Possible Clues:

• Neurologist throws out crisp banalities
• One knowing everything about The Crown has an ability to get into your head
• Recognises a good head on one's shoulders presumably by opening 11 across for unique winner
• Presumably, Scarecrow should have gone to see one crown distinctive winner
• Expert attending to 11 across knows a swelled head when they see it
• Presumably knows why someone has a swelled head and is capable of changing their mind
• Ben Carson, notably