MyVisionsComeFromSoup info is prob more up to date.
When I did Psychology (and I only did it for a year before specialising in maths - Scottish uni system), you needed to be able to collate info and write it up the way you would expect a history student to work. The exams involved essays where you were profiling some research, comparing and contrasting it and describing the conclusions.
Coming from a science background, i found that really challenging.
You also needed to be able to remember a lot of Biology, especially learning how the brain works. there was a lot fo what the GCSE specs would call "Scientific thinking".
Then there were the practicals, and the compiling the data, and testing for significance. This was fairly entry level statistics, but its one of those things that if you struggle with stats then you'll think it a big deal, and if statistics comes easily to you, then you will wonder why some of the other students are making a fuss. So, just like the Arts faculty students must have wondered why I struggled so much with those essays...
Sorry, i know that is not helpful.