The apparent heaviness of weights placed on the skin depends on their temperature. We studied the effects of such a temperature-weight illusion (TWI) on perception and action in 21 healthy volunteers. Cold (18 °C), thermal-neutral (32 °C, skin temperature) and warm (41 °C) test objects were placed onto the palm of the non-dominant hand. Their veridical mass was 350 g (light) or 700 g (heavy). Perception of heaviness was assessed with two psychophysical experiments (magnitude estimation, cross modal matching). Cold heavy objects felt about 20% heavier than thermal-neutral objects of the same mass, shape and material. In a subsequent grip-lift experiment, the test objects were grasped with a precision grip of the dominant hand and lifted off the palm of the non-dominant hand. The grip and lift forces exerted by the fingertips were recorded. The temperature of the objects had significant effects (ANOVA, p < 0.05) on the peak grip and lift forces and on the peak grip force rate (i.e., the initial force incline). The peak grip force was about 10% higher when cold heavy objects were grasped and lifted, compared to lifts of otherwise identical thermal-neutral objects. The TWI was less pronounced when light objects or warm objects were handled. In conclusion, cooling of an object increases its apparent heaviness (perception) and influences scaling of the fingertip forces during grasping and lifting (action).

中文翻译：

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寒冷而沉重：掌握温度-重量幻觉。

放在皮肤上的砝码的表观重量取决于其温度。我们研究了这种温度-重量幻觉（TWI）对21名健康志愿者的知觉和行动的影响。将冷的（18°C），热中性的（32°C，皮肤温度）和暖的（41°C）测试对象放在非优势手的手掌上。他们的垂直质量为350克（轻）或700克（重）。通过两个心理物理实验（幅度估计，交叉模态匹配）评估沉重感。与质量，形状和材料相同的热中性物体相比，冷的重物感觉重约20％。在随后的抓举实验中，用占优势的手的精确抓握力抓住测试对象，并将其举离非占优势的手掌。记录指尖施加的抓握力和提拉力。物体的温度对峰值抓地力和升力以及峰值抓地力率（即初始力倾斜度）有显着影响（ANOVA，p <0.05）。与其他相同的热中性物体的举升相比，抓握和举起冷的重物时，峰值抓地力高约10％。处理轻物或温暖物体时，TWI不太明显。总之，物体的冷却会增加其表观重量（感知），并在抓握和提起（动作）期间影响指尖力的缩放比例。与其他相同热中性物体的举升相比。处理轻物或温暖物体时，TWI不太明显。总之，物体的冷却会增加其表观重量（感知），并在抓握和提起（动作）期间影响指尖力的缩放比例。与其他相同热中性物体的举升相比。处理轻物或温暖物体时，TWI不太明显。总之，物体的冷却会增加其表观重量（感知），并在抓握和提起（动作）期间影响指尖力的缩放比例。