Temporal estimation with two moving objects: overt and covert pursuit

Abstract

The current study examined temporal estimation in a prediction motion task where participants were cued to overtly pursue one of two moving objects, which could either arrive first (i.e., shortest TTC) or second (i.e., longest TTC) after a period of occlusion. Participants were instructed to estimate TTC of the first-arriving object only, thus making it necessary to overtly pursue the cued object while at the same time covertly pursuing the other (non-cued) object. A control (baseline) condition was also included in which participants had to estimate TTC of a single, overtly pursued object. Results showed that participants were able to estimate the arrival order of the two objects with very high accuracy irrespective of whether they had overtly or covertly pursued the first-arriving object. However, compared to the single-object baseline, participants' temporal estimation of the covert object was impaired when it arrived 500 ms before the overtly pursued object. In terms of eye movements, participants exhibited significantly more switches in gaze location during occlusion from the cued to the non-cued object but only when the latter arrived first. Still, comparison of trials with and without a switch in gaze location when the non-cued object arrived first indicated no advantage for temporal estimation. Taken together, our results indicate that overt pursuit is sufficient but not necessary for accurate temporal estimation. Covert pursuit can enable representation of a moving object's trajectory and thereby accurate temporal estimation providing the object moves close to the overt attentional focus.

The common rate control account of prediction motion

“…Several PM experiments have documented dual-task interference costs (Baurès, Bennett, & Causer, 2015;Baurès, DeLucia, Olson, & Oberfeld, 2017;Baurès et al, 2010Baurès et al, , 2011DeLucia & Novak, 1997;Lyon & Waag, 1995;Oberfeld & Hecht, 2008). These experiments illustrate the difference between pre and post occlusion explanations.…”

Time‐to‐contact perception in the brain

“…To understand what could be the implication of this region in the TTC estimation, it is important to describe the different steps of the task. In the prediction motion paradigm we used, the task requires overt attention to the ball (Baurès et al, 2015), pursuit eye movements (Bennett et al., 2010), a dynamical representation of the ball's position (according to the cognitive motion extrapolation strategy) or TTC (according to the clocking strategy) during the occlusion time (Bosco et al., 2015; Makin, 2018) and a motor response to indicate the estimated arrival time. All these processes are known to involve the parietal area (e.g., Astafiev et al., 2003; Bisley et al., 2011; Harrison et al., 2010).…”

Asymmetric interference in concurrent time-to-contact estimation: Cousin or twin of the psychological refractory period effect?

“…In Experiment 1, the two objects moved on parallel trajectories, separated by a small vertical distance that putatively permitted efficient perception of the TTCs of both objects. Indeed, it has recently been shown that observers can efficiently fixate on one object while accessing another object's TTC if the two objects are temporally or spatially close (Baurès, Bennett, & Causer, 2015). In Experiment 2, the two objects were distant from each other, likely making it much more difficult for participants to share visual attention between the two objects while maintaining their gaze on one of the objects.…”