Ember - 'this' undefined in callback function

I have an ajax request that I pass a callback function to. When the ajax succeeds it successfully triggers the callback. But when I enter the function (which is nested in the route) and try to call this it errors saying that this is undefined.

Here's what the route looks like:

export default Ember.Route.extend(UnauthenticatedRouteMixin, {
  session: Ember.inject.service('session'),
  user_service: Ember.inject.service('user'),
  actions: {
      this.get('user_service').logInUser(email, password, handleResponse, handleError);


     this.get('session').authenticate('authenticator:oauth2', email, password).catch((reason) => {
        console.log(reason.error || reason);
      });
    },
    handleResponse: function(request) {
      console.log(this);
    },
    handleError: function(error) {
      console.log(error);
    }
  },
});