Visual salience of 3D and 2D spoons determines S-R mapping and flanker effects

Abstract

This study tested the hypothesis that affordances for grasping with the corresponding hand are activated more strongly by three-dimensional (3D) real objects than by two-dimensional (2D) pictures of the objects. In Experiment 1, participants made left and right keypress responses to the handle or functional end (tip) of an eating utensil using compatible and incompatible mappings. In one session, stimuli were spoons mounted horizontally on a blackboard with the sides to which the handle and tip pointed varying randomly. In the other, stimuli were pictures of spoons displayed on a black computer screen. Three-dimensional and 2D sessions showed a similar benefit for compatible mapping when the tip was relevant and a small cost of compatible mapping when the handle was relevant. Experiment 2 used a flanker task in which participants responded compatibly to the location of the handle or the tip, and spoons located above and below the target spoon could have congruent or incongruent orientations. The difference between 3D and 2D displays was not obtained in the flanker effect for reaction time. There was little evidence that 3D objects activate grasping affordances that 2D images do not. Instead, we argue that visual salience of the tip is the critical factor determining these correspondence effects.

Practice and transfer with mappings of spoon tip and handle to keypress responses

“…RT was shorter for the tip-compatible mapping than for the tip-incompatible mapping, and the difference between the two mappings was larger than the difference between the RTs of the handle-compatible and handle-incompatible conditions. This result is consistent with the view that the change in position of the spoon tip is more visually salient than that of the handle, and responding compatibly to the tip location was natural for participants (e.g., Ferguson et al, 2021; Kostov & Janyan, 2021; Xiong et al, 2019, 2021).…”

“…A highlight at the top of the left image was at the bottom of the right one, which was rotated 180°. Similar results have been shown to occur when this factor is not present (Xiong et al, 2019, 2021). The spoon was displayed at the centre of the black background of a computer monitor and subtended 13.7° × 2.9° of visual angle when viewed from a distance of approximately 60 cm.…”

“…Experiment 1 provided evidence that some participants in the handle-incompatible test session adopted a strategy of responding compatibly to the tip, consistent with our prior findings (Xiong et al, 2019, 2021). Because such a strategy would defeat the purpose of examining transfer of incompatible associations after practice with the instructed handle-incompatible mapping, we chose instead to focus in Experiment 2 on the extent to which participants instructed with the handle-incompatible mapping would report using the tip-compatible strategy in a first (practice) session.…”

“…LCD monitor on a 76 cm high table on which a Chronos response box with a row of five response buttons was placed. The stimuli were the same as the 2D images used by Xiong et al (2021): A standard, white plastic spoon was presented horizontally, centred on the computer monitor on each trial. There were two spoon orientations—tip on the left side (and handle on the right) and tip on the right side (handle on the left; see Figure 1).…”

“…Note that this conclusion is in agreement with that of Bub et al (2021), in that there is no overlap of the left and right tip positions compared with overlap for approximately half of the handle. Consequently, the ratio between the areas of the parts that switch between left and right is more than three times as large for the tip than the handle (Xiong et al, 2021).…”