Neural Mechanisms of Object Prioritization in Vision

Grignolio, Damiano; Meyyappan, Sreenivasan; Geng, Joy; Mangun, George; Hickey, Clayton · 2025 · Crossref

DOI: 10.1111/psyp.70147

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 the neural mechanisms underlying object-based attention, addressing a debate regarding whether visual attention spreads along the contours of attended objects or if behavioral findings are confounded by perceptual factors like visual clutter and hemifield anisotropies. While behavioral studies using the two-rectangle paradigm have historically suggested that attention prioritizes entire objects, recent critiques argue these effects may reflect low-level perceptual costs or strategic biases rather than genuine attentional deployment. To resolve this ambiguity, the authors employed electroencephalography (EEG) to directly measure the allocation of visual attention before target onset, bypassing the confounds inherent in reaction time data. The experimental design involved 30 participants performing a visual cueing task where an auditory cue indicated a likely target location at one of four screen corners. Throughout each trial, two task-irrelevant rectangles were displayed, oriented either vertically or horizontally. The critical manipulation was the rectangle orientation: vertical rectangles confined stimulus locations to a single visual hemifield, while horizontal rectangles spanned both hemifields. The researchers analyzed two neural indices of attentional deployment: lateralized posterior alpha oscillations, which reflect sensory preparation, and the anterior directing-attention negativity (ADAN), an event-related potential component associated with strategic attentional control. The results demonstrated that neural indices of attention were sensitive to the orientation of the task-irrelevant rectangles. Specifically, lateralized alpha power and the ADAN were significantly stronger in the vertical rectangle condition compared to the horizontal condition. This indicates that when attention was cued to a location on a vertical rectangle, it remained strongly lateralized, whereas attention spread across hemifields when the rectangle was horizontal, reducing lateralization. These findings support the hypothesis that attention spreads along object boundaries. In contrast, behavioral data showed no main effect of object prioritization on reaction times or accuracy, though significant interactions emerged when analyzing rectangle orientation separately, highlighting the limitations of behavioral measures in this context. The study concludes that the allocation of visual attention is indeed influenced by object boundaries, providing direct neural evidence for object-based attentional prioritization. By demonstrating that attention spreads along object contours as measured by EEG, the authors argue that previous failures to replicate behavioral effects may stem from the sensitivity of reaction times to confounding variables like visual complexity and cue-target timing. This work validates models of object-based attention and underscores the utility of neural measures in disentangling attentional mechanisms from perceptual artifacts.

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 2026-06-25; verification: verified.

Topics

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

• attention selective divided