Here's a breakdown of some related fields:

* Neurologist: A medical doctor who diagnoses and treats diseases of the nervous system. They focus on the brain, spinal cord, and nerves.

* Neuroscientist: A broader term encompassing researchers who study the nervous system from various perspectives, including its structure, function, development, and disorders. They can have backgrounds in biology, psychology, chemistry, or other fields.

* Neuropsychologist: Focuses on the relationship between the brain and behavior, often assessing and treating cognitive and emotional problems.

* Neuropathologist: Studies the diseases and disorders of the nervous system through examining tissues and cells.

So, depending on the specific area of focus, a scientist studying the nervous system could be called a neurologist, neuroscientist, neuropsychologist, or neuropathologist.