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Updated: Sep 14, 2025
Eye-Tracking Control to Assess Cognitive Functions in Patients with Amyotrophic Lateral Sclerosis
Published on: October 13, 2016
Pupil response as a window into cognitive processing in amyotrophic lateral sclerosis
Mohamad El Haj1,2, Souheil Hallit3,4,5, Claire Boutoleau-Bretonnière6,7
1Nantes Université, Univ Angers, Laboratoire de Psychologie des Pays de la Loire (LPPL - EA 4638), F-44000 Nantes, France.
Purpose:
This preliminary study aimed to investigate whether the pupil size reflects cognitive load in patients with amyotrophic lateral sclerosis (ALS).
Methods:
Pupil activity was monitored in three patients with ALS and a group of healthy control participants (n = 16) while performing three tasks: a forward span task, a backward span task, and a control task involving counting aloud. These tasks were designed to impose increasing cognitive demands, with the backward span task being the most challenging.
Results:
Analysis revealed no significant difference in pupil size between patients with ALS and controls for the forward or backward spans or the control condition. Both groups demonstrated a consistent pattern of increased pupil size during the backward span task compared to the forward span task, and during the forward span task compared to the control condition.
Conclusion:
These findings suggest that pupil dilation reflects task-related cognitive load similarly in ALS patients and healthy controls. This supports the use of pupillometry as a non-invasive and sensitive marker of cognitive processing in ALS.
