1. If the Weber fraction for brightness, k, is 1/14, how many more candles must you light in a room with 42 burning candles for it to seem just noticeably brighter (i.e., different)? Explain your answer in a sentence.
2. A blind person who has his or her sight restored is likely to have trouble distinguishing faces by looking at them, at least for a while. Would you diagnose prosopagnosia in such a person? Why or why not?.
3. Explain how lateral inhibition accounts for Mach bands.