Altered insula modulation during salience processing in chronic spinal cord injury: A functional magnetic resonance...

Executive functions are critical for problem-solving, planning and interference control. Even in the absence of brain damages, individuals with spinal cord injury (SCI) may experience difficulties with executive functions, but the underlying neural mechanisms remain unclear. This study addressed this issue by investigating the neural correlates of interference control in SCI. Twenty-six individuals with chronic SCI and twenty-six controls performed the Flanker task during functional magnetic resonance imaging. Interaction effects between group and condition (congruent, incongruent, neutral) with respect to performance were assessed using linear mixed-effects models. Imaging data were pre-processed and between-group differences were analyzed using a general linear model. Family-wise error correction was applied at a cluster level. Spearman correlation was computed to investigate the link between performance and brain activity. Significantly lower performance in the Flanker task was recorded in individuals with SCI compared to controls and there was a significant interaction effect between group and condition, with lower performance in the neutral condition in SCI. In the left insula and right precuneus there was a significant interaction effect between group and condition (incongruent versus neutral). Flanker accuracy significantly correlated with insular activity in controls, but not in SCI. Individuals with SCI demonstrated altered condition-specific perceptual conflict and differential brain activity in regions associated with salience processing. The insula appears less engaged in supporting further cognitive processing in SCI. Findings of this study advocate for a more comprehensive assessment of cognitive changes after SCI.