Topical issues
Question 1 (10 marks)
Contrary to popular belief, the Great Wall of China cannot be seen from space, and this
has been confirmed by astronauts. The wall is approximately 6 m wide. Ignoring any
shadow that it might cast, what is the minimum width the Great Wall would have to be in
order for it to be visible to an astronaut with average vision who is orbiting 200 km above
the Earth? Explain how you reached your conclusion and include the calculation that you
made.
Question 2 (10 marks)
(Relevant module learning outcomes: KU2, CS2 and KS1)
Explain how trichromatic vision enables humans to distinguish between different colours,
and how opponent processing contributes to the process.
Question 3 (10 marks)
(Relevant module learning outcomes: KU2, CS1 and KS1)
The sensitivity of vision and touch can vary according to the position of the stimulus.
Describe how this variation may arise and what effect it has on the functioning of vision
and touch.
Question 4 (10 marks)
(Relevant module learning outcomes: KU1, KU4, CS2 and KS1)
Briefly discuss the extent to which cortical processing of signals is similar in the auditory
and visual systems.
