Document Type
Article
Publication Date
8-2025
Publisher
American Physiological Society
Source Publication
Journal of Neurophysiology
Source ISSN
1522-1598
Original Item ID
DOI: 10.1152/jn.00554.2024
Abstract
Object-based attention prioritizes the processing of information appearing within a selected object. We previously showed an object-based shift direction anisotropy (SDA) whereby horizontal shifts are more efficient than vertical shifts (Barnas AJ, Greenberg AS. Atten Percept Psychophys 78: 1985–1997, 2016; Barnas AJ, Greenberg AS. Vis Cogn 27: 768–791, 2019), an effect modulated by the visual field meridians (Barnas AJ, Greenberg AS. Q J Exp Psychol (Hove) 77: 2516–2532, 2024). Our present aim was to understand how the functional brain mechanisms of attention give rise to the SDA. We hypothesized that the SDA arises from attentional resources being partitioned differently by horizontal and vertical meridians. To test this, we used fMRI of the visual cortex while subjects shifted attention horizontally and vertically within a single, L-shaped object. An SDA was observed when targets crossed the visual field meridians, and the object vertex was positioned in the upper-left corner. However, no SDA was observed when the object vertex was positioned in the lower-right corner. Cue-related activations revealed that attention spreads throughout the vertical component of each object (even to locations where the target never appeared). In addition, the vertical meridian seemed to impede the spread of attention for the upper-left object’s horizontal component. However, for the lower-right object, the horizontal component showed a similar attentional modulation to its vertical component, commensurate with behavioral performance in response to that object. These results suggest the efficiency of horizontal shifts crossing the vertical meridian is enhanced by the support of attentional resources from both hemispheres. As such, we offer a refinement of how the visual field meridians may influence the spread of object-based attention via an anisotropic attention gradient.
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Recommended Citation
Hughes, David H.; Barnas, Adam J.; and Greenberg, Adam S., "Anisotropic Object-Based Shifts of Attention Arise From Unequal Influences of Visual Field Meridians on Neural Attention Gradients" (2025). Biomedical Engineering Faculty Research and Publications. 749.
https://epublications.marquette.edu/bioengin_fac/749
ADA Accessible Version
Comments
Published version. Journal of Neurophysiology, Vol. 134, No. 2 (August 2024): 504-516. DOI. © The Authors, published by American Physiological Society. Used with permission.