Walking reduces the gap between encoding and sensorimotor alignment effects in spatial updating of described environments

Spatial updating allows people to keep track of the self-to-object relations during movement. Previous studies demonstrated that physical movement enhanced spatial updating in remote environments, but failed to find the same effect in described environments. However, these studies mainly considered rotation as a physical movement, without examining other types of movement, such as walking. We investigated how walking affects spatial updating within described environments. Using the judgement of relative directions task, we compared the effects of imagination of rotation, physical rotation, and walking on spatial updating. Spatial updating was evaluated in terms of accuracy and response times in different perspectives, and by calculating two indexes, namely the encoding and sensorimotor alignment effects. As regards response times, we found that in the imagination of rotation and physical rotation conditions the encoding alignment effect was higher than the sensorimotor alignment effect, while in the walking condition this gap disappeared. We interpreted these results in terms of an enhanced link between allocentric and sensorimotor representations, due to the information acquired through walking.     

Measuring the meter: on the constancy of lightness scales seen against different backgrounds

The constancy of a 16-step achromatic Munsell scale was tested with regards to background variations in two experiments. In experiment 1 three groups of observers were asked to find lightness matches for targets in simultaneous lightness displays by using a 16-step achromatic Munsell scale placed on a white, black, or white-black checkered background. In experiment 2, a yellow-blue checkered background and a green-red checkered background replaced Munsell scales on the black and on the white backgrounds. Significant effects of scale background on matches were found only in experiment 1, suggesting that background luminance is a crucial factor in the overall appearance of the scale. The lack of significant differences in experiment 2, however, may stand for an overall robustness of the scale with respect to background luminance changes occurring within certain luminance ranges.     

Magnitude and Order are Both Relevant in SNARC and SNARC-like Effects: A Commentary on Casasanto and Pitt (2019)

In a recent paper by Casasanto and Pitt (2019), the authors addressed a debate regarding the role of order and magnitude in SNARC and SNARC-like effects. Their position is that all these effects can be explained by order, while magnitude could only account for a subset of evidence. Although we agree that order can probably explain the majority of these effects, in this commentary we argue that magnitude is still relevant, since there is evidence that cannot be explained based on ordinality alone. We argue that SNARC-like effects can occur for magnitudes not clearly characterized by overlearned ordinality and that magnitude can prevail on order, when the two are pitted against each other. Finally, we propose that different interpretations of the role of order and magnitude depend on the interaction of stimulus properties and task demands.     

A new effect of luminance gradient on achromatic simultaneous contrast

A new effect in the domain of achromatic simultaneous contrast has been observed. A middle gray region placed at the center of an area filled by a linear achromatic gradient from black (outer part) to white (inner part) is perceived as being much darker than an identical middle gray region surrounded by a reversed gradient. By using a matching task in two experiments, it has been shown that this phenomenon is much stronger than the classical achromatic simultaneous contrast effect. The new effect is interpreted in terms of thealbedo hypothesis.     

Perceptual organization overcomes the effects of local surround in determining simultaneous lightness contrast

Lightness induction can occur on the basis of the immediate surround of a region (local interactions) and also on the basis of global factors of perceptual organization. The experiments reported in this article used novel displays that made it possible to differentiate the contributions of these two kinds of factors. The experiments demonstrated, for the first time, that when higher-level factors act contemporaneously with lower-level factors, the contrast effect induced by the global-organization principle of perceptual belongingness overcomes the effect due to retinal lateral inhibition.     

Intuitionistic Non-normal Modal Logics: A General Framework

Journal of Philosophical Logic - We define a family of intuitionistic non-normal modal logics; they can be seen as intuitionistic counterparts of classical ones. We first consider monomodal logics,...     

Measuring Adolescents’ Affective Civic Competence: Validity and Cross-Group Equivalence of a Second-Order Hierarchical Latent Construct

Applied Research in Quality of Life - In the last few decades, educational literature and policy makers have increasingly supported research into affective competencies—attitudes, emotions,...     

Testing the validity of the paddle method for the kinesthetic and visual-kinesthetic perception of inclination

We tested the validity of the paddle method for measuring both the kinesthetic and visual-kinesthetic perception of inclination. In three conditions, subjects performed three different tasks: (1) rotating a manual paddle to a set of verbally given inclinations (blindfolded subjects), (2) rotating a manual paddle to the same set of verbally given inclinations after specific kinesthetic training (blindfolded subjects), and (3) rotating the paddle to a set of fixed visual inclinations after the kinesthetic training. The results showed a high degree of accuracy and precision in the second and third task but not in the first one. When subjects were asked to rotate a manual paddle to a set of verbally given inclinations, they used three main anchors (0°, 45°, 90°). Furthermore, the paddle method is biased by a kinesthetic deficiency, namely a rotational problem of the wrist that can be corrected by means of specific training.     

Impossible shadows and lightness constancy

The intersection between an illumination and a reflectance edge is characterised by the 'ratio-invariant' property, that is the luminance ratio of the regions under different illumination remains the same. In a CRT experiment, we shaped two areas, one surrounding the other, and simulated an illumination edge dividing them in two frames of illumination. The portion of the illumination edge standing on the surrounding area (labelled contextual background) was the contextual edge, while the portion standing on the enclosed area (labelled mediating background) was the mediating edge. On the mediating background, there were two patches, one per illumination frame. Observers were asked to adjust the luminance of the patch in bright illumination to equate the lightness of the other. We compared conditions in which the luminance ratio at the contextual edge could be (i) equal (possible shadow), or (ii) larger (impossible shadow) than that at the mediating edge. In addition, we manipulated the reflectance of the backgrounds. It could be higher for the contextual than for the mediating background; or, vice versa, lower for the contextual than for the mediating background. Results reveal that lightness constancy significantly increases when: (i) the luminance ratio at the contextual edge is larger than that at the mediating edge creating an impossible shadow, and (ii) the reflectance of the contextual background is lower than that of the mediating one. We interpret our results according to the albedo hypothesis, and suggest that the scission process is facilitated when the luminance ratio at the contextual edge is larger than that at the mediating edge and/or the reflectance of the including area is lower than that of the included one. This occurs even if the ratio-invariant property is violated.