2x interviews (30 mins each; 2 interviewers each); 1 pre-interview essay (1 hour)
Pre-interview essay: choice of 4 questions; Interview 1: general motivations; Interview 2: graphs, general questions about psychology and neuroscience
Revision of subject material; podcasts; public and Youtube talks and lectures
It's not a knowledge test; just read and think about your subject
Remember this advice isn't official. There is no guarantee it will reflect your experience because university applications can change between years. Check the official Cambridge and Oxford websites for more accurate information on this year's application format and the required tests.
Also, someone else's experience may not reflect your own. Most interviews are more like conversations than tests and like, any conversation, they are quite interactive.
1 hour timed essay with a choice of 4 questions. Followed by a college interview and an academic interview (both with 2 interviewers each and lasting 30 mins).
College interview asked specific questions about my personal statement which was enjoyable since I'd spent a lot of time thinking about psychology and why I wanted to study it, so I could easily stand behind the content of my personal statement.
Academic interview tested my ability to infer information from a graph, discuss possible variables, and some more general questions about psychology and neuroscience. These are my hobbies so I enjoyed the chat. The key was just staying relaxed and reminding myself that I was there to have a conversation about topics which I find fascinating.
The content of my Social Science Access to HE course helped, particularly with regards to the scientific method. My main resources otherwise were the Waking Up podcast (psychology, neuroscience, philosophy of mind, ethics and more) and lectures and long-form discussions on YouTube by professors such as Jordan Peterson (personality), Robert Sapolsky (endocrinology, primatology), and Steven Pinker.
It's not a knowledge test. They just want to see if you're a) interested enough in the subject to have spent some time reading and thinking about it, and b) flexible enough in your thinking to work through some questions with them in real time, which you will be if you've done step a) :)