Oculomotor responses provide evidence of neurodegenerative mechanisms underpinning memory binding impairments in Alzheimer's disease

Pupil behaviours inform about cognitive load and performance during online activities (Laeng et al., 2012). Contrary to other ocular responses such as Gazing, which heavily relies on cortical networks, pupil behaviour is thought to rely on neurotransmitter systems located in the brainstem (Alnaes et al., 2014). We have recently shown that Gazing can inform about underpinnings of memory binding deficits in patients with Alzheimer's disease (Fernández et al., 2018). As a cortical response, Gazing is more prompted to cognitive bias whereas pupil behaviour, might provide an unbiased biological measure of cognitive performance during a task known to be a marker for AD (the short-term memory binding task – STMBT). This study investigated if the combined analysis of pupil behaviour during the STMBT test could enhance the sensitivity to detect AD.