Effects of social and emotional context on neural activation and synchrony during movie viewing

Abstract

Sharing emotional experiences impacts how we perceive and interact with the world, but the neural mechanisms that support this sharing are not well characterized. In this study, participants (N = 52) watched videos in an MRI scanner in the presence of an unfamiliar peer. Videos varied in valence and social context (i.e., participants believed their partner was viewing the same (joint condition) or a different (solo condition) video). Reported togetherness increased during positive videos regardless of social condition, indicating that positive contexts may lessen the experience of being alone. Two analysis approaches were used to examine both sustained neural activity averaged over time and dynamic synchrony throughout the videos. Both approaches revealed clusters in the medial prefrontal cortex that were more responsive to the joint condition. We observed a time-averaged social-emotion interaction in the ventromedial prefrontal cortex, although this region did not demonstrate synchrony effects. Alternatively, social-emotion interactions in the amygdala and superior temporal sulcus showed greater neural synchrony in the joint compared to solo conditions during positive videos, but the opposite pattern for negative videos. These findings suggest that positive stimuli may be more salient when experienced together, suggesting a mechanism for forming social bonds.

Keywords: affect; social attention; social context; social neuroscience.

FIGURE 1

Behavioral results. (a) Group average (N = 52) in‐scanner ratings of how emotional participants felt after watching each video on a scale of 0 (very negative) to 9 (very positive). (b) Group average (N = 38) in‐scanner ratings of how alone or together they felt with their partner after watching each video on a scale of 0 (very alone) to 9 (very together). Fewer subjects are included in this data as the togetherness question was added after 14 scans had already been completed. (c) Group average (N = 27) of the proportion of time spent looking at the partner video feed compared to the main video feed. (d) Group average (N = 27) of the correlation between individual and group (N – subject) time spent looking at the confederate through the duration of each condition

FIGURE 2

ANOVA main effect result maps from the time‐averaged (GLM) data. Significant clusters are outlined in black at a voxel threshold of p < .001 (cluster α = 0.05). Sub‐threshold effects (i.e., F > 0, p > .001) are displayed with transparent fade and not outlined. (a) Social main effect within the mentalizing network. (b) Emotion main effect within the emotion network. (c) Emotion main effect within the reward network

FIGURE 3

ANOVA social‐emotion interaction result maps from the time‐averaged (GLM) data. Significant cluster is outlined in black at a voxel threshold of p < .001 (cluster α = 0.05). Sub‐threshold effects (i.e., F > 0, p > .001) are displayed with transparent fade and not outlined. Line graphs plot extracted values from each relevant condition to illustrate direction of significant effects. (a) The same vmPFC region located within both mentalizing and reward masks was found to be significant in the 2 × 2 and 2 × 3 models, although the cluster size and peak voxel location differed by model (2 × 2 reward mask results shown: Table 3 shows all cluster information). (b) Extracted values for from the 2 × 2 (emotion, neutral) model in the reward mask. (c) Extracted values from the 2 × 3 (positive, neutral, negative) model in the reward mask

FIGURE 4

ANOVA main effect result maps from the time‐dependent (ISC) data. Significant clusters are outlined in black at a voxel threshold of p < .001 (cluster α = 0.05). Sub‐threshold effects (i.e., F > 0, p > .001) are displayed with transparent fade and not outlined. (a) Main social effect within the mentalizing network. (b) Main 2 × 3 emotion (positive, neutral, negative) effect within the emotion network. (c) Main 2 × 3 emotion (positive, neutral, negative) effect within the reward network

FIGURE 5

ANOVA social‐emotion interaction result maps from the time‐dependent (ISC) data. All group tests were conducted within three separate masks generated from Neurosynth and reflecting different brain networks: mentalizing, emotion, and reward. Significant cluster is outlined in black at a voxel threshold of p < .001 (cluster α = 0.05). Sub‐threshold effects (i.e., F > 0, p > .001) are displayed with transparent fade and not outlined. Line graphs plot extracted values from each relevant condition to illustrate direction of significant effects. (a) Interaction from the 2 × 2 valence‐combined (emotion, neutral) model found in the mentalizing network. (b) Interaction from the 2 × 3 valence‐separated (positive, neutral, negative) model found in the mentalizing network. (c) Interaction from the 2 × 3 valence‐separated model found in the reward network