Figure 1.
Point-light displays showing social interactions (A) and no social interactions (B).
The example of SI depicts an actor showing something on the ground to another actor, who responds by coming closer. The example of NSI depicts one actor raising a leg and the second one jumping. In this illustration, in order to help to distinguish the human form, the dots have been linked by full lines.
Figure 2.
Sequence of trial presentation across time.
The training sequence contained a plain green rectangle (shown in grey in the figure) and a red rectangle (in white here) divided into two parts. The plain green rectangle symbolized the two persons acting together; and the red rectangle divided in two parts stood for the two agents moving independently.
Figure 3.
fMRI results from random-effects analyses: social interaction > non social interaction.
Significant activations (p<0.05, corrected) in the whole-brain random effects analysis during the observation of social interaction displays (SI) versus non social interaction displays (NSI). Group activations are projected onto the normalized anatomical brain of one of the participants. pSTS = superior temporal sulcus (posterior part), TPJ = temporo-parietal junction, IFG = inferior frontal gyrus, PM = premotor cortex, aSTS = superior temporal sulcus (anterior part), dMPFC = medial prefrontal cortex (dorsal part), IaPS = intraparietal sulcus, R/L = right and left hemispheres.
Table 1.
Brain areas showing increased activity in response to the social interaction condition.