Erlewine, Michael Yoshitaka, 2014. “Anti-Locality and Kaqchikel Agent Focus.”
Proceedings of the 31st West Coast Conference on Formal Linguistics (WCCFL 31), pages 150–159.

In many Mayan languages, A-bar extraction of subjects of transitive clauses triggers a change to that verb’s morphology, known as Agent Focus. Previous researchers have assumed an exceptionless correlation between AF and the A-bar extraction of a transitive subject. In this paper new data from Kaqchikel (Mayan, Guatemala) shows that AF is a response to A-bar movement of a transitive subject that is too short. Movement of a transitive subject does not trigger AF if the movement chain is made longer by adding intervening material. An anti-locality constraint is proposed: "Spec-to-Spec Anti-Locality," which bans movement between successive specifier positions. Spec-to-Spec Anti-Locality explains the full distributional pattern of AF in Kaqchikel.

For full discussion, see “Anti-locality and optimality in Kaqchikel Agent Focus” in NLLT.