Fig. 1
From: Social memory deficits and their neural correlates in multiple sclerosis
Schematic representation of the social navigation task performed during fMRI. (a) Overview of MRI acquisition sequence and structure of the social navigation task. MRI scans were acquired in the chronological order shown from left to right: T2-weighted FLAIR imaging, T1-weighted imaging, task-based fMRI, and diffusion tensor imaging (DTI). fMRI was acquired during a structured, narrative-driven task in which participants assumed the role of a person relocating to a new city. The task included three types of slides: narrative slides, which presented contextual information or character dialogue; decision slides, in which participants chose between two response options; and black slides, which served as a “baseline” for fMRI analysis. Each decision slide was followed by a black screen upon the participant’s response; together, these lasted a total of 12 s. (b) Conceptual representation of the latent social space underlying the task. This two-dimensional space was defined by orthogonal axes of affiliation (x-axis; related to intimacy, empathy, or emotional closeness) and power (y-axis; related to hierarchy, dominance, or authority). Prior to the experiment, all possible interaction options were pre-classified as reflecting either affiliation or power, with each choice scored as + 1 or − 1 depending on whether it reinforced or opposed the respective dimension. These cumulative scores determined the evolving position of each character (C) in the social space, relative to a fixed central position representing the participant (6,0). The resulting position of each character was represented as a vector (V), with the angle (θ) encoding the relative weighting between power and affiliation in the relationship, and the length indicating the character’s distance in this latent space. (c1, c2) Example social maps from two participants. Each map illustrates the trial-by-trial trajectory of the five main characters through the two-dimensional power-affiliation space. Colored lines represent the cumulative path of each character, beginning at the neutral origin (0, 0) and evolving according to the participant’s decisions across 12 interactions. The maps demonstrate individual variability in how social relationships were shaped throughout the task.
