Related Clues:

• Brains
• *Mental material,
• The trouble with this is it's a shade brainy
• It's a rather colourless affair, mind
• Issue of pensions, for instance, needing intelligence
• Brain tissue
• The brain?
• Nondescript, dull peer, oddly lacking in intelligence
• Elderly issue requiring intellectual capacity?
• Issue lacking clear boundaries needs intelligence
• Somehow treat germy stuff in the head
• Intelligence; the brain
• The brain
• Intelligence? Dull subject!
• Brains ... or this puzzle's four circled names?