单选题 To function well in the world, people need a good sense of where their body is in space and how it's postured. This "position sense" helps us coordinate high-fives, boot a soccer ball or pick up the remote. But that doesn't seem to mean that our brains have an accurate sense of our body's precise proportions. A new study found that people tend to have rather inaccurate mental models of their own hands. When asked to estimate where the fingertips and finger joints of their hidden hands were, study volunteers were way off. But they were all incorrect in the same directions, guessing that their hands were both shorter and wider than they actually were. The findings come from a study led by Matthew Longo of the Institute of Cognitive Neuroscience at University College London. "Our results show dramatic distortions of hand shape, which were highly consistent across participants," Longo said in a prepared statement. He and his co-author, Patrick Haggard, had subjects place their left hand on a platform (using different orientations in different groups), which was then covered with a board to obscure the hand. The subjects were asked to use their free right hand point with a stick to the location of each finger joint and fingertip of their left hand. The process was filmed and compared to before and after pictures of the hand. On average, the volunteers judged their hands to be 27.9 percent shorter and 69 percent wider than they were measure to be. Underestimation of each finger length, from the thumb to the little finger, increased by about 7 percent in each finger, rendering the little finger quite a bit littler than it really was. This trend "mirrors similar grades of decreasing sensory acuteness," the authors pointed out, and the results seem to back up models of the human body constructed from the amount of sensory cortex dedicated to various body parts. In these models the hands and face are disproportionately large in comparison to most of the body. But Longo and Haggard are still not sure why the brain has such a distorted perception of our hand proportions. Longo speculated that these disproportions might occur in other parts of the body as well. "These findings may well be relevant to psychiatric conditions involving body image such as anorexia nervosa, as there may be a general bias toward perceiving the body to be wider than it is," Longo said. "Our healthy participants had a basically accurate visual image of their own body, but the brain's model of the hand underling position sense was highly distorted. This distorted perception could come to dominate in some people, leading to distortions of body image."

单选题 It can be learned from the first paragraph that _____.

单选题 In Longo's study, volunteers' estimations of hand shape _____.

单选题 According to Paragraph 3, which of the following is true of Longo's study?

单选题 According to Longo and Haggard, the reason for inaccurate sense of hand shape is _____.

单选题 Longo would most likely agree that_____.