I think it depends on the centre's policies. I once asked my therapist if I could have access to my file. She said that she wasn't allowed to show her files at her previous workplace, but that she would check with her supervisor. In the end, it turned out that not only was she allowed to let me see my file, I was allowed to get a photocopy of the files from each of my sessions (for a fee). I know it can be nerve-wracking to ask, but it really can't hurt, especially if you're curious.