Action Interrupted: Movement and Breakpoints in the Processing of Motion Violations in Toddlers and Adults

Abstract

From early in development, segmenting events unfolding in the world in meaningful ways renders input more manageable and facilitates interpretation and prediction. Yet, little is known about how children process action structure in events comprised of multiple coarse-grained actions. More importantly, little is known about the time-course of action processing in young children or about the specific features that recruit attention. This is particularly true when we consider action that pauses unexpectedly—as actions sometimes do—violating the expectation of a continuous unfolding of motion. We assessed visual preference to intact and disrupted actions embedded within a multi-action event in toddlers and adults. In one condition, pauses were inserted at intact action boundaries whereas in the other condition they disrupted action. Attention in both groups was recruited to the disrupted relative to intact events. Time-course analyses, however, revealed developmental differences in sensitivity to the movement features (e.g., motion, pauses, and transitions) of disrupted events.

Finding events in a continuous world: A developmental account

“…As early as 9–11 months, infants segment a variety of goal‐directed action events into units that align with actors’ goals (Baldwin et al, ; Friend & Pace, ; Pace et al, ; Saylor, Baldwin, Baird, & LaBounty, ; Sharon & Wynn, ; Wynn, ). For example, Baldwin et al () familiarized infants with videos of everyday actions such as cleaning a kitchen, and in the following test phase, infants were presented with versions of these videos containing pauses inserted in the motion either at the completion of a goal‐directed action or in the midst of (i.e., interrupting) the execution of a goal‐directed action.…”

Parallels in Processing Boundary Cues in Speech and Action

“…For example, a change in motion velocity occurs at the boundary between sub-units of action sequences, (rapid acceleration/deceleration; Zacks et al, 2009; McAleer et al, 2014) suggesting that changes in speed of the movement around the time of the boundary offer a kinematic cue to the location of the boundary within the sequence. A pause in an action sequence (i.e., a motionless interval) can also be a kinematic cue that signals a boundary between actions: Participants report the use of pauses to determine boundaries between actions (Bläsing, 2014) and expect pauses to occur at boundaries in action sequences (Friend and Pace, 2016). The similarity of the low-level cues (i.e., change in duration of the pre-boundary unit, presence of a pause) raises the prospect that the cognitive processes involved in the perception of these kinematic boundary cues are similar to those involved in prosodic boundary cue processing.…”