 In addition to animal research, a human positron emission tomography (PET) imaging study found that 200 mg and 300 mg doses of modafinil resulted in DAT occupancy of 51.4% and 56.9%, respectively, which was described as "close to that of methylphenidate".Another human PET imaging study similarly found that modafinil occupied the DAT and also determined that it significantly elevated extracellular levels of dopamine in the brain, including in the nucleus accumbens.Modafinil has been described as an "atypical" DAT inhibitor, and shows a profile of effects that is very different from those of other dopaminergic stimulants.