A scientist uses a radioactive glucose tracer in a PET scan while a volunteer completes two activities.
In activity 1, the volunteer copies a sequence of numbers.
In activity 2, the volunteer uses the same numbers to solve a puzzle.
| Brain region | Tracer uptake during activity 1 / arbitrary units | Tracer uptake during activity 2 / arbitrary units |
|---|---|---|
| S | 30 | 48 |
| T | 60 | 68 |
Calculate the percentage increase in tracer uptake for each brain region from activity 1 to activity 2.
Give your answers to one decimal place.
The scientist concludes that only region S is involved in the additional thinking needed to solve the puzzle rather than copy the numbers.
Evaluate this conclusion using the results.
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.