Reinforcement-Based Head Scan Training for Drivers With Homonymous Visual Field Loss: Improves Blind-Side Detection

Objective: To evaluate whether a reinforcement-based head scanning training program improves blind-side hazard detection in drivers with homonymous visual field loss. Design: Single-arm nonrandomized clinical trial with 1-month follow-up. Setting: Research laboratory. Participants: Inclusion criteria included ≥3 months post–onset hemianopia or quadrantanopia, no neglect or major cognitive decline, and current or former driving experience. Sixteen of 23 volunteers met criteria and completed the study (median age=52.5y; 56% left-sided field loss). Interventions: Participants completed three 1-hour sessions of a reinforcement-based head scanning training program in a driving simulator. An auditory reminder cue served as immediate, error-contingent feedback, sounding from a loudspeaker on the participant's blind-side if they failed to make a large, early head scan to their blind-side before an intersection. Main Outcomes Measures: The primary outcomes were rates of proactive blind-side scanning (the proportion of intersections with an early large head scan) and blind-side hazard detection (the proportion of hazards detected) assessed without reminder cues at pretraining, 1 week posttraining, and 1 month posttraining. All hypotheses were prespecified. Results: Proactive blind-side head scanning increased significantly from 17.5% (95% CI, 8.9%-26.0%) at pretraining to 83.6% (95% CI, 76.5%-90.7%) at 1 week posttraining and 72.6% (95% CI, 63.4%-81.9%) at 1 month posttraining. Likewise, blind-side hazard detection improved significantly from 55.6% (95% CI, 41.3%-69.9%) to 85.6% (95% CI, 76.3%-95.0%) at 1 week posttraining and 82.5% (95% CI, 70.1%-94.9%) at 1 month posttraining. Improvements were primarily because of fewer scanning-related errors. Conclusions: Three sessions of reinforcement-based head scanning training significantly improved blind-side head scanning and hazard detection in drivers with homonymous visual field loss, with benefits lasting at least 1 month. These results support the promise of this rehabilitation approach for poststroke driving and warrant further evaluation in a randomized controlled trial. © 2026 American Congress of Rehabilitation Medicine