Olfactory simulators can be integrated within the HMD for additional limbic stimulation and realism. Vibrational and acceleration stimulation can assist in simulating posterior column and vestibular inputs of an actual subject environment. This produces nausea and vertigo and evokes sympathetic responses. On the other hand, the patient is aware that he is in fact in a safe environment. Thus a cognitive dissonance is evoked, the sensorineural perception of height juxtaposed with knowledge of the actual safe environment.
Neuroplastic mechanisms can then come into play to begin resetting the brainstem-visual interaction.
The symptoms remain overpowering if the cognitive damping effect of knowledge of the actual safe environment is absent. In this case the patient is unable to endure the exposure to the height necessary for the neuroplastic response to develop. Moreover, the patient can be exposed to a gradually increasing level of stimulation by increasing the perceived height of the building or decreasing the distance to the ledge. The patient can also control the configuration of the environment by walking closer to the virtual edge, or by looking up or down. In each case, the virtual environment is recalculated in essentially real time to produce the needed environmental consistency.