005.3327.
We examined whether the detection of audio-visual temporal synchrony is determined by a pre-attentive parallel process, or by an attentive serial process using a visual search paradigm. We found that detection of a visual target that changed in synchrony with an auditory stimulus was gradually impaired as the number of unsynchronized visual distractors increased (experiment 1), whereas synchrony discrimination of an attended target in a pre-cued location was unaffected by the presence of distractors (experiment 2). The effect of distractors cannot be ascribed to reduced target visibility nor can the increase in false alarm rates be predicted by a noisy parallel processing model. Reaction times for target detection increased linearly with number of distractors, with the slope being about twice as steep for target-absent trials as for target-present trials (experiment 3). Similar results were obtained regardless of whether the audio-visual stimulus consisted of visual flashes synchronized with amplitude-modulated pips, or of visual rotations synchronized with frequency-modulated up-down sweeps. All of the results indicate that audio-visual perceptual synchrony is judged by a serial process and are consistent with the suggestion that audio-visual temporal synchrony is detected by a 'mid-level' feature matching process.
我们使用视觉搜索范式研究了视听时间同步的检测是由前注意并行过程决定，还是由注意串行过程决定。我们发现，随着非同步视觉干扰物数量的增加，与听觉刺激同步变化的视觉目标的检测逐渐受到损害（实验1），而在预提示位置上被注意的目标的同步辨别不受干扰物存在的影响（实验2）。干扰物的影响不能归因于目标可见性的降低，并且误报率的增加也不能由噪声并行处理模型预测。目标检测的反应时间随着干扰物数量的增加而线性增加，对于无目标试验，斜率大约是有目标试验的两倍（实验3）。无论视听刺激是由与调幅短音同步的视觉闪光组成，还是由与调频上下扫频同步的视觉旋转组成，都获得了相似的结果。所有结果表明，视听感知同步是由串行过程判断的，并且与视听时间同步是通过“中级”特征匹配过程检测的这一观点一致。
