Biomarkers of cognitive deficits for assessment and rehabilitation protocols in immersive virtual reality

Existing evidence suggests that oculomotors and cardiac metrics may offer non-invasive, objective, real-time means to investigate attentional processes. Recording these measures in environments that closely resemble everyday life, such as immersive virtual reality (iVR), could enhance ecological validity and improve their reliability as clinical biomarkers. These methods could also address limitations of current neuropsychological tools and help in mitigating the pervasive consequences of attention impairments after acquired brain injuries. Therefore, the present work aimed at examining whether oculomotor and heart rate variability metrics, collected within newly developed iVR software, serve as reliable biomarkers of attention and as tools for diagnosis and prognosis. Chapter 1-4 provide a theoretical overview of the neuroscientific principles and neuropsychological challenges around which the thesis is based. Studies in chapters 5 and 6 demonstrated that heart rate variability and oculomotor metrics, collected in iVR, predict attentional performance and clarify how these biomarkers relate to distinct attentional processes. In addition, chapter 6 highlighted the specificity of a set of oculomotor metrics for targeting alertness, spatial and selective components of attention. Based on this evidence, chapter 7 and 8 applied the same iVR-oculomotor approach to patients with attention deficits after brain injuries. In detail, chapter 7 supports clinical translation by accurately distinguishing patients with and without attention deficits and by demonstrating a neuroanatomical foundation. Similarly, results in chapter 8 showed the feasibility of iVR-based rehabilitation to promote improvements in attention components, while concurrently using embedded oculomotor metrics to predict individual recovery trajectories. As discussed in chapter 9, these findings converge in underscoring the value of examining biomarkers within iVR to deepen understanding of their link with attention and to provide reliable methods for assessing, monitoring and rehabilitating attention impairments. Ultimately, the present evidence supports integrating these innovative methods into clinical practices to complement and enhance current neuropsychological procedures.