Perception
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Randomized Controlled Trial
"Which feels heavier--a pound of lead or a pound of feathers?" A potential perceptual basis of a cognitive riddle.
"Which weighs more--a pound of lead or a pound of feathers?" The seemingly naive answer to the familiar riddle is the pound of lead. The correct answer, of course, is that they weigh the same amount. ⋯ When blindfolded participants hefted a pound of lead and a pound of feathers each contained in boxes of identical size, shape, and mass, they reported that the box containing the pound of lead felt heavier at a level above chance. Like the size-weight illusion, the naive answer to the riddle may reflect differences in how easily the objects can be controlled by muscular forces and not a perceptual or cognitive error.
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Randomized Controlled Trial
Remembering object position in the absence of vision: egocentric, allocentric, and egocentric decentred frames of reference.
In three experiments we examined whether memory for object locations in the peri-personal space in the absence of vision is affected by the correspondence between encoding and test either of the body position or of the reference point. In particular, the study focuses on the distinction between different spatial representations, by using a paradigm in which participants are asked to relocate objects explored haptically. Three frames of reference were systematically compared. ⋯ Here, the allocentric condition was found to be more difficult than the decentred egocentric condition. Taken together, the results suggest that also in the peripersonal space and in the absence of vision different frames of reference can be distinguished. In particular, the decentred egocentric condition involves a frame of reference which seems to be neither allocentric nor totally egocentric.