Individuals with left hemianopic field loss (HFL), especially with neglect history, may have greater difficulties than individuals with right HFL in judging the direction of another person's gaze.
Individuals with HFL often show a spatial bias in laboratory-based perceptual tasks. We investigated whether such biases also manifest in a more real-world task, perception of mutual gaze direction, an important, nonverbal communication cue in social interactions.
Participants adjusted the eye position of a life-size virtual head on a monitor at a 1-m distance until (1) the eyes appeared to be looking straight at them, or (2) the eyes were perceived to be no longer looking at them (to the right and left).
Participants with right HFL (n = 8) demonstrated a rightward error in line bisection but made gaze judgments within the range of normally sighted controls (n = 17). Participants with left HFL without neglect history (n = 6) made leftward errors in line bisection and had more variable gaze judgments; three had estimates of gaze direction outside the reference range. Four participants with left HFL and neglect history made estimates of gaze direction that were to the right of the reference range.
Our results suggest that individuals with left HFL, especially with neglect history, may have greater difficulties than individuals with right HFL in compensating for low-level spatial biases (as manifested in line bisection) when performing the more complex, higher-level task of judging gaze direction.
1Schepens Eye Research Institute of Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts
2Department of Psychology, University of Alberta, Edmonton, Alberta, Canada
3Psychologisches Institut, Johannes Gutenberg-Universität, Mainz, Germany
Submitted: August 8, 2018
Accepted: July 6, 2019
Funding/Support: National Eye Institute (R01-EY025677; to ARB) and National Eye Institute (T35-EY007149).
Conflict of Interest Disclosure: None of the authors have reported a financial conflict of interest. The sponsor provided financial and material support but had no role in the study design, conduct, analysis and interpretation, or writing of the report. Each of the authors had access to the study data and take full responsibility for their presentation in this article.
Author Contributions and Acknowledgments: Conceptualization: ARB, HH; Data Curation: ARB, SS; Formal Analysis: ARB, SS; Funding Acquisition: ARB; Investigation: SS; Methodology: ARB, SS, HH; Project Administration: ARB; Resources: ARB; Software: HH; Supervision: ARB; Writing – Original Draft: ARB, SS, HH; Writing – Review & Editing: ARB, SS, HH.
The authors thank Anna Sterczek for help with data collection.
Online date: October 29, 2019