For example, neuroimaging approaches have been used to examine the effect of specific environmental manipulations such as exposure to a drug cue or drug itself on neurocognitive function in humans. In fact, studies with humans have proven to be largely consistent with the animal literature, leading to the integration of translational models that span animal and human findings (Kalivas & Volkow, 2005). Thus, for a GXE study, there are clearly approaches that provide common ground in terms of the environmental manipulation (e.g., exposure to drug cues) and phenotypes (e.g., changes in neurobiological variables). There are also a number of human studies that have examined the effect of GXE interactions in the context of neuroimaging. For example, several studies have demonstrated an interaction between an environmental manipulation (exposure to a drug cue) and a specific polymorphism on brain function (e.g., Hutchison et al., 2008; Filbey et al., 2008, McClernon et al., 2007). It seems likely that these observations actually reflect the long-term consequences of a gene by chronic drug exposure interaction that alters the neurobiological pathways that mediate the attribution of incentive salience to drug related stimuli.
