Fig. 2

Boxplots of CR (A–C) and RT (D–F) in patients with PCS and controls across each disparity (275″, 550″, 1100″). Boxplots of LS-Means of CR [decimal] and RT [ms], adjusted for covariates. An ANCOVA test for group membership was done. Group membership shows statistically significant differences for CR (disparity 275″ p-value < 0.001, 550″ p-value = 0.003, 1100″ p-value = 0.019) and RT (disparity 275″ p-value = 0.001, 550″ p-value = 0.001, 1100″ p-value = 0.003) at all difficulties (disparities). Decreasing CR and increasing RT can be observed for increased difficulty (lower disparity) at all levels for both groups. (CR = correct responses; RT = reaction time; decimal = percentage in decimal; ms = milliseconds; PCS = Post-COVID syndrome; ″=arc-seconds; LS-Means = least square means)