Mizan

From Memory Alpha, the free Star Trek reference.

Doctor Mizan was a Ktarian exobiologist who was an expert in interspecies reproduction.

He had unconventional ways of researching his field of expertise and he attended a psychological conference discussing deep space assignments in 2369. While on their way back to the USS Enterprise-D, Deanna Troi told Captain Picard, Geordi La Forge, and Data about her encounter with Doctor Mizan. She said that he talked to her after the reception and that he had heard that she was an empath. He was interested in doing empirical research for interspecies mating rituals and called himself a very sensitive man. He misspelled Deanna as Diane. (TNG: "Timescape")

His field of study could have been Interspecies Protocol.