Type in one field, show in two in Cocoa and Core Data

Question

I have two controls (NSTextField and a NSTableView column) that are bound to the same attribute in core data. I've set up a timer that starts after the NSTextField starts editing and I'd like it to periodically commit the editing as the user is typing (type in one field, see it in both places). If the user hits the Enter key I do see the text in both places but I want those updates to go as the user types.

[myTextField commitEditing]  //this doesn't work

[[myTextField window] endEditingFor:nil] //this works but the NSTextField loses focus

Any suggestions?