A behavioral and electrophysiological investigation of conflict monitoring in cystinosis (CTNS gene mutations) using the flanker paradigm

Cystinosis, a rare lysosomal storage disease, is characterized by cystine crystallization and accumulation within tissues and organs, including the kidneys and brain. Its impact on neural function appears mild relative to its effects on other organs, but therapeutic advances have led to substantially increased life expectancy, necessitating deeper understanding of its impact on neurocognitive function. Behaviorally, some deficits in executive function have been noted in this population, but the underlying neural processes are not understood. Using standardized cognitive assessments and a Flanker task in conjunction with high-density electrophysiological recordings (EEG), we investigated the neural dynamics of conflict monitoring in individuals with cystinosis, when compared to age-matched controls. Thirty-six individuals diagnosed with cystinosis (8–38 years old, 25 women) and 39 age-matched controls (23 women) participated in this study. As expected, slower reaction times and larger amplitudes were observed in incongruent vs congruent trials in both groups, suggesting largely maintained conflict monitoring in cystinosis. However, when compared to their age-matched peers, individuals with cystinosis presented larger differences between congruent and incongruent trials both behaviorally (reaction times) and electrophysiologically (N2, P3). Our findings suggest that individuals with cystinosis are able to monitor and adapt to conflict, even if slower, less accurately, and more effortfully than their age-matched peers.