Demographic and clinical profiles of participants in the MGL paradigm.

Demographic and clinical profiles of participants in the sequential paradigms.

Schematic design of visual working memory (WM) paradigms.

(A) In the memory-guided localization (MGL) paradigm, participants were asked to memorize and then localize the position of the target circle following a random delay interval of 0.5, 1, 2, 4, or 8 seconds. Following their response, visual feedback was presented. (B) In the sequential paradigm with 3 bar (high memory load condition), a sequence of three colored bars was presented consecutively. Participants were asked to match the orientation of the probe bar to the previously presented bar with the same color. Visual feedback was displayed following their response. (C) The 1-bar paradigm (low memory load condition) has the same structure as the 3-bar paradigm except for presenting one bar instead of three.

Recall error and precision of healthy control and multiple sclerosis (MS) subtypes (relapsing-remitting, RRMS and secondary progressive, SPMS) in visual WM paradigms.

(A) Recall error, (B) recall precision, (C) and reaction time as a function of distance for the MGL paradigm. (D, E, and F) The same as a function of delay interval. (G) Recall error and (H) precision and (I) reaction time as a function of bar order in the sequential paradigms with 3 bar (left) and 1 bar (right). Data are represented as mean ± SEM.

The sources of recall error in high and low memory load conditions (3-bar and 1-bar, respectively).

(A) von Mises SD (circular standard deviation of von Mises distribution), (B) Target proportion (probability of response around the target value), (C) swap error (probability of response around the non-target values), and (D) uniform proportion (probability of random response) for healthy control and MS subtypes in the sequential paradigms with 3 bar (left of each subplot) and 1 bar (right of each subplot). Data are represented as mean ± SEM.

Classifying performance of visual WM paradigms in differentiating healthy control from MS and MS subtypes, and MS subtypes from each other.

Receiver operating characteristic (ROC) curve demonstrated the accuracy of (A) MGL and sequential paradigms with (B) 3 bar and (C) 1 bar in distinguishing healthy control from MS patients. The precision of these paradigms in dissociating healthy control from MS subtypes (RRMS and SPMS) and MS subtypes from each other is represented as the area under the curve (AUC) for (D) MGL and sequential paradigms with (E) 3 bar and (F) 1 bar.