Department of Psychology, Macquarie University, Sydney, Australia.
ARC Centre of Excellence in Cognition and its Disorders, Macquarie University, Sydney, Australia.
Sci Rep. 2017 Jan 10;7:40392. doi: 10.1038/srep40392.
Although research addressing body size misperception has focused on socio-cognitive processes, such as internalization of the "ideal" images of bodies in the media, the perceptual basis of this phenomenon remains largely unknown. Further, most studies focus on body size per se even though this depends on both fat and muscle mass - variables that have very different relationships with health. We tested visual adaptation as a mechanism for inducing body fat and muscle mass misperception, and assessed whether these two dimensions of body space are processed independently. Observers manipulated the apparent fat and muscle mass of bodies to make them appear "normal" before and after inspecting images from one of four adaptation conditions (increased fat/decreased fat/increased muscle/decreased muscle). Exposure resulted in a shift in the point of subjective normality in the direction of the adapting images along the relevant (fat or muscle) axis, suggesting that the neural mechanisms involved in body fat and muscle perception are independent. This supports the viability of adaptation as a model of real-world body size misperception, and extends its applicability to clinical manifestations of body image disturbance that entail not only preoccupation with thinness (e.g., anorexia nervosa) but also with muscularity (e.g., muscle dysmorphia).
尽管研究已经关注了身体大小感知的社会认知过程，例如内化媒体中“理想”身体形象，但这一现象的感知基础在很大程度上仍未可知。此外，尽管身体大小取决于脂肪和肌肉量，但大多数研究都集中在身体大小本身，而这两个变量与健康的关系非常不同。我们测试了视觉适应作为诱导身体脂肪和肌肉质量感知错误的机制，并评估了这两个身体空间维度是否独立处理。在检查了来自四个适应条件（增加脂肪/减少脂肪/增加肌肉/减少肌肉）之一的图像之前和之后，观察者操纵了身体的表观脂肪和肌肉量，以使它们看起来“正常”。暴露导致主观正常点沿着相关（脂肪或肌肉）轴向适应图像的方向移动，这表明涉及身体脂肪和肌肉感知的神经机制是独立的。这支持了适应作为真实世界身体大小感知错误模型的可行性，并将其适用性扩展到涉及不仅对消瘦（例如神经性厌食症）而且对肌肉发达（例如肌肉变形症）的身体形象障碍的临床表现。
