Functional activation of the parahippocampal cortex and amygdala during social statistical information processing

Social statistical information can be used to quantitatively describe external events or facts, such as statistics on products, incomes, or sales, which consist of two basic features: associations and sociality. Previous studies in cognitive psychology have investigated statistical graph comprehension, but the neural basis of social statistical information processing has not been examined. In our study, 36 subjects were scanned using functional magnetic resonance imaging (fMRI) while reading statistical information visually presented in one of three basic forms: as text, as statistical graphs, and as both graphs and text. All three forms consistently activated the right posterior tip of the parahippocampal cortex (PHC) and the left amygdala, suggesting that both regions contribute to social statistical information processing, regardless of the presentation form. Previous studies have implicated the posterior tip of the PHC in contextual associations and the amygdala in processing emotion-related events and social cognition. Taken together with previous studies, we proposed that the posterior tip of the PHC is more involved in establishing associations during social statistical information processing, while the amygdala is more related to the social component. This study provides neuroimaging evidence for commonly processing of the two basic features of social statistical information by the PHC and amygdala.