how use graphAlbum facebook api in php

I'm trying to use the "api graph" of Facebook, to display data from an album of facebook in a page of my site. using them for user data all goes well. when I try with the data instead of an album I can not extrapolate data the code is as follows:

$request = new FacebookRequest( $session, 'GET', '/{album-id}/photos'); $response = $request->execute();

but after this code, I can only see the structure with serialize(), without being able to use any property, as in the case of user data with getProperty ("name")

can you help me?