ALCORN — Exploring Action-Specific Effects with Perceptual Spatial Displacements: Does the ‘Pong Effect’ modulates Representational Momentum?
Abstract:
The existence and robustness of ‘action-specific effects’, that is, an effect of action capabilities, intentions or the difficulty/ease in performing a certain action on perception, have been fiercely debated. While the proponents hold that ‘action-specific effects’ reflect actual perceptual phenomena, critics often point out that some of the alleged favourable results can actually be accounted for by demand characteristics of the experimental tasks, prompting the participants to bias their responses accordingly, and, hence, reflect not perceptual but rather judgemental factors. One such putative ‘action-specific effect’ is the so called ‘Pong Effect’: The perceived speed of the ball in a Pong-like game is increased when observers control a smaller paddle to intersect the ball, arguably due to the heightened difficulty in performing such action. Unlike other presumed ‘action-specific effects’, the ‘Pong Effect’ has been shown to be resistant to several experimental manipulations preventing possible confoundings. Notwithstanding, seldomly has the ‘Pong Effect’ been tested with tasks which involve an implicit measure of perceived speed, instead of overt judgements, which would greatly support its robustness and, by extension, speak favourably to the perceptual nature of ‘action-specific effects’. The present research proposal thus aims to ascertain if the ‘Pong Effect’ manifests in a phenomenon known to be highly sensitive to perceived target’s speed – Representational Momentum (RM). RM refers to a forward bias, in the direction of motion, for the perceived vanishing location of a moving target when observers are required to indicate its offset position. RM’s magnitude is known to be increased for faster targets across multiple paradigms – spatial localization with a computer mouse, probe judgements (where observers indicate if a probe shown in the vicinity of the target’s offset location is in that same or in a different spatial location) and when directly pointing to the perceived vanishing location. As such, the research proposal sets forth to test one main hypothesis – bigger RM should be observed for moving targets in a version of Pong when observers control a smaller paddle. Finding empirical support to that hypothesis would favour that (a) the ‘Pong Effect’ reflects an actual ‘action-specific effect’, and not solely a judgemental phenomenon, and (b) that RM, thought to subserve intersective actions, is permeable to ‘action-specific effects’. In contrast, findings not conforming to the main hypothesis would imply either (a), (b) or both to be unwarranted, and call for a revision of current theories on ‘action-specific effects’ and RM. The research plan is thus designed to systematically test the main hypothesis in a series of interrelated studies, with some of those being conducted or deferred contingent on the results of the preceding ones. Study 1 aims to establish if RM is increased for a target ball in a simplified version of the Pong game, when the participants have control over a smaller paddle, in conformity with ‘action-specific effects’. Study 2, to be conducted in case of a null effect found in study 1, explores if the ‘Pong Effect’ modulates RM when measured with other experimental paradigms, known either to be more sensitive to high-level factors (probe method) or more reliant on sensorimotor processes (direct motor localization). Study 3, contingent on disclosing evidence in favour of the main hypothesis in study 1, will ascertain if the modulation of RM’s magnitude by the paddles’ size depends on participants having active control over the paddle, by employing a Yoked Control Design. Finally, study 4 will investigate if the ‘Pong Effect’ amplifies RM for faster moving target balls, as should be the case if ‘action-specific effects’ are perceptually rooted. If, on the other hand, the ‘Pong Effect’ is found to be independent from the effect of targets’ speed on RM (as signalled by a null interaction), that would constitute evidence for an involvement of attentional, not purely perceptual, factors – controlling a smaller paddle, by making intersective actions more challenging, would increase attentional load which, in its turn, would lead to bigger RM, irrespective of the target’s speed. Taken together, the planed experimental studies offer the possibility to strongly test for the robustness of the ‘Pong Effect’ and, consequently, for the cogency of ‘action-specific effects’. Outcomes would thus speak favourably to the proposal that perception codes stimuli in terms of action contingencies – if positive results are disclosed in studies 1, 3 and 4 – or add to the critical literature – if negative results and found in studies 1, 2 and 4. The present research proposal thus offers the prospect to further enlighten the nature of perceptual abilities and their interrelation with action capabilities.
Funding
Fundação para a Ciência e Tecnologia – FCT; nº 2024.16483.PEX (€49 175,73).