Relative clauses -- TOPIC or FOCUS?

[Chris Manning]

On 20 March 2000, Joan Bresnan wrote:
 > Aaron Broadwell's interesting notes from Mayan suggest that the
 > relative verb in actor voice might be specifying FOCUS of the head
 > WITHIN THE MATRIX (HIGHER) CLAUSE.  This would imply a job for
 > constructive morphology (inside-out fn application).  Within the
 > relative clause, the relative element itself could still be "topical"
 > or a "theme" in accordance with the previous work mentioned.

Back on Mayan, I found this hard to see.  Don't the alternate voice
markings cited have to refer to function in the relative clause? -- the
relativized on word is in both cases the subject (and presumably topic)
of the higher clause.

 > Now the problem is that relative clauses show the same pattern as focus
 > constructions, and not the pattern seen in topic constructions:
 >
 > The dog John grabbed has mange.		grab is neutral voice
 > The man who grabbed the dog is my uncle	grab is actor focus voice
 >
 > That suggests to me that the head of the relative clause has the discourse
 > role FOCUS, and not TOPIC.

Chris.