Eye Movements When Observing Predictable and Unpredictable Actions

Abstract

We previously showed that, when observers watch an actor performing a predictable block-stacking task, the coordination between the observer's gaze and the actor's hand is similar to the coordination between the actor's gaze and hand. Both the observer and the actor direct gaze to forthcoming grasp and block landing sites and shift their gaze to the next grasp or landing site at around the time the hand contacts the block or the block contacts the landing site. Here we compare observers' gaze behavior in a block manipulation task when the observers did and when they did not know, in advance, which of two blocks the actor would pick up first. In both cases, observers managed to fixate the target ahead of the actor's hand and showed proactive gaze behavior. However, these target fixations occurred later, relative to the actor's movement, when observers did not know the target block in advance. In perceptual tests, in which observers watched animations of the actor reaching partway to the target and had to guess which block was the target, we found that the time at which observers were able to correctly do so was very similar to the time at which they would make saccades to the target block. Overall, our results indicate that observers use gaze in a fashion that is appropriate for hand movement planning and control. This in turn suggests that they implement representations of the manual actions required in the task and representations that direct task-specific eye movements.

The role of observers' gaze behaviour when watching object manipulation tasks: predicting and evaluating the consequences of action

“…In both the weight judgement task (figure 3b) and the corresponding self-guided action-observation condition (figure 3a), gaze behaviour was very similar to that previously seen during natural or self-guided action-observation [6,9] (see also figure 2a). (Note that figure 3a,b show data from all trials from all participants.)…”

“…We asked for a quick response because we wanted to identify the gaze behaviour associated with predicting, as opposed to simply reporting, the actor's target, and because target prediction during natural action -observation occurs quickly [9]. The actor's performance was similar in the target prediction task and the corresponding self-guided action-observation condition, as assessed by the duration of the hand movement from the start block to the target block and the maximum vertical displacement of the hand during this movement.…”

Predictive Gaze During Observation of Irrational Actions in Adults with Autism Spectrum Conditions

“…However there are a number of methodological problems with the way in which the stimuli was constructed for this type of analysis. Firstly, latency of fixation measures are extremely sensitive to the action kinematics and timing used (Rotman, Troje, Johansson, & Flanagan, 2006), two features that were not matched between conditions in this study. Secondly, predictive eye movements Predictive Gaze in Autism P a g e | 8…”

Infants’ understanding of everyday social interactions: A dual process account

“…We believe that the current results, as such, provide a more ecologically valid estimate of infant's action understanding during everyday social interactions. However, the added uncertainty that comes with multiple action sequences and diverse action goals (Gredebäck, Stasiewicz, Falck-Ytter, Rosander, & von Hofsten, 2009;Rotman, Troje, Johnson, & Flanagan, 2006) suggests that we should be careful about deducing minimum ages for anticipation and retrospective evaluation based on these results. The current study does not suggest a lower age limit for retrospective evaluations, since the youngest age group demonstrated this ability.…”