Armando Mónica Oliveira

The Representational Dynamics of Remembered Projectile Locations

When people are instructed to locate the vanishing location of a moving target, systematic errors forward in the direction of motion (M-displacement) and downward in the direction of gravity (O-displacement) are found. These phenomena came to be linked with the notion that physical invariants are embedded in the dynamic representations generated by the perceptual system. We explore the nature of these invariants that determine the representational mechanics of projectiles. By manipulating the retention intervals between the targets disappearance and the participants responses, while measuring both M- and O-displacements, we were able to uncover a representational analogue of the trajectory of a projectile. The outcomes of three experiments revealed that the shape of this trajectory is discontinuous. Although the horizontal component of such trajectory can be accounted for by perceptual and oculomotor factors, its vertical component cannot. Taken together, the outcomes support an internalization of gravity in the visual representation of projectiles.

Disambiguating the effects of target travelled distance and target vanishing point upon representational momentum

Representational Momentum (RM) was the name given to a phenomenon whereby the last seen position of a suddenly vanished moving target is judged as located further ahead in the direction of movement. We argue in this paper that the role of target travelled distance and of target vanishing position in the modulation of RM have been unduly confounded in previous research. Shortcomings arising from this confounding are noticed and discussed. An experiment that dissociates factorially the effects of these two variables in Michotte-like causal displays as well as in noncausal displays is presented and concludes that vanishing point, not length of travel, is the relevant factor to consider.

Spatial and Foveal Biases, Not Perceived Mass or Heaviness, Explain the Effect of Target Size on Representational Momentum and Representational Gravity

The spatial memory for the last position occupied by a moving target is usually displaced forward in the direction of motion. Interpreted as a mental analogue of physical momentum, this phenomenon was coined representational momentum (RM). As momentum is given by the product of an objects velocity and mass, both these factors came to be under scrutiny in RM studies, the goal being to provide support for the internalization hypothesis. Although velocity was found to determine RMs magnitude, possible effects of mass were more elusive. Recently, an effect of target size on RM was reported, adding to previous findings that bigger targets were more mislocalized downward in the direction of gravity (via perceived heaviness and representational gravity; RG). The aim in the present research was to test that those outcomes reflect an internalization of momentum by excluding oculomotor factors. The results showed that an effect of target size, when it emerged, could be accounted for by a foveal bias such that bigger targets were more displaced toward gaze than were smaller ones. Specific contingencies between eye movements and target size seem to account for previous reports regarding the alleged effects of perceived mass on both RM and RG. This phenomenon seems furthermore to be modulated by the presence of other visual elements (fixation point) and the range of target velocities. These outcomes are taken as a rebuttal to the claim that cognitive analogues of mass or heaviness are responsible for previously reported effects of target size on both RM and RG.

The embodied dynamics of perceptual causality: a slippery slope?

In Michottes launching displays, while the launcher (object A) seems to move autonomously, the target (object B) seems to be displaced passively. However, the impression of A actively launching B does not persist beyond a certain distance identified as the “radius of action” of A over B. If the target keeps moving beyond the radius of action, it loses its passivity and seems to move autonomously. Here, we manipulated implied friction by drawing (or not) a surface upon which A and B are traveling, and by varying the inclination of this surface in screen- and earth-centered reference frames. Among 72 participants (n = 52 in Experiment 1; n = 20 in Experiment 2), we show that both physical embodiment of the event (looking straight ahead at a screen displaying the event on a vertical plane vs. looking downwards at the event displayed on a horizontal plane) and contextual information (objects moving along a depicted surface or in isolation) affect interpretation of the event and modulate the radius of action of the launcher. Using classical mechanics equations, we show that representational consistency of friction from radius of action responses emphasizes the embodied nature of frictional force in our cognitive architecture.

Explorando a trajetória espácio-temporal da representação dinâmica de projéteis

When human observers are shown a horizontally moving target which suddenly disappears and they are further instructed to locate its vanishing position, both forward in the direction of motion (M Displacement) and downward in the direction of gravity (O Displacement), errors of localization typically occur. Though several determinants of those errors have been ascertained, little is known regarding their time course. The present study attempts to fill this gap. Horizontally moving targets were presented and participants instructed to locate their vanishing position, either via a mouse or a pointer (on a touch screen) after a variable time delay. Outcomes revealed an orderly time-dependent trajectory of errors being describable in two stages - during the first 300ms, the errors increased in the direction of motion with a constant vertical error; after 300ms the downward error increased with no further horizontal displacement. Similarities between this pattern and reported results from the Intuitive Physics (Road Runner Physics) and the History of Ancient Physics are noticed and discussed under the notion of an implicit representation of physical invariants in the perception of dynamic events.

Uma análise funcional da Wong-Baker Faces Pain Rating Scale: linearidade, discriminabilidade e amplitude

Background: Self-report measures of pain intensity are often treated as interval level measures, which is a rarely tested assumption. Objectives: To assess...

Representational momentum in dynamic facial expressions is modulated by the level of expressed pain: Amplitude and direction effects

Humans have developed a specific capacity to rapidly perceive and anticipate other people’s facial expressions so as to get an immediate impression of their emotional state of mind. We carried out two experiments to examine the perceptual and memory dynamics of facial expressions of pain. In the first experiment, we investigated how people estimate other people’s levels of pain based on the perception of various dynamic facial expressions; these differ both in terms of the amount and intensity of activated action units. A second experiment used a representational momentum (RM) paradigm to study the emotional anticipation (memory bias) elicited by the same facial expressions of pain studied in Experiment 1. Our results highlighted the relationship between the level of perceived pain (in Experiment 1) and the direction and magnitude of memory bias (in Experiment 2): When perceived pain increases, the memory bias tends to be reduced (if positive) and ultimately becomes negative. Dynamic facial expressions of pain may reenact an “immediate perceptual history” in the perceiver before leading to an emotional anticipation of the agent’s upcoming state. Thus, a subtle facial expression of pain (i.e., a low contraction around the eyes) that leads to a significant positive anticipation can be considered an adaptive process—one through which we can swiftly and involuntarily detect other people’s pain.

Benefits of radial distortion correction in arthroscopic surgery: a first experimental study on a knee model

Lens probes used in arthroscopy typically have a small diameter and wide field‐of‐view. This introduces strong radial distortion (RD) into the image, ultimately affecting the surgeons hand–eye coordination. This study evaluates potential benefits of using distortion‐free images in arthroscopic surgery.

Aristóteles versus Philoponus: a functional approach to the intuitive physics of projectiles

Intuitive physics is a popular field of research within cognitive psychology which addresses the common-sense beliefs about the physical world, particularly about classical mechanics. An influential stream of research argues for the striking resemblance between common-sense beliefs and those embodied in pre-Newtonian theories, such as the medieval physics of impetus. In this study, two early algebraic proposals for the relation between the force applied to an object, the resistance to its motion and its resulting velocity are compared, the first one derived from Aristotle, the other set forth by Philoponus (VIth century). The methodology of Information Integration Theory was used, revealing a dividing cognitive integration rule in agreement with Aristotle’s proposal. The significance of this finding is discussed through a suggested link with the mental models framework.Intuitive physics is a popular field of research within cognitive psychology which addresses the common-sense beliefs about the physical world, particularly about classical mechanics. An influential stream of research argues for the striking resemblance between common-sense beliefs and those embodied in pre-Newtonian theories, such as the medieval physics of impetus. In this study, two early algebraic proposals for the relation between the force applied to an object, the resistance to its motion and its resulting velocity are compared, the first one derived from Aristotle’s Physics, the other set forth by Philoponus, in the VIth century. To this end, the methodology of Information Integration Theory and Functional Measurement was used, revealing a dividing cognitive integration rule in agreement with Aristotle’s proposal. The significance of this finding is discussed through a suggested link with the mental models framework. The potential contribution of cognitive algebra to the field of intuitive physics is also briefly pinpointed.