Decision-making requires the brain to integrate multiple stimuli and elicit an appropriate behavioral response. However, a singular input does not always produce the same output. An animal’s external environment, internal physiological state, and behavior will determine how it assigns the appropriate valence or value to a stimulus. Stress has been shown to directly effect multisensory processing, but the mechanisms of this remain largely unknown. We use behavioral and physiological assays, in which Drosophila melanogaster (the fruit fly) are able to control their sensory experiences in real time. We combine these ‘virtual reality’ flight simulators with molecular, genetic, optogenetic and opto-physiological techniques to investigate the neuronal circuitry that is able to process a variety of states and produce an adapted behavioral response. Currently we are investigating the neuromodulatory mechanisms by which internal state alters visual and olfactory behaviors.