Naylor Caitlin Elisabeth, Power T J, Buckingham Gavin
Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, Exeter, UK.
J Cogn. 2020 Jan 31;3(1):3. doi: 10.5334/joc.93.
It is well established that manipulations of low-level stimulus properties unrelated to mass can impact perception of heaviness, the most famous example being the size-weight illusion whereby small objects feel heavier than equally-weighted larger objects. Interestingly, manipulations of high-level cues such as material have also induced weight illusions, highlighting that cognitive expectations alone are enough to create illusory weight differences. Less is known, however, about what type of cognitive expectations can influence perception of heaviness. As labels are often used to signify the heaviness of objects, this study examined whether semantic cues could induce a novel weight illusion. Participants lifted equally-sized and equally-weighted sets of objects labelled as 'light' and 'heavy' and reported their perceived heaviness both prior to and after lifting. Fingertip forces were also measured to understand how semantic cues may influence sensorimotor prediction. The labels clearly affected pre-lift-off expectations of heaviness. By contrast, we found no effect of these labels on the perceived heaviness of objects, nor on the forces used to grip and lift them on early trials. In other words, we find no evidence that semantic cues affect perception or action enough to induce a novel weight illusion. These findings suggest that the explicit expectations created by the labels did not dominate the implicit expectations created by the equal sizes of the objects, highlighting the segregated nature of cognitive expectations and their variable influences on perception and action.
众所周知，对与质量无关的低水平刺激属性进行操控会影响对重量的感知，最著名的例子是大小-重量错觉，即小物体比同等重量的大物体感觉更重。有趣的是，对诸如材质等高水平线索的操控也会引发重量错觉，这突出表明仅认知预期就足以产生虚幻的重量差异。然而，对于何种类型的认知预期会影响对重量的感知，人们了解得较少。由于标签常被用于表示物体的重量，本研究考察了语义线索是否会引发一种新的重量错觉。参与者拿起标有“轻”和“重”的同样大小、同样重量的物体组，并在拿起之前和之后报告他们感知到的重量。还测量了指尖力量，以了解语义线索可能如何影响感觉运动预测。这些标签明显影响了拿起前对重量的预期。相比之下，我们发现这些标签对物体的感知重量没有影响，对早期试验中用于握持和拿起物体的力量也没有影响。换句话说，我们没有发现证据表明语义线索对感知或行动的影响足以引发一种新的重量错觉。这些发现表明，标签所产生的明确预期并没有主导由物体相同大小所产生的隐性预期，突出了认知预期的分离性质及其对感知和行动的可变影响。
