Buckingham Gavin, MacDonald Aimee
a Department of Psychology , School of Life Sciences, Heriot-Watt University , Edinburgh , UK.
Q J Exp Psychol (Hove). 2016;69(9):1831-41. doi: 10.1080/17470218.2015.1100642. Epub 2015 Dec 11.
In the size-weight illusion, small objects feel heavier than identically weighted larger objects. This illusion is thought to be a consequence of how one's prior expectations can influence conscious perception--lifters expect the large object to outweigh the small object and subsequently experience it as feeling lighter than they expected it to be. Here, we directly examined how a familiar object's identity can affect how heavy someone expects it to be, and how these expectations will influence subsequent perceptions of heaviness. We describe two novel weight illusions induced with familiar objects. In one condition, participants judged the weight of a set of similar-size objects with very different natural weights (a polystyrene sphere, a tennis ball, and a cricket ball), which had all been adjusted to weigh the same amount as one another. In this condition, participants experienced a small, but reliable, weight illusion, with the lightest looking ball feeling heavier than the heaviest looking ball. In the other condition, participants judged the weights of a different set of balls, which were different sizes, but similar natural weights, to one another (a golf ball, a foam soccer ball, and an inflated beach ball). Again, participants experienced a perceptual illusion, but in the opposite direction. Surprisingly, participant's perceptions matched, rather than contrasted with, their explicit expectations such that, even though they expected the golf ball to outweigh the beach ball they perceived the golf ball as feeling heavier than the beach ball. The effect of object mass appeared to dominate the effect of conscious expectations, suggesting that contrasting expectations of heaviness are not necessary to experience weight illusions and that current models of this robust perceptual effect must be revised.
在大小-重量错觉中，小物体比重量相同的大物体感觉更重。这种错觉被认为是一个人先前的期望如何影响有意识感知的结果——举重者期望大物体比小物体重，因此随后感觉它比预期的要轻。在这里，我们直接研究了熟悉物体的身份如何影响人们对其重量的预期，以及这些预期将如何影响随后对重量的感知。我们描述了两种由熟悉物体引起的新型重量错觉。在一种情况下，参与者判断一组大小相似但自然重量非常不同的物体（一个聚苯乙烯球、一个网球和一个板球）的重量，这些物体都被调整为彼此重量相同。在这种情况下，参与者体验到了一种微小但可靠的重量错觉，看起来最轻的球感觉比看起来最重的球更重。在另一种情况下，参与者判断另一组球的重量，这些球大小不同，但彼此自然重量相似（一个高尔夫球、一个泡沫足球和一个充气沙滩球）。同样，参与者也体验到了一种感知错觉，但方向相反。令人惊讶的是，参与者的感知与他们的明确预期相符，而不是形成对比，以至于即使他们预期高尔夫球比沙滩球重，但他们却感觉高尔夫球比沙滩球更重。物体质量的影响似乎主导了有意识预期的影响，这表明体验重量错觉并不一定需要对重量有对比性的预期，并且必须修订这种强烈感知效应的当前模型。
