Idiot turned up? Refuse to receive one contribution to thinking, perhaps (8)
I believe the answer is:
midbrain
'contribution to thinking perhaps' is the definition.
I can't tell whether this definition defines the answer.
'idiot turned up? refuse to receive one' is the wordplay.
'idiot' becomes 'dim' (both can mean stupid).
'turned up?' is a reversal indicator.
'refuse' becomes 'bran' (I've seen this before).
'to receive' indicates putting letters inside.
'one' becomes 'i' (Roman numeral).
'dim' backwards is 'mid'.
'bran' enclosing 'i' is 'brain'.
'mid'+'brain'='MIDBRAIN'
Can you help me to learn more?
(Another definition for midbrain that I've seen is " Some mind".)