Perception
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Randomized Controlled Trial
Moderate movement, more vision: effects of physical exercise on inattentional blindness.
Research on inattentional blindness shows that individuals fail to notice unexpected objects or events when attention is focused elsewhere. The majority of previous studies on inattentional blindness have been performed at rest, even though there are several real-life situations that require both physical exercise and focus of attention to accomplish a particular task. A number of different studies have demonstrated that physical exercise influences cognitive performance and attention processes in a variety of ways. ⋯ The results showed a decrease of inattentional blindness effects from the resting to the moderate exercise condition, and then an increase for the high physical exercise condition, representing an inverted-U plot. Findings support the notion that physical exercise influences individuals' attention performance. We concluded that moderate physical exercise has a positive impact on inattentional blindness, given that people under moderate physical exercise more frequently notice an unexpected object when attention is diverted to another task, and that this evidence should be taken into account when considering certain real-life events.
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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.
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Randomized Controlled Trial Clinical Trial
Classical and inverted White's effects.
In classical White's effect, intermediate-luminance targets appear lighter when they interrupt the dark stripes of a grating and darker when they interrupt the light stripes. The effect is reversed when targets are of double-increment or double-decrement luminance, relative to the luminances of grating stripes. To find a common explanation for classical and inverted effects, we ran two experiments. ⋯ This result weakens transparency-based accounts of White's effect. In experiment 2, we varied grating contrast and target luminance to measure the classical effect in seven intermediate-target cases, as well as the inverted effect in four double-increment and four double-decrement cases. Both types of effect are explained by a common model, based on assimilation to the top region and contrast with the interrupted region, weighted by adjacency along the luminance continuum.