Poster #160 - What eye tracking and EEG tell us about perception of future-directed actions in children and adults

• In Event: 3-159 - Poster Session 12
  In Poster Session: PS 12 Section - Perceptual, Sensory, Motor

Integrative Statement

Goal-directed motor action requires planning a series of movements to achieve a goal. For many motor actions, the end-goal is visible at the outset of the plan (e.g., grasping a rod). But for some actions, planning must stretch several steps into the future because the end-goal is not immediately visible in the scene (e.g., grasping a hammer to pound a peg). Planning for an unseen future end-goal can require flexible, non-habitual, initial movements to ensure that the final position enables efficient achievement of the goal. For example, if a hammer handle points away from their dominant hand, adults use a flexible underhand grip to allow for the subsequent steps of pounding the peg. In contrast, young children frequently grasp the handle using their habitual overhand grip, putting their hand in an awkward inefficient position to achieve the end-goal of pounding the peg.

Despite a growing literature on children’s ability to plan movements several steps into the future, little is known about how children and adults perceive the actions of others when the end-goal is not immediately visible in the scene. To address this question, we used an integrated approach, combining remote eye tracking, electroencephalography (EEG), and machine learning to examine action perception in 4-year-olds (current N = 15) and adults (N = 25) as they observed video clips of actors grasping a hammer and pounding a peg (Figure 1A). For each age group, we assessed differences in looking patterns and neural activity while participants viewed actions featuring flexible and non-flexible tool use. In the “flexible” condition, the initial grasp was an adult-like underhand/radial grip that led to a comfortable overhand/radial grip to pound the peg (Figure 1B, left panel). In the “non-flexible” condition, the initial grasp was a habitual, overhand/ulnar grip that led to inefficient tool use (Figure 1B, right panel). Five different actors performed the actions in each condition, with location of the hammer and peg constant across displays.

Children and adults equally fixated on the task-relevant areas of the scene (Figure 2A) including the performing hand, the tool (hammer), and the goal (peg), indicating similar attention across participants. However, looking patterns differed between age groups—children primarily focused on the goal, whereas adults looked more at the performing hand and the hammer (Figure 2B). Adults also displayed more gaze shifts among task-relevant areas than children (Figure 2C). At the neural level, both age groups showed action-related neural activity (significant suppression in mu and beta bands over motor sites contralateral to the performing hand). However, adults exhibited differences in action-related neural activity when they observed flexible tool use compared with non-flexible tool use (low mu suppression, 8-10Hz; Figure 2D). Children did not show similar neural differentiation (Figure 2D), reflecting low neural sensitivity to how others plan future actions. Taken together, findings provide insights into how young children perceive motor planning in others when the end goal stretches far into the future and what they (do not) perceive when they watch others’ movements.

Authors

• Ori Ossmy, New York University
  Non-Presenting Author

• Brianna Kaplan, New York University
  Presenting Author

• Danyang Han, New York University
  Non-Presenting Author

• Melody Xu, New York University
  Non-Presenting Author

• Catherine Bianco, New York University
  Non-Presenting Author

• Karen E Adolph, New York University
  Non-Presenting Author