Read about new research on visual and olfactory perception from Psychological Science.
Jonas K. Olofsson, Nicholas E. Bowman, Katherine Khatibi, and Jay A. Gottfried
There is some debate over how we perceive odor. Object-centered accounts of odor perception suggest that an odor is identified before its valence is determined, whereas valance-centered accounts suggest the opposite. Participants were presented with several categories of odors (floral, fishy, minty, and fuel). They were asked to smell two fragrances and tell if the second fragrance was in the same category as the first (object evaluation) or whether the second smell was more pleasant than the first (valence category). Object evaluations were completed faster and more accurately than valence evaluations. Additionally, object evaluations significantly predicted valence evaluations of the odors. These results support the object-centered account of odor perception.
Basic Characteristics of Simultaneous Color Contrast Revisited
Vebjørn Ekroll and Franz Faul
Classical laws of simultaneous contrast indicate that the gamut expansion effect and the crispening effect are fundamentally different from one another. Participants were shown a target disk in a purple surround and a target disk in a grey surround and were instructed to adjust the color of the target disk in the purple surround until it matched the target disk in the grey surround. In some conditions, a thin black ring separated the target disk from the surround. Results in the no-ring condition exhibited strong nonlinearity, whereas results in the ring condition were approximately linear. These findings suggest that simultaneous color contrast, the crispening effect, and the gamut expansion effect may be different terms for the same basic phenomenon.
Tobias Borra, Ignace T. C. Hooge, and Frans A. J. Verstraten
Does the visual system use the same strategy to determine the orientation of real and subjective objects? Participants were shown a Kanizsa square — an illusory, subjective square, the sides of which are not defined by luminance contrast — or a real square. The square was then shown at a different angle, and participants were instructed to indicate whether the square had rotated clockwise or counter-clockwise. Participants’ orientation discrimination threshold values for the Kanizsa squares were identical to those for real squares, suggesting that the visual system determines object orientation on the basis of features of perceptually completed objects and not what is projected onto the retina.