Neural correlates of causality judgment in physical and social context--the reversed effects of space and time.

The perception of causal relationships is crucial to understanding and interacting with our physical and social environment. However, whether the same or different neural processes are involved in perceiving physical and social causality is unknown. Therefore, this study is focused on commonalities and differences in the neural correlates of causality perception in both contexts. During fMRI data-acquisition, participants judged causal relationships of objects in two types of animated video clips (physical/social) with similar manipulations of temporal and spatial stimulus characteristics. Four conditions were analyzed in a two-factorial design [physical causal (PC), physical non-causal (PNC), social causal (SC), social non-causal (SNC)]. We found that higher angles and longer time delays led to decreasing judgments of causality in the physical context, whereas the same manipulations led to increasing judgments in the social context. Instead of a common network for causal judgments (PC>PNC∩SC>SNC), we found a reversed activation pattern for the factors context and judgment. PC and SNC [(PC>PNC)>(SC>SNC)] produced activations in the bilateral insula, the right angular and inferior frontal gyrus and the medial supplementary motor area. PNC and SC [(PC>PNC)<(SC>SNC)] produced activity in medial frontal, left superior temporal and anterior cingulate brain regions. Our data suggest, that the same brain regions contribute to the impression of physical and social causality. However, they demonstrate a reversed activation pattern that reflects the stimulus characteristics of the respective conditions. Thus, specific stimulus characteristics are crucial for the perception of causality.