Recent developments in brain functional neuroimaging studies have established important physiological links between environmental stimuli and robust differences in emotional processing within distinct brain regions and circuits that have been linked to the manifestation of various conditions. Such techniques might enable us to evaluate information processing at the brain level in individuals by exploring the impact of genetic variation and provide an approach to perform functional genomic studies. Here, I propose that psychological and brain function imaging studies with concurrent biochemical and pharmacological measurement, in particular those investigating the effect of gene polymorphisms, appear to be quite useful in clarifying the relationships between emotion, brain and gene functions.