Ocr a level psychology g542 section c exam. 2014!Watch
If I was to say the physiological approaches weakness is that it is a reductionist approach, (along with explaining why that is a weakness) I would then move on to say something similar to "This is illustrated in Maguire, as Maguire believes that it is the brain function and structure alone that causes changes to the spatial navigation of a person, and does not include cognitive explanations". The reasons why you don't evaluate the method itself, is that that is evaluation of a specific study not the approach.
Hope this helped!
individual differences and physiological came up last year
The only study in the cognitive approach is loftus and palmer so you should have talked about it helps establish cause and effect, it can be replicated an weaknesses low ecologic validity etc