Visual Selection of the Future Reach Path in Obstacle Avoidance

Baldauf, Daniel · 2018 · Crossref

DOI: 10.1162/jocn_a_01310

archive: archived pipeline: cataloged verified

Get this paper ↗ (DOI — opens at the source; we link to it, we don't host it)

Summary

This study investigates how visual attention is deployed during the preparation of manual movements that require avoiding obstacles. Specifically, it addresses the "motor equivalence" problem, questioning whether the brain selects specific intermediate points along a future trajectory or merely attends to the goal and the obstacle itself. The authors hypothesized that visual attention selectively preselects the planned path of the hand around an obstacle, rather than just the obstacle or the target. To test this, the researchers conducted two EEG experiments using a dot-probe paradigm. In Experiment 1, participants performed rapid reaches to a target while avoiding a central obstacle, with the side of avoidance (left or right) cued by an auditory signal. A task-irrelevant visual dot probe was flashed briefly after the cue but before movement onset, either on the side of the planned path (congruent) or the opposite side (incongruent). Experiment 2 modified the design to include a third condition where the probe was flashed on the margin of the obstacle facing the planned path, allowing for a direct comparison of attentional allocation to the path versus the obstacle itself. Eye movements were monitored, and in Experiment 2, participants fixated the target throughout the trial. The results from Experiment 1 showed that the P1 and N1 event-related potential components, which index early visual processing, were significantly enhanced when the probe appeared on the planned movement path compared to the irrelevant side. This enhancement occurred despite the probe being task-irrelevant, indicating that attention was covertly directed to the future trajectory. Experiment 2 confirmed these findings and demonstrated that the attentional facilitation on the planned path was comparable to the facilitation observed on the obstacle’s margin. Statistical analyses revealed significant main effects for probe position, with enhanced amplitudes at occipital and parieto-occipital sites for congruent trials. These findings suggest that during movement preparation, visual attention is not limited to the goal or the obstacle but is selectively allocated to the specific trajectory the hand will take. This supports the view that the brain uses intermediate goals or "via points" to plan complex curved movements, effectively preselecting the spatial route in advance. The study provides neural evidence that visual resources are flexibly adjusted to support motor planning, highlighting a tight coupling between visual attention and the preparation of obstacle-avoidance movements.

Provenance

The full processing record for this entry. Every stage of this paper's journey through the pipeline is logged — what ran, with which tool and model, how many attempts it took, and when it last completed.

Summary generated by qwen3.6-27b-prismaquant on 2026-06-26; verification: verified.

Topics

Ranked by relevance to this paper. Hover a topic for its definition.

• peripheral attention