Humans are known to regulate the timing of interceptive actions by modeling, in a simplified way, Newtonian mechanics. Specifically, when intercepting an approaching ball, humans trigger their movements a bit earlier when the target arrives from above than from below. This bias occurs regardless of the ball's true kinetics, and thus appears to reflect an a… (More)
Experimental studies of visual mechanisms suggests that the CNS represents image information with respect to preferred horizontal and vertical axes, as shown by a phenomenon known as the "oblique effect". In the current study we used this effect to evaluate the influence of gravity on the representation and storage of visual orientation information.… (More)
The eye perceives the length of vertical and horizontal lines with an inherent asymmetry. A vertical line having the same length as a horizontal one is usually perceived to be longer. In this experimental investigation we tested the hypothesis that gravity has a direct role in producing the observed perceptual asymmetry. To this end we performed experiments… (More)
We are interested in this paper in the family of curves M (p, k, r, n), solutions of equation z n = αz k + (1 − α), where z is a complex variable, n, k, p and r are nonzero integers and α is a real number greater than 1. Expressing each of these curves in polar coordinates (ρ, θ), we will prove that ρ (θ) is an increasing function.