Why can electrical stimulation help map brain function but also make conclusions uncertain?
Stimulation can produce an image, but the skull blocks all electrical activity from neurones.
Stimulation can show blood flow, but blood cannot enter active regions of the brain tissue.
Stimulation can trigger a response, but current may affect more than one nearby brain region.
Stimulation can repair neurones, but repaired neurones always perform several unrelated functions.
40 exam-style questions on AQA GCSE Biology 5.2 The human nervous system, covering 5.2.1 Structure and function, 5.2.2 The brain, 5.2.3 The eye, and 5.2.4 Control of body temperature. Each one has a worked solution and a mark scheme showing where the marks go.