 Furthermore, "[the] neurochemical effects [of modafinil] and anatomical pattern of brain area activation differ from typical psychostimulants and are consistent with its beneficial effects on cognitive performance processes such as attention, learning, and memory", and a study found that modafinil-induced increased locomotor activity in animals was dependent on histamine release and could be abolished by depletion of neuronal histamine, whereas those of methylphenidate were not and could not be.As such, although it is established that modafinil is a clinically significant DRI, its full pharmacology remains unclear and may be more complex than this single property (i.e., may also include DAT-independent actions, such as "activation of the orexin system").In any case, there is nonetheless a good deal of evidence to indicate that modafinil is producing at least a portion of its wakefulness-promoting effects by acting as a DRI, or at least via activation of the dopaminergic system.