Final answer:
The patient may experience dizziness from the rapid movement affecting the inner ear, and the unusual taste could be due to metallic fillings interacting with MRI's magnetic fields or from Lorentz effect on moving conductive fluids.
Step-by-step explanation:
A patient experiencing dizziness and an unusual taste in the mouth while in an MRI unit could have several possible causes. First, the rapid head movement could have momentarily affected the vestibular system in the inner ear, which is responsible for maintaining balance and spatial orientation, leading to dizziness. Secondly, the strange taste could be a result of the magnetic fields used in MRI scanning interacting with the metallic elements in the mouth fillings or braces, if present. Lastly, the phenomenon known as 'Lorentz effect', where the strong magnetic field interacts with moving conductive fluids like blood, could stimulate nerves or taste receptors in the mouth.