Volunteers have PET scans on two occasions. They first hear a spoken message that makes sense. They then hear the same words spoken by the same person, but arranged in an order that does not make sense. The recordings have the same loudness and duration.
One brain region shows increased tracer uptake during both recordings.
Why can this region not be identified from these results as specifically responsible for understanding the message?
a region can only be linked to an ability when damage to it is seen on a CT scan
PET scans show structural differences between brain regions rather than activity during a task
a brain region active in both conditions cannot contribute to understanding spoken messages
the region is active whenever the words are heard, whether or not they make sense
111 exam-style questions on Edexcel GCSE Biology 2.3 The nervous system and brain, covering 2.3.1 Structures and functions of the brain, 2.3.2 Imaging brain function with scanning, 2.3.3 Limitations in treating nervous system damage, 2.3.4 Neurones and impulse transmission, and 2.3.5 Structure and function of a reflex arc. Each one has a worked solution and a mark scheme showing where the marks go.