Spatial neglect, a common cognitive deficit following stroke, is also one of the clearest predictors of poor functional recovery. Stroke survivors may fail to notice people, objects or even parts of their own body on one side of space, making everyday activities such as reading, walking or crossing the road difficult and potentially dangerous.

Researchers at the University of Lucerne and the Lucerne Cantonal Hospital (LUKS) have now taken an important step towards improving the diagnosis of this condition and advancing the use of eye-tracking technology as a modern neuropsychological assessment tool.

In a new study, Professor Thomas Nyffeler, Dr Brigitte Kaufmann and colleagues demonstrate that a brief eye-tracking assessment can reliably detect signs of neglect across adults of all ages. By establishing reference values from healthy participants aged 20 to 89, the researchers provide the standard measures needed to implement eye-tracking for neglect diagnosis in a wide range of clinical settings, including hospitals, neurorehabilitation centres and neuropsychological services.

During the assessment, participants simply look at photographs of everyday scenes while a high-precision eye tracker records their gaze. The findings show that the key measure – the overall direction of gaze – remains stable throughout adulthood, making the assessment a robust indicator of neglect regardless of a person's age.

Looking where the eyes go

Neglect most commonly occurs after a stroke affecting the right side of the brain, causing people to ignore information on their left. Although conventional bedside tests can identify cases, they do not always reflect the difficulties patients experience in everyday life.

Eye tracking offers a different perspective. By analysing natural viewing behaviour, researchers can detect subtle attention deficits that may otherwise remain unnoticed until they begin to affect everyday functioning later. The new study also confirms that the assessment produces consistent results across repeated timepoints, highlighting its potential not only for diagnosis but also for monitoring patients' recovery during rehabilitation.

Building the foundations for better rehabilitation

The study addresses one of the main barriers to bringing eye-tracking technology into routine clinical care: the lack of reliable reference data. To facilitate the wider adoption of the method, the normative reference data has been made openly available, enabling clinicians and researchers to immediately apply these benchmarks in their own settings. The researchers also confirmed that a benchmark developed in an earlier study correctly identified more than 95% of healthy participants. This increases confidence that unusual eye-tracking results are likely to reflect genuine neurological impairment rather than normal differences in how people look at their surroundings. 

Together, these findings support the wider implementation of eye-tracking assessments in hospitals, neurorehabilitation centres and neuropsychological services. Because the test is brief, standardised and requires little verbal interaction, it may be particularly valuable for stroke patients. Since no language-based responses are required, the assessment can be used regardless of a person's first language and is well suited for repeated evaluations during recovery.

Part of a broader effort to understand attention after stroke

The research is a collaboration between a four-year Ambizione project funded by the Swiss National Science Foundation and led by Dr Brigitte Kaufmann at the Faculty of Behavioural Sciences and Psychology, and a project funded by the Swiss National Science Foundation led by Professor Thomas Nyffeler at the Faculty of Health Sciences and Medicine. 
 

Michael Jehle, Manuela Pastore-Wapp, Dario Cazzoli, Thomas Nyffeler, Brigitte C. Kaufmann
Toward clinical implementation of free visual exploration in neglect diagnostics: Reference data and psychometric properties across adulthood
Neuropsychological Rehabilitation, Volume 36, Taylor & Francis, 2026
Open Access link