Schneider Keith A
University of Rochester, Rochester, New York, USA.
Percept Psychophys. 2006 Jul;68(5):800-14. doi: 10.3758/bf03193703.
Abrupt onsets in the visual field can change the appearance of subsequent stimuli, according to one interpretation, by engaging an attentional mechanism that increases effective stimulus contrast. However, abrupt onsets can also engage capacity-unlimited and thus attention-independent sensory mechanisms. We conducted a series of experiments to differentiate the sensory and attentional accounts. Observers compared the contrasts of uncued low-contrast peripheral targets with simultaneous targets cued by one of three cue types with different sensory attributes: white or black peripheral abrupt onsets and central gaze direction cues devoid of sensory activity near the target locations. Each cue facilitated the perception of perithreshold targets; however, the white abrupt onsets increased the perceived contrast of suprathreshold targets, whereas the black abrupt onsets tended to reduce the perceived contrast, and the gaze direction cues had no significant effect. The effectiveness of the gaze direction cues in automatically orienting attention was demonstrated in a control experiment in which they consistently speeded response times. The results suggest that sensory interaction, and not attention, is responsible for changes in appearance.
根据一种解释，视野中的突然出现会改变后续刺激的外观，这是通过激活一种增加有效刺激对比度的注意机制来实现的。然而，突然出现也可以激活容量无限且因此与注意无关的感觉机制。我们进行了一系列实验来区分感觉和注意的解释。观察者将未提示的低对比度周边目标的对比度与由三种具有不同感觉属性的提示类型之一提示的同时出现的目标的对比度进行比较：白色或黑色周边突然出现以及在目标位置附近没有感觉活动的中央注视方向提示。每种提示都促进了阈下目标的感知；然而，白色突然出现增加了阈上目标的感知对比度，而黑色突然出现则倾向于降低感知对比度，并且注视方向提示没有显著影响。在一个对照实验中证明了注视方向提示在自动引导注意方面的有效性，在该实验中它们持续加快了反应时间。结果表明，外观变化是由感觉相互作用而非注意引起的。
