Using UI hash key in an events hash

I am using marionette version 1.2.3 and backbone version 1.1.0

Here is my UI and events hash:

ui:{
    title : '#modelTypeTitle'
},
events:
{
    'change @ui.title' : 'validateTitle'
},

This seems to match what the documentation says: "You can also use the ui hash values from within events and trigger keys using the '@ui.elementName'"

To clarify I want to know why what I am trying above does not work. but the following works fine:

events:
{
    'change #modelTypeTitle' : 'validateTitle'
},